Clinical study of failure in continuous spinal anesthesia with XXXX .

@entity1341 @entity3303
BACKGROUND: Continuous spinal anesthesia (CSA) has been considered to be better in temporal and dose flexibility, as well as hemodynamic stability than single dose spinal anesthesia. However, the failure of spinal anesthesia is not a rare experience for anesthesiologists. Here we present our experience in solving the problem and discuss the possible causes for the failure. METHODS: 236 cases were studied retrospectively from January to December in 1996. All were over 65 years old, ASA III, scheduled for transurethral procedures or orthopedic operation. CSA was performed with 0.2% @entity1341 . Failed CSA was confirmed by positive pin-prick test at T10 dermatome(umbilicus) 30 minutes after 20 mg @entity1341 was injected. For failed cases, 5 mL 1% @entity3303 was injected intrathecally for rescue. The failure rate, sensory and motor blockade, success rate by changing to @entity3303 and its dosage were recorded. RESULTS: Eleven of 236 cases (4.7%) were considered spinal failure since the initial 20 mg @entity1341 could not provide adequate T10 anesthesia in 30 minutes. Addition of 5 mL 1% @entity3303 produced a profound sensory and motor blockade in 9 cases, while further @entity3303 injection was required in two cases. The success rate by rescuing @entity3303 was 100% with an average @entity3303 consumption by 52.5 +/- 4.5 mg. DISCUSSION: Factors contributed to failure spinal anesthesia including failure of technique, errors of judgment, maldistribution and failure of local anesthetic itself. However, we thought that change of pH value of local anesthetic in CSF may play a great part in these failed CSAs. Despite the reasons for failure, we demonstrate that failure of continuous spinal anesthesia by 0.2% @entity1341 can be readily resolved by 1% @entity3303 .
