Effects of Inspiratory Flow Waveforms on Preload

Cardiac Output, Low Clinical Trial

Official title:

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01892696
• Other study ID #: CvDVPPIVC
• Secondary ID: CvD1977
• Status: Completed
• Phase: N/A
• First received: June 26, 2013
• Last updated: November 7, 2016
• Start date: May 2013
• Est. completion date: August 2013

Study information

• Verified date: November 2016
• Source: Military Hospital of Tunis
• Contact: n/a
• Is FDA regulated: No
• Health authority: Tunisia:Military hospital of tunisTunisia: Office of Pharmacies and Medicines
• Study type: Interventional

Clinical Trial 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.

Description:

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).

Recruitment information / eligibility

• Status: Completed
• Enrollment: 60
• Est. completion date: August 2013
• Est. primary completion date: July 2013
• Accepts healthy volunteers: No
• Gender: Both
• Age group: N/A and older

Eligibility

Inclusion Criteria:

• mechanical ventilation

• Volume AssistControl Ventilation

• sinus rhythm

Exclusion Criteria:

• pressure mode

• arrhythmia

Study Design

Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Supportive Care

Related Conditions & MeSH terms

• Cardiac Output, Low
• Respiratory Aspiration

Intervention

Device:
• varying inspiratory flow waveforms
inspiratory flow waveform was changed, in a randomized sequence using a computer ,to one of the following modalities: 1) constant inspiratory flow; 2) decelerating inspiratory flow Each inspiratory flow waveform was maintained for 30 min. During the last 5 min of this period the physiological signals were collected and measures were performed.

Locations

Country	Name	City	State
Tunisia	Military hospital of tunis	Tunis	Mont Fleury

Sponsors (1)

Lead Sponsor	Collaborator
Military Hospital of Tunis

Country where clinical trial is conducted

Tunisia, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	change in pulse pressure variation (?PP) and distensibility index of the inferior vena cava (dIVC)when varying inspiratory flow waveforms	Each inspiratory flow waveform was maintained for 30 min with 60 minutes washout period	2h	No