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Better patient outcomes for deep anaesthesia vs light anaesthesia during LSG

Maintaining a deeper depth of anaesthesia during laparoscopic sleeve gastrectomy (LSG) reduces acute postoperative pain, causes less need for additional analgesic drugs and improves patient satisfaction, according to researchers from Xuzhou Medical University, Jiangsu, China.

(Credit: Biswarup Ganguly)

The study investigators noted that with the popularity of anaesthesia depth monitoring equipment, such as the Narcotrend Index and Bispectral Index (BIS), it is now feasible to monitor anaesthesia depth and implement personalised anaesthesia depth management during general anaesthesia, which reduces the consumption of anaesthetics and promotes the early recovery after surgery.

Previous studies have reported that maintaining a deeper depth of anaesthesia during surgery may reduce acute postoperative pain (APP) in patients. However, they noted that there are few studies on patients with obesity, therefore, they investigated the effect of different depths of anaesthesia on post-LSG pain in patients.

The ninety patients were divided equally into two groups: light anaesthesia group (BIS 50) and deep anaesthesia group (BIS 35). The authors explained that anaesthesia was induced with intravenous 1μg/kg dexmedetomidine, 2–3mg/kg propofol, 0.15–0.25mg/kg cisatracurium and 0.3–0.5μg/kg sufentanil. The anesthesia depth needed to be changed to the objective value within ten minutes after the skin incision in accordance with the grouping.

To prevent vomiting, all patients received dexamethasone 10mg and palonosetron hydrochloride 0.25mg intravenously, and to reduce the awakening pain, 40mg parecoxib sodium was given half an hour before the end of the surgery.

The primary outcome of the trial was pain evaluated by visual analogue scale (VAS) at 0, 12, 24, 48, and 72 hours when returned to the ward. Secondary outcomes include the extra use of analgesics, patient satisfaction, Quality of Recovery-15 (QoR-15) score and postoperative nausea and vomiting (PONV).


The average BIS values for the BIS 50 group were 49.71±4.1 and 35.60±4.8 in the BIS 35 group (p<0.001). In the BIS 35 group, the total propofol dosages were higher (p=0.041). However, there were no differences between the groups in the length of anaesthesia or surgery, infusion volume, the use of nitroglycerin, norepinephrine or cisatracurium.

The VAS score in the BIS 35 group were lower than that in the BIS 50 group in all time frames. Pain intensities at rest or coughing in the BIS 35 group patients at 0, 12, and 24 h were significantly lower than those in the BIS 50 group (p<0.05).

In the initial three days after surgery, fewer patients in the deep anaesthesia group needed additional analgesia and patient satisfaction was higher at the time of recovery (p<0.015, p<0.032, respectively). For postoperative anaesthesia recovery, in the BIS 50 group, the extubation time and PACU stay time were shorter after surgery, and the difference was statistically significant (p<0.001 and p=0.038, respectively). There were no statistical differences in the postoperative QoR-15 scores and the PONV grade at 24h after surgery between the groups.

The findings were reported in the paper, ‘The Effect of Depth of Anesthesia on Postoperative Pain in Laparoscopic Sleeve Gastrectomy: A Randomized Controlled Trial’, published in Obesity Surgery. To access this paper, please click here


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