Clinical Trial: Effects of Inspiratory Flow Waveforms on Preload

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: Arterial Pulse Pressure Variation and Inferior Vena Cava Distensibility Affected by Inspiratory Flow Waveforms in Mechanically Ventilated Patients: Time for a Change

Brief Summary: The clinical usefulness of inspiratory flow pattern manipulation during mechanical ventilation remains unclear. The aim of this study was to investigate the effects of different inspiratory flow waveforms, i.e. constant and decelerating, on cardiac preload in mechanically ventilated patients assessed by arterial pulse pressure variation (PPV) and inferior vena cava distensibility.

Detailed Summary: During mechanical ventilation the lungs can be inflated with different pressure and flow waveforms. Originally the piston-driven mechanical ventilators generated a quasi-sinusoidal flow waveform, whereas the newer electronically controlled ventilators can also produce constant and decelerating waveforms. According to several theoretical,animal and clinical studies,the inspiratory flow waveform affects the distribution of the inspired gas as well as respiratory mechanics and gas exchange. However, other studies failed to show any significant effect.But there is no study interested to the effects of inspiratory flow waveforms on cardiac preload. Thus, the clinical usefulness of inspiratory flow pattern manipulation remains unclear, though the capacity for selection of different inspiratory flow waveforms is provided by most modern, microprocessor-equipped ventilators. Therefore, the purpose of this study was to compare the effects of flow patterns (sinusoidal, constant and decelerating) on dynamic measurements of cardiac preload dependence such as arterial pulse pressure variation (ΔPP) and distensibility index of the inferior vena cava (dIVC).
Sponsor: Military Hospital of Tunis

Current Primary Outcome: change in pulse pressure variation (ΔPP) and distensibility index of the inferior vena cava (dIVC)when varying inspiratory flow waveforms [ Time Frame: 2h ]

Each inspiratory flow waveform was maintained for 30 min with 60 minutes washout period


Original Primary Outcome: Same as current

Current Secondary Outcome:

Original Secondary Outcome:

Information By: Military Hospital of Tunis

Dates:
Date Received: June 26, 2013
Date Started: May 2013
Date Completion:
Last Updated: November 7, 2016
Last Verified: November 2016