Bioelectrical Impedance Analysis in Patients Undergoing Major Head and Neck Surgery: A Prospective Observational Pilot Study

Background: Head and neck patients are prone to malnutrition. Perioperative fluids administration in this patient group may influence nutritional status. We aimed to investigate perioperative changes in patients undergoing major head and neck surgery and to examine the impact of perioperative fluid administration on body composition and metabolic changes using bioelectrical impedance. Furthermore, we sought to correlate these metabolic changes with postoperative complication rate. In this prospective observational pilot study, bioelectrical impedance analysis (BIA) was performed preoperatively and on postoperative days (POD) 2 and 10 on patients who underwent major head and neck surgeries. BIA was completed in 34/37 patients; mean total intraoperative and post-anesthesia fluid administration was 3682 ± 1910 mL and 1802 ± 1466 mL, respectively. Total perioperative fluid administration was associated with postoperative high extra-cellular water percentages (p = 0.038) and a low phase-angle score (p < 0.005), which indicates low nutritional status. Patients with phase angle below the 5th percentile at POD 2 had higher local complication rates (p = 0.035) and longer hospital length of stay (LOS) (p = 0.029). Multivariate analysis failed to demonstrate that high-volume fluid administration and phase angle are independent factors for postoperative complications. High-volume perioperative fluids administration impacts postoperative nutritional status with fluid shift toward the extra-cellular space and is associated with factors that increase the risk of postoperative complications and longer LOS. An adjusted, low-volume perioperative fluid regimen should be considered in patients with comorbidities in order to minimize postoperative morbidity.

The Effect of Fluid Overload on Attributable Morbidity after Cardiac Surgery: A Retrospective Study

Introduction. Although the detrimental effects of excessive perioperative fluid administration are generally well established, data in the setting of cardiac surgery remain less robust. Methods. In this retrospective single-center observational study, the total fluid balance in the first 12 hours during and after surgery was evaluated. Primary endpoint was the relationship between total fluid balance and the incidence of prolonged mechanical ventilation. For this purpose, data were divided into quartiles (Q); prolonged mechanical ventilation and prolonged length of stay (LOS) in the ICU were defined as Q4. Secondary endpoints were prolonged LOS in the ICU, incidence of acute kidney injury (AKI; defined as a 1.5-fold increase in serum creatinine during, relative to baseline), and ICU mortality. Results. In a 3-year period, 748 patients were included. In a univariate analysis, the median duration of mechanical ventilation was 2.9 h [2.4–3.7] in Q1 of the fluid balance and increased significantly to 4.7 h [3.1–9.2] in Q4 of the fluid balance p < 0.001 . In addition, patients in Q4 of the fluid balance had a significantly longer LOS in the ICU, as well as a higher incidence of AKI and ICU mortality. In a multivariate analysis, Q4 of the fluid balance was independently associated with prolonged mechanical ventilation (OR 4.9, CI 2.9–8.4, p < 0.001 ) and prolonged LOS in the ICU (OR 11.3 CI 6.1–20,9, p < 0.001 ), but not with the incidence of AKI or ICU mortality. Conclusions. Perioperative fluid administration in cardiac surgery patients was independently associated with prolonged mechanical ventilation and prolonged LOS in the ICU.