title: Effects of posture on the spread of spinal anaesthesia with isobaric 0.75% or 0.5% bupivacaine.
abstract: In a double-blind study the effects of posture on the spread of 3 ml of isobaric bupivacaine 5 and 7.5 mg ml-1 were compared after intrathecal injection in 40 patients undergoing orthopaedic surgery. Three millilitre of isobaric bupivacaine 7.5 mg mg-1 administered with the patient in a sitting position during and for 2.5 min after injection produced the highest spread of analgesia (T4). Horizontal posture, and the smaller dose in both positions, resulted in spread of analgesia to T7-8. Motor block in the legs was good in all cases. Horizontal posture at the time of injection resulted in the longest mean duration of analgesia and motor block, although there was no statistically significant difference in mean times between the groups. The longest mean duration of pin-prick analgesia (329 +/- 23 min) was in the patients injected in the horizontal posture with bupivacaine 7.5 mg ml-1. The course of anaesthesia and recovery were uneventful in all patients.
mesh_terms: D000368:Aged; D000775:Anesthesia, Spinal; D002045:Bupivacaine / Q000008:administration & dosage*; D004311:Double-Blind Method; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D011187:Posture; D013046:Specific Gravity; D013997:Time Factors
chemical_list: D002045:Bupivacaine