Abstract: Assessment of preoperative fluid depletion using bioimpedance analysis.

Authors:

Ackland GL, Singh-Ranger D, Fox S, McClaskey B, Down JF, Farrar D, Sivaloganathan M, Mythen MG.

Institution:

Centre for Anaesthesia, University College London Hospitals, London W1T 3AA, UK.

Source:

Br J Anaesth. 2004 Jan;92(1):134-6.

Abstract:

BACKGROUND: Fluid depletion during the perioperative period is associated with poorer outcome. Non-invasive easurement of total body water by bioimpedance may enable preoperative fluid depletion and its influence on perioperative outcome to be assessed. METHODS: 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. RESULTS: Body weight fell by 1.27 kg (95% CI 1.03-1.50 kg; P<0.0001) and foot bioimpedance increased by 51 ohm after bowel preparation (95% CI 36-66; P<0.0001). Weight change after the nil-by-mouth period in day-surgery patients (mean -0.22 kg, 95% CI -0.05 to -0.47 kg; P=0.07) correlated (r=-0.46; P=0.005) with an increase in bioimpedance (16 ohms, 95% CI 5-27 ohms; P=0.01). No difference between two separate bioimpedance measurements was seen in the volunteer group. CONCLUSIONS: Further work is warranted to determine if bioimpedance changes may serve as a useful indicator of perioperative fluid depletion.

Keywords:

Recovery Anaesthesia Surgery Fluid depletion measurement