Emergency Medicine

Critical Care Emergencies 13

Acute Upper Airway Obstruction

10 When to stop
The decision to cease further attempts at resuscitation is difficult. Only the
senior ED doctor should take this. Survival from out-of-hospital cardiac arrest
is greatest when:
(i) The event is witnessed.
(ii) A bystander starts resuscitation, even if only chest compressions
(doubles or triples survival rate).
(iii) The heart arrests in VF or VT (22% survival).
(iv) Defibrillation is carried out at an early stage, with successful
cardioversion achieved within 3–5 min (49–75% survival), and
not more than 8 min:
(a) each minute of delay before defibrillation reduces survival to
discharge by 10–12%
(b) survival after more than 12 min of VF in adults is less than 5%.

DIAGNOSIS

1 Acute upper airway obstruction may be due to choking on an inhaled foreign
body, epiglottitis, croup, facial burns and/or steam inhalation, angioedema,
trauma, carcinoma or retropharyngeal abscess.

2 There may be sudden wheeze, coughing, hoarseness or complete aphonia,
with severe distress, ineffective respiratory efforts, stridor and cyanosis,
followed by unconsciousness.

3 Attach a cardiac monitor and pulse oximeter to the patient.

MANAGEMENT

This depends on the suspected cause.

1 Sit the patient up and give 100% oxygen via a face mask. Aim for an oxygen
saturation above 94%.

2 Inhalation of a foreign body
(i) Perform up to five back blows between the shoulder blades, using
the heel of your hand with the victim leaning well forwards or
lying on the side.

Tip: make special considerations in near-drowning, hypothermia and

acute poisoning (especially with tricyclic antidepressants). Full recovery

has followed in apparently hopeless cases (fixed dilated pupils, non-

shockable rhythm) with resuscitation prolonged for several hours.

✓

ACUTE UPPER AIRWAY OBSTRUCTION