Postoperative fasting is associated with longer ICU stay in oncologic patients undergoing elective surgery

BACKGROUND: Cancer patients present nutritional and complications risks during the postoperative period. Fasting contributes to surgical catabolic damage. This study evaluates the consequence of fasting time on the surgical outcomes of cancer patients undergoing elective surgeries. METHODS: Prospective cohort, evaluating two categories of patients according to postoperative fasting: less than or greater than 24 h. Outcomes: Hospitalization time, 28-day mortality, ICU stay and infection rates. DISCUSSION: We included 109 patients (57% men, 60 ± 15 years, BMI: 26 ± 5 kg/m(2), SAPS3 43 ± 12), hepatectomy was the most frequent surgery (13.8%), and colon and rectum were the most common neoplasia (18.3%). The ICU stay was longer in postoperative fasting > 24 h (5.5 [4–8.25] vs. 3 [2–5] days, p < 0.001). Fasting > 24 h persisted as a risk factor for longer length of stay (LOS) in the ICU after adjustments. There were no differences in the mortality analysis within 28 days and total hospitalization time between groups. A tendency to experience more infections was observed in patients who fasted > 24 h (34.8% vs. 16.3%, p = 0.057). Onset of diet after the first 24 h postoperatively was a risk factor for longer ICU stay in cancer patients who underwent major surgeries. GRAPHICAL ABSTRACT: [Image: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13741-022-00261-4.