Preoperative fasting duration and perioperative effects in high-risk surgical patients with planned high-risk procedures

Preoperative fasting is advised to minimize pulmonary aspiration risk during elective surgeries. Current guidelines recommend fasting from clear liquids two hours and solid foods six hours before surgery. However, clinical practice often involves longer fasting times. This study aimed to evaluate current fasting practices, propose improvements, and observe perioperative outcomes in elective surgery patients. Eighteen ASA III-IV adult patients scheduled for high-risk neurosurgical procedures were included following ethical approval. Patients were divided into a control group (n=9) with standard practice and a study group (n=9) informed about recommended fasting times. Preoperative fasting durations, intraoperative vital parameters, postoperative nausea and vomiting (PONV), postoperative acute kidney injury (PO-AKI), and ICU and ward stays were recorded. PPV (Pulse Pressure Variation) monitoring guided fluid management when PPV exceeded 13%. The study group had significantly shorter fasting durations. MAP changes after induction were significantly higher in the control group at the 20th and 30th minutes (p=0.002 and p=0.004). Three control group patients with PPV >13% required colloid infusion. Fasting durations were not significantly correlated with PONV, PO-AKI, or ward stay length, but ICU stays were significantly shorter in the study group (p=0.011). In conclusion, fasting times exceed guideline recommendations in practice. Educating healthcare teams and patients can reduce unnecessary fasting. Prolonged fasting may contribute to post-induction hypotension, which can be mitigated through PPV-guided fluid replacement. Keywords: preoperative fasting, hemodynamics, pulse pressure variation education, fasting instructions