Research Article: Randomized, double-blind, placebo-controlled study of the analgesic effect of intraoperative esmolol for laparoscopic gastroplasty1

Date Published: June 12, 2020

Publisher: Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia

Author(s): Vinicius Barros Duarte de Morais, Rioko Kimiko Sakata, Ana Paula Santana Huang, Leonardo Henrique da Cunha Ferraro.


To evaluate the analgesic effect of esmolol in patients submitted to laparoscopic gastroplasty.

Forty patients aged between 18 and 50 years with American Society of Anesthesiologists (ASA) physical status scores of II and III who underwent gastric bypass were allocated to two groups. Group 1 patients received a 0.5-mg/kg bolus of esmolol in 30 mL of saline before induction of anesthesia, followed by an infusion at 15 µg/kg/min until the end of surgery. Group 2 patients received 30 mL of saline as a bolus and then an infusion of saline. Anesthesia included fentanyl (3 µg/kg), propofol (2-4 mg/kg), rocuronium (0.6 mg/kg), and 2% sevoflurane, with remifentanil if necessary. The following parameters were evaluated: pain intensity over 24h, remifentanil consumption, the first analgesic request, morphine consumption, and side effects.

Pain intensity was lower in the esmolol group except at T0 (after extubation) and 12h postoperatively. Remifentanil supplementation, recovery time, and postoperative morphine supplementation were lower in the esmolol group. No differences in the time to the first analgesic request or side effects were found between the groups.

Intraoperative esmolol promotes reductions in pain intensity and the need for analgesic supplementation without adverse effects, thus representing an effective drug for multimodal analgesia in gastroplasty.

Partial Text

Postoperative analgesia and recovery of patients undergoing bariatric surgery are challenging. Opioids are effective in relieving postoperative pain; however, especially in morbidly obese, these drugs are associated to side effects1,2. Other drugs are often given to increase the analgesic effect of opioids and decrease the incidence and severity of side effects. Also, lower half-life drugs are recommended for these patients1. Thus, multimodal analgesia with drugs of different actions is the most prudent approach for morbidly obese patients. A combination of short-acting drugs with a focus on opioid reduction can reduce vomiting and pulmonary complications, enabling early ambulation and shortening the hospital stay3.

The study was prospective, randomized, comparative, double-blind, and paired sample. The sample size was calculated using the SPSS17® software. The test of choice was Student’s t for two independent paired sample with 80% for power and alpha at 5%. To calculate the sample, it was set 2.4 point for the pain score for the difference between the groups. The result was 19 participants in each group, and it was allocated 20 in each group.

The CONSORT flowchart is shown in Figure 1. There was no difference in demographic data, duration of surgery and ASA between the groups (Table 1).

We found that intraoperative continuous infusion of esmolol reduce pain intensity in the first 24 h, the morphine dose over 24 h and the amount of remifentanil use during bypass laparoscopic gastroplasty. These results indicated that esmolol may be used effectively to achieve an opioid-sparing effect during surgery and qualitatively better recovery from anesthesia.

Reduced incidence of nausea and vomiting by the administration of prophylactic antiemetic may have influenced the absence of difference in these adverse effects.

Intraoperative esmolol promotes reduction in pain intensity, and need for supplementation, without increased risks and represents an effective drug for multimodal analgesia in obese patients submitted to gastroplasty.




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