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
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)
When Low risk
suppressed, symptomatic HIV) Start of list Between patients End of list 20 min 20 min 20 min 20 min 1 hour 1 hour
Change the disinfectant when the manufacturers 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
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 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)
b) List 5 causes of atrial fibrillation. (25%)
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 onset48 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 AFpre 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 o o o o o o o symptoms of severe headache diplopia, or flashing lights in vision Severe epigastric pain or vomiting, liver tenderness papilloedema signs of clonus (3 beats) HELLP syndrome platelet count falling to below 100 x 109 per litre abnormal liver enzymes (ALT or AST rising to above 70 iu/litre).
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 childs 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 clinical presentation). l injury. -oral trauma. -oral frena, or unexplained frenum injury in a non-ambulant child. Unusual or excessive bruising, particularly in the non ambulant baby/child.
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 childs 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- CRPSComplex 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 o o o o o o o o o o o Loud snoring Daytime somnolence Observed cessation of breathing Male Age 40-70 Smoker Excess alcohol Low physical activity Surgical patient Pregnancy Tonsil and adenoidal hypertrophy Craniofacial abnormalities
o o o o
On examination: Obese BMI > 35 Neck circumference > 40 cm 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, 1530 moderate and greater than 30, severe. OSA Is a common medical condition affecting 2-26% of general population, affecting all age groups. Its 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. 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 doesnt 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. Other
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 specicity 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 15;Moderate- 15-30; severe >30
follows; Normal- AHI 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 1.5 o 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 Jehovahs 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. Im 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 ) decreases. Power is equal to 1 and is sometimes referred to as the sensitivity. By convention a power of 0.8 ( = 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
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