Fasting abbreviation among patients submitted to oncologic surgery: systematic review

The abbreviation of perioperative fasting among candidates to elective surgery have been associated with shorter hospital stay and decreased postoperative complications. To conduct a systematic review from randomized controlled trials to detect whether the abbreviation of fasting is beneficial to patients undergoing cancer surgery compared to traditional fasting protocols. A literature search was performed in electronic databases: MEDLINE (PubMed), SciELO, EMBASE and Cochrane, without time restriction. Were used the descriptors: "preoperative fasting", "cancer", "diet restriction" and "perioperative period". Randomized trials were included in adults of both sexes, with diagnosis of cancer. Exclusion criteria were: use of parenteral nutrition and publications in duplicate. All analyzes, selections and data extraction were done blinded manner by independent evaluators. Four studies were included, with a total of 150 patients, 128 with colorectal cancer and 22 gastric cancer. The articles were published from 2006 to 2013. The main outcome measures were heterogeneous, which impaired the unification of the results by means of meta-analysis. Compared to traditional protocols, patients undergoing fasting abbreviation with the administration of fluids containing carbohydrates had improvements in glycemic parameters (fasting glucose and insulin resistance), inflammatory markers (interleukin 6 and 10) and indicators of malnutrition (grip strength hand and CRP/albumin ratio), and shorter hospital stay. The methodological quality of the reviewed articles, however, suggests that the results should be interpreted with caution. The abbreviation of perioperative fasting in patients with neoplasm appears to be beneficial.