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Updated: Apr 16, 2026

Roux-en-Y Gastric Bypass Operation in Rats
Published on: June 11, 2012
Patients With Roux-en-Y Gastric Bypass Require Increased Sedation During Upper Endoscopy
Pichamol Jirapinyo1, Nitin Kumar2, Christopher C Thompson2
1Department of Internal Medicine, Yale-New Haven Hospital, New Haven, Connecticut.
Background & Aims:
After Roux-en-Y gastric bypass (RYGB), many patients experience changes in metabolism that could affect the amount of sedative they require. We assessed whether patients who have vs have not received RYGB have different sedation requirements during esophagogastroduodenoscopy (EGD).
Methods:
In a retrospective study, we collected data from patients who had received RYGB (n = 200; mean age, 45 years; 188 women; body mass index [BMI], 34.0 ± 7.1 kg/m2) or had not (controls, n = 200; mean age, 45 years; 188 women; BMI, 34.1 ± 7.2 kg/m2) and underwent EGD under conscious sedation from 2005 through 2010; groups were matched for age, sex, and BMI. Sedative doses were compared by using the Student t test. Multivariate linear regression was used to identify factors associated with sedation dose. We performed a subgroup analysis of RYGB patients who underwent EGD before and after RYGB, comparing sedative doses with a paired t test.
Results:
Patients with RYGB were given 132.4 ± 40.4 μg fentanyl and 5.4 ± 1.5 mg midazolam, whereas controls received 108.6 ± 31.6 μg fentanyl (P < .001) and 4.3 ± 1.2 mg midazolam (P < .001). Increased time from RYGB, higher American Society of Anesthesiologists class, and therapeutic procedure were associated with higher doses of sedation (P < .05). Thirty-two patients underwent EGD before and after RYGB. Patients were given 95.0 ± 39.0 μg fentanyl before RYGB and 130.5 ± 41.3 μg fentanyl afterward (P < .05); they were given 4.0 ± 1.0 mg midazolam before RYGB and 5.5 ± 1.7 mg midazolam afterward (P < .05).
Conclusions:
Patients with RYGB require larger amounts of fentanyl and midazolam during EGD than patients without RYGB, despite similar age, sex, and BMI. Among patients who underwent EGD before and after RYGB, levels of drugs required for sedation increased after gastric bypass, despite weight loss.
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