This review evaluates recent evidence surrounding this long-standing debate. The findings support many of the perceived benefits of regional (intrathecal (spinal) and epidural) anaesthetic techniques over general anaesthesia and opioid-based analgesia, such as reductions in the duration of surgery, incidence of thromboembolic complications, blood transfusion rate and post-operative nausea and vomiting.The data were unable to show a difference in intraoperative blood loss, mortality and hospital length of stay. Interestingly differences in non-thromboembolic cardio-respiratory complications and post-operative pain were not examined, though these data may not have been as widely sought in the studies included in this meta-analysis.
Many reviews and guidelines suggest that neuraxial anaesthetic techniques, with or without general anaesthesia and regardless of surgical site, reduce respiratory complications (such as pneumonia and respiratory depression), venous thromboembolism and myocardial infarction.1-3 It is thought that a number of mechanisms are responsible, including reduction in surgical stress responses, improved post-operative mobilisation and respiratory effort, and greater blood flow. However, historically there has been much wariness of central neuraxial (spinal & epidural) anaesthesia in combination with perioperative heparin-based thromboprophylaxis potentially leading to an increased risk of spinal haematoma and possible permanent neurological damage. A recent national ‘snapshot’ audit of central neuraxial block in the United Kingdom reported the ‘optimistic’ and ‘pessimistic’ incidences of permanent nerve injury (all aetiologies) following perioperative central neuraxial block as 8.2 and 17.4 per 100 000 respectively.4 Of the patients that required decompressive laminectomy less than half (four out of twelve) had vertebral canal haematomas (the remainder consisted seven epidural abscesses and one spinal stenosis). It would be reasonable to attribute such a low incidence of vertebral canal haematoma to the widespread use of internationally accepted guidelines concerning the use and perioperative timing of heparin-based thromboprophylaxis and central neuraxial regional anaesthesia.
Several peripheral nerve blocks may be used either alone or in combination with general anaesthesia for hip or knee arthroplasty. Possible advantages of such techniques include a reduction in the use of systemic opioids and their consequent side effects, technically easier to site than a central neuraxial block, though still allowing for the placement of a catheter for a continuous post-operative infusion of local anaesthetic solution to prolong the block.
Blockade of the lumbar plexus from either the psoas compartment (posterior approach) or a ‘3 in 1 femoral’ block (anterior approach), in combination with patient-controlled intravenous opioid infusion, has been shown to provide good post-operative analgesia for total hip arthroplasty, the former approach providing more reliable block of the obturator nerve.5 Lumbar plexus blocks provide similar pain relief to that seen with central neuraxial analgesia or patient controlled intravenous morphine (alone) following total hip arthroplasty, with fewer side effects.5,6
Femoral nerve block with or without a sciatic nerve block may be used for post-operative analgesia following total knee arthroplasty. Patient controlled intravenous opioid is required post-operatively if femoral nerve block is used alone. This technique has been shown to provide similar post-operative analgesia following total knee arthroplasty to that seen with central neuraxial analgesia or patient controlled intravenous opioid alone.5,7
Peripheral nerve block (with or without general anaesthesia) for total hip or knee arthroplasty is becoming the significant anaesthetic component of the drive towards multi-modal peri-operative analgesia. Such a regimen would typically consist of a pre-operative (or at induction of anaesthesia) opioid and COX-2 inhibitor, a peripheral nerve block (with or without a catheter), and post-operatively a patient-controlled intravenous opioid infusion in combination with regular paracetamol-based oral analgesia and oral or intravenous non-steroidal anti-inflammatories.8-10 The PNB permits a reduction in the use of opioids, both as part of the general anaesthetic and the post-operative infusion, thus reducing the incidence of opioid-induced post-operative nausea and vomiting, sedation and respiratory depression. There is less likely to be a severe (central) neuraxial complication, in addition to the more minor potential consequences of central neuraxial block such as urinary retention, hypotension and weakness of both lower limbs (if too high a concentration of local anaesthetic is used) possibly delaying early post-operative mobilisation.
The challenge of the perfect anaesthetic technique for hip and knee arthroplasty remains, and Hu and colleagues have successfully explained the current trend towards regional anaesthesia for these procedures. However, as our understanding of the mechanisms of pain evolves, accompanied by the ever-increasing economic demands put upon healthcare providers, the multi-modal approach to post-operative analgesia will gain more spokes to its wheel.
1. Rodgers A, Walker N, Schug S, et al. Reduction of postoperative mortality and morbidity with epidural or spinal anaesthesia: results from overview of randomised trials. BMJ 2000;321:1-12.
2. Kehlet H, Wilmore DW. Multimodal strategies to improve surgical outcome. Am J Surgery 2002;183:630-41.
3. Qaseem A, Snow V, Fitterman N, et al. Risk assessment for and strategies to reduce perioperative pulmonary complications for patients undergoing non-cardiothoracic surgery: a guideline from the American College of Physicians. Ann Intern Med 2006;144:575-80.
4. Cook TM, Counsell D, Wildsmith JAW. Major complications of central neuraxial block: report on the Third National Audit Project of the Royal College of Anaesthetists. Br J Anaesth 2009;102:179-90.
5. Touray ST, de Leeuw, MA, Zuurmond WWA, Perez RSGM. Psoas compartment block for lower extremity surgery: a meta-analysis. Br J Anaesth 2008;101:750-60.
6. Singelyn FJ, Ferrant T, Malisse MF, Joris D. Effects of intravenous patient-controlled analgesia with morphine, continuous epidural analgesia and continuous femoral nerve sheath block on rehabilitation after unilateral total-hip arthroplasty. Reg Anesth Pain Med 2005;5:452-7.
7. Fowler SJ, Symons J, Sabato S, Myles PS. Epidural analgesia compared with peripheral nerve blockade after major knee surgery: a systematic review and meta-analysis of randomized clinical trials. Br J Anaesth 2008;100:154-64.
8. Fischer HBJ, Simanski CJP. A procedure-specific systematic review and consensus recommendations for analgesia after total hip arthroplasty. Anaesthesia 2005;60:1189-202.
9. Fischer HBJ, Simanski CJP, Sharp C et al. A procedure-specific systematic review and consensus recommendations for post-operative analgesia following total knee arthroplasty. Anaesthesia 2008;63:1105-23.
10. Hebl JR, Kopp SL, Ali MH et al. A comprehensive anesthesia protocol that emphasises peripheral nerve blockade for total knee and total hip arthroplasty. J Bone Joint Surg (Am) 2005;87-A(Suppl 2):63-70.
Walker C, FRCA, FFPMRCA, Consultant, Anaesthesia & Pain Management
London, United Kingdom