Regional anaesthesia for caesarean section

Abstract

In the UK, over 80% of caesarean sections are performed under regional anaesthesia. There are four categories of surgery depending on the degree of urgency. Informed consent is vital and must be documented. All women should receive aspiration prophylaxis premedication (H 2-antagonist, metoclopramide, and within 30 minutes of surgery, a non-particulate antacid). Regional anaesthesia should be established in theatre. In emergencies, some authorities advocate topping up indwelling epidural catheters before transfer to theatre. Standards for monitoring and anaesthetic assistance are the same for obstetric and general surgery. Intravenous access must always be obtained before regional anaesthesia. Fetal heart rate monitoring should be continued during institution of the block and until the start of surgery. Supplemental oxygen is no longer considered mandatory for the mother in the absence of fetal distress. Institution of blockade must be performed in an aseptic manner. Sterile gloves are essential and face masks and gowns are highly recommended. Hypotension should be minimized by avoiding aortocaval compression, vasopressors (prophylactically/therapeutically) and colloid preloading. Single-shot spinal (SSS), combined spinal-epidural (CSE), and epidural may be used. SSS is simple and quick to perform. CSE is associated with the lowest rate of conversion to general anaesthesia and greater haemodynamic stability than SSS. Epidural anaesthesia has the highest failure rate, but if an epidural has been placed for labour, most practitioners would advocate its use rather than resorting to intrathecal anaesthesia. A block to touch from S1 to T5 or above is essential. All patients should be assessed postoperatively.