The Distribution of Pressure in the Thorax During Mechanical Ventilation and Its Effects on the Circulation

Not Applicable

• Conditions: Fluid Responsiveness
• Interventions: Other: ventilatory protocol; Other: Elastic band; Other: passive leg raising test

• Registration Number: NCT01113073
• Lead Sponsor: Radboud University Medical Center

Brief Summary

Fluid administration is a daily intervention on the intensive care unit to improve cardiac output (CO) and stabilize circulation in critically ill patients. Simultaneously, the volume status of the patient is very difficult to assess. Too little volume leads to inadequate organ perfusion followed by ischemia and organ failure. Too much volume may worsen heart failure and cause pulmonary and peripheral edema and contribute to further tissue injury and organ dysfunction. Although dynamic indices have been shown to be more accurate predictors of fluid responsiveness, this relevant and complex task is usually guided by static clinical variables and the specialist's interpretation due to the fact that the interpretation of dynamic parameters is not fully developed and that they are not universally available. This lack of understanding is partially because of the complex interaction with mechanical ventilation. The investigators hypothesize that knowing the distribution of ventilatory pressures will make it possible to index dynamic parameters to tidal volume and improve their predictive value concerning the volume status of the patient. In addition, it would be of interest to be able to predict fluid responsiveness in a non-invasive way, especially in critically ill patients. Up to now, continuous non-invasive cardiac output monitoring using Nexfin in critically ill patients has not been validated and also not tested for its ability to predict fluid responsiveness. The present research proposal evaluates the possibility and accuracy of the model flow analysis obtained by non-invasive finger arterial pressure measurements to determine fluid responsiveness using passive leg raising. It will also be compared to a more invasive method (that is currently used in the clinic) to assess its ability to measure absolute CO levels accurately. It may make it possible to assess fluid responsiveness in a non-invasive and patient friendly way.

Detailed Description

Not available

Study Timeline

• Status Verified: 2010-01
• Study Start: 2010-01
• Study First Submitted: 2010-04-22
• Study First Submitted QC: 2010-04-28
• Study First Posted: 2010-04-29
• Last Update Submitted: 2010-08-30
• Last Update Posted: 2010-08-31
• Primary Completion: 2010-09
• Study Completion: 2010-09

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 20

Inclusion Criteria

• Elective open heart surgery.

Exclusion Criteria

• Significant cardiac arrhythmias, including atrial fibrillation.
• Hemodynamical instability, as defined by a variation in heart rate, blood pressure and cardiac output of more than 10% during the 15-min period before starting the protocol.
• Recent myocardial infarction (< 3 mnd, troponine > 50 ug/l).

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Elective open heart surgery	ventilatory protocol	Patients who had undergone elective open heart surgery
Elective open heart surgery	Elastic band	Patients who had undergone elective open heart surgery
Elective open heart surgery	passive leg raising test	Patients who had undergone elective open heart surgery

Primary Outcome Measures

Name	Time	Method
fluid responsiveness	30 minutes around fluid challenge	pulse pressure variation (PPV), systolic pressure variation (SPV), stroke volume variation (SVV), pre-ejection period variation (dPEP)

Secondary Outcome Measures

Name	Time	Method
Pressure distribution in thorax due to mechanical ventilation	30 minutes of varying tidal volumes	mechanical ventilation with 4 different tidal volumes and decreased chest compliance
Dynamic indices in pressure support ventilation	30 minutes of pressure support
non invasive prediction of fluid responsiveness	30 minutes around fluid challenge	pulse contour analysis of cardiac output with finger cuff combined with passive leg raising test
pressure distribution and dynamic indices during spontaneous breathing	5 minutes of spontaneous breathing

Trial Locations

Locations (1)

Radboud University Nijmegen Medical Centre; 🇳🇱 Nijmegen, Netherlands