ORIGINAL ARTICLE   Free access

Minerva Anestesiologica 2019 October;85(10):1071-9

DOI: 10.23736/S0375-9393.19.13396-2

Copyright © 2019 EDIZIONI MINERVA MEDICA

lingua: Inglese

Body Mass Index does not affect intraoperative goal-directed fluid requirements

Andrea HOLZER ¹, Barbara SITTER ¹, Oliver KIMBERGER ¹, René WENZL ², Edith FLEISCHMANN ¹ ✉, Daniela MARHOFER ¹, Barbara KABON ¹

¹ Unit of General Intensive Care and Pain Medicine, Department of Anesthesiology, Medical University of Vienna, Vienna, Austria; ² Department of Obstetrics and Gynecology, Medical University of Vienna, Vienna, Austria

BACKGROUND: Perioperative normovolemia is a major determinant of tissue oxygen availability and postoperative outcome. Thus, adequate volume replacement therapy remains an essential part of perioperative management. Nevertheless, volume optimization in overweight and obese surgical patients with alterations in cardiovascular function, peripheral perfusion, and body composition remains challenging. We, therefore, tested the hypothesis that Body Mass Index (BMI) correlates with fluid requirements during goal-directed management. Furthermore, we evaluated subcutaneous tissue oxygen tension (PsqO2) as an indicator of intravascular volume status and peripheral perfusion.
METHODS: Ninety women, undergoing open gynecologic surgery, were assigned to three groups according to their BMI, (lean: BMI 18.5 to 24.9 kg/m2, overweight: BMI 25 to 29.9 kg/m2, obese: BMI>30 kg/m2). Esophageal Doppler monitoring guided intraoperative crystalloid administration. Tissue oxygen tension was measured with a polarographic electrode in the subcutaneous tissue of the upper arm and served as a secondary outcome parameter.
RESULTS: BMI and fluid requirements did not correlate (r=0.093, P=0.384). Total amounts of administered crystalloids were comparable. Lean patients received 2223±1811 mL in total, while overweight patients received 1866±1261 mL. Obese patients required 2416±1143 mL of total crystalloids (P=0.327). Intra- and postoperative PsqO2 did not differ significantly (97.3 vs. 86.8 vs. 79.6 mmHg, P=0.06 and 74.5 vs. 83 vs. 81.5 mmHg, P=0.63, respectively).
CONCLUSIONS: BMI did not affect intraoperative fluid requirements. Doppler-guided intravascular volume optimization was associated with well-maintained subcutaneous tissue oxygen availability in all BMI groups.

KEY WORDS: Crystalloid solutions; Body Mass Index; Obesity; Oxygen; Subcutaneous tissue