Effectiveness and safety of continuous wound infiltration for postoperative pain management after open gastrectomy

AIM: To prospectively evaluate the effectiveness and safety of continuous wound infiltration (CWI) for pain management after open gastrectomy. METHODS: Seventy-five adult patients with American Society of Anesthesiologists (ASA) Physical Status Classification System (ASA) grade 1-3 undergoing open gastrectomy were randomized to three groups. Group 1 patients received CWI with 0.3% ropivacaine (group CWI). Group 2 patients received 0.5 mg/mL morphine intravenously by a patient-controlled analgesia pump (PCIA) (group PCIA). Group 3 patients received epidural analgesia (EA) with 0.12% ropivacaine and 20 mu g/mL morphine with an infusion at 6-8 mL/h for 48 h (group EA). A standard general anesthetic technique was used for all three groups. Rescue analgesia (2 mg bolus of morphine, intravenous) was given when the visual analogue scale (VAS) score was >= 4. The outcomes measured over 48 h after the operation were VAS scores both at rest and during mobilization, total morphine consumption, relative side effects, and basic vital signs. Further results including time to extubation, recovery of bowel function, surgical wound healing, mean length of hospitalization after surgery, and the patient's satisfaction were also recorded. RESULTS: All three groups had similar VAS scores during the first 48 h after surgery. Group CWI and group EA, compared with group PCIA, had lower morphine consumption (P < 0.001), less postoperative nausea and vomiting (1.20 +/- 0.41 vs 1.96 +/- 0.67, 1.32 +/- 0.56 vs 1.96 +/- 0.67, respectively, P < 0.001), earlier extubation (16.56 +/- 5.24 min vs 19.76 +/- 5.75 min, P < 0.05, 15.48 +/- 4.59 min vs 19.76 +/- 5.75 min, P < 0.01), and earlier recovery of bowel function (2.96 +/- 1.17 d vs 3.60 +/- 1.04 d, 2.80 +/- 1.38 d vs 3.60 +/- 1.04 d, respectively, P < 0.05). The mean length of hospitalization after surgery was reduced in groups CWI (8.20 +/- 2.58 d vs 10.08 +/- 3.15 d, P < 0.05) and EA (7.96 +/- 2.30 d vs 10.08 +/- 3.15 d, P < 0.01) compared with group PCIA. All three groups had similar patient satisfaction and wound healing, but group PCIA was prone to higher sedation scores when compared with groups CWI and EA, especially during the first 12 h after surgery. Group EA had a lower mean arterial pressure within the first postoperative 12 h compared with the other two groups. CONCLUSION: CWI with ropivacaine yields a satisfactory analgesic effect within the first 48 h after open gastrectomy, with lower morphine consumption and accelerated recovery.