None listed
Conditions
Brief summary
The proper infusion of fluids is a challenge in critically ill patients undergoing partial support ventilation. The clinically used indexes for fluid-responsiveness are affected by several limitations. In the present study we hypothesized and aim to verify if the application of incremental values of positive airway pressures are able to predict the fluid responsiveness in patients with clinical signs of fluid repletion and undergoing Pressure Support Ventilation.
Interventions
Patients will be monitored with a monitor for hemodynamic assesment (Most Care, Vytech Health, Padova, Italy), which uses a Pressure Recording Analytical Method (PRAM).
PRAM is a method designed for arterial pressure-derived continuous Cardiac Output and it is the only methodology that does not need any starting calibration, central venous catheterization, or any adjustments based on experimental data. As a consequence, PRAM needs only an arterial line (radial, brachial, femoral) for working.
Patients will be monitored with a monitor for hemodynamic assesment (Most Care, Vytech Health, Padova, Italy), which uses a Pressure Recording Analytical Method (PRAM). PRAM is a method designed for arterial pressure-derived continuous Cardiac Output and it is the only methodology that does not need any starting calibration, central venous catheterization, or any adjustments based on experimental data. As a consequence, PRAM needs only an arterial line (radial, brachial, femoral) for working. When the patient has been monitored with Most Care device, baseline data will be acquired for 2 minutes. Afterwards, incremental values (15, 25 and 35 cmH2O) of positive airway pressure will be applied for a short period of 4 seconds in a random order. Between each single trial of incremental pressures, a return to baseline conditions will be guarantee for 3 minutes, to avoid carry-over effects. In the end, a fluid challenge of 500 ml of normal saline will be infused in 5 minutes and the hemodynamic response will be evaluted to define if the patient is fluid responsive or not (i.e. if the cardiac index incremented of 15% at least, or not). Furthermore, in the first 10 consecutive patients, we will insert a catheter able to measure the esophageal pressure to properly assess the incidence of inspiratory effort during each single trial of incremental pressures (i.e. 15, 25 and 35 cmH2O randomly applied for a short period of 4 seconds).
Sponsors
Federico Longhini MD
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Diagnosis
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
All patients > 18 years/old undergoing invasive mechanical ventilation in Pressure Support mode (se with a positive end-expiratory pressure between 4 and 6 cmH2O and a Pressure Support betweeen 8 and 12 cmH2O), with a clinical need for fluid infusion, i.e. systolic arterial blood pressure < 90 mmHg or 50 mmHg reduction of values in patients with chronic hypertension, oliguria as defined by a diuresis < 0.5 ml/kg/h, need for inotropes, lactate > 2 mmol/L.
Exclusion criteria
Patients will be excluded if meeting one or more off the following criteria: 1) cardiac arrhythmia; 2) atrial fibrillation or flutter; 3) patients undergoing any form of renal replacement therapy; 4) valvular defects of moderate to severe grade; 5) history of congestive cardiac failure; 6) previous or presence of pneumothorax or emphysema; 7) patients with Chronic Obstructive Pulmonary Disease (COPD); 8) patients with kyphoscoliosis; 9) use of expiratory muscles and 10) arterial partial pressure to inspired fraction of oxygen (PaO2/FiO2) ratio < 200.
Outcome results
None listed