Low Nutritional Risk Means Lower Remimazolam Doses for Sedation in Older Adults

Older patients with poorer nutritional status need markedly less remimazolam to achieve effective sedation during gastrointestinal endoscopy, according to a prospective dose-finding study published in BMC Anesthesiology.

The study, a single-center prospective dose-finding clinical trial registered with the Chinese Clinical Trial Registry, enrolled patients aged 65 years and older undergoing elective painless gastrointestinal endoscopy.

All participants received remifentanil, after which remimazolam was administered using a modified Dixon up-and-down method. The initial dose was 0.20 mg/kg, and the dose was adjusted in steps of 0.02 mg/kg between successive patients depending on whether the previous dose had been effective. Effective sedation was defined as completion of the procedure without body movement or other interfering responses.

The results showed a clear separation between the two groups. Using the modified Dixon method, the median effective dose, or ED50, of remimazolam was significantly lower in the low-GNRI group than in the high-GNRI group: 0.125 mg/kg (95% CI 0.116–0.134) versus 0.173 mg/kg (95% CI 0.162–0.184), a difference that was statistically significant with P < 0.001.

Probit regression analysis produced similar estimates of the ED50, at 0.127 mg/kg for the low-GNRI group and 0.170 mg/kg for the high-GNRI group. The corresponding ED95 values, the doses expected to be effective in 95 percent of patients, were 0.154 mg/kg and 0.227 mg/kg, respectively. The authors noted that the confidence interval for the ED95 in the high-GNRI group was wide and should be interpreted cautiously, and that the dose-response curve was shifted leftward in the low-GNRI group, meaning that effective sedation occurred at lower doses across the response range.

The study’s authors point out that nutritional risk may influence sedative requirements in older adults, but that the association between GNRI and remimazolam dose requirements during gastrointestinal endoscopy sedation had remained unclear before this work.

The clinical implication is straightforward: older patients classified as having low GNRI required a lower dose of remimazolam for effective sedation.

Several limitations deserve emphasis. The study was single-center and relatively small, with 27 patients per group, and the wide confidence interval around the ED95 in the high-GNRI group means the upper dose estimate should be treated with caution. As a dose-finding study, it establishes an association between nutritional status and sedative requirements in this specific procedural context; it does not by itself establish clinical outcomes such as safety, recovery times, or patient satisfaction. The findings apply to older adults undergoing elective gastrointestinal endoscopy with a remifentanil and remimazolam regimen, and further research would be needed before the results are translated into routine dosing guidance.

Subject of Research: The relationship between the geriatric nutritional risk index and remimazolam dose requirements for sedation in older adults undergoing gastrointestinal endoscopy.

Article Title: Association between geriatric nutritional risk index and remimazolam dose requirements for gastrointestinal endoscopy sedation in older adults: a prospective dose-finding study

Article References: Ye, Y., Zeng, J., Hua, J., Liang, X., Cai, L., Ren, A., Zhang, Y., Li, Z., & Huang, D. (2026). Association between geriatric nutritional risk index and remimazolam dose requirements for gastrointestinal endoscopy sedation in older adults: a prospective dose-finding study. BMC Anesthesiology. https://doi.org/10.1186/s12871-026-04388-5

Image Credits: AI Generated

DOI: 10.1186/s12871-026-04388-5

Keywords: remimazolam, geriatric nutritional risk index, GNRI, sedation, gastrointestinal endoscopy, older adults, ED50, ED95, probit regression, dose-finding study, anesthesiology, nutritional risk