BIA-Guided vs. Conventional Fluid Resuscitation in ICU Patients

Fluid resuscitation plays a critical role in the perioperative care of patients undergoing major surgery. Traditionally, fluid therapy decisions in the intensive care unit (ICU) have relied on static clinical parameters, which may not always reflect the patient's actual volume status. Bioelectrical impedance analysis (BIA) offers a noninvasive and dynamic assessment of hydration status, enabling more precise fluid management tailored to individual needs. This prospective, randomized controlled study aims to compare BIA-guided fluid resuscitation with conventional fluid management strategies in postoperative ICU patients. A total of 80 adult patients who meet the inclusion criteria will be randomized into two groups. Group 1 will receive standard fluid therapy based on clinical evaluation, including heart rate, blood pressure, urine output, passive leg raising test, and vena cava ultrasound assessment. Group 2 will undergo BIA measurements at 0, 12, 24, and 48 hours post-ICU admission to guide fluid management according to hydration status (dehydrated, euvolemic, or hypervolemic). The primary outcome is 28-day all-cause mortality. Secondary outcomes include cumulative fluid balance, ICU and hospital length of stay, duration of mechanical ventilation, and need for vasopressors or inotropic agents. By evaluating clinical outcomes between the two approaches, this study seeks to determine whether BIA-guided fluid management offers a clinically meaningful advantage in postoperative critical care.