Continuous epidural analgesia: analysis of efficacy, side effects and risk factors

BACKGROUND AND OBJECTIVES: Epidural analgesia with local anesthetics and opioids has a reputation of high efficacy with low incidence of side effects. This study aimed at determining incidence, type and severity of postoperative complications related to epidural analgesia and catheter insertion. METHODS: Participated in this retrospective study 469 patients submitted to postoperative epidural analgesia in the period 10/18/99 to 10/18/01. Epidural analgesia was induced with 0.1% bupivacaine and fentanyl (1 to 5 microg.mL-1), at a 3 mL.h-1 rate. Infusion rate was adjusted according to patients' pain complaint. The following variables were evaluated: epidural infusion duration; incidence of side-effects and complications related to demographics, type of surgery and epidural catheter position; and quality of analgesia by means of a pain visual analog scale and a patients' satisfaction index. RESULTS: Epidural catheters remained in place 2.2 days in average, varying from 6 to 10 days. Global rate of technique-related complications was 46.3%, most of them minor complications without clinical repercussion. From these, 13.9% were directly related to the epidural catheter (disconnection, externalization, low back pain, inflammation and local infection). Other common complications were vomiting and urinary retention. Postoperative analgesia was effective in 97.2% of the patients which referred satisfaction with the technique. Patients without pain or slight pain during the first, second and third postoperative day represented 80.1%, 92.8% and 93.3%, respectively, of the studied population. CONCLUSIONS: Continuous epidural analgesia is effective and safe. Complications were not severe. However, strict vigilance is mandatory to achieve satisfactory analgesia and a low incidence of complications.