4.1 NAP 4

Question 1

The 4th National Audit Project (NAP4) was published in 2011.
a) Which factors are most likely to lead to an adverse airway event when using a supraglottic airway
device (SAD)? (30%)

Answer 1

Patient factors:
1.&raquo_space; Obesity.

2&raquo_space; Known/predicted difficult airway.

3&raquo_space; Irritable airway: asthma, recent chest infection.

4&raquo_space; Obstructive sleep apnoea.

5&raquo_space; Aspiration risk:

obesity, reflux, hiatus hernia,
raised abdominal pressure,
pregnancy,

drugs or conditions affecting gastric emptying.
(recent trauma, recent pancreatitis,
pain, ileus, bowel obstruction,
diabetes mellitus, chronic kidney disease)

Surgical factors:

1&raquo_space; Urgent surgery, inadequate fasting time.

2&raquo_space; Lithotomy, prone, semi-prone
or Trendelenberg positioning.

3&raquo_space; Prolonged surgery.

4&raquo_space; Abdominal surgery.

5» Laparoscopic surgery.

6&raquo_space; Shared airway surgery.

Anaesthetic factors:
 1 >> Junior anaesthetists, 
inadequate training, 
poor supervision, poor
attention to detail, 
poor patient selection, poor judgment.

2&raquo_space; Use of SAD to avoid
intubating patients with
known/predicted difficult airway.

3&raquo_space; Difficulty siting SAD,
resulting in problems during maintenance
or emergence.

4&raquo_space; Light anaesthesia.

5&raquo_space; First-generation SAD use.

Question 2

b) How would you recognise that a patient has regurgitated and aspirated gastric contents during an
anaesthetic administered via a SAD? (30%)

Answer 2

A:
» Gastric contents visible in the oropharynx/tube of SAD.

B:
>> Desaturation.
>> Cyanosis.
>> Bronchospasm.
>> Increased airway pressures/reduced tidal volumes 
in ventilated patient.
>> Abnormal auscultation.

C:
» Tachycardia.

Question 3

c) How would you manage this patient? (40%)

Answer 3

This is an anaesthetic emergency. I would alert the theatre team, call for
help and adopt an ABC approach, assessing and managing the patient
simultaneously.

A:
» Head down tilt +/− lateral tilt.
» Remove SAD.
» Oropharyngeal suction.

B:
>> 100% oxygen.
>> RSI 
(with cricoid pressure and 
avoidance of stomach inflation).

> > Ideally, tracheal suction prior
to ventilation but oxygenation is paramount.

> > Positive pressure ventilation with PEEP.

> > Symptomatic treatment with
bronchodilators if necessary.

C:
» Ensure cardiovascular stability;
manage as appropriate.

Once the patient is stable:
» Early bronchoscopy if particulate
matter has been aspirated.

> > Decision to continue with
surgery depends on circumstances.

> > Extubation or ventilation on ICU:
dependent on clinical condition.

> > If extubated,
extended recovery stay for observation of respiratory rate, oxygen saturations, other signs of respiratory distress.

> > CXR.

> > Maintain a high index of suspicion
for aspiration pneumonia and treat
early (antibiotics not routinely advocated).

> > Discussion with patient and/or
family followed up by written information
of what symptoms should prompt the patient to seek medical help.