Otherwise known as 'crash induction', rapid-sequence induction is the method employed to intubate a patient rapidly while protecting against the possibility of aspiration of gastric contents.
The patient is prepared as described above, adopting the most favorable position and preparing drugs and equipment. An experienced assistant is required for this maneuver, to help make equipment available when required and to apply cricoid pressure. This consists of application of moderate pressure to the cricoid cartilage with thumb and index finger. It is important that the correct pressure is applied as the aim is to prevent only passive reflux of gastric fluid. If the patient actively vomits on induction, the cricoid pressure should be released and the patient turned on his or her side, as the continuing application of excessive cricoid pressure could result in esophageal rupture. Overenthusiastic cricoid pressure can also distort the anatomy and make an intubation more difficult than it need be.
The patient is preoxygenated by firmly applying the oxygen mask and administering high-flow oxygen. Oxygen is administered over 2 to 3 min, with the aim of replacing the air occupying the 2 liters of functional residual capacity in the lungs with approaching 100 per cent oxygen. This provides almost 2 liters of oxygen as a metabolic reserve, so that when the patient is rendered apneic for intubation, hypoxemia does not occur for several minutes, allowing more time for intubation, particularly if difficulty is encountered.
When the patient has been preoxygenated, the intravenous induction agent is administered. As the patient becomes unconscious, cricoid pressure is applied by the assistant and succinylcholine (suxamethonium) is administered. Its effect is usually observed within 1 min by peripheral muscular fasciculation. The operator should then proceed to laryngoscopy and intubation. As soon as the endotracheal tube is in place, the tracheal cuff is inflated, the ventilating circuit is attached, and the patient's lungs are inflated. The intubator should not ask for the cricoid pressure to be released until lung inflation is confirmed and there is no audible leak of gas around the cuff.
Correct placement of the endotracheal tube should be confirmed by observing bilateral chest wall movement, auscultating both axillas, negative auscultation of the epigastrium, and capnography of the expired gases if available.
Was this article helpful?