Use of epidural analgesia for pain management after major spinal surgery

Journal of Orthopaedic Surgery, Jun 2003 by Kumar, R J, Menon, K V, Ranjith, T C

ABSTRACT

Purpose. This is a retrospective study of the role of postoperative epidural analgesia in major spinal surgical procedures. With the number and complexity of the procedures performed on the spine ever-increasing, this method of analgesia is becoming more important.

Methods. Results of 74 consecutive cases of major spinal surgeries between January 2000 and January 2001 at the Spine Division, Amritha Institute of Medical Sciences and Research Centre, Kochi, India, were studied. 32 cases were posterior procedures and the other 42 were anterior procedures of the thoracic and lumbar regions. The use of various combinations of local anaesthetic and opioid to control postoperative pain after spinal surgery were analysed.

Results. 36 (49%) of 74 patients did not require any patenterai supplements. Of the remaining 38 patients who required supplementary parenteral analgesia in the first 48 hours, 25 (34%) received a single dose and 13 (18%) required more than one dose. The number of patients requiring parenteral analgesia immediately after operation were 11; between 2 and 6 hours were 12; and between 6 and 24 hours were 11. Of the 74 patients, 67 had a sound sleep after epidural administration. There were 2 cases of respiratory depression and 2 of transient hypotension.

Conclusion. Most epidural analgesic regimens significantly reduced postoperative pain, and the requirement for supplementary parenteral analgesics was minimal. Adverse effects were rare, yet we recommend that patients treated with this protocol be managed in high-dependency units.

Key words: analgesia, epidural; postoperative analgesia; spine; surgery

INTRODUCTION

It has been well documented that immediate postoperative pain control can significantly affect the outcome of surgical procedures and operative morbidity.1 After major abdominal, chest, or pelvic surgery, adequate analgesia promotes early ambulation and aggressive pulmonary rehabilitation. Cullen et al. and Benzon et al.2-4 have suggested that for these procedures, epidural analgesia is the technique of choice. Epidural analgesia is superior to parenteral analgesia in high-risk patients undergoing major surgical interventions.5 Similar findings have been reported by Rechtine and Love.6 However, little information exists regarding postoperative pain management after major spinal surgery and how it affects the final outcome.7 Ibrahim et al.8 have shown that epidural administration of morphine is superior to parenteral analgesia for laminectomies. A prospective double-blind randomised control study9 of intraspinal morphine found that this method of analgesia is an effective adjunct to postoperative pain management in spinal surgery. A number of small studies using continuous infusion techniques have reported the benefits of epidural analgesia, with minimum complications, for spinal procedures such as idiopathic scoliosis.10,11 Some centres have been reluctant to administer epidural local anaesthetics, even though they have been proven to enhance the analgesic effect of narcotics,12-14 because of the concern of late respiratory depression, particularly if supplemental systemic narcotics are used. At our institution, we use this modality as the procedure of choice for all major spinal procedures, unless contraindicated. Although patient-controlled analgesia (PCA) has been recommended as the technique of choice in many centres,15,16 the adoption of this technique in the developing world has not been encouraging, because of factors such as the cost of equipment and patient acceptance. Some studies have not found any advantage of epidural opioids over PCA.17

In this study, we used a local anaesthetic alone or in combination with an opioid to control pain after major spinal procedures. Early results were rewarding, complications minimum, and the recuperation from surgery and final outcome excellent.

MATERIALS AND METHODS

This study is a retrospective report of 74 consecutive cases of major spinal surgeries that were performed between January 2000 and January 2001 at the Amritha Institute of Medical Sciences and Research Centre, Kochi, India. 32 cases were posterior procedures and the other 42 were anterior procedures of the thoracic and lumbar regions; all cases were managed with continuous postoperative epidural analgesia. Major surgery in this study refers to an operating time of more than 2 hours, blood loss of more than 500 ml, and the involvement of spinal instrumentation or bone grafting. The following operative procedures were included:

(1) Anterior release of scoliosis;

(2) Anterior instrumentation for scoliosis;

(3) Posterior instrumentation for scoliosis;

(4) Anterior corpectomy and fusion for tuberculosis, tumour, and fracture;

(5) Posterior lumbar interbody fusion;

(6) Reduction and fusion of spondylolysthesis;

(7) Posterolateral decompression and fusion for tuberculosis;

(8) Combined anterior and posterior vertebrectomy and fusion for tumours or fractures; and

(9) Laminectomies or expansive laminoplasties with instrumentation and fusion.