Late venous perforations due to percutaneous central venous cannulation.

mean total dose of 0.5 per cent bupivacaine injected epiduraUy was 8.1 +0.26 ml (range 5-10 ml). The subarachnoid block usually extended from $5 to T7 dermatomes. The usual upper level of the CSE block after injection of local anaesthetic via the epidural catheter was T4. In six patients (25 per cent) the subarachnoid block reached the T4-5 level and further extension of block by epidural injection of local anaesthetic was not required. All patients had good to excellent surgical analgesia. Similar assessment was made by the obstetric surgeon and the nurse anaesthetist. During surgery supplemental analgesics were not required in any patient. However, three patients (13 per cent) complained of nausea following manipulation of the peritoneum, and this was treated by an antiemetic. In this study hypotension (defined as a 30 per cent fall in blood pressure compared to preoperative values or a systolic blood pressure below 100 mmHg) was uncommon (13 per cent) following subarachnoid block. When the CSE block was extended to the T4 dermatome by epidural injection of bupivacaine four patients (17 per cent) developed hypotension. However, the occurrence of this complication was considerably less frequent and less severe than that reported for epidural or subarachnoid block alone.L-4 Although the number of patients is too small to draw definite conclusions none of the 24 parturients developed postspinal headache in spite of early postoperative ambulation due to effective pain relief. The advantages of CSE block over epidural block for Caesarean delivery are: minimal risk of maternal toxic reaction due to requirement of considerably smaller doses of local anaesthesia drug, more reliable block and less risk of maternal hypotension. As compared to subarachnoid block the advantages of CSE block are: possibility of extending an inadequate block, possibility of providing postoperative analgesia by local anaesthetics or opioids, less risk of severe maternal hypotension and apparent absence of postdural puncture headache if opioids are administered epidurally. Controlled studies are necessary to evaluate the technique further.