Background and objectives: To investigate the effects of oral preoperative regimens on gastric emptying time in relation to BMI in Chinese adults.
Methods and study design: The enrolled 56 adults were divided into three groups (normal-weight, underweight, and overweight) and completed a regimen of two drinks after a 2-week interval. After drinking a carbohydrate regimen (CD, 50 g carbohydrates) or a carbohydrate glutamine regimen (CGD, 44 g carbohydrates and 6 g glutamine) labelled with 99mTc-DTPA (99mTc-diethylenetriaminepentaacetic acid), gastric emptying times T50 and T90 were measured using a curve derived from scintigraphic images.
Results: T50 and T90 had no significant difference between the CD and CGD regimens. T50 was significantly delayed in the underweight participants (BMI <18.5 kg/m2, as Chronic Energy Deficiency, CED) compared with the normal-weight participants after drinking CD (p=0.003) or CGD (p=0.002), as well as T90 after CD (p=0.019). There was no difference in glucose concentrations between the three groups. There are negative correlations between body weight and gastric emptying time T50 (r=-0.461, p=0.016) or T90 (r=-0.553, p=0. 003) after drinking CD, as well as T50 (r=-0.553, p=0.003) after drinking CGD.
Conclusions: Underweight adults should be careful to take oral preoperative regimens 2 hours before surgery and consider reducing the volume because of a slower gastric emptying rate.