Effects of perioperative fasting abbreviation in orthognathic surgery

Prolonged preoperative fasting increases the metabolic stress of trauma and peripheral insulin resistance, negatively influencing the recovery of patients after surgical procedures. The potential benefits of shortening preoperative fasting to three hours with clear liquids are already well established for other surgeries. A prospective, randomized, open, controlled study was developed with 25 participants. Participants were randomized and allocated into two groups: conventional fasting (n=13) and abbreviated fasting (n=12). The following were evaluated: serum insulin and glucose values, and insulin resistance; of the endocrine-metabolic response through measurements of C-reactive protein, IL-6, albumin and leukocytes. Indices of anxiety and discomfort were verified preoperatively. The presence of postoperative nausea and vomiting, pain and muscle strength analysis in the perioperative period were evaluated and compared. Statistical differences between the groups were found in the assessment of preoperative discomfort from hunger (p=0.002) and thirst (p=0.003). We found that in the group that shortened fasting there was less postoperative thirst and less need for postoperative opioid use (p=0.03). However, we found no statistical difference in postoperative insulin resistance, nor in the inflammatory response to surgical trauma. The results of this study indicate that there is no advantage in using conventional fasting regimes in orthognathic surgery and that abbreviated fasting is capable of reducing pre- and postoperative discomfort.