Effect of preoperative intravenous carbohydrate loading on preoperative discomfort in elective surgery patients

Abstract

We studied the effect of three different fasting protocols on preoperative discomfort and glucose and insulin levels. Two hundred and ten ASA I-III patients undergoing general or gastrointestinal surgery were randomly assigned to three groups: overnight intravenous 5% glucose infusion (1000 ml), carbohydrate-rich drink (400 ml) at 6-7 a.m., or overnight fasting. The subjective feelings of thirst, hunger, mouth dryness, weakness, tiredness, anxiety, headache and pain of each patient were questioned preoperatively using a visual analogue scale. Serum glucose and insulin levels were measured at predetermined time points preoperatively. During the waiting period before surgery, the carbohydrate-rich drink group was less hungry than the fasting group (P = 0.011). No other differences were seen in visual analogue scale scores among the study groups. Trend analysis showed increasing thirst, mouth dryness and anxiety in the intravenous glucose group (P < 0.05). The carbohydrate-rich drink group experienced decreasing thirst but increasing hunger and mouth dryness (P < 0.05). In the fasting group, thirst, hunger, mouth dryness, weakness, tiredness and anxiety increased (P < 0.05). Both intravenous and oral carbohydrate caused a significant increase in glucose and insulin levels. Intravenous glucose infusion does not decrease the sense of thirst and hunger as effectively as a carbohydrate-rich drink but does alleviate the feelings of weakness and tiredness compared with fasting.