Preemptive analgesia: intraperitoneal local anesthetic in laparoscopic cholecystectomy. A randomized, double-blind, placebo-controlled study.

BACKGROUND: A controversy exists over the effectiveness and clinical value of preemptive analgesia. Additional studies are needed to define the optimum intensity, duration, and timing of analgesia relative to incision and surgery. METHODS: One hundred twenty patients undergoing laparoscopic cholecystectomy under general anesthesia plus topical peritoneal local anesthetic or saline were studied. Local anesthetic (0.5% bupivacaine with epinephrine) or placebo solutions were given as follows: immediately after the creation of a pneumoperitoneum (blocking before surgery), and at the end of the operation (blocking after surgery). Patients were randomly assigned to one of four groups of 30 patients each. Group A (placebo) received 20 ml 0.9% saline both before and after surgery, group B received 20 ml 0.9% saline before surgery and 20 ml local anesthetic after surgery, group C received 20 ml local anesthetic both before and after surgery, group P received 20 ml local anesthetic before and 20 ml 0.9% saline after surgery. Pain was assessed using a visual analog scale and a verbal rating scale at 0, 4, 8, 12, and 24 h after surgery. Metabolic endocrine responses (blood glucose and cortisol concentrations) and analgesic requirements also were investigated. RESULTS: Pain intensity (visual analog and verbal rating scales) and analgesic requirements were significantly less in the group receiving bupivacaine after surgery compared to placebo. However, in the groups receiving bupivacaine before surgery, both pain intensity and analgesic consumption were less than in the group receiving bupivacaine only after surgery. Blood glucose and cortisol concentrations 3 h after surgery were significantly less in groups receiving bupivacaine before surgery. CONCLUSIONS: The results indicate that intraperitoneal local anesthetic blockade administered before or after surgery preempts postoperative pain relative to an untreated placebo-control condition. However, the timing of administration is also important in that postoperative pain intensity and analgesic consumption are both lower among patients treated with local anesthetic before versus after surgery.

The effects of intraperitoneal local anesthetic on analgesic requirements and endocrine response after laparoscopic cholecystectomy: a randomized double-blind controlled study.

This randomized double-blind placebo-controlled study was designed to evaluate the effects on postoperative pain of the local anesthetic, 0.5% bupivacaine with epinephrine, sprayed hepatodiaphragmatically under the surgeon's direct view during laparoscopic cholecystectomy. Metabolic endocrine responses to surgery (glucose and cortisol) and nonsteroidal anti-inflammatory drug requirements were investigated, as well as the presence of nausea, vomiting, and sweating. Local anesthetics or placebo solutions were given as follows. Immediately following the creation of a pneumoperitoneum, surgeons sprayed the first 20 mL of solution (S1), and an additional 20 mL of solution (S2) was sprayed at the end of the operation. Patients were classified into three groups (14 patients per group). Group A received 20 mL of saline during both S1 and S2, group B received 20 mL of saline during S1 and 20 mL of bupivacaine during S2, and group C received 20 mL of bupivacaine during both S1 and S2. The degree of postoperative pain was assessed using the visual analogue scale (VAS) and the verbal rating scale (VRS) on arrival in the recovery room and subsequently at time intervals of 4 h, 8 h, 12 h, and 24 h. The results of this study indicate a significant decrease of postoperative pain in patients treated with local anesthetic. VAS and VRS pain scores, as well as respiratory rate and analgesic requirements, were significantly lower in group C. The postoperative plasma cortisol level in group C was significantly lower than in groups A and B.