NAP 4 projectObstructed Airway

Dr Adrian PearceGuy’s and St Thomas’ Hospital

A patient with an advanced transglottic tumour required tracheostomy prior to radiotherapy.

Anaesthesia was induced with total intravenous anaesthesia in the anaesthetic room.

Intubation was attempted unsuccessfully by rigid videolaryngoscopy.

Rapid oxygen desaturation developed and both facemask ventilation and needle cricothyroidotomy failed.

A late peri-arrest attempt at intubation was made by the surgeon.

The patient died in the anaesthetic room.

NAP 4 data for Head and Neck disease

72 reports (55 anaesthesia, 10 ICU/HDU, 7 ED forms)

More than one-third of all cases in the project

70% patients in this group had obstructed airway

Qualifying events:

Death or brain damage 13

Emergency surgical airway 50

Unexpected ICU admission 27

Outcome at time of form completion:

Death 17

Partial recovery 2

Full recovery 51

Not recorded 2

Airway obstruction is a blockage of the airway, resulting in reduced or absent gas flow to and from the alveoli

Flavell EM, Stacey MR, Hall JE Clinical management of airway obstruction. Current Anaesthesia and Critical Care 2009, 20: 102-112

Airway obstruction is the clinical situation in which a patient develops signs or symptoms due to narrowing or ? distortion of

the airway

NAP 4 data

~ 50 patients with airway obstruction

Anaesthesia for diagnostic/resective surgery

Airway intervention to maintain airway

Patients admitted via ED

Patients in ICU

An ASA 3 elderly patient was scheduled for panendoscopy and biopsy of a presumed airway tumour.

Preoperatively, the patient appeared comfortable, with mild stridor and was able to lie flat without any distress.

No airway investigations had been undertaken and general anaesthesia was induced.

The tumour obscured the larynx, intubation and mask ventilation were impossible and the patient suffered a cardiac arrest from gross hypoxia.

The ENT surgeon performed an urgent surgical tracheostomy and the patient was resuscitated.

The patient died several months later from inoperable disease.

A middle aged, but not obese patient was scheduled for biopsy of a suspected tumour of the base of tongue.

The patient had undergone radiotherapy to the head/neck following the discovery of a malignant neck node four years previously and had continued

to smoke.

The consultant anaesthetist did not expect any particular problems.

However, after induction of general anaesthesia, on attempting laryngoscopy no recognisable laryngeal structures could be seen and mask ventilation was

difficult.

Fibreoptic endoscopy showed an ‘inflamed and swollen epiglottis’ and fibreoptic intubation was not successful.

The patient had an emergency surgical tracheostomy in the anaesthetic room with satisfactory maintenance of oxygenation via facemask ventilation.

Learning points

• Anaesthetists should be familiar with the tools of assessment of the airway

• Stridor/respiratory distress at rest may not be present in chronic obstruction

• Flexible nasendoscopy is very useful and was the commonest additional airway investigation

• There is benefit in reviewing all scans/endoscopy with the surgeon prior to starting

Learning point

• The anaesthetist should try to have a good idea of the

- Degree of narrowing- Site of narrowing

above the vocal cordsinvolving vocal cordsbelow vocal cords

- Type of narrowingbefore starting

A middle aged ASA 3, slim patient presented for elective clearance of infected tissue following pharyngeal surgery and radiotherapy.

Facemask ventilation, direct laryngoscopy, laryngeal mask placement and direct tracheal access were all predicted to be difficult.

Facemask ventilation was optimal following induction of anaesthesia and muscle relaxation but deteriorated after four attempts at direct

laryngoscopy with increasing bleeding, oedema and secretions.

Ventilation became impossible and a surgical tracheostomy was performed.

An elderly, ASA 3 patient was known to have a grade 4 direct laryngoscopy view due to oral carcinoma and radiotherapy.

Presented as an emergency with stridor.

Inhalational induction with halothane failed, ventilation was impossible and the patient deteriorated to PEA cardiac arrest

requiring CPR.

Attempted fibreoptic intubation failed and the airway was successfully rescued with a surgical airway.

An elderly, ASA 4 patient presented with stridor, due to invasive thyroid carcinoma.

Inhalational induction and maintenance of spontaneous ventilation with sevoflurane was planned.

Following induction, airway obstruction and laryngospasm occurred. No muscle relaxant was administered.

Direct laryngoscopy revealed a grade 2 laryngeal view, attempted intubation resulted in trauma and oedema with no ventilation.

A surgical airway was required.

A young fit and slim adult presented with a dental abscess and facial swelling.

Inhalational induction and maintenance of spontaneous ventilation with sevoflurane was planned.

Following induction airway obstruction and laryngospasm occurred.

No muscle relaxant was administered, airway obstruction persisted with desaturation.

Direct laryngoscopy and laryngeal mask ventilation failed.

Airway obstruction and inability to ventilate required a surgical airway.

A theme that emerged from the project data was the deterioration in the airway following inhalational induction and subsequent inability

to maintain spontaneous ventilation.

Following induction of anaesthesia; No compromise to spontaneous ventilation in 4 patients

Airway compromise with oxygen desaturation in 12 patients

Failure of ventilation, either because the airway deteriorated

Inhalational induction – what actually happened

further or after direct laryngoscopy attempts were made in 11 patients

Another consistent theme to emerge from patients with head and neck pathology was the deterioration in the airway following single or repeated

attempts at direct laryngoscopy.

Following induction of anaesthesia and attempts at direct laryngoscopy the airway deteriorated with increasing difficulty in ventilation in 13

patients.

With repeated attempts the airway became impossible to ventilate in 15 patients. All these 15 patients subsequently required a surgical airway.

Direct laryngoscopy – what actually happened

23 attempts to use flexible fibreoptic techniques 14 failed9 successful

Of the 14 failures with this technique4 awake and 10 asleep

Awake failure was due to an inability to either identify the glottic inlet or an inability to pass either the

fibreoptic scope or tracheal tube.

Asleep fibreoptic failure in ten patients was as a result of repeated attempts, inability to identify the glottic

inlet, inability to pass the fibreoptic scope or the tracheal tube, bleeding and airway obstruction.

In those patients where fibreoptic techniques were unsuccessful a surgical airway was usually required.

Flexible fibreoptic techniques - what actually happened

Needle cricothyrotomy often fails

Of 27 uses of cannula cricothyroidotomy in head and neck patients 12 were successful (by both large and small bore devices) and 15 failed.

Failure of cannula cricothyroidotomy was due to misplacement, inability to place, fracture, kinking, blockage, dislodgement and barotrauma.

It is important to recognise that cannula cricothyroidotomy has a significant failure rate in CICV, and for head and neck patients a surgical tracheostomy is often required.

We may love our anaesthetic rooms but ….

A patient bleeding after radical neck dissection returned to theatre in the early hours of the morning. The patient was asymptomatic apart from a dull ache and previous laryngoscopy was grade 2.

The anaesthetist undertook a RSI in the anaesthetic room. At laryngoscopy the tissues were completely oedematous Larynx was not visible. A blind attempt in placing a bougie failed. A prepared fibrescope was inserted but again no landmarks Ventilation via a SAD failed Large-cannula cricothyroidotomy was performed but unsuccessful

The patient was rushed into theatre for a surgical tracheostomy with an intubating LMA in place but before intubation through this was started the thiopentone and suxamethonium used at induction wore off enabling the patient to awaken. A difficult awake tracheostomy was undertaken and the patient made a full recovery.

What can NAP4 tell us about the best approach to managing the obstructed airway?

We must move away from talking about primary plans (I am going to do an inhalational/IV/fibreoptic) to formulating logical, coherent strategies

There must be a strategy of primary and back-up plans with all the equipment and personnel ready before starting

The outcome depends on the strategy adopted and not the initial or primary approach to securing the airway

There is no obvious benefit in starting difficult cases in the anaesthetic room when the back-up/rescue plan involves other members of the theatre/surgical team

Needle cricothyrotomy has a high failure rate in practice – urgent surgical tracheostomy appears to be a more successful back-up

Limitations on NAP4 and the obstructed airway

• Successful primary tracheostomy under LA or GA was not reported to the project

• A rescue surgical airway may well be part of an excellently planned and managed obstructed airway

• ‘Successful’ airway management which did not lead to a qualifying event was not reported

Recommendations for management of the obstructed airway 1

• Senior anaesthetic and surgical staff should be involved

• Anaesthetists should gain useful information from CT, MR imaging and nasendoscopy whenever possible

• Airway investigations should be reviewed jointly by the surgeon and anaesthetist

• The level of obstruction in the airway should be determined whenever possible

Recommendations for management of the obstructed airway 2

• If no additional investigations are available consideration should be given to awake nasendoscopy in theatre to reassess the situation prior to starting

• An agreed airway management strategy should be formulated by the anaesthetist, surgeon and theatre team prior to starting

• The anaesthetic management of any case in which surgical tracheostomy is a rescue option should start in the operating theatre with everyone assembled and ready

Recommendations for management of the obstructed airway 3

• Multiple attempts at direct laryngoscopy should be avoided

• If FOI is the primary plan, there are good reasons for undertaking this in the awake patient and this should be considered

• Inhalational induction may fail with loss of airway and failure to wake and a clear rescue plan should be ready

• Emergency needle or large-bore cricothyrotomy cannot be assumed to be possible or successful

Recommendations for management of the obstructed airway 4

• The team managing the patient should not disperse after extubation until the airway is safe

• Patients in ICU (intubated or with tracheostomy) require a continuously-ready strategy for reintubation if the tube dislodges or blocks

A patient with an advanced transglottic tumour required tracheostomy prior to radiotherapy.

Anaesthesia was induced with total intravenous anaesthesia in the anaesthetic room.

Intubation was attempted unsuccessfully by rigid videolaryngoscopy.

Rapid oxygen desaturation developed and both facemask ventilation and needle cricothyroidotomy failed.

A late peri-arrest attempt at intubation was made by the surgeon.

The patient died in the anaesthetic room.

The report illustrating the largest number of learning points