Objectives

On successfully completing this topic, you will be able to:

• appreciate the risks posed to the pregnant women by anaesthetic drugs and techniques

• understand anaesthetic emergency problems affecting the pregnant woman.

Introduction and incidence

The proportion of women dying from complications of anaesthetics has declined markedly over the last 20 years. Deaths from airway-related problems have declined over the last ten years of Confidential Enquiry reports, but failure to ventilate the lungs is still a major concern. The risk of death from an obstetric general anaesthetic has been estimated at one in 20 000. In 2011, a large series of obstetric patients in Canada undergoing general anaesthesia confirmed that difficult intubation still occurs in 3.3% (range 1.3–16.3%) and failed intubat ion in one in 250 patients. The events occur almost exclusively in emergency cases and are associated with the most urgent of cases, inexperienced staff and failure to follow standard practice. Box 38.1 indicated the problems highlighted by the Confidential Enquiry reports. However improved assessment and anticipation of airway problems has led to series with fewer failed intubations.

Difficult intubations – prevention better than cure

Preparation for an intubation

1. Appropriately trained staff – anaesthetist and assistant.

2. Correct equipment checked and available to hand, including airway adjuncts for difficult airways.

3. Position of the woman optimised.