The influence of epidural volume extension on spinal block with hyperbaric or plain bupivacaine for Caesarean delivery.

BACKGROUND AND OBJECTIVE: Epidural volume extension via a combined spinal-epidural is the enhancement of a small-dose intrathecal block by an epidural injection of physiological saline solution. We evaluated the effect of epidural volume extension on the combined spinal-epidural technique of providing spinal anaesthesia for Caesarean section with hyperbaric or plain 0.5% bupivacaine. METHODS: Patients (n = 240) with height >163 cm received 9 mg and patients <163 cm received 8 mg of bupivacaine. Each study drug was combined with 20 mug fentanyl. Using the combined spinal-epidural technique, Group A (n = 60) received hyperbaric bupivacaine, and Group B (n = 60) received hyperbaric bupivacaine and 10 mL saline epidurally 5 min after subarachnoid injection. Group C (n = 60) received plain bupivacaine and Group D (n = 60) received plain bupivacaine and 10 mL saline epidurally 5 min after subarachnoid injection. An anaesthetist blinded to the anaesthetic solution injected examined the level of analgesia by the pinprick method and motor block with the modified Bromage scale for 30 min after subarachnoid injection, during the intraoperative period and subsequently every 15 min for 135 min during the recovery period. RESULTS: Time to reach a sensory block at T4 was significantly shorter in Groups C and D than in Groups A (P = 0.003 and 0.017) and B (P = 0.006 and 0.048), respectively. During the intraoperative period, sensory block levels were significantly higher in Group C than in Group A. Recovery was similar in all groups; only onset was faster in Groups C and D. CONCLUSION: There was no effect of epidural volume extension on the profile of spinal anaesthesia with the combined spinal-epidural technique for Caesarean section using hyperbaric or plain bupivacaine.

Comparison of sedation requirements for cataract surgery under topical anesthesia or retrobulbar block.

PURPOSE: Topical anesthesia is increasingly being used for cataract surgery. However, it is believed that topical anesthesia causes an increased risk of intraoperative complications from unrestricted eye movement and insufficient pain control and more need for sedation. It is difficult to compare pain and anxiety experienced by individual patients; therefore, the authors used the method of patient-controlled sedation to determine whether there is a difference in sedation requirements under topical or retrobulbar anesthesia. METHODS: In this prospective study, patients received either topical anesthesia (n=87) or retrobulbar block (n=104) and self-administered a mixture of midazolam (0.5 mg) and fentanyl (25 microg) in increments using a patient controlled analgesia infuser to achieve sedation. At the end of surgery, patients rated their pain on a 10-point numerical rating scale and their comfort on a 5-point scale. The number of demands and deliveries were noted from the patient controlled analgesia infuser display. RESULTS: Pain scores were between 0 and 2 in 95.4% in the topical and in 94.2% in the retrobulbar group (p>0.05). Patient comfort was equal in both groups with 2.94+/-0.92 in the topical group and 2.92+/-0.99 in the retrobulbar group (p>0.05). Mean sedation requirements were similar in both groups: 26.4% of patients in the topical group and 19.2% in the retrobulbar group did not request any sedation (not significant, p>0.05). CONCLUSIONS: Sedation requirements were similar for cataract surgery under topical and retrobulbar anesthesia.

EMLA does not permit pain-free retrobulbar injection.

BACKGROUND: Retrobulbar injection can be associated with significant pain, due to both needle insertion and deposition of the local anaesthetic solution. The local anaesthetic cream EMLA (eutectic mixture of local anaesthetics) which contains a mixture of lignocaine and prilocaine has been shown to reduce the pain associated with skin puncture. The efficacy of EMLA in alleviating the pain of retrobulbar injection for cataract surgery was assessed in this study. METHODS: In this, randomised double-blind study, EMLA (n = 53) or lignocaine 5% ointment (n = 50) was administered to the inferior orbital margin at least 45 min before retrobulbar block in 103 patients. Pain assessed during retrobulbar block was marked subjectively by the patient on a 10-point numerical rating scale. RESULTS: Median verbal pain scores were 3.0 with an interquartile range of 1.5-6.5 in the control group and 3.50 with an interquartile range of 2.0-6.0 in the EMLA(R) group (P = 0.67). There was no significant difference between the EMLA group and the lignocaine ointment group according to this pain assessment. CONCLUSION: EMLA does not permit pain-free retrobulbar injection.