The Effect of Depth of Anesthesia on Postoperative Pain in Laparoscopic Sleeve Gastrectomy: A Randomized Controlled Trial.

BACKGROUND: Patients with obesity are more sensitive to pain and more likely to have acute postoperative pain (APP). Studies have shown that the depth of anesthesia may affect the incidence of APP. The purpose of the study was to look into the connection between APP and depth of anesthesia in patients with obesity undergoing laparoscopic sleeve gastrectomy. METHODS: This is a prospective, double-blinded randomized clinical trial, 90 patients undergoing laparoscopic sleeve gastrectomy were randomly divided into two groups: the light anesthesia group (Bispectral Index of 50, BIS 50) and the deep anesthesia group (BIS 35). The degree of pain was evaluated by the visual analogue scale (VAS) at 0, 12, 24, 48, and 72 h after surgery. The use of analgesics, grade of postoperative nausea and vomiting (PONV), and the Quality of Recovery-15 (QoR-15) score were recorded. RESULTS: The VAS scores at rest or coughing at 0, 12, and 24 h after surgery in the BIS 35 group were lower than those in the BIS 50 group (P < 0.05). Fewer patients in the deep anesthesia group needed analgesia during the recovery period, and patient satisfaction was higher on the 3rd day after surgery (P < 0.015, P < 0.032, respectively). CONCLUSIONS: For patients with obesity, maintaining a deeper depth of anesthesia during surgery is beneficial to reduce APP causes less need for additional analgesic drugs, and improves patient satisfaction.

Transesophageal Echocardiographic Measurements of the Superior Vena Cava for Predicting Fluid Responsiveness in Patients Undergoing Invasive Positive Pressure Ventilation.

OBJECTIVES: Preoperative fasting, water deprivation, and intraoperative fluid loss and redistribution result in hypovolemia in patients undergoing surgery. Some findings have indicated that the superior vena cava (SVC) diameter and variation, as determined by transesophageal echocardiography during surgery, do not reflect central venous pressure effectively. This study aimed to compare and correlate the SVC diameter and variation with the stroke volume variation for predicting fluid responsiveness in patients undergoing invasive positive pressure ventilation. METHODS: Thirty-six patients scheduled for elective gastrointestinal surgery under general anesthesia with invasive positive pressure ventilation were included in this study. After anesthesia induction, the stroke volume variation, SVC diameter, mean arterial pressure, central venous pressure, and pulse were recorded, and measurements after fluid challenge were recorded as well. The SVC variation was calculated before and after the fluid challenge. RESULTS: After the fluid challenge, the SVC diameter markedly increased, whereas the SVC variation and stroke volume variation significantly decreased (P < .05). The optimal cutoff value for the SVC variation was 21.1%, and the area under the curve (AUC) from a receiver operating characteristic curve analysis was 0.849. The optimal cutoff value for the minimal SVC diameter was 1.135 cm, and that AUC was 0.929. In addition, the optimal cutoff value for the maximal SVC diameter was 1.480 cm, and the AUC was 0.862. CONCLUSIONS: The minimal SVC diameter may be an effective indicator for predicting fluid responsiveness in patients undergoing invasive positive pressure ventilation.