Diagnostic performance of qualitative ultrasound assessment for the interpretation of point-of-care gastric ultrasound to detect high gastric fluid volume: A prospective randomized crossover study.

STUDY OBJECTIVE: This study aimed to assess whether elevating the head of the bed to 45° was associated with sensitivity >90% of the qualitative ultrasound assessment for the diagnosis of gastric fluid volume > 1.5 ml.kg-1. We also assessed the performance of qualitative assessment, composite ultrasound scale, and clinical algorithm, for the diagnosis of fluid volume > 1.5 ml.kg-1 according to whether the head of the bed was elevated to 45° or not. DESIGN: Prospective randomized observer-blind crossover trial. SETTING: Hospices Civils de Lyon, France. PATIENT: Healthy adult volunteers. INTERVENTIONS: Two separate study sessions in fasting volunteers: with and without head-of-bed elevation to 45°, in a randomized order. Each session consisted of three tests, each corresponding to a randomized and different volume of water (either 0, 50, 100, 150 or 200 ml); the same volumes were used in both sessions and in a randomized order. Gastric ultrasounds were performed three minutes after the ingestion of water by an investigator blinded to the volume ingested. MEASUREMENTS: Diagnostic performance of each approach for the diagnosis of gastric fluid volume > 1.5 ml.kg-1. MAIN RESULTS: Twenty volunteers were included, and 120 measurements were analyzed. The sensitivity of the qualitative assessment for the diagnosis of gastric fluid volume > 1.5 ml.kg-1 with and without head-of-bed elevation was 91% (95%CI: 75-98) and 75% (95%CI: 57-89), respectively. The clinical algorithm with head-of-bed elevation had significantly better sensitivity than the qualitative assessment with no head-of-bed elevation; there was no significant difference for other comparisons. CONCLUSIONS: The results suggest that qualitative examination of gastric antrum in the supine position with head-of-bed elevation to 45° can discriminate between low and high gastric fluid volume with high sensitivity, while neither the composite ultrasound scale nor the clinical algorithm improved the diagnostic performance of gastric ultrasound for the diagnosis of gastric fluid volume > 1.5 ml.kg-1.

Effects of opioid-free anesthesia on postoperative morphine consumption after bariatric surgery.

STUDY OBJECTIVES: The objective of this study was to determine whether postoperative morphine requirement in obese patients undergoing laparoscopic bariatric surgery was reduced by opioid-free anesthesia (OFA), as compared to an anesthetic strategy using opioids (opioid balanced anesthesia (OBA)) and to investigate the differences that may exist between the use of clonidine and dexmedetomidine in the context of OFA. DESIGN: Retrospective cohort study. SETTING: Academic medical center in Lyon, France. PATIENTS: 257 patients who underwent laparoscopic bariatric surgery between March 2017 and March 2019. 77 patients were included in the OBA group and 180 in the OFA group. The OFA group was subdivided in two: 90 patients received OFA with clonidine (OFAC) and 90 received OFA with dexmedetomidine (OFAD). MEASUREMENTS: Proportion of patients who did not receive morphine during the first 24 postoperative hours. MAIN RESULTS: During the first 24 postoperative hours, the proportion of patients who did not require morphine was significantly higher in the OFA (87%) than in the OBA (52%) group (OR: 6.31; 95% CI [3.38; 11.80], P < 0.001). This difference remained significant after adjustment for age, body mass index, sex, type and duration of surgery (OR: 7.99; 95% CI [4.05; 16.48], P < 0.001). A greater proportion of patients in the OFAD (93%) than in the OFAC group (81%, P = 0.026) did not receive morphine during the same period. CONCLUSIONS: OFA is associated with a lower morphine requirement than with OBA during the first 24 h after bariatric surgery. In addition, OFAD seems to be more effective than OFAC in order to reduce morphine consumption.