Test of Ventricular Stimulation as Immediate Predictor of Hypovolemia After Cardiac Surgery: Non-randomized Open Label Trial.
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- Enrollment
- 30
- Locations
- 2
- Primary Endpoint
- Evaluate the correlation between thes stimulation test and the cardiac output
Study Overview
Brief Summary
The purpose of the study is to validate a ventricular pacing test as a predictor of preload dependency in post cardiac surgery patients.
Detailed Description
In the immediate postoperative period of cardiac surgery and in intensive care unit (ICU), a systemic arterial hypotension is frequently observed. This hypotension is often due to hypovolemia but also to pump dysfunction and/or vasoplegia. Early recognition of the hypotensive mechanism is necessary because it requires immediate specific treatment.
The interest of a vascular filling is usually estimated by a preload dependence test (fluid responsiveness), showing an increase in the stroke volume when preload is increased according to the Starling the law of the heart. To date, a preload dependency test is usually performed by passive leg raise (PLR) or by measuring the respiratory pulse variation (ΔPP).
The PLR response varies according to the legs venous volume and capacitance. The derivation of ΔPP has been validated in patients intubated, sedated, and ventilated in standard conditions, in sinus rhythm but the ΔPP directly displayed by the monitors is unreliable and the manual calculation on pressure curve is fastidious. Faced with these difficulties, the trend is to realize a blind filling with physiologic saline solution and to judge his interest on clinical and / or hemodynamic criteria.
After cardiac surgery, ventricular epicardial electrodes are systematically placed allowing a temporary stimulation by an external pacemaker in case of postoperative atrio-ventricular blocks. The ventricular stimulation without atrial pacing (VESAP) leads to a loss of the atrial systole and therefore a decrease in the left ventricular preload. During the functional test of epicardial electrodes at a frequency greater than the patient's, it is possible to observe in certain circumstances a decrease of the arterial blood pressure, but of varying importance.
The investigators suspect that the eventual fall in blood pressure during a ventricular pacing test, could be correlated with preload dependence. Therefore, investigator hypothesize that ventricular pacing can be used to realize a functional testing of preload dependence, easy to achieve. Indeed, if doctors admit that during a brief ventricular stimulation, heart rate and systemic vascular resistance remain unchanged, the drop in blood pressure should reflect the decrease in stroke volume.
Study Design
- Study Type
- Interventional
- Allocation
- Na
- Intervention Model
- Single Group
- Primary Purpose
- Diagnostic
- Masking
- None
Eligibility Criteria
- Ages
- 18 Years to — (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •Over 18 years old,
- •Programmed for cardiac surgery with the need for invasive hemodynamic monitoring (pulmonary artery catheter) according to the recommendations:
- •Euroscore with predicted mortality> 10%
- •Left ventricular ejection fraction (LVEF) <40%
- •Left ventricular ejection fraction (LVEF) <50% for mitral insufficiency
- •pulmonary artery hypertension (PAH)> 50 mmHg
- •Tricuspid insufficiency> 3.4 m / s
- •Tricuspid annular plane systolic excursion (TAPSE) <16 mm
- •Dilatation of the inferior vena cava under respiratory collapse
- •Sinus rhythm in immediate postoperative period,
- •Sedated with mechanical ventilation,
- •Having given their written participation consent in accordance with the regulations,
- •Benefiting from a social security
Exclusion Criteria
- •Pregnant or lactating women,
- •Patient under guardianship, Under curatorship or court of justice,
- •Discomfort to communication or neuropsychic disorders,Inability to understand, to read or to write the French language,
- •Patients for whom a fluids overload seems obvious to the intensivist and for whom a crystalloids filling would be contraindicated,
- •Patients for whom respiratory changes in pulse pressure (ΔPP) measurement is not validated: patients with spontaneous ventilation, atrial fibrillation, non-sedated
Outcomes
Primary Outcomes
Evaluate the correlation between thes stimulation test and the cardiac output
Time Frame: 1 hour
Measure the cardiac flow before and after the VESAP, and after an infusion of 500 cc of crystalloid solution.
Secondary Outcomes
- Collection of the possible complications due to the VESAP(2 hours and 24 hours)
- Look for pertinent VESAP threshold in correlation with the expected increase in stroke volume(1 hour)
- Evaluate the correlation between the VESAP and the ΔP(1 hour)