Tidal Volume Challenge to Reliably Predict Fluid Responsiveness in Critically Ill Patients – An Interim Analysis

INTRODUCTION: Fluid administration is the first line of treatment in patients with acute circulatory failure. Although hypovolemia leading to organ dysfunction and death, excessive fluid loading is associated with increased complications, mortality, and length of ICU stay(1). Only half the patient with circulatory failure respond positively to fluid administration, Hence it is necessary to detect fluid responders Dynamic indices like CO (VTi) and PPV are superior to static indices to predict fluid responsiveness, However these dynamic indices are unreliable during low tidal volume (Vt) ventilation, It is hypothesized that a low Vt might be insufficient to produce a significant change in intrathoracic pressure, thus these indices may indicate a nonresponsive status even in responder(2). The Aim of this study is to evaluate the change in Haemodynamics parameter using Tidal Volume Challenge and predict Fluid Responsiveness. OBJECTIVES: To study the reliability of Tidal volume challenge test in predicting Fluid Responsiveness in Critically ill patient, to establish correlation with other test for assessment of fluid responsiveness, to identify non responsive patient. Material and methods: All Adult patients with hemodynamic Instability who are intubated and mechanically Ventilated with volume assist control ventilation (VAC) and using low tidal volume strategy (6ml/kg/IBW). Exclusion criteria were: age <18 years or pregnancy, cardiac arrhythmias, open chest, right sides heart failure, pulmonary or intra abdominal hypertension.. In this Interventional prospective study, we recorded Haemodynamics (HR, MAP, PPV, RR, VTi, IVC-DI), First set of recording were taken at TV 6ml/kg, then we serially increased the TV for 1 min and take measurements. In the end of TVC we gave mini fluid bolus (250ml of balanced Crystalloid solutions) over 10 min to see the Responder &Non responder. RESULTS: During study period of intrim analysis, 10 patient were analysed. The absolute change in pulse pressure variation after increasing tidal volume from 6 to 8ml/kg predicted body weight predicted fluid responsiveness with areas under the receiver operating characteristic curves (with 95% CIs) being 0.99 (0.98-1.00) and 0.97 (0.92- 1.00), respectively. The cutoff values of absolute changes in pulse pressure variation and CO (VTi) after increasing tidal volume from 6 to 8ml/KG predicted body weight were 3.2% and 2.5%, respectively Haemodynamics (HR, MAP, PPV, RR, VTi, IVC-DI) during tidal volume 6mL/Kg predicted body weight did not predicted fluid responsiveness. DISCUSSION: As in Our study till now we found Tidal Volume Challenge helps us to predict fluid responsiveness in Critically ill patients but the analysis was done here on small sample size, so we would like to further extend our study and discover the reliability of test and side effects it bring along with it.