Final FRCA Practice SAQ Paper 1 - for discussion on Saturday, 19th January 2013
Candidates MUST answer all 12 questions. Candidates will fail the written section if one or
more questions on the SAQ paper are not attempted. All 12 questions carry equal marks,
although their pass marks may vary
Where examiners have indicated the way marks are allocated, candidates are advised to
spend their time accordingly
You will need to have your answers ready prior to the discussion session in order to
benefit from the discussion.
1. a) What are the considerations when administering a general anaesthetic to a
patient in the neuroradiology suite? (50%)
b) List the common interventional neuro-radiological procedures that may require
general anaesthesia. (20%)
c) Outline the possible complications of interventional neuro-radiological procedures.
(30%)
Answer contributed by Dr. Madhuvanti Achawal
a) What are the considerations when administering a general anaesthetic to a patient in the neuroradiology suite? (50%) b) List the common interventional neuro-radiological procedures that may require general anaesthesia. (20%) c) Outline the possible complications of interventional neuro-radiological procedures. (30%)
Interventional neuro radilogical procedures are part of trends towards minimally invasive
neurosurgery. Prolonged procedures, improved patient safety and optimal imaging have
resulted in a trend towards greater use of general anaesthesia, specially for aneurysm
coilings and arterio venous (AV)malformations.
Important considerations while anaesthetising these patients are related to the
disease process, the neuro radiology environment and demands of neuro radiological
procedures.
Neurological disease process demand thorough preoperative examination of the patient
including neurological examination and thorough systemic examination to assess associated
systemic effects. Aneurysmal subarachnoid haemorrhage along with altered GCS, can
present with cardiac dysrrhythmias, pulmonary atelectasis, pneumonia, pulmonary oedema
and electrolyte imbalance.
Neuroradiology suites pose unfamiliar environment, often remote. The staff is not always
familiar with anaesthetic practice and help not always readily available. Ensuring a skilled
assistance, availability of necessary and emergency equipment and dedicated recovery area
and staff is vital.
The anaesthetist works amongst ample radiology equipment and access to the patient is
often with obstacles. Securing airway access, lines and monitoring cables in an appropriate
manner is helpful.
These are intracranial procedures and demand close monitoring of PaCO2, arterial blood
pressure and intravascular volume to manipulate intracranial pressure. To avoid image
degradation respiratory immobility could be essential. Short acting anaesthetic agents
enable postoperative recovery and neurological testing.
Use of radiology contrast and flush demand vigilance for hyperoslarity, hypervolaemia and
later dehydration and renal impairment.
Use of heparin, antiplatelet drugs and thrombolytics is common and hence one must be
prepared to monitor ACT and use protamine.
The procedure could involve transfers between radiology, CT or MRI, theatres and hospitals.
This demands close and vigilant observation and monitoring of patient.
List of procedures that require GA
Embolisation: cerebral aneurysm, arteriovenous malformations (intracranial/ spinal)
Embolisation: tumours, carotid cavernous fistulae, epistaxis
Stenting: Carotid/ cerebral arteries
Sclerotherapy: Venous angiomas
Balloon angioplasy: carotid stenosis and vasospasm
Thrombolysis: acute thromboembolic stroke
Intraarterial chemotherapy: head and neck tumours
Complications
Vascular complications are either haemorrhagic or occlusive and need immediate attention.
Vascular rupture or perforation could be
- spontaneous
- due to hypertention
- brought about by micro catheter, guide wire, coil or injection of contrast.
These can present with signs of raised ICP and demand reversal of anticoagulation and
control of ICP.
Cerebral occlusion leading to infarction and ischaemia can occur due to thromboembolism,
arterial dissection, coil misplacement or vasospasm. These could be avoided by maintaining
collateral flow with controlled hypertention and anticoagulation.
Cerebral vasospasm is one of the most serious consequences of subarachnoid
haemorrhage . Medical treatment consists of oral or intravenous nimodipine,
Haemodilutional, hypervolemic, hypertensive therapy (triple H). Intra arterial nemodipine can
be administered during the procedure.
Systemic shunting of particulate material, pulmonary embolism and neurological deficit and
severe bleeding can occur with embolisation of AV maformations.
2. a) What are the diagnostic (25%) and therapeutic (25%) indications for
bronchoscopy?
b) List the major contraindications for bronchoscopy. (20%)
c) How should a fibreoptic bronchoscope be reprocessed after use? (30%)
Answer contributed by Dr. Ajith Vijayan
INTRODUCTION
Bronchoscopy is a common procedure, and both fibreoptic and rigid bronchoscopies
have their own indications and involve specilized techniques. Indications for bronchoscopy
can be divided into one of the three categories: diagnostic, therapeutic, and preoperative
evaluation of pathology.
In many units rigid scope alone or in combination used for the interventional procedures.
However the units outside the thoracic surgery centres do not have ready access to rigid
bronchoscopy as a back up for , or as an alternative to flexible bronchoscopy.
The main advantages of flexible bronchoscope are:
It is widely available
It does not require general anaesthesia
It provide access to more distal airways and good access to the upper lobe bronchi
Rigid bronchoscope
Control of ventilation and oxygenation
Permits removal of large volumes of tumour
Obstructing airway lesions can be cored out.
most interventional procedures can be carried out via flexible or rigid bronchoscopy.
Diagnotic uses
Evaluate lung lesions of unknown etiology that appear on chest X-ray( lung malignancy top
priority)
To assess airway patency
To ascertain correct placement double-lumen endotracheal tube(DLT), to visualise the
single lumen tube position with in the trachea in difficult circumstances ( persisting
desaturation inspite of endotracheal intubation and adequate ventilation.)
To evaluate problems associated with endotracheal tubes such as tracheal damage,
airway obstruction
To obtain material for microbiologic studies in suspected pulmonary infections
To investigate unexplained hemoptysis
To investigate the etiology of unexplained paralysis of vocal cord, superior venacava
syndrome, chylothorax, pleural effusion.
Evaluate airway injury in thoracic trauma
To evaluate the location and extent of respiratory tract injury after acute inhalation on
noxious fumes or aspiration of gastric contents
To evaluate a suspected tracheo esophageal fistula, interstial lung disease,
bronchiectasis.
Indications for preoperative assessment of pathology with Bronchoscopy
Before lobectomy or pneumenectomy - allows surgeon to evaluate the extent of the tumor
and rule out malignancy of the contralateral lung
Therapeutic uses
Most interventional procedures are , can be undertaken by flexible or rigid bronchoscopy
Flexible bronchoscope
To remove retained secretions or mucosal plugs
To remove foreign bodies
Tumour debulking with diathermy
Argon plasma coagulation
Cryoextraction and photodynamic therapy(PDT)
Metallic stent insertion
Rigid bronchoscope
Massive haemoptysis
Dilatation of stenosis
Removal of larger central foreign body
Silicone and Y-stents insertion
Thermal laser
Tumour resection
Contraindications for Bronchoscopy
For rigid bronchoscopy
Atlanto axial instability
Severe vertebro-basilar insufficiency
previous cervical spine fusion
Severe facial fractures
patients who are at risk of dental damage
Patient refusal
There are no absolute contraindication for flexible fibreoptic bronchoscopy other than patient
refusal
Risks should be weighed against the benefits
Special caution
1. in patients at risk of developing hypoxia
2. cardiac instability
3. bleeding diathesis
How should Fibre optic scope reprocessed after use
Should be undertaken by the trained staff only.
Thorough cleaning with the detergent most important initial step
sterile or bacteria free water is used for rinsing the bronchoscope
20 minutes immersion in 2% gluteraldehyde manual or automated disinfection
this will destroy most bacteria , including mycobacterium tuberculosis and viruses.
Longer immersion times of 60 minutes if atypical mycobacteria or HIV positive with
respiratory symptoms
Patients with suspected Tuberculosis should undergo bronchoscopy at the end of the list.
compatibility of the decontamination methods should be checked with the manufactures of
bronchoscopic instruments and accessories.
NICE clinical guideline 36
Answer contributed by Dr. Raj Ramchandran
A] Indications for bronchoscopy
Diagnostic
Airway obstruction (e.g. tracheomalacia, bronchomalacia)
Persistent/recurrent pneumonia
Tracheo-oesophageal fistula
Brushings for cytology
Diagnostic
Transbronchial biopsy for histology
Failure to wean from ventilator
Haemoptysis
Therapeutic
Removal of foreign body
Suctioning mucus plugs (e.g. in cystic fibrosis)
Facilitate endobronchial intubation for one lung anaesthesia
Laser therapy
Balloon dilatation of trachea/bronchus
Stent insertion
B] Major Contraindications:
Absolute
Lack of patient consent
Untreatable life-threatening arrhythmias
Inability to adequately oxygenate the patient during the procedure
Mechanical ventilation with high positive end expiratory pressure
Relative
Uncooperative patient
Recent MI or unstable angina
Severe tracheal stenosis or obstruction
Uncorrectable coagulopathy
Pulmonary hypertension [increased risk of bleeding]
C] Reprocessing of FOB after use
Principles for Cleaning/disinfection
1. To ensure that all staff comply with appropriate standards of cleaning & disinfection,
written policies and procedures should be developed
2. To follow the endoscope, accessories and AER manufacturers’ advice and
instructions for use regarding the leak testing, cleaning, disinfection,
decontamination, sterilization and storage of endoscopes.
3. A record should be kept of which bronchoscope is used on an individual patient and
also of the decontamination procedure.
4. Decontamination and disinfection should be carried out at the beginning and end of a
list and between patients.
5. Cleaning and disinfection of bronchoscopes should be undertaken by trained staff in
a dedicated room preferably inside a fume cabinet and to wear protective clothing
and respiratory protection
6. Wherever possible, autoclavable or disposable accessories should be used
7. Bronchoscopy staff need to be trained in patient care, infection control, and
instrument decontamination including the safe use of aldehydes and the potential
health risks
N.B: Not sure whether to include cleaning in detail as follows:
Cleaning
1. Need to wipe clean external surfaces with detergent.
2. Suction valve is separately cleaned.
3. Suitable cleaning brush is used to clean the channel and port.
4. To flush the channel through with detergent followed by air.
Disinfection
1. Use automated systems whenever possible as they protect the user from hazardous
processing chemicals. (Automated endoscope reprocessor) (AER)
(NB: To ensure that AER machine disinfection is carried out at the start of each session/day.
This includes filters and pipework for rinse water.)
2. Immerse the bronchoscope in glutaraldehyde
2% Glutaraldehyde disinfectant contact times - in room temperature)
Patient category When Low risk High risk (e.g.TB, immune
suppressed, symptomatic HIV)
Start of list 20 min 20 min
Between patients 20 min 1 hour
End of list 20 min 1 hour
Change the disinfectant when the manufacturer’s recommended use life is reached.
3. Rinse the instrument with sterile or filtered tap water
4. Change the detergent and rinse water regularly (after each cycle) if reused.
5. Dry the instrument with air and/or alcohol. A 70% alcohol rinse may be used for the
channel
6. Accessories should be cleaned and wherever possible sterilised by autoclaving.
7. Alternatives for Glutaraldehyde
-peracetic acid, chlorine dioxide, superoxidised water and ethylene oxide.
Sterilization of FOB done by gas plasma a complex process
Storage of processed endoscopes
1. On completion of disinfection, the endoscope should be purged with compressed air
to facilitate thorough drying. Alternatively, 70% alcohol may be used to dry internal
surfaces and channels.
2. Flexible endoscopes should be stored suspended vertically in ventilated storage
cabinets, to allow circulation of air.
3. They should not be in contact with other endoscopes or flat surfaces. Ideally, control
valves, distal hoods, caps and other detachable components should be stored
separately.
References – CEACCP, British Thoracic Society Guidelines
American thoracic society
Mhra.gov.uk
3. a) Describe how atrial fibrillation may present. (15%)
b) List 5 causes of atrial fibrillation. (25%)
c) What principles underlie the management of atrial fibrillation? (25%)
d) What are the anaesthetic considerations when performing elective DC
Cardioversion? (35%)
Answer contributed by Dr. Raj Ramchandran
a) Describe how atrial fibrillation may present. (15%)
Palpitation, Irregular pulse
breathlessness
fatigue
syncope
light headedness or dizziness
chest discomfort or pain
heart failure
Stroke or TIA may be the first manifestation of AF
b) List 5 causes of atrial fibrillation. (25%)
Cardiac – IHD, Valvular disease (mitral)
Surgery – Cardiac surgery, pneumonectomy, oesophageal surgery etc.
Sepsis
Electrolyte abnormality – hypokalemia, hypomagnesemia
Endocrine - Hyperthyroidism
Accessory pathway - Wolff-Parkinson-White syndrome (WPW)
c) What principles underlie the management of atrial fibrillation? (25%)
Underlying cause to be corrected for acute AF.
If onset less than 48 hrs, symptomatic AF – To try rhythm control by drugs first
and if unsuccessful DC cardioversion [DCCV].
Onset Unknown or more than 48 hrs - clot formation in atria can cause systemic
embolism - need anticoagulation for at least 3 weeks after risk stratification for
thromboembolism or stroke
Rhythm control in this group – chemical or electrical cardio version – to be preceded
by therapeutic anticoagulation
CHADS2 risk stratification – CCF, Hypertension, Age >75 years, and Diabetes
mellitus - all assigned 1point each. A previous transient ischaemic attack (TIA) or
stroke is assigned 2 points. Patients with a CHADS2 score of 0 can be treated with
aspirin. If one risk factor is present, either aspirin or warfarin can be used. In high risk
patients (CHADS2 score >2), warfarin is the anticoagulation drug of choice
If cardio version cannot be postponed for 3 weeks - give heparin before cardio
version and give Warfarin for at least 4 weeks after cardio version
After cardio version, continue anticoagulation long term in patients with a high risk of
AF recurrence
Patients with asymptomatic AF - same antithrombotic therapy as those
with symptomatic AF as per risk stratification
To aim for rate control [if haemodynamically stable] if onset more than 48 hrs and
also in chronic AF unsuitable for cardio version, IHD, when anti-arrhythmic drugs are
contraindicated
d) What are the anaesthetic considerations when performing elective DC
Cardioversion? (35%)
Day case procedure, Non-theatre and remote location such as CCU etc.
Cardiovascularly compromised patient
Pre procedure
To ensure availability of physician ready for cardioversion
Potassium should be normal – to correct electrolyte imbalance prior to the procedure
Omit Digoxin on the day [increased risk of arrhythmia]
To remove GTN patch before shock
For elective procedure – advisable to transfer to anaesthetic room
Adequate fasting or to consider RSI if risk of aspiration
Anaesthesia
Anaesthetic drug for DCCV should produce the least cardiovascular compromise possible
and enable rapid recovery
Slow induction and should use careful titration of the drug needed
To follow ALS protocol for safe cardio version – Oxygen away during shock, synchronisation
must be on - to prevent R on T phenomenon
Post-procedure
Patient to be in recovery position, Oxygen and monitoring to be continued until ready for
home
Reference – NICE Guidelines for managing AF – recommended reading
Answer contributed by Dr. Ajith Vijayan
How Atrial fibrillation may present
Atrial fibrillation is a common arrhythmia, occuring in 5-10% patients over 65 years of age. It
can also occur in a paroxysmal form in younger patients.
Presentation highly variable
Incidental finding (30%),
some deterioration of exercise capacity or well being
On investigation for the cause of CVA
Sudden onset of heart failure – leading to emergency department admission
Rheumatic valvular heart disease - sudden worsening, leading to heart failure
Patient maybe any where from asymptomatic ----- heart failure
very irregular pulse
ECG showing fine oscillation of baseline and no clear P waves
QRS rhythm is rapid and irregular
untreated ventricular rate 120-180/ min
can also present as wide QRS tachycardia when associated with LBBB
List 5 causes of atrial fibrillation
Hypertension, Congestive heart failure, Coronary artery disease &myocardial infarction,
Valvular heart disease, Non cardiac related -Thyrotoxicosis, Acute and chronic pulmonary
disease( pneumonia, COPD)
Principles underlie the management of atrial fibrillation :
Treatment of AF depends on onset, paroxysmal or persistent , structural heart disease
present or not
If the onset<48 hrs associated with haemodynamic instability treatment should include
attempted restoration of sinus rhythm by synchronised cardioversion. If more >48 hrs,
anticoagulation needed. At any point life threatening deterioration in haemodynamic
stability- emergency electrical cardioversion
Immediate correction of precipitating causes, such as electrolyte abnormalities
If electrical cardioversion fails – chemical cardioversion
Amiodarone 300mg IV over 1hr infusion, followed the rate even if by 900 mg IV over 23hr,
amoidarone will at least slow the rate even if it fails to restore sinus rhythm.
In non-life threatening haemodynamic instability, AF>48hrs, anticoagulation needed before
cardioversion. Heparin or 3 weeks of anticoagulation with warfarin depends on the
underlying circumstances
Rate control can be achieved with IV beta blockers (Esmolol, metoprolol)/ rate controlling
calcium antagonists. Amiodarone when these fail
If a delay in organising electrical cardioversion, IV amiodarone should be used. If any known
WPW syndrome or doubts , AV node blocking drugs such as diltiazem, verapamil or
digoxin should not be used
Class IC agents are recommended for rate and rhythm control on long term basis.
Sotalol very commonly used has additional class III activities, can be progressively titrated
from 80mg twice daily, to 240 mg Bd
Treat the precipitating reversible causes (electrolyte abnormalities, hypovolaemia, sepsis)
Suitable long term anticoagulation strategy
Class1agents (propafenone, flecainide ) contraindicated in significant ischaemic heart
disease or abnormal LV function. Amoidarone or sotalol should be used in those
circumstances
*Vernakalant – A new anti arrhythmia agent with class III action,( atrial selective potassium &
sodium channel blocker) faster conversion in acute onset AF. Contraindicated in heart failure
,NICE still evaluating
*Dronedarone a benzofuran derivative, analogue of amiodarone, has a better side effect
profile in chronic therapy. contraindicated in NYHA3&4 patients
Anaesthetic consideration when performing elective DC cardioversion
Could be a remote site, ideal to treat as any surgical procedure and a physician should be
available to cardiovert the patient
Preop fasting status, reflux, potassium levels - should be in normal range as myocardium
may become irritable.
Digoxin increases the risk of arrhythmias – omit on the day, continue amiodarone
If AF>24 hrs, no anti coagulation, coming after 3 weeks anticoagulation for persisting AF-
pre procedure TOE to screen the LA clot, can be done under conscious sedation with
propofol. Proceed only if no LA clot.
Standard monitoring, IV access as for a GA day case, ECG leads connected to defibrillator:
check synchronising with R wave
Induction – pre oxygenate , minimal dose of propofol only needed, Etomidate if
haemodynamically unstable, GA spontaneous ventilation with face mask.
RSI/ ETT if risk of aspiration
Obese patients, can be cardioverted in the lateral positon
ALS protocol, remove oxygen during shock. 150 J biphasic/ 200J monophasic. Limit to three
shocks. Aflutter to start with lower energy levels
Recover in the lateral position, recover with full monitoring like any GA with face mask only
Links
British Thoracic Soceity flexible broncho scopy guidelines 2001
British Thoracic Soceity guidelines for advanced diagnostic & therapeutic flexible
bronchoscopy in adults 2011
Joel A Kaplan, Peter D Slinger, Thoracic Anaesthesia 3rd edition
Clinical experience of Rigid bronchoscopy, Tuberc Respr Dis 2012;72;
Kumar & Clark Clinical Medicine - Atrial Fibrillation management
Issue date: June 2006
NICE guidelines
Atrial fibrillation
The management of atrial fibrillation
Guidelines for the management of atrial
fibrillation
The Task Force for the Management of Atrial Fibrillation of the
European Society of Cardiology (ESC)
Developed with the special contribution of the European Heart Rhythm Association 2010
2012 focused update of the ESC Guidelines for the management of atrial fibrillation
4. a) How may ultrasound techniques be used in anaesthetic and critical care
practice? (40%)
b) What information can 2D echo provide in a haemodynamically unstable patient?
(45%)
c) What is the Doppler Effect? How may this be used in echocardiography? (15%)
Answer contributed by Dr. E Balakumar
4. a) How may ultrasound techniques be used in anaesthetic and
critical care practice? (40%)
Uses of ultrasound in anaesthetic and critical care practice include
Diagnostic
a. Pulmonary - pneumothorax, pleural effusion, empyema, consolidation, collapse,
congestion
b. Cardiac - tamponade, valvular abnormalities, wall motion abnormalities,
pulmonary embolism etc
c. Abdominal - intra-abdominal bleeding and organ injury as in trauma patients,
abdominal aortic aneurysms etc
d. Vascular - DVT, flow related problems as in acute limb ischemia, vasospasm using
TCD etc
e. Volume - hypovolemic shock
Therapeutic
a. Pulmonary - Insertion of chest drain, pleural aspiration, percutaneous
tracheostomy, confirmation of endotracheal intubation etc
b. Cardiac – RWMA (ischemia/infarction), Tamponade with guided pericardial drain,
Thrombolysis in PE etc
c. Abdominal - Insertion of ascitic drains, as an alternative to DPL in trauma etc
d. Vascular - Insertion of CVCs
e. Volume - Goal directed fluid therapy using Oesophageal Doppler/TTE
f. Ultrasound guided regional and peripheral nerve blocks in pain management
b) What information can 2D echo provide in a haemodynamically
unstable patient? (45%)
2D can provide vital information (chamber volumes, pressures, ejection fraction, and
valvular function) in management of HD unstable patients. Based on the 2D ECHO
HD unstable patients can be divided into several categories so that appropriate
intervention can be instituted. They are as follows:
a. Normal - unlikely to see in HD unstable patients
b. Empty - Reduced LVEDV/Normal EF/Low LAP - infuse volume
c. Systolic failure - Increased LVEDV as dilated heart/Reduced EF as poorly
contracting/Normal LAP - use inotropes
d. Diastolic failure - Reduced LVEDV as small stiff ventricle/Normal EF as
contractility is preserved/Increased LAP as high filling pressure - control heart rate,
maintain preload, consider combination of vasodilator with low dose inotropes
e. Systolic and diastolic failure - Usually increased LVEDV as dilated heart/Reduced
EF as contractility is poor/Increased LAP as high filling pressure - Key principle is to
improve systolic function while reducing preload - diuretics, and inodilators while
maintaining high normal heart rate
f. Right ventricular failure - Combination of RV systolic failure with secondary LV
diastolic dysfunction with high LAP/RAP - principle as above but maintain adequate
volume and use drugs that will reduce pulmonary vascular resistance
g. Vasodilatation - Reduced LVEDV as decreased venous return secondary to
relative +/- true hypovolemia as in sepsis/Normal EF with hyper dynamic LV/
Reduced LAP - Vasoconstrictors +/- volume
c) What is the Doppler Effect? How may this be used in
echocardiography? (15%)
Change in frequency of a wave for an observer moving relative to its source
(Austrian physicist - Christian Doppler 1842). Re-arranging Doppler equation from
classic format gives v = cx fD/2x fT cosQ where
v velocity of the blood/red blood cells
c speed of the ultrasound transmission through the tissues
fD Doppler frequency shift
fT frequency of the transmitted ultrasound waves
Q insonation angle between the emitted ultrasound beam and the direction of blood
flow
Pulse wave/continuous/colour Doppler
Doppler
a. allows measurement of blood flow velocity which gives information on flow
characteristics, pressure gradients, and anatomical abnormalities within the heart
b. incorporation of Doppler wave values into formulas give vital information on
cardiac performance(SV/CO), valvular function and intracardiac pressure gradients.
5. a) What are i) diagnostic and ii) other clinical features of severe pre-eclampsia?
(35%)
b) What are the indications for magnesium therapy in severe pre-eclampsia
/eclampsia and which administration regimen(s) should be used? (25%)
c) What are the signs and symptoms of magnesium toxicity and how should it be
managed? (40%)
Answer contributed by Dr. Sarah Price
2. a) What are i) diagnostic and ii) other clinical features of severe pre-eclampsia?
(35%)
Pre-eclampsia is a multi-system disease which normally presents after 20 weeks gestation.
The main features are hypertension and proteinuria.
Diagnostic criteria:
1. Hypertension:
Mild hypertension- BP 140/90-149/99 mmHg
Moderate hypertension -BP 150/100- 159/109mmHg
Severe hypertension - BP > 160/110mmHg
2. Proteinuria:
2 dipstick reagent tests with >2+ protein
> 300 mg protein in 24 hr urinary collection
Severe pre-eclampsia is identified by severe hypertension with proteinuria or mild or
moderate hypertension with proteinuria with at least one of the following:
Severe headache
Problems with vision such as blurring or flashing
Severe pain just below ribs or vomiting
Papilloedema
Signs of clonus (> 3 beats)
Liver tenderness
HELLP syndrome
Platelet count falls to < 100 x 109/llitre
abnormal liver enzymes (ALT or AST rises to > 70iu/litre)
b) What are the indications for magnesium therapy in severe pre-eclampsia
/eclampsia and which administration regimen(s) should be used? (25%)
Indications:
Any woman who has had a fit due to (suspected) eclampsia
Consider if:
Patient has severe preeclampsia and birth is planned within 24 hours
Severe hypertension and proteinuria or
mild or moderate hypertension and proteinuria with one or more of the following:
o symptoms of severe headache
o diplopia, or flashing lights in vision
o Severe epigastric pain or vomiting, liver tenderness
o papilloedema
o signs of clonus (≥3 beats)
o HELLP syndrome
o platelet count falling to below 100 x 109 per litre
o abnormal liver enzymes (ALT or AST rising to above 70 iu/litre).
Administration regime:
5 g loading dose, usually as 25mls Magnesium Sulphate 20% IV over 25 minutes
Then 1g per hour using 50mls Magnesium sulphate 20% I.V. over 24 hours (run at
5mls/hr via syringe pump)
If patients on magnesium sulphate suffer a fit consider reloading with a further dose
c) What are the signs and symptoms of magnesium toxicity and how should it be
managed? (40%)
Signs and symptoms are primarily cardiovascular and neurological, and tend to be dose
related. Therapeutic range: 2 – 3.5 mmol / L. Magnesium is excreted renally therefore those
patients with reduced urine output (e.g. pre-eclampsia) are at increased risk of toxicity.
Initially non-specific signs: nausea and vomiting, headache
4 - 5mmol / L
Loss of deep tendon reflexes (First repeatable sign, therefore patella reflex should be
monitored during magnesium therapy)
Muscle weakness
5 - 7.5 mmol/L
Respiratory muscle weakness
Hypotension
Bradycardia
ECG: AV prolongation, widening QRS
>12 mmol / L
Severe arrhythmias
Cardiac arrest
Management:
Specific treatment: stop infusion, calcium gluconate (2.5 to 5 ml) – physiological
antagonist.
Non-specific: protection of airway, intubation and ventilation if respiratory
compromise, CPR if full arrest.
Suggested reading
NICE guidance for multiple pregnancy and pre-eclampsia
Local guidance for multiple pregnancy and pre-eclampsia
CEACCP journal article on pre-eclampsia and magnesium
6. All health care professionals have a responsibility to act if they suspect that a child
has been subjected to physical abuse.
a) In what situations may the anaesthetist encounter possible child abuse? (25%)
b) List clinical features that would arouse suspicion that physical child abuse has
occurred. (40%)
c) What should the anaesthetist do if they suspect child abuse has taken place? (35%)
Answer Contributed by Dr. James Walkington
6. All health care professionals have a responsibility to act if they suspect that a child has
been subjected to physical abuse.
a) In what situations may the anaesthetist encounter possible child abuse? (25%)
Resuscitation of a child who has sustained injuries under circumstances that cannot
be wholly explained or are consistent with intentional abuse or trauma
Paediatric Intensive Care unit – particularly following head injury
When asked to conduct anaesthesia for formal forensic examination
During a routine pre operative visit or surgical procedure you may notice suspicious
signs of physical or sexual abuse.
Rarely a child may disclose directly to the anaesthetist
b) List clinical features that would arouse suspicion that physical child abuse has occurred.
(40%)
Unusual or excessive bruising, particularly in the non ambulant baby/child.
Cigarette burns.
Bite marks.
Unusual injuries in inaccessible places e.g. neck, ear, hands, feet & buttocks.
Intra-oral trauma.
Damage to intra-oral frena, or unexplained frenum injury in a non-ambulant child.
Genital/ anal trauma (where no clear history of direct trauma is offered or part of the
clinical presentation).
Trauma without adequate history eg. Intra abdominal injury.
c) What should the anaesthetist do if they suspect child abuse has taken place? (35%)
The child’s safety is paramount
Essential to involve personnel with expertise in child protection
Advice from duty senior paediatrician or for junior anaesthetists to involve their
consultant
A visual inspection is acceptable but any invasive / intimate examination needs
further consent.
Do not allow the anaesthetic time to become too prolonged waiting for a second
opinion.
Full and clear documentation should be ensured
Although usually undertaken by a senior paediatrician, the parents should be
informed of the concerns unless in doing so it is felt that the child would be placed at
further danger.
Reference:
Child Protection and the Anaesthetist: Safeguarding Children in the Operating
Theatre Jointly developed and produced by the Royal College of Anaesthetists, the
Association of Paediatric Anaesthetists, and the Royal College of Paediatrics and
Child Health, March 2007
Protecting Children and Young People: the responsibility of all doctors July 2012
Answer Contributed by Dr. Subhashini Naik
a) In what situations may the anaesthetist encounter possible child abuse? (25%)
Anaesthetists may encounter abused children in a number of situations:
1. Resuscitation of a critically ill child who has sustained an injury under circumstances
that cannot wholly be explained by natural circumstances or is consistent with intentional
trauma or abuse.
2. In the paediatric intensive care unit e.g. following severe head injury, where the
above needs to be considered.
3. When called upon to anaesthetise a child for a formal forensic examination, possibly
involving colposcopy, sigmoidoscopy and the collection of specimens. This may also include
medical photography/video records.
4. Rarely a child may tell the anaesthetist about abuse (“disclosure”).
5. During the course of a routine pre-op examination or surgical procedure, the
anaesthetist or surgeon notes unusual or unexplained signs which may be indicative of
physical or sexual abuse.
b) List clinical features that would arouse suspicion that physical child abuse has
occurred. (40%)
There are occasions when a child is anaesthetised (for emergency or elective surgery) and
concerns are noted about possible physical or sexual abuse e.g. on exposure of the child
possible cigarette burns are seen. The interpretation of a flaccid or dilated anus is
particularly difficult. This can be a normal finding in an anaesthetised patient and especially
where a caudal/epidural block has been performed. Great care is required before raising
suspicions about abuse in the child, as knowledge about what constitutes normal
appearance is sparse. Physical signs can rarely be interpreted in isolation.
Suspicious signs which may be indicative of abuse
Unusual or excessive bruising, particularly in the non ambulant baby/child.
-oral trauma.
-oral frena, or unexplained frenum injury in a non-ambulant child.
clinical presentation).
l injury.
c) What should the anaesthetist do if they suspect child abuse has taken place? (35%)
If the anaesthetist becomes concerned about the possibility of abuse, during a procedure for
an unrelated condition, then contact with the child’s paediatrician or the on call consultant for
acute paediatrics is advised. If there is genuine uncertainty about whether signs are
consistent with those caused by intentional harm, this should be discussed at an early stage
with a senior paediatric or anaesthetic colleague who may attend and give advice. A visual
inspection (e.g. of a skin lesion) is acceptable, but any additional or intimate / invasive
examination requires additional consent. This should not result in the anaesthetic being
markedly prolonged if
a second opinion is not readily available. It should be emphasised that any member of the
multi-professional team should be able to initiate the process.
It is essential to involve personnel with special expertise in Child Protection. In the first
instance, it may be appropriate to seek advice from the duty paediatric consultant, or for
junior anaesthetists to consult a more senior colleague . In addition, all Trusts have access
to specific child protection experts.These are the Named Doctors and Nurses, who usually
work within the Trust, and Designated Doctors, who often work within the local area. It is
crucial that all anaesthetic departments know who these people are and how to contact them
(see page 8). If there are very serious concerns, Social Services need to be informed this
will generally be decided upon by the Named or Designated Doctor or Nurse.
7. a) Describe the symptoms and signs of Complex Regional Pain Syndrome. (50%)
b) How many symptoms and signs are required to make the diagnosis? (25%)
c) What are the other pre-requisites for the diagnosis? (25%)
Answer Contributed by Dr. Seshu Tatikola
Must include- CRPS-
Complex regional pain syndrome (CRPS) is a debilitating, painful condition in a limb
associated with sensory, motor, autonomic, skin and bone abnormalities. Pain is typically the
leading symptom, but is often associated with limb dysfunction and psychological distress.
Prompt diagnosis and early treatment is required to avoid secondary physical problems
related to disuse of the affected limb and the psychological consequences of living with
undiagnosed chronic pain.
Pain and motor limitation is disproportionate to the pathology and it is a diagnosis by
exclusion
Budapest criteria is based on 4 categories
Sensory
Motor /Trophic
Vasomotor
Sudomotor/Edema
3 symptoms in different categories + 2 signs in different categories
Sensory- Allodynia, Hyperalgesia
Vasomotor- Skin color asymmetry, temperature either hot or cold
Sudomotor- Edema/Sweating changes – or asymmetry
Motor- decreased mobility, tremor, weakness, dystonia, trophic skin, hair nail changes
It is diagnosis by exclusion so all the differential diagnosis should be excluded
Neuropathic pain
Infection
Compartment syndrome
Raynauds
Arterial insufficiency
Lymphatic obstruction
Thoracic outlet syndrome
http://crpsuk.com/2012/02/21/crps-budapest-diagnostic-criteria/
A quite pointed question only diagnosis was asked so all the above must be included.
8. a) What features in the clinical history and examination would increase your
suspicion that an adult patient has obstructive sleep apnoea (OSA)? (25%)
b) List the preoperative investigations that may be useful in the assessment of the
OSA patient. For each investigation, indicate the abnormality you would expect to
find. (35%)
c) An adult patient with known OSA is listed for an open cholecystectomy. How will
the presence of OSA influence your perioperative management of this patient? (40%)
Answer contributed by Dr. J. Biddulph
a) What features in the clinical history and examination would increase your suspicion that
an adult patient has obstructive sleep apnoea (OSA)? (25%)
History of:
o Loud snoring
o Daytime somnolence
o Observed cessation of breathing
o Male
o Age 40-70
o Smoker
o Excess alcohol
o Low physical activity
o Surgical patient
o Pregnancy
o Tonsil and adenoidal hypertrophy
o Craniofacial abnormalities
o Neuromuscular disease
On examination:
o Obese BMI > 35
o Neck circumference > 40 cm
o Hypertension
b) List the preoperative investigations that may be useful in the assessment of the
OSA patient. For each investigation, indicate the abnormality you would expect to
find. (35%)
Full blood count – polycythaemia
Blood glucose – diabetes
U+Es – renal disease ( complication of diabetes)
Oximetry - supine desaturation
Arterial blood gas - hypoxaemia, hypercarbia
Spirometry- obstructive or restrictive lung disease
Sphygmomanometry – hypertension
ECG- ischaemic heart disease, arrhythmias, left / right ventricular hypertrophy
Chest x ray – congestive cardiac failure
Echo- right/left ventricular hypertrophy, cardiac failure
Polysomnography (PSG) apnoea/hypopnoea index (AHI) > 5
c) An adult patient with known (OSA) is listed for an open cholecystectomy. How will
the presence of OSA influence your perioperative management of this patient?
(40%)
Preop
check prior anaesthetic charts for evidence of difficult airway
Optimise conditions associated with OSA (diabetes, hypertension, heart disease)
Ask patient to continue their usual CPAP regime.
Consider the need for prolonged PACU stay or HDU
If the patient is obese check appropriate manpower and equipment is available
Consider proton pump inhibitor to reduce risk of aspiration in the obese OSA patient
Avoid sedative premed
Consider need for epidural analgesia or other regional techniques
Plan for difficult intubation / ventilation
Intra op –
consider rapid sequence induction
Pre oxygenation in reverse trendelenberg position
Avoid gastric insufflation during bag mask valve ventilation
Place patient in ramped position for intubation
Intubate and ventilate patient
Use peep
Short acting opiates
Multimodal analgesia
Monitor neuromuscular blockade
Adequate reversal of neuromuscular blockade
Extubate awake and sitting up.
Post op-
Patients own CPAP
Teds and early mobilisation if obese.
May need continuous oxygen saturation monitoring in an appropriate ward
Prescribe post op oxygen
Answer contributed by Dr. Prasad Lanka
a) What features in the clinical history and examination would increase your
suspicion that an adult patient has obstructive sleep apnoea (OSA)? (25%) .
Definition:
OSA is intermittent complete or partial airway collapse, resulting in frequent episodes
of apnea and hypopnea. It is generally agreed that an apnoea, defined as a cessation of
airflow, has to exceed 10 s duration to be considered significant. No standard definition
of hypopnoea exists. It is usually defined as a reduction in airflow or respiratory effort for
more than 10 s accompanied by a desaturation of 3% or more and/or
electroencephalographic evidence of arousal. "Arousals" are sudden shifts in brain wave
activity
The apnoeas may be obstructive, central or mixed. URAS-Upper Airway Resistance
Syndrome: Increased airway resistance not sufficient to cause apnoea ,hypopnoea.
The grading of OSA is as follows, AHI of five to 15 represents mild sleep apnoea, 15–30
moderate and greater than 30, severe.
OSA Is a common medical condition affecting 2-26% of general population, affecting all
age groups. It’s estimated that 82% 0f men and 92% of women with OSA have not been
diagnosed.
Warning features in History and examination:
Most significant: witnessed apnoeic episodes[usually by partners] ,BMI>35[70%
prevalence in morbidly obese],Greater Neck circumference[>17inches or 42cms ]
snoring. Other
features :Excessive daytime sleepiness, sudden awakening, morning headache,
Structural features that give rise to a narrowed airway[Marfans, Downs], retrognathia
Neuromuscular[brain injury ,stroke], decreased muscle tone[ old age, sedatives, alcohol.]
smoking, estrogen depletion in menopause
Metabolic[hypothyroid],connective tissue disorder, nasal obstruction, laryngeal
obstruction
Explanations : witnessed apnoeic episode is a significant feature,2-3 times more
common in men [ one hypothesis is hormones like oestrogen and progesterone,but
injecting in men and post menopausal women doesn’t cured OSA;sex-based phenotypes
including physical features, occupational and other environmental exposures, and health
behavior put men at higher risks for disease ],older age[reaches plateau after 65
yrs],14% of pregnant women snores compared to 4%[due to↑ weight,pharyngeal edema
,decreased pharyngeal muscle dilator activity].The presence of unexplained respiratory
and heart failure, polycythaemia also suggests OSA.
b) List the preoperative investigations that may be useful in the assessment of the
OSA patient. For each investigation, indicate the abnormality you would expect to
find. (35%)
1.Epworth: 8 situations[Sitting and reading, Watching TV, Sitting inactive in a public place,
Being a passenger in a motor vehicle for an hour or more, Lying down in the afternoon
Sitting and talking to someone, Sitting quietly after lunch (no alcohol Stopped for a few
minutes in traffic
while driving), each scored 0-3[0=no chance of dozing,1 slight chance,2 moderate chance, 3
high chance]. A score of 10 or more is considered sleepy. A score of 18 or more is very
sleepy.Not very sensitive to diagnose OSA.
2.STOP BANG:
8 QUESTIONS[Snoring,Tired,Observed you stpopped breathing,High Blood
pressure,BMI>35,Age >50,Neck circumference >40 cms, Gender[male].
Low risk of OSA – ‘yes’ to less than three items , score of 5-8 identified patients with high
probability of moderate/severe OSA. For a STOP-Bang score of 5, the odds ratio (OR) for
moderate/severe and severe OSA was 4.8 and 10.4, respectively. For STOP-Bang 6, the
OR for moderate/severe and severe OSA was 6.3 and 11.6, respectively. For STOP-Bang 7
and 8, the OR for moderate/severe and severe OSA was 6.9 and 14.9, respectively A score
of ≥3 has shown a high sensitivity for detecting OSA: 93% and 100% for moderate and
severe OSA, respectively. The probabilities of having OSA were greater as the STOP-Bang
scoreincreased Owing to its high sensitivity at a score of ≥3, the STOPBang questionnaire is
considered very helpful to rule out patients having moderate and severe OSA. However, the
specificity at the same cut-off is low: 47% and 37% for moderate and severe OSA,
respectively, resulting in fairly high false-positive rate.
3.Polysomnography (PSG), also known as a sleep study is the gold standard
,multiparametric test which monitors brain function[EEG],Eye movements[EOG],muscle
activity[EMG],ECG,breathing functions[ respiratory airflow and respiratory effort] and pulse
oximetry. Any breathing irregularities; mainly apneas and hypopneas. Apnea is a complete
or near complete cessation of airflow for at least 10 seconds followed by an arousal and/or
3% oxygen desaturation; hypopnoea is a 50% decrease in airflow for at least 10 seconds
followed by an arousal and/or 3% oxygen desaturation. ..The severity of obstructive sleep
apnoea is graded by Apnoea –Hyponoea index as follows; Normal- AHI<5;Mild 5-
15;Moderate- 15-30; severe >30
c) An adult patient with known OSA is listed for an open cholecystectomy. How
will the presence of OSA influence your perioperative management of this
patient? (40%).
Why OSA increases periop morbidity and mortality: The breathing pauses[apnoea
hypopnoea] cause acute adverse effects, including oxyhemoglobin desaturation,
fluctuations in blood pressure and heart rate, increased sympathetic activity, cortical
arousal, and sleep fragmentation,which can cause cardiovascular[pulmonary
HY,Right heart failure , cerebrovascular complications,Intracranial hypertension and
poor wound healing. Undiagnosed sleep apnoea poses a variety of problems for
anaesthesiologists. OSA patients are known to have a higher incidence of difficult
intubation, postoperative complications, increased intensive care unit admissions,
greater duration of hospital stay and significantly higher incidence of pulmonary
complications.
The anaesthetic management [pre,intra and postop] plan is determined by the
severity of sleep apnoea, how it has been managed prior to anaesthesia, the planned
surgical procedure and the likely postoperative analgesic requirements. Patients with
diagnosed apnoea who are being treated with CPAP should take their equipment to
the operating theatre with them for use postoperatively. sedative premedicants
should be avoided.It’s not known whether Perioperative management of OSA by
means such as non-invasive ventilation [continuous positive airway pressure (CPAP)
or bi-level PAP] and postoperative monitoring may affect outcomes.
Pre op: Assess the patient for the cause of OSA, severity of OSA and the effect of
OSA on other organs. upper airway abnormalities that predispose to breathing
obstruction during sleep may also make tracheal intubation difficult.
STOP-BANG questionnaire,Epworth scoring and sleep studies helps for risk
assessment, moderate to severe OSA patients can be treated with CPAP. As OSA
can cause cardiovascular complications like pulmonary hypetension,right heart
failure ,these need to be ruled out [Echo] and should be optimized prior to the
surgery. 60% of patients will have pulmonary hypertension. Preop CPAP[ may
improve pulmonary hypertension] smoking[cessation].Alcohol [cessation],Obesity[wt
reduction and excercise] may improve the patient condition .
Airway assessment [ prone for difficult ventilation and intubation ] and Post op HDU
with CPAP should be organized. Preop sedative premedicants better avoided .Solo
regional tehniaques or supplementary regional tehniques are useful . Non opioid
[NSAID,Paracetamol,Gabapentin]Pre emptive analgesia may reduce the postop
opioid based rescue analgesia.
If the patient is Obese,preop antacid and VTE prophylaxis is desirable.
Intra op:as this patient needs GA, Prepare for difficult ventilation and intubation
Regional [ sub costal TAP block,pain burster,epidural etc],
limit Narcotics, use short acting opioids [Remifentanil] and NSAID
Limit the use of muscle relaxant
Adequate reversal .
Extubate in controlled environment
It’s feasible to do Laparoscopic cholycystectomy under CSE. Laparoscopic
cholecystectomy under segmental thoracic spinal anaesthesia: a feasibility study Van
Zundert AA, Br J Anaesth 2007; 98: 682–6
.
Post –op: Manadatory overnight admission either in HDU or ward with outreach
input , continuous O2 and pulse ox monitoring, PRN CPAP
Article Reviews: Br. J. Anaesth. Loadsman JA ,Hillman DR (2001) 86 (2):254-266.
BJA CEPD Reviews (2003) 3 (3): 75-78
Br. J. Anaesth. (2011) 106 (1):131-139.
9. A patient has died unexpectedly during a routine anaesthetic for minor surgery.
(a) What immediate administrative actions should be considered following such an
event? (70%)
(b) What steps should be taken to support all the people concerned? (30%)
Answer Contributed by Dr. Anita Samaan
9. A patient has died unexpectedly during a routine anaesthetic for minor surgery.
(a) What immediate administrative actions should be considered following such an event?
(70%)
Immediate Actions following the unexpected death of a patient
Keeping Records
Accurate and contemporaneous recording of events which are legible, timed and
signed by the anaesthetist are essential. If available, an electronic record should be
kept. All interventions including doses of drugs used should be included in the
record. A full retrospective account of the event should be completed as soon as
possible. A critical incident record should be completed
Dealing with the anaesthetist
In case of a trainee or an SAS doctor, the responsible consultant should attend to
make sure that all the essential steps are carried out and to look after the
anaesthetist. If a consultant is involved then a more senior consultant or the CD
should attend. A decision should be made as to whether the list should continue or
whether it needs to be cancelled
Dealing with the patient
The appropriate doctor will need to inform the coroner of the death. All lines/tubes
and other equipment need to be left in place.
Dealing with relatives
It is important that the relatives are informed and there should be a team approach
to the interview which should be conducted in a quiet room free from interruptions.
The events should be described in simple language and questions should be
answered as honestly as possible
Clinical Directors responsibilities
The Clinical director for anaesthesia should inform the Medical Director of the
death. If there are any issues regarding equipment or drugs then the anaesthetic
machine should be removed for checking and any other anaesthetic
equipment/drugs should be kept for further testing
(b) What steps should be taken to support all the people concerned? (30%)
Supporting the theatre team includes critical incident stress debriefing. The team
should be initially debriefed at a time to suit all staff and preferably within a few
hours of the catastrophe. The aim is to provide and record information, and to gain
feedback while details are still fresh. It is also useful to allay anxieties or
misconceptions experienced by members of theatre team. The presence of a
trained counsellor may be useful to assist staff traumatised by the event
Supporting the anaesthetist
It is vital that members of the anaesthetic department support the anaesthetist who
may be stressed and traumatised. It is important to listen to the individual and
encourage him/her to talk and refrain from being judgemental. Informal,
sympathetic peer review with a few colleagues is often useful.
Support by mentoring
It maybe helpful to appoint a mentor to support the anaesthetist through the
difficult initial months.
Support by the occupational health department
MUST READ This is the glossy from
AAGBI http://www.aagbi.org/sites/default/files/catastrophes05.pdf
Answer Contributed by Dr. I.F. Russell
9. A patient has died unexpectedly during a routine anaesthetic for minor surgery.
(a) What immediate administrative actions should be considered following such an
event? (70%)
(b) What steps should be taken to support all the people concerned? (30%)
Another example of a poorly worded question!
Personally, I find it difficult to separate out “administrative” from “practical” as both are
important.
“Administrative” = “activities related to an organization's administration and management.”
I have identified what I think are administrative, but there is lots of “wriggle” room and other
may define some actions differently. May be interesting to discuss the definition! But from
the way the marks are distributed (70% for this section) I suspect that what I call practical
should also be included.
Also, what is the time limit of “immediate”? Is “immediate” the first few minutes or is it many
hours in the case of the death occurring at 02:00! Would informing senior administrative
staff, Coroner, or defence organisation at 09:00 be classed as “immediate” in this scenario?
(a) What immediate administrative actions should be considered following such an
event? (70%)
If there is a hospital protocol this should be obtained and followed, but in general the
following should occur early: (1) dealing with the incident, (2) dealing with the patient’s
relatives, (3) dealing with the theatre team, and later investigating the event and, if
necessary, formulating implementing and monitoring recommendations to prevent a similar
incident in the future.
(1) Dealing with the event
All lines, tubes and other equipment connected to the patient must be left in place,
undisturbed. If there is any cause for concern regarding the placement of the endotracheal
tube, its position should be confirmed and recorded by an independent anaesthetist but the
tube should not be moved. (Not strictly administrative)
If a trainee, inform supervising consultant. (Probably administrative)
All documentation should be completed, and detailed print outs of anaesthetic record
obtained. If someone (usually a nurse, or midwife has been keeping records (eg during
resuscitation), read these and make sure they make sense. Do not alter anything, but add
amendments in your own “write up” of the event. (Not strictly administrative)
The operating list may need to be cancelled or another team arranged to complete the list.
(Administrative)
As soon as possible inform Clinical Director, who should inform higher Trust mangers – eg
Medical Director. There may be an on-call senior manager who should be informed.
(Administrative).
As soon as possible inform (or get consultant to inform) the Coroner (England and Wales) or
Procurator Fiscal (Scotland) and the patient's general practitioner as soon as possible by
telephone or other immediate means. The Coroner or Procurator Fiscal may decide to
conduct their own investigation. (Administrative)
If there is suspicion of a criminal act then the police need to be informed.
The clinical director or a consultant not involved with the incident should take responsibility
for checking the patient, drugs and equipment. If there is suspicion of equipment failure or a
hazard affecting the theatre, a decision may be required to take the theatre or anaesthetic
machine out of commission until further notice.(partly administrative, partly not
administrative?)
All anaesthetic equipment, drug syringes and ampoules should be kept, and moved to a
secure store room for investigation. An accurate record should be made of all the checks
undertaken including time and date of inspection. All disposable equipment including
syringes and ampoules, airway devices etc. should be kept in a secure box. This is
necessary as further investigation may be required by medical equipment maintenance
personnel, manufacturers or toxicologists. (partly administrative, partly not administrative?)
The anaesthetist involved should contact his/her defence organisation. (Administrative)
It is important to complete a Trust critical or adverse incident form. (Administrative)
The body should be transferred to an appropriate area for further investigation if necessary.
(probably administrative)
Arrange for statements to be made by all who were present during the incident using the
Trust proforma. Statements should be descriptions of what happened rather than
interpretations of events.
(b) What steps should be taken to support all the people concerned? (30%)
(1) Dealing with relatives
Arrangements made to contact relatives if they are not in the hospital. Breaking bad news
should not be done over the telephone. It will be necessary to invite the relatives to come to
hospital informing them that some complication had occurred but no details should be given.
If there is no immediate family to accompany the relative, ask the relative to bring a friend.
Some hospitals have established a bereavement service which can be helpful for grieving
relative
A senior surgeon, anaesthetist and nurse as a minimum should be involved, but chaplain,
interpreter or social workers may also be involved. Decide before the meeting who will take
the lead, but leader can ask others to talk/explain
(2) Dealing with the theatre team
The team should be initially debriefed at a time to suit all staff and preferably within a few
hours of the catastrophe, to gain feedback, and allay anxieties or misconceptions. The
presence of a trained counsellor may be useful to assist staff traumatized by the event.
Longer term counselling may be required by some.
Staff informed that all media enquiries be directed to the Trust media manager.
(3) Dealing with the Anaesthetist
It is vital that members of the anaesthetic department support the anaesthetist who may be
stressed and traumatised with various symptoms – poor sleep, nightmares, using
alcohol/drugs excessively to help cope, depression, feeling lonely or isolated.
It is vital, particularly if there is no fault by the anaesthetist, that the anaesthetic department
protect the individual from, and stand up to, senior administration, whose first knee jerk
reaction is (a) “guilty until proven innocent” and (b) to suspend that anaesthetist. Suspension
will only make things worse in some situations.
It is important to listen to the individual and encourage him/her to talk but refrain from being
judgemental. Informal, sympathetic peer review with a few colleagues is often useful and
one (known and accepted by the anaesthetist) should be assigned as “mentor” to provide
support as long as necessary.
The department may have to cover operating lists & on call etc for the involved anaesthetist
if s/he is unable to continue.
10. a) Who in a Trust are responsible for minimising the risk of transmission of
infection between patients in the operating theatre? (20%)
b) What general practices may be employed in the operating theatre to minimise the
risk of transmission of infection between patients? (30%)
c) What specific considerations determine choice of single use or reusable equipment
in the context of airway equipment and anaesthetic breathing systems? (50%)
Answer contributed by Dr. Ramesh Ananth Manohar
Health care associated infections occur as a result of health care interventions or being in
contact with health care systems. DOH has released the code of practice for prevention and
control of health care associated infections.
According to this
1. Trust chief executive is responsible for the overall standard of care given to patients and
to ensure that this meets the standards.
2. Infection control committee and infection control team are responsible for preparing and
monitoring of policies for infection control.
3. A designated consultant microbiologist is responsible for providing advice on
decontamination and sterilization.
4. AAGBI recommends a designated consultant in the department to liaise with the
infection control department to ensure standards are met.
AAGBI recommends a number of standard precautions to anaesthetists irrespective of
patient’s diagnosis and infection status. They are
1. Hand hygiene: decontamination before every episode of patient contact and hand wash
with soap and water if contaminated.
2. Bare below the elbow with rings removed and cuts / abrasions closed with plasters.
3. Gloves: sterile for high risk procedures like CVP line insertion and central neuraxial
blocks.
4. Face mask with shield for sterile procedures.
5. Theatre caps.
6. Theatre suit in theatre with sterile water repellant gown for sterile procedures.
7. Theatre shoes in theatre with facilities to wash if soiled.
8. Decreased movement in theatre complex with closed doors to avoid unnecessary
movement. Visitors to be provided with theatre attire.
9. Management of theatre lists in a way to accommodate dirty cases at the end or allow
enough time [15 mins] for the plenum ventilation to work after the case. Dirty linen to
be disposed safely. Trolleys to be cleaned. Adequate time between cases for the
theatre to be cleaned.
10. Safe disposal of sharps.
11. Prevention of drug contamination: aseptic preparation of drugs in clean tray, single
use of the ampoule, syringes to be capped, safe disposal of drugs, avoid 3 way taps,
sterile IV cannulation, one way valves and avoid multiple use.
12. Appropriate use of single use anaesthetic equipment and decontamination /
sterilization of reusable equipment
Airway equipment and breathing circuits need to be risk stratified for risk of infection.
Risk can be classified as
1. High risk: any equipment piercing skin, mucous membrane or vascular system. Such
kind of equipment need to be single use or sterilized.
2. Intermediate risk: any equipment in contact with intact mucous membrane. They
need to be single use, disinfected or sterilized.
3. Low risk: any equipment in contact with intact skin. They need to be decontaminated.
In the context of airway equipment AAGBI recommendations are
1. Tubes- single use.
2. Supra glottic airway- single use or to be cleaned according to recommendations.
Single use for adeno tonsillectomy.
3. Catheter mounts and filters- single use.
4. Breathing systems- if filters are used circuits could be used up to 5 days. AAGBI
recommends daily change. Circuits to be changed following infectious patients like
open T.B.
5. Laryngoscope- single use or clean as per recommendation.
6. Bougie- single use or clean as per standard.
7. Bronchoscope- decontaminate with sufficient contact time in an automated
system.
11. a) List the indications for intra-operative cell salvage (ICS). (20%)
b) Which therapeutic substances should not be aspirated into the ICS system? (15%)
c) What are the current controversies regarding the use of ICS in obstetrics and in
patients with malignancy? (25%)
d) What additional measures can be applied to reduce the need for allogeneic blood
transfusion during an operation? (40%)
Answer Contributed by Dr. Muthuraj Kanakaraj
a) List the indications for intra-operative cell salvage (ICS). (20%)
In surgeries with, anticipated blood loss > 1000 ml or > 20 % estimated blood
volume.
Patients with low haemoglobin or increased risk factors for bleeding.
Patients with multiple antibodies or rare blood types.
Patients with objection to receive allogenic donor blood.
b) Which therapeutic substances should not be aspirated into the ICS system? (15%)
Antibiotics not licensed for IV use.
Iodine
Topical clotting agents.
Orthopaedic cement.
c) What are the current controversies regarding the use of ICS in obstetrics and in
patients with malignancy? (25%)
Malignancy:
There is a concern that blood with malignant cells, re-infused may result in
metastasis.
But studies done in surgery involving urological and hepatocellular malignancies did
not show any difference in the incidence of metastasis between patients who
received and who did not receive cell salvage blood.
In 2008, NICE approved use of ICS in urological malignancies.
Avoiding blood around the tumour site and use of leukodepletion filters reduces the
incidence of malignant cell numbers.
Obstetrics:
The concern is the re-infusion of foetal contaminants causing amniotic fluid
embolism. But there is no evidence to prove this.
NICE has approved the use of ICS in obstetrics.
d) What additional measures can be applied to reduce the need for allogeneic blood
transfusion during an operation? (40%)
Pre-operative:
1. Iron supplements.
2. Erythropoietin.
3. Determining acceptable safe level of haemoglobin appropriate for the patient.
4. Autologous donation before an elective surgery.
5. Thromboembolic prophylaxis dose appropriate to body weight and coagulation
status.
Intra-operative:
1. Maintenance of physiologic body temperature. A fall of 1.5o C of body temperature is
associated with increased blood loss of about 50% in total hip replacements.
2. Hypotensive epidural anaesthesia if appropriate to the patient and surgery.
3. Normovolemic haemodilution.
4. Usage of thrombotic agents like platelet gels and fibrin sealants.
5. Anti-fibrinolytic agents: Tranexamic acid is safe and more effective than aprotinin.
6. Goal directed transfusion, (i.e.) Optimizing coagulation before red cell transfusion.
Needs point of care monitoring of coagulation (TEG)
Post-operative:
Reinfusion of salvaged red cells during the first 8 hours after surgery.
Reference:
AAGBI: Guidelines on Intra operative cell salvage and red cell transfusion.
Perioperative cell salvage CEACCP, volume 10 Number 4 2010.
Answer contributed by Dr. Raj Ramchandran
11. a) List the indications for intra-operative cell salvage (ICS). (20%)
b) Which therapeutic substances should not be aspirated into the ICS system? (15%)
c) What are the current controversies regarding the use of ICS in obstetrics and in patients
with malignancy? (25%)
d) What additional measures can be applied to reduce the need for allogeneic blood
transfusion during an operation? (40%)
A) Indications for intra-operative cell salvage (ICS)
ICS is indicated in surgery with:
• Anticipated blood loss of >1000mls or >20% Estimated Blood Volume.
• Patients with a low Hb or increased risk factors for bleeding.
• Patients with multiple antibodies or rare blood types.
• Patients with objections to receiving allogenic (donor) blood.
Procedures and situations which may be suitable for ICS
Vascular Surgery, Trauma & Orthopaedics
Open aortic aneurysm repair - elective and emergency
Splenic/liver trauma
Spinal surgery
Revision hip replacement, Pelvic fractures
Urology
Radical cystectomy, Radical prostatectomy
Nephrectomy
General Surgery
Hepatectomy
Abdominal/thoracic trauma
Cardiac
Open heart surgery
Obstetric Emergency use:
Major obstetric haemorrhage, laparotomy for PPH.
Elective use: anticipated haemorrhage at LSCS e.g. placenta praevia/accreta, large
fibroid
Gynaecology
All major procedures, e.g. pelvic clearance
Head and Neck
Major procedures
Jehovah’s Witnesses or any patient refusing a blood transfusion
B) Which therapeutic substances should not be aspirated into the ICS system? (15%)
• Antibiotics not licensed for IV use
• Iodine or cleaning agents used in surgery
• Topical clotting agents e.g: collagen, cellulose & thrombin
• Orthopaedic cement
C) What are the current controversies regarding the use of ICS in obstetrics and in
patients with malignancy? (25%)
Malignancy
1) Manufacturers of ICS devices do not recommend its use in patients undergoing surgery
for malignancy - concerns about the possibility of malignant cells being reinfused and
leading to metastases.
2) However two recent studies have shown no difference in biochemical recurrence or long
term survival after radical prostatectomy and cystectomy and also a recent prospective study
of hepatocarcinoma surgery also showed no difference in recurrence rates
3) In contrast, there is evidence that allogenic transfusion is independently associated with
an increased rate of both postop. infection and disease recurrence .
4) Hence, NICE approved the use of ICS in urological malignancies
- Aspiration of blood from around the tumour site to be avoided.
5) There is in vitro evidence that leucodepletion filters significantly reduce malignant cell
numbers.
Obstetrics
1) Main concern for use of ICS - risk of reinfusing fetal contaminants with risk of causing
amniotic fluid embolus (AFE).
2) However, to date there are no proven cases in the literature of AFE caused by reinfusion
of salvaged blood, and the use of cell salvage in obstetrics is approved by NICE.
3) Leucodepletion filters - Has shown a significant reduction in contamination from amniotic
fluid
4) The other concern of reinfusion of fetal RBCs from the operative field, as the cell saver
cannot distinguish fetal from maternal red cells.
5) If the mother is rhesus negative (and the fetus RhD positive) the extent of maternal
exposure should be determined by Kleihauer testing as soon as possible and a suitable
dose of Anti D given.
D) What additional measures can be applied to reduce the need for allogenic blood
transfusion during an operation? (40%)
Surgery
To consider staged or laparoscopic surgery as appropriate or possible
Meticulous technique, use of laser scalpels, biological haemostats, fibrin glues and sealants
Anaesthetic
To reduce venous oozing – careful positioning to avoid congestion, to avoid increased
intrathoracic pressures and hypercarbia
To prevent hypothermia
Low threshold for invasive monitoring
To outweigh the merits & demerits of hypotensive anaesthesia and regional anaesthesia as
necessary or appropriate
Drugs
To consider these drugs during major surgery
Antifibrinolytics – EACA, Tranexamic acid
Desmopressin – improves platelet adhesion
References – AAGBI Guidelines on ICS – recommended reading
12. (a) What are the main types of studies that must be done on a drug in order to obtain
marketing authorization (formerly called a product licence) from the Medicines and
Healthcare products Regulatory Agency (MHRA)? (30%)
(b) Define what is meant by ‘a double blind randomised controlled trial with adequate power’,
and explain the reasons for these methods? (50%)
(c) Under what circumstances might an observational study be an acceptable method of
investigation? (20%)
Answer Contributed by Dr. Dan Harper
What are the main types of studies that must be done on a drug in order to obtain
marketing authorization (formerly called a product licence) from the Medicines and
Healthcare products Regulatory Agency (MHRA)? (30%)
Phase 0: Pharmacodynamics and pharmacokinetics
The first in-human trials given to small number (10-15) in sub therapeutic doses to determine
how the drug is handled within the body
Phase I: Screening for safety
Usually involve small numbers of healthy people. They are designed to find out how the
treatment works in the body and how those treated react to it. This type of trial also aims to
find out the lowest dose at which the treatment is effective, known as the minimum
therapeutic dose, and the highest dose at which it can be taken without causing harm.
Phase II: Establishing the testing protocol
Test the treatment in several hundred people with a given disease or condition. They aim to
find out how well the treatment works in larger numbers, identify common side effects, and
refine the dose and length of treatment.
Phase III: Final testing
Compare the treatment on several thousand patients, to gather more detailed information on
how well it works and in which groups of patients, as well as its safety. The results influence
the prescribing and patient information of a medicine once it is marketed.
Phase IV: Post approval studies
Carried out after a medicine has been licensed, put on the market and prescribed to
patients. Part of the monitoring process, these trials are designed to find out more about the
long term harms and benefits of a medicine, and to discover new uses for it.
NOTE: Phase 0 is not always described in books etc it is a more recent addition.
Technically phase IV trials are performed after the marketing authorisation is granted. I’m
not sure the best way of dividing the marks. Assuming a mark is roughly 5% then 6 are
available for this question. Maybe half a mark for each phase I – IV then a whole mark for
the explanation?
Define what is meant by ‘a double blind randomised controlled trial with adequate power’,
and explain the reasons for these methods? (50%)
This is the gold standard in medical research
Double blind
Blinding in a trial attempts to eliminate bias. Singly blinded trials do not tell the patient which
treatment they are receiving such as active or inactive drug. In some occasions this can be
very difficult to achieve but investigators go to great lengths such as performing dummy
procedures to maintain blinding. Blinding in the patient group is important because it helps
to control the placebo effect.
In double blind trials neither the investigators nor the patients are aware of which treatment
the participant is receiving. This helps to eliminate the chance of the investigators own
agenda might influence the results.
Randomised
The group to which the participant is allocated to is randomly allocated. This can be
achieved in a number of ways but generally patients are allocated a number which a
computer program then allocates to different groups. This is an attempt to ensure that
patient demographics which might influence the outcome such as age, weight, sex medical
history etc are matched between each group.
Controlled
The trial is performed in two groups, the treatment and control groups. The control group
might receive dummy medicines or procedures in which case it would be placebo controlled.
In some trials it would be unethical to treat a patient with a placebo for example in patients
with cancer. Here the control group is treated with the current standard of care and the
outcome is compared with that in the group receiving the product under investigation.
Controlling a trial simply allows for a comparison to be made and as long as all other
variables are controlled for the effect seen can then be attributed to the product with
reasonable confidence.
Adequate power
The power of a statistical test is the probability that a test will reject the null hypothesis when
it is in fact false. As the power increases the chance of committing a type II error (false
negative or β) decreases. Power is equal to 1 – β and is sometimes referred to as the
sensitivity. By convention a power of 0.8 (β = 0.2) is an acceptable level of power. A power
of 0.8 means that the study has an 80% chance of producing a p value of <0.05 when the
required difference between variables is observed. A power calculation is performed to
determine the minimum sample size which can be reasonably expected to demonstrate this
observed difference.
Under what circumstances might an observational study be an acceptable method of
investigation? (20%)
An observational study is one in which the allocation of subjects into control and treatment
group is outside the influence of the researcher. Observational study is a collective term for
cohort, cross sectional and case-control studies. The primary reason for using an
observational study is when ethical considerations preclude allocation of asymptomatic,
randomly allocated subjects to certain variables for example the link between smoking and
lung cancer.
This example also demonstrates the other situation in which an observational study might be
employed, specifically when it using a randomized controlled methodology would be
impractical due to the long natural history of cause and effect. Studying the effects of
smoking on cancer would result in a study would run for 20 or more years. In observational
studies the researcher might select a group of patients with lung cancer and work backwards
to identify a causative influence. The same is true when investigating conditions or effects
which are rare and would therefore require a prohibitively large number of subjects in which
to observe the effect. Once again patients are selected with the condition and the
researcher would work retrospectively to try and determine cause and effect.
Answer Contributed by Dr. P Balaji
(a) What are the main types of studies that must be done on a drug in order to obtain
marketing authorization (formerly called a product licence) from the Medicines and
Healthcare products Regulatory Agency (MHRA)? (30%)
Before obtaining the marketing authorisation, the drug company has to provide more
information and paperwork to prove how the drug work, its side-effect and efficacy. MHRA is
more concerned about the safety and efficacy. Any trial conducted in UK would suffice. Step
wise approach would be to conduct a trial in animals followed by any evidence (trial
information) obtained elsewhere from other countries. This would be followed by Phase-2
trial (observational) in a controlled and restricted manner. Once they are satisfied, they
would provide MA following which RCT could be done to know its efficacy for which every
hospital has to obtain MHRA approval.
Must include: MHRA looks for safety and efficacy. Clinical trials have to be conducted in UK.
(b) Define what is meant by ‘a double blind randomised controlled trial with adequate
power’, and explain the reasons for these methods? (50%)
The randomized controlled trial is one of the simplest but most powerful tools of research. In
essence, the randomized controlled trial is a study in which people are allocated at random
to receive one of several clinical interventions. On most occasions, the term “intervention”
refers to treatment, but it should be used in a much wider sense to include any clinical
manoeuvre offered to study participants that may have an effect on their health status. Such
clinical manoeuvres include prevention strategies, screening programs, diagnostic tests,
interventional procedures, the setting in which health care is provided, and educational
models. Randomized controlled trials are used to examine the effect of interventions on
particular outcomes such as death or the recurrence of disease. Some consider randomized
controlled trials to be the best of all research designs, or “the most powerful tool in modern
clinical research”, mainly because the act of randomizing patients to receive or not receive
the intervention ensures that, on average, all other possible causes are equal between the
two groups.
In addition to randomization, the investigators can incorporate other methodologic strategies
like blinding to reduce the risk of ascertainment and observation biases. A single-blinded
randomized controlled trial is one in which a group of individuals involved in the trial (usually
patients) does not know which intervention is given to each participant. A double-blinded
randomized controlled trial, on the other hand, is one in which two groups of individuals
involved in the trial (usually patients and treating physicians) do not know which intervention
is given to each participant.
The most important limitations of research methods for RCT include the following:
Insufficient power.—A survey of 71 randomized controlled trials showed that most of these
trials were too small (i.e., had insufficient power to detect important clinical differences) and
that the authors of these trials seemed unaware of these facts. So Power is important to
interpret the effectiveness of the trial. More often we talk about the power of a study to detect
an effect of a specified sample size where the power is 1-beta, where beta is type-II error
which is usually designed for 85-90% in order to detect a difference ( as significant) that is
real (due to the drug).
Must include: definition for RCT, double blind and power
(c) Under what circumstances might an observational study be an acceptable method
of investigation? (20%)
Observational studies include Cohort, cross sectional and case-control studies. Often these
studies are the only practicable method of studying various problems, for example, studies of
aetiology, instances where a randomised controlled trial might be unethical, or if the
condition to be studied is rare. Cohort studies are used to study incidence, causes, and
prognosis. Because they measure events in chronological order, they can be used to
distinguish between cause and effect. Cross sectional studies are used to determine
prevalence. They are relatively quick and easy but do not permit distinction between cause
and effect. Case controlled studies compare groups retrospectively. They seek to identify
possible predictors of outcome and are useful for studying rare diseases or outcomes. They
are often used to generate hypotheses that can then be studied via prospective cohort or
other studies. On those circumstances, Observational study would be an acceptable method
of investigation.
Must include that there are various studies like cohort, cross-sectional and case-control and
few examples why it is acceptable and why RCT can't be done. Even a single example
would be sufficient.
Reading materials: Practical statistics for medical research by Douglas Altman; very simple
and easy to read.