What is the UK incidence of failed intubation for obstetric general anaesthesia?
What are the risk factors for failed intubation for obstetric surgery?
How is failed intubation managed?
What are the maternal outcomes after failed intubation?
What are the neonatal outcomes after failed intubation?
Reports from the Confidential Enquiries into Maternal Deaths have shown a decrease in the number of anaesthetic related deaths over recent years. However, a consistent cause of death is hypoxia relating to a failure to intubate and ventilate. The incidence of failed intubation among the pregnant population is estimated to be up to 8 times that of the non-pregnant population, but, as yet, no national data exist.
The reasons for this higher incidence in the obstetric population are multiple. Anatomical changes in the airway due to physiological changes in pregnancy have been noted. Additionally, the physiological changes of a reduced functional residual capacity and an increased metabolic rate in pregnancy lead to a rapid progression to hypoxia following induction and apnoea. This adds pressure on the anaesthetist to intubate quickly before desaturation occurs. These issues are compounded by the fact that obstetric surgical procedures are now less frequently performed under general anaesthesia, so that training opportunities for junior anaesthetists are becoming more rare. The procedures are also frequently required "out of hours" when the trainee anaesthetist is likely to be not to be working under direct supervision. Also, the amount of time spent in training is reduced overall.
The study will aim to collect data on 140 cases and 280 controls over two years.
Any woman of over 20 weeks gestation given a general anaesthetic (whether on delivery suite or another hospital department) where a failed intubation has occurred.
Failed intubation is defined as failure to achieve tracheal intubation during a rapid sequence induction for obstetric anaesthesia, thereby initiating a failed intubation drill.
Obstetric Anaesthetists Association (OAA).
The study has been approved by the London MREC (study ref 08/H0718/1).
David Milne, Audrey Quinn, Amanda Pinder, Heather Gorton
Leeds General Infirmary