Change in End-Tidal Co2 After Mini-Fluid Challenge to Determine Fluid Responsiveness.

Abstract

Single-center prospective study. Patients were enrolled from 2019 to 2021 from the medical ICU within a single academic hospital. Thirty-eight patients with paired measurements of fluid responsiveness as determined by bioreactance who were admitted to the ICU with a diagnosis of distributive shock and on mechanical ventilation. Stroke volume index (SVI), cardiac index, heart rate, systolic blood pressure, diastolic blood pressure, mean arterial pressure, and ETco2 were measured before and after completion of a mini-fluid challenge. Test characteristics of change in ETco2 (ΔETco2) greater than or equal to 2 after mini-fluid challenge to determine fluid responsiveness were calculated with percentage change in SVI greater than or equal to 10% used as the reference standard. The sensitivity and specificity of a ΔETco2 greater than or equal to 2 mm Hg as a predictor of a change in SVI greater than or equal to 10% following a mini-fluid challenge were 20.0% and 91.3%, respectively. The area under the receiver operating characteristic curve was 0.62. A ΔETco2 greater than or equal to 2 mm Hg after mini-fluid challenge has limited test performance for determining fluid responsiveness in intubated patients with distributive shock.