Abstract
Objective:Assessment of fluid responsiveness is problematic in intensive care unit patients. Lung recruitment maneuvers (LRM) can be used as a functional test to predict fluid responsiveness. We propose a new test to predict fluid responsiveness in mechanically ventilated patients, analyzing the variations of central venous pressure (CVP) and systemic arterial parameters during a prolonged sigh breath LRM without the use of a cardiac output measuring device. Design:Prospective observational cohort study.Setting:Intensive Care Unit, Saint-Etienne University Central Hospital.Patients:Patients under mechanical ventilation, equipped with invasive arterial blood pressure, CVP, pulse contour analysis (PICCOTM), requiring volume expansion, with no right ventricular dysfunction.Interventions:None.Measurements and Main Results:CVP, systemic arterial parameters and stroke volume (SV) were recorded during prolonged LRM followed by a 500mL fluid expansion to asses fluid responsiveness. 25 patients were screened, 18 patients were analyzed. 9 patients were responders to volume expansion and 9 were not. Evaluation of hemodynamics parameters suggested the use of a linear interpolation model. Slopes for systolic aortic pressure, pulse pressure (PP), CVP and SV were all significantly different between responders and non-responders during pressure increase phase of LRM (STEP-UP) (p = 0.022, p = 0.014, p= 0.006 and p = 0.038, respectively). PP and CVP slopes during STEP-UP were strongly predictive of fluid responsiveness with an AUC of 0.926 (95% CI, 0.78 to 1.00), sensitivity = 100%, specificity = 89% and an AUC = 0.901 (95% CI, 0.76 to 1.00), sensibility = 78%, specificity = 100%, respectively. Combining sensitivity of PP and specificity of CVP, fluid responsiveness prediction can be obtained with 100% sensibility and 100% specificity (AUC=0.96; 95% CI, 0.90 to 1.00). 1 patient presented inconclusive values using the grey zone approach (5.5%).Conclusions:In patients under mechanical ventilation with no right cardiac dysfunction, the association of PP and CVP slope analysis during a prolonged sigh breath lung recruitment maneuver seems to offer a very promising method for fluid responsiveness prediction without the use and cost of a cardiac output measurement device.Trial registration: NCT04304521, IRBN902018/CHUSTERegistered 11 March 2020, Fluid responsiveness predicted by a stepwise PEEP elevation recruitment maneuver in mechanically ventilated patients (STEP-PEEP)https://www.clinicaltrials.gov/ct2/show/NCT04304521?term=NCT04304521&cntry=FR&draw=2&rank=1
Influence of Respiratory Rate on Stroke Volume Variation in Mechanically Ventilated Patients
