Fluid Responsiveness Tested by the Effective Pulmonary Blood Flow During a Positive End-expiratory Trial

Study Overview
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Brief Summary
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Fluid responsiveness is difficult to assess at the bedside. The accuracy of published techniques to detect preload-dependent patients have many pitfalls and limitations. The present study test the role of noninvasive effective pulmonary blood flow measured by expired carbon dioxide to detect fluid responsivess in mechanically ventilated patients.

Detailed Description
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This is a prospective and observational study designed to test the accuracy of the non-invasive effective pulmonary blood flow measured by the capnodynamic methodology for detect preload-dependent patients. Fourty patients undergoing mechanical ventilation during surgery will be studied. Preload-depency (fluid responsiveness) will be tested during an increase in end-expiratory pressure (PEEP) from 5 to 10 cmH2O during one minute. Pulse pressure variation will be use as the reference method to detect preload-dependency. The effective pulmonary blood flow will be continuously recorded during the PEEP maneuver. Receiver Operator Curves will be used to detect fluid responsiveness taking a pulse pressure variation higher than 13%.The corresponding cut off value for the effective pulmonary blood flow signal will be determined..

Official Title
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The Reliability of Noninvasive Effective Pulmonary Blood Flow to Detect Fluid Responsiveness During a Positive End-expirator Trial in Ventilated Patients

Conditions
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Cardiovascular Diseases

Intervention / Treatment
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* Procedure: PEEP trial


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Written informed consent Programmed cardiac and noncardiac surgeries Need of invasive arterial blood pressure monitoring. Exclusion Criteria: Emergency surgeries. Acute pulmonary diseases Arrhytmias Congestive cardiac failure

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Patients undergoing surgeries<br>Patients undergoing surgery with general anesthesia and controlled mechanical ventilation with indication of invasive arterial blood pressure. Classification ASA 2-4 | Procedure: PEEP trial<br>* Positive end-expiratory pressure (PEEP) is increased from 5 to 10 cmH2O during one minute.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Fluid responsivess assessment with the effective pulmonary blood flow | Comparison between standard method (pulse pressure variation) with a new method of fluid responsiveness (Effective pulmonary blood flow). | 10 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Carbon dioxide, Pulmonary blood flow, Ventilation