Postoperative epidural infusion of morphine and bupivacaine is safe on surgical wards - Organisation of the treatment, effects and side-effects in 2000 consecutive patients

Background: There was an obvious need to improve the quality and safety of our postoperative pain treatment and to introduce an improved routine service on surgical wards. Methods: It was decided to use postoperative epidural infusion of morphine 0.04 mg/ml and bupivacaine 2.5 mg/ml (0.25%): 4-8 ml/h as pain relief after major surgery. An education programme was run emphasising the benefits, side-effects and the importance of regular monitoring of pain intensity, vital functions (respiratory rate, blood pressure, heart rate), motor function of the legs and the need for additional drugs in order to detect side-effects as well as lack of adequate analgesic effect, A detailed observation sheet was used collecting information every 2 h throughout the epidural treatment period in order to secure monitoring and adjustment of the treatment, Close contact was maintained with the wards. Results: We present a detailed analysis of our first 2000 postoperative patients, mainly after orthopaedic (46.1%), gastrointestinal (32.0%), urologic (8.7%) and vascular (8.5%) surgery. Duration of the treatment was less than 24 h in 41.4% and more than 48 h in 29.7%. Pain relief was adequate in most patients, best after vascular surgery in the lower extremities (mean VAS 0.15/10.0 (95% confidence interval 0.09-0.23)) and less after gastrointestinal (mean VAS 0.49/10 (0.43-0.54)) and thoracic surgery (mean VAS 0.59/10 (0.38-0.81)). The infusion was stopped due to respiratory depression in 3 patients (0.15%). Four (0.2%) had systolic blood pressure <80 mmHg and had to be treated with vasopressors. A total of 56 (2.8%) patients were considered to be problem patients due to excessive sedation (0.4%), hypotension (0.7%), respiratory depression (1.6%) or lower extremity paralysis (0.05%). All patients had urinary catheter until 6 h after termination of the epidural treatment. One patient had the epidural catheter accidentally placed subarachnoidally and experienced severe respiratory depression, No permanent sequelae were recorded in the postoperative patients, but 2 traumatised patients developed epidural abscesses after 3 weeks of treatment, which resulted in lower extremity paralysis. Late response to the warning signs might have contributed to the irreversible paraplegia. Conclusion: Our experience with this postoperative epidural analgesia regime is favourable. It has been easy to administer and monitor. pain relief was excellent, side-effects were few and picked up by the established routines followed by the ward staff except in the 2 trauma patients who developed epidural abscesses. The staff on the surgical wards were motivated for this kind of work. Education and strict surveillance routines are mandatory in order to secure prompt action when warning signs develops (e,g, lower limb paralysis).