Passive Leg Raise and Mini-fluid Challenge Effect on Various Cardiac Output Surrogates Such as Pulse Pressure Variation (PPV), End-tidal CO2 (Carbon Dioxide), Bioreactance (Stroke Volume Index -SVI) and Velocity Time Integral on Echocardiographic Exam for Fluid Responsiveness in Patients With Moderately Severe ARDS (Acute Respiratory Distress Syndrome)
Trial Snapshot
- Phase
- Not Applicable
- Status
- Recruiting
- Sponsor
- CentraCare
- Enrollment
- 64
- Locations
- 1
- Primary Endpoint
- Vasopressor dose in Nor-epinephrine equivalents (NE) measured as mcg/kg/min
Study Overview
Brief Summary
In the critically ill population, fluid administration in an unstable patient is perhaps the most common intervention that is performed. Uncorrected hypovolemia with inappropriate vasopressors lead to organ hypoperfusion where as overzealous fluid administration especially in ARDS (Adult respiratory distress syndrome) can increase mortality. It has been estimated that only 50% of hemodynamically unstable critically ill patients are volume responsive, hence dynamic assessment of preload responsiveness has been proposed to better identify those individuals who would benefit from fluid bolus.
Detailed Description
Fluid responsiveness in patients with moderate to severe ARDS is crucial, as additional unnecessary fluid may be harmful. Various techniques of hemodynamic assessment exist, each with its own advantages and limitations. This study compares different techniques of preload responsiveness that include passive leg raise (PLR) and mini-fluid challenge induced changes in Pulse pressure variation (PPV), End tidal CO2, Bioreactance based Stroke volume index (SVI) and velocity time integral (VTI) on Echocardiogram.
Study protocol :
Baseline Echo with VTI will be obtained Bed side monitor will be set to display PPV and end tidal CO2 Baxter Starling system will be connected to the patient All baseline values will be recorded Tidal volume will be temporarily adjusted to 8 ml/kg , which will be reverted back to 6ml/kg after the measurements. This has proven to be a safe maneuver.
All the above hemodynamic assessments will be performed for eligible patients by measuring before and after PLR and repositioning to baseline. VTI will be estimated by bed side Echocardiogram. SVI will be estimated using the Starling system (Baxter). PPV and End tidal CO2 will be recorded from the bed side monitors.
Fluid responsiveness is presumed with a change in VTI of 10%. For these patients a mini-fluid challenge of 250 cc of crystalloids (NS, RL or Normosol) will be given over 10 min and PPV, VTI, End tidal CO2 and SVI will be recorded before and after fluid challenge. Patients with VTI change of < 10%, as non-responders, who will also be included in the analysis for assessment of reliability using the ROC curves. hemodynamic assessments and repeated fluid challenge will be considered as needed. Stability of vasopressor dose with maximum of 500 cc of crystalloid will be considered as positive fluid responder. This cohort of patients will be considered as gold standard for preload responsiveness and will be categorized based on a nominal scale. Patients who need higher vasopressor support despite 1L of crystalloid within 3 hours will be considered fluid non-responders.
Study Design
- Study Type
- Observational
- Observational Model
- Cohort
- Time Perspective
- Prospective
Eligibility Criteria
- Ages
- 30 Years to 90 Years (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •Age between 30 - 90 years
- •Diagnosis of Vasodilatory Shock with no other obvious cause of hypotension
- •Diagnosis of ARDS with PF ratio < 150 , PEEP > 8
- •Patients who are under paralysis or deeply sedated, on a mechanical ventilator
Exclusion Criteria
- •Patients with arrhythmias including atrial fibrillation
- •Patients with chest tube, intra-abdominal hypertension or with its risk factors
- •Patients with structural heart disease including pulmonary hypertension (RVSP > 45) and heart failure
- •Patients on extracorporeal support such as ECMO, CRRT or MCS.
- •Patients with COPD with a premorbid FEV1 < 1.5 L
- •Severe atherosclerotic vascular disease
Outcomes
Primary Outcomes
Vasopressor dose in Nor-epinephrine equivalents (NE) measured as mcg/kg/min
Time Frame: 3 hours after the initial passive leg raise
We shall assess the need for vasopressor dose e.g nor-epinephrine dose. If the dose remains constant after fluid bolus until 3 hours, we shall consider them fluid resposive. If the dose requirement goes up despite fluid bolus, we shall label them fluid un-responsive
Secondary Outcomes
No secondary outcomes reported
Investigators
Ramakanth Pata
Principal Investigator
CentraCare