Epidural catheter analgesia for the management of postoperative pain.
ABSTRACT Since its introduction to North America in 1942, the use of epidural catheter analgesia has increased dramatically. Improved equipment, methods and medications have broadened its application to include among others, surgical anesthesia, chronic pain relief and the management of postoperative pain. Numerous techniques for epidural puncture and insertion of the catheter have been described. Although complications have been associated with placement of an epidural catheter, these are rare when performed by an experienced anesthesiologist. Epidural analgesia was first accomplished by blockade with local anesthetics. Bupivacaine has been called the local anesthetic of choice for epidural infusion. Bolus administration of epidural local anesthetics gives effective analgesia; however, its use is limited by brief duration and occasionally severe hypotension. Epidural local anesthetics have been administered by continuous infusion in an attempt to minimize side effects. Nevertheless, hypotension, as well as motor block, numbness, nausea and urinary retention have occurred. Epidural analgesia with local anesthetics is effective in relieving postoperative pain, but its safety and feasibility have been questioned because of the frequent, potentially serious side effects. These problems led to trials of epidural narcotics for postoperative pain management. The exact site of action of epidural narcotic analgesics is debatable; however, the bulk of evidence supports a direct spinal action. Epidural narcotics appear to specifically inhibit nociceptive stimuli. The prolonged and profound analgesia that occurs with epidural narcotics relative to parenteral administration is due to a higher concentration of drug reaching the CSF through the epidural route. Since nervous transmission is not completely blocked this technique cannot provide anesthesia during operation. Morphine has been the most frequently used narcotic for epidural analgesia. Results of several recent, randomized double-blind studies have shown that epidural narcotics give adequate analgesia comparable with that observed with epidural bupivacaine. Epidural morphine provides a greater duration of analgesia and may cause fewer side effects. Improved analgesia has been reported when epidural narcotics are used in combination with local anesthetics. Continuous administration of low dosage epidural narcotics has been shown to have less frequent side effects than bolus administration. Nevertheless, pruritus, urinary retention, hypotension and severe respiratory depression have been reported with both methods.(ABSTRACT TRUNCATED AT 400 WORDS)
- [Show abstract] [Hide abstract]
ABSTRACT: This study examined the effect of epidural analgesia on the development of postoperative fatigue and the ability to ambulate after surgery. Seventeen patients admitted for elective abdominal surgery were randomized to receive postoperative analgesia with a continuous infusion of epidural fentanyl (epidural group) or intermittent intramuscular morphine (non-epidural group). Fatigue was assessed on an analogue scale of 1 (fit) to 10 (fatigued). Steady state measurements of respiratory gas exchange, respiratory rate, tidal volume and heart rate were made before operation and repeated on the third postoperative day. Energy expenditure was calculated from Weir's formula. Ambulatory measurements were made during treadmill walking at a work rate of 20 kpm min-1 (3.3 W). At rest, patients in both groups had a similar cardiorespiratory response to surgery irrespective of the method of analgesia. Subjective feelings of fatigue were significantly greater in those patients who had received epidural analgesia (P less than 0.01) and patients in this group expended significantly more energy in performing the postoperative exercise test than did those in the non-epidural group (P less than 0.05). The use of epidural opiate analgesia does not limit postoperative fatigue in patients undergoing upper abdominal surgery.British Journal of Surgery 01/1992; 78(12):1457-60. · 4.84 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: The purpose of this study was to examine the effects of interpleural bupivacaine on analgesia and ventilatory capacity after cholecystectomy. Forty-two patients undergoing elective cholecystectomy were randomly assigned to two groups: one to receive interpleural administration of bupivacaine-adrenaline mixture (Group 1 = 22 patients) and the other standard administration of intramuscular meperidine (Group 2 = 20 patients) for postoperative pain relief. The intensity of pain was evaluated by a visual analogue scale (VAS) preoperatively as well as at 2, 8, 24 and 48 hr postoperatively. At the same time, FVC and FEV1.0 measurements were obtained for all patients. The group given interpleural bupivacaine had better pain relief with mean VAS of 0.6 +/- 0.9 (mean +/- SD) 1.1 +/- 1.4, 0.6 +/- 0.9 and 0.8 +/- 1.2 compared with 5.2 +/- 2.2, 5.8 +/- 2.7, 5.5 +/- 2.2 and 4.5 +/- 1.8 for patients receiving meperidine (P less than 0.001). The patients in Group 1 also had larger FVC and FEV than those in Group 2: FVC 22 +/- 14.5 per cent vs 32 +/- 15.2 per cent (P less than 0.005), FEV1.0 25 +/- 15.5 vs 38 +/- 14.8 per cent (P less than 0.001) (mean +/- SD). We conclude that the interpleural analgesia can achieve better pain relief with greater ventilatory capacity than a standard analgesic regimen in the first two days after cholecystectomy.Canadian Journal of Anaesthesia 02/1991; 38(1):71-4. · 2.13 Impact Factor