Assessment of preoperative fluid depletion using bioimpedance analysis

Fluid depletion during the perioperative period is associated with poorer outcome. Non-invasive measurement of total body water by bioimpedance may enable preoperative fluid depletion and its influence on perioperative outcome to be assessed. Weight and foot bioimpedance were recorded under standardized conditions in patients undergoing bowel preparation (n=43) or day surgery (n=44). Fifteen volunteers also followed standard nil-by-mouth instructions on two separate occasions to assess the variabilities of weight and bioimpedance over time. Body weight fell by 1.27 kg (95% CI 1.03–1.50 kg; P