Home readiness after spinal anaesthesia with low-dose hyperbaric bupivacaine 0.5%: 19.

Hyperbaric lignocaine has been recommended for spinal anaesthesia for short surgical procedures due to its short duration of action. Unfortunately, the use of hyperbaric lignocaine has recently been shown to be associated with post-operative neurological symptoms called transient radicular irritation (TRI) [1]. Therefore alternatives for lignocaine are warranted for day-case surgery. The duration of action of hyperbaric 0.5% bupivacaine is dose-dependent and may be shortened by reducing the dose [2]. We studied the quality of the block and the patients' home readiness following spinal anaesthesia after small doses of hyperbaric 0.5% bupivacaine. Twenty-eight patients were randomly allocated to receive spinal anaesthesia with either 1 mL (group 1) or 2 mL (group 2) of hyperbaric 0.5% bupivacaine for procedures with an expected duration of less than 1 h (minor orthopaedic, urological or anal surgery). The subarachnoid puncture was made in the midline of L3-4 interspace using a 27-gauge spinal needle with patients in a horizontal side position. Immediately thereafter the patients were turned to the supine position. Level of analgesia (pin prick) and motor block (Bromage) were tested during 20 min at 5 and later at 10 min intervals until L1 had recovered. If the peak level was below L1 these parameters were followed until recovery of two segments. The time of home readiness was assessed using the following criteria: no signs of sensory or motor block, no pain, nausea or vomiting, the patient able to walk, eat, drink and void urine. Surgical anaesthesia was adequate in all patients. Maximum cephalad spread of analgesia was T5 in group 1 and 2 in group 2. On average 12 and 16 dermatomes were anaesthetised in the group 1 and group 2, respectively (P<0.01). No patients in group 1 had motor block (grade 3) (P<0.01). Bradycardia (heart rate less than 45 bpm) was seen in one patient in group 2. Otherwise all the anaesthetics were uneventful. Recovery of L1 or two upper most segments was 79±35 (SD) min in group 1 and 119±45 min in group 2 (P<0.01). One patient in both groups needed urinary bladder catheterisation after an anal operation. The discharge criteria were fulfilled in 246±84 (SD) min in group 1 and in 333±110 min in group 2 (P<0.05). In small doses hyperbaric 0.5% bupivacaine for spinal anaesthesia provided stable haemodynamic conditions. The duration of analgesia and the time interval to home readiness were dose dependent. In reduced doses hyperbaric bupivacaine 0.5% is a good alternative for short procedures and day-case surgery.