Description

Design. Double-blind, parallel-group randomized controlled trial with two arms and a 1:1 allocation ratio. Participants are recruited consecutively and allocated by computer-assisted block randomization. Setting: Central Surgical Installation and inpatient wards, Prof. Dr. I.G.N.G. Ngoerah General Hospital, Denpasar, Bali.

Procedure. Eligible patients are selected from the elective operating list the day before surgery and give written informed consent. All patients fast from solid food for 6 hours. In the reception area, age, sex, height, weight, body mass index, last meal and fasting duration are recorded. Baseline gastric ultrasound (right lateral decubitus, curvilinear probe) and capillary blood glucose are measured, and a blood sample for neutrophil and lymphocyte counts is taken. The participant then drinks 400 mL of the assigned drink within 15 to 30 minutes, 2 hours before anesthesia. Two hours later gastric ultrasound and blood glucose are repeated by the same operator. Anesthesia is neuraxial: spinal bupivacaine heavy 0.5% 10 to 12.5 mg at L3-L4, or epidural bupivacaine up to 0.25% in 10 to 12 mL. Six hours after the end of surgery, blood glucose and a complete blood count are repeated. Surgery type, duration and blood loss are taken from the electronic medical record.

Masking. The drinks are served in identical, opaque, unbranded, closed containers labeled A or B, with the same volume, temperature and timing, and drunk through a straw. The participant, the ultrasound operator who collects the data, and the data analyst do not know the allocation. The person who prepares and hands over the drinks knows it. The drinks differ in taste and appearance, so masking of participants relies on the opaque containers.

Hypothesis. The primary hypothesis is one-sided: gastric volume 2 hours after the maltodextrin drink is lower than after sugar water. The hypotheses for blood glucose and neutrophil-lymphocyte ratio are two-sided.

Sample size. The planned sample is 62 participants (31 per arm). The calculation used blood glucose as the driving outcome (28 per group, alpha 0.05, power 80%) plus 10% allowance for dropout.

Safety. Adverse events (allergy, nausea, bloating, regurgitation, hypotension, bradycardia) are managed by the anesthesia team, recorded, and reported to the hospital patient safety committee and the ethics committee.

Analysis. Normality is tested with Kolmogorov-Smirnov and variance homogeneity with Levene. Two groups are compared with the independent t-test or Mann-Whitney test. Repeated measurements use repeated-measures ANOVA or the Friedman test. Confounders are examined by stratification and a general linear model. Software: IBM SPSS Statistics 29.