Angioneurotic oedema following etomidate/lignocaine

The introduction to the study of hyperbaric lignocaine (Anaevthesia 1986; 41: 906-9) rcfcrs to the high blocks obtained with isobaric bupivacaine and, thus. its unsuitability for operative delivery in obstetrics, particularly after failed intubation. We agree with the findings of the few reports of the use of plain 0.5% bupivacainc for spinal Caesarean that the spread can on occasions be high and unpredictable but Russell’s case4 which is quoted was of a total spinal using 2 ml of 0.75% bupivacaine. We wish to report our own experience of the use of plain 0.5% bupivacaine for spinal Caesarean section to give some perspective. In this hospital’s obstetric unit approximatcly 250 women have received spinal anaesthesia for Caesarean scction with 0.5% plain bupivacaine during the past 2 years. This has become our most commonly used tncthod of regional anaesthesia for elective Caesarean section, and has remained popular because of the rapid onset of the block and the quality of analgesia produced for surgery. The need for supplementary analgesic drugs at any stage during the operation has been rare. iIigh levels of sensory block have occurred and a number of women have reported paraesthesiae in their hands. However, the high levels of block, which tend to he sensory rather than motor, do not cause difticulties with respiration and recede rapidly. In only one patient has the level of block caused concern, when for 5 minutes she had difficulty in swallowing her saliva and required oral suction. Injection is made in the left lateral position using a 26-gauge needle and the volume of 0.5% bupivacaine varies between 2.5 and 3.5 ml depending on the patient’s height. She is turned to the supine wedged position which encourages earlier spread and minimises further extension of the block when she is moved into theatre. Hypotension occurs with any form of subarachnoid analgesia in the obstetric patient, except perhaps a saddle block, unless care is taken to avoid it by preload with intravenous fluids and vasopressors as required. It is not a technique for the inexperienced operatoranaesthetist or for those with inadequate assistance. Headache is low in both incidence and severity; were it otherwise, nursing staff and obstetricians would have encouraged us to stop the technique. However, we feel that one disadvantage of subarachnoid rather than epidural bupivacainc, is the rate a t which pain increases once the block begins to recede. Epidural block wears off more gradually and allows the opportunity to anticipate the pain with intramuscular papaveretum, whereas adequate pain control after subarachnoid block in the immediate postoperative period has proved difficult on occasions. This is the subject of further investigation. I n conclusion, we d o not wish to champion the use of 0.5% plain bupivacaine for spinal anaesthesia for Caesarean section but, since we have found something that works well for us. we have chosen to stick with it.