Spinal anaesthesia: a comparison of plain ropivacaine 5 mg ml(-1) with bupivacaine 5 mg ml(-1) for major orthopaedic surgery

Editor—I am interested in the article by McNamee and colleagues¹comparing the use of plain bupivacaine 0.5% with plain ropivacaine0.5% during spinal anaesthesia for orthopaedic surgery. Bothgroups received 3.5 ml of 0.5% of the chosen local anaesthetic. The authors report spinal blockade with a median sensory blockof T2 in the bupivacaine group and T3 in the ropivacaine group.They report ‘moderate fall in arterial blood pressurein keeping with expected sympathetic block’. Hypotensionrequiring ephedrine in the two groups occurred in 12 and 26%of patients, respectively. Up to ephedrine 35 mg was requiredin patients in either group. Adverse events included oliguria,hypotension and nausea, although incidences are not reported.The high levels of sensory blockade are considered as acceptableand part of the consequences of regional anaesthesia in elderlypatients. I