Objectives

The objectives of this chapter are to understand:

• the importance of pre-oxygenation

• the technique of rapid sequence induction (RSI) of anaesthesia and tracheal intubation

• the confirmation of successful intubation

• the importance of immediate review of patient physiology after intubation.

Introduction

Rapid sequence induction of anaesthesia (RSI) involves injecting an anaesthetic induction drug to achieve hypnosis, rapidly followed by a neuromuscular blocking drug to produce complete paralysis. To prevent inflation of the stomach, the lungs are not usually ventilated between induction and intubation, and the airway is protected by applying cricoid pressure to prevent regurgitation of gastric contents. The time from loss of consciousness to securing the airway is minimized because the patient's stomach is assumed to be full.

Pre-oxygenation

Effective pre-oxygenation replaces the nitrogen in the alveoli with oxygen, which increases the oxygen reserve in the lung. Pre-oxygenation maximizes the time before desaturation occurs following the onset of apnoea. This provides more time for intubation to be attempted before having to stop to re-oxygenate the patient's lungs (see Chapter 2). Whenever possible, give 100% oxygen for three minutes before induction of anaesthesia. A patient who is breathing inadequately may not achieve enough alveolar ventilation to replace nitrogen in the lungs with oxygen. These patients may therefore require assisted ventilation to achieve adequate pre-oxygenation before RSI.

The time to desaturation is related not only to the effectiveness of the pre-oxygenation phase, but also to the age and weight of the patient and their physiological status.