Preoperative Fasting: An Outdated Concept?

Abstract

Recent studies have shown that fasting during the preoperative period for elective surgery induces a metabolic state that seems unfavorable for patients. Results from animal studies indicate that rapid depletion of liver glycogen before surgery leads to mobilization of muscle glycogen after surgery, in turn leading to reduced muscle strength. Depletion of liver glycogen also influences the function of the mononuclear phagocytic system (MPS), which is located predominantly in the liver. The MPS is essential in restricting endotoxin, which may translocate from the gut. In addition, surgery per se puts a substantial physical strain on the patient, and fasting may adversely affect the metabolic response to surgery. This paper presents experimental and clinical data that, when combined together, prove that fasting before surgery has adverse consequences for the patient.

Reducing preoperative fasting in elective adult surgical patients: a case–control study

“…In the setting of mechanical bowel preparation, preoperative fasting can be as long as 40 h [4]. Prolonged fasting is deleterious for the patient since the post-operative period is characterised by increased metabolic rate, hypercatabolism, gluconeogenesis and insulin resistance [5], a key determinant of post-operative outcome and an independent predictor of the length of hospital stay after surgery [6].…”

The impact and safety of preoperative oral or intravenous carbohydrate administration versus fasting in colorectal surgery – a randomized controlled trial

“…Moreover, some authors have used new strategies in perioperative care for patients, abandon ing bowel preparation, fluid overload, preoperative fast ing, premedication, nasogastric tubes and drains and favoring stimulation of gut motility and carbohydrate loading [24,25]. In animal studies, rodents that were fed before stress induction showed improved muscle and cardiac function, better immunologic performance and, most prominently, better survival rates with complete recovery after hemorrhage or endotoxemia when com pared with fasting subjects [26,27].…”

Preoperative Carbohydrate Loading in Patients Undergoing Coronary Artery Bypass or Spinal Surgery

“…Moreover, processes such as gluconeogenesis, and fat and protein catabolism are heightened during the perioperative period (54). Surgery itself results in a physiological state of hypercatabolism which is further compounded by the metabolic stress of preoperative fasting.…”