Slope of the Pressure-Time Waveform Predicts Resistance and Compliance in Mechanically Ventilated Subjects

NCT00750074 | Completed

• 1 other identifier: 200608720
• Study Type: observational
• Target: 12
• Locations: 1 country
• Sites: 1

Brief Summary

There are two fundamentally different ways to ventilate critically ill patients: constant flow, volume-preset modes (such as volume assist-control) and pressure-preset modes (such as pressure-control and pressure-support). Critically ill patients suffer mechanical derangements of the respiratory system that raise the work of breathing. Knowledge of these mechanical properties is useful diagnostically and as a measure of response to treatment over time. It has been proposed that only constant flow, volume-preset modes are able to offer diagnostic information about the changes in the subject's lungs in terms of resistance and elastance properties. This study proposes to examine if similar information can be extracted from pressure-preset modes by comparing information from both modes of ventilation.

Conditions

Respiration Disorders

Keywords

mechanical ventilation

Outcome Measures

Primary Outcomes (1)

• Outcome measure: resistance and compliance measured during pressure control versus volume control ventilation

  duration of study

Study Arms (1)

1

During volume assist-control ventilation, a 0.4 second end-inspiratory pause will be set and the following pressures measured: peak pressure; plateau pressure; and PEEP. The following ventilator settings will be recorded: inspiratory flow; expired tidal volume; and rate. The presence or absence of autoPEEP will be noted. During pressure-control ventilation, the flow versus time waveform will be printed from the ventilator using a conventional computer printer for later analysis. The following ventilator settings will be recorded: inspiratory pressure; PEEP; and expired tidal volume.

Eligibility Criteria

• Age: 18 Years - 99 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Probability Sample

Study Population

Inclusion Criteria Subjects may be included in the study if they meet the following inclusion criterion and no exclusion criteria: \[1\] Adult medical or surgical ICU patients who are mechanically ventilated. Using a random number generator each subject will be assigned to pressure control or volume control for initial set of measurements.

You may not qualify if:

• Adult medical or surgical ICU patients who are mechanically ventilated.
• Subjects with planned extubation at time of screening
• Subjects who are judged too hemodynamically unstable by their attending physician to participate in the study
• Subjects on high-frequency ventilation
• Subjects whose oxyhemoglobin saturation cannot be maintained at 88% or greater
• Subjects with large air leaks around the endotracheal or tracheostomy tube
• Subjects younger than 18 years old
• Inability to obtain informed consent from the subject or the subject's authorized representative

Sponsors & Collaborators

• Gregory A. Schmidt: lead

Study Sites (1)

Univesity of Iowa

Iowa City, Iowa, 52242, United States

Location

MeSH Terms

Conditions

Respiration Disorders

Condition Hierarchy (Ancestors)

Respiratory Tract Diseases

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Professor

Study Record Dates

• First Submitted: September 9, 2008
• First Posted: September 10, 2008
• Study Start: November 1, 2007
• Primary Completion: September 1, 2009
• Study Completion: October 1, 2010
• Last Updated: February 28, 2017

Record last verified: 2017-02

Locations

US (1)