The Geraldine O’Sullivan Lecture: conversion from labour analgesia to Caesarean section anaesthesia: how to avoid general anaesthesia?

Sunday 4 June, 11h00-11h45, Room A

This year’s annual Geraldine O’Sullivan lecture, on avoiding general anaesthesia in Caesarean section, will be given by Dr Emilia Guasch, Head of Obstetric Anaesthesia at the University Hospital La Paz, Madrid, Spain.

“Labour epidural failure is a challenging situation for the obstetric anaesthetist, especially when associated with a high risk of caesarean delivery, obesity, and difficult airway predictors,” says Dr Guasch, who is also Vice-President of the Spanish Society of Anaesthesia and Reanimation (SEDAR).Labour epidural failure still has no standard definition, and consequently its incidence is uncertain. Improving knowledge of risk factors related to labour epidural failure will increase the epidural block success rate and will decrease the risk of general anaesthesia (GA) in cases that require caesarean delivery (CD).”

Prolonged labour, previous history of epidural failure, and repeated top-ups needed during labour are recognised risk factors for failure. Clinical experience and the use of modern equipment (ultrasound guided blocks), as well as the choice of neuraxial technique (epidural versus combined spinal epidural) may affect failure rate. Software-controlled infusion pumps seem to increase the epidural analgesia success rate.

Dr Guasch will add that non-technical skills and good communication among team members and the patient about to give birth are also essential to achieve satisfactory analgesia for labour. Defined algorithms should be promoted where epidural failure during labour or CD may occur.

The choice of alternative anaesthetic techniques after catheter failure (CF) is sometimes determined by the urgency of CD. Urgent CD is a well-recognised risk factor for CF. The choices are: epidural; intradural single shot; combined spinal and epidural; continuous spinal anaesthesia; and sedation.

The main objective in the epidural analgesia conversion scenario when CD is needed is to avoid conversion failure. A correct and careful continuous assessment of women under epidural analgesia for labour reduces failure rate. Only a full knowledge of failure risk factors can orientate the obstetric anaesthetist toward successful conversion. Dr Guasch says: “According to our experience, once conversion failure has been recognised, combined spinal and epidural anaesthesia allows general anaesthetic to be avoided in most cases.”

She continues: “Knowledge of local protocols, teamwork and communication are the best strategies to control risk factors in order to reduce failure incidence.  Risk of local anaesthetic system toxicity must be considered every time epidural top-ups are administered. Top-ups given through untested catheters may lead to severe complications.”

She concludes: “Delaying a category one Caesarean delivery because of a conversion failure is not acceptable. Keeping a patient in pain during labour and/or during surgery is also not acceptable. Whenever safe airway management is necessary, a GA must be induced promptly. For all of the issues mentioned in my talk, local, defined and well known protocols are the best solution.”