Effects of Inspiration Rise Time on Work of Breathing and Comfort of Conscious Patients on Mechanical Ventilation

Mechanical Ventilation Clinical Trial

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00294879
• Other study ID #: LBCH 0601
• Status: Completed
• Phase: N/A
• First received: February 21, 2006
• Last updated: May 30, 2008
• Start date: February 2006
• Est. completion date: March 2008

Study information

• Verified date: May 2008
• Source: Radboud University
• Contact: n/a
• Is FDA regulated: No
• Health authority: Netherlands: The Central Committee on Research Involving Human Subjects (CCMO)
• Study type: Interventional

Clinical Trial Summary

Introduction Pressure Support Ventilation is widely used in patients in the ICU. Matching the patient's respiratory needs with adequate ventilator settings is necessary to ensure a low work of breathing (WOB) and maximal patient comfort. The inspiratory rise time (IRT) determines the time to reach the selected airway pressure. A short IRT results in a high peak inspiratory flow and a short time to reach that peak, but is also associated with the development of turbulent flow, resulting in increased WOB. Aim of this study is to investigate the effects of different IRT settings on WOB and patient comfort during pressure support ventilation.

Methods We will performed a prospective, single blind cohort study in patients on Pressure Support Ventilation. 10 healthy adult patients admitted to the ICU after elective facial or neck surgery will be included. All patients will be ventilated in pressure support mode using a Servo 300 ventilator (Siemens. Elema, Solna, Sweden), with a positive end expiratory pressure of 5 cm H2O, pressure support level of 12 cm H2O above PEEP and an inspiratory oxygen fraction of 0.40. Patients have to be awake and cooperative (Ramsay 2). WOB will be measured with an esophageal balloon, and miniature flowmeter (Bicore system). Breathing comfort will be evaluated using a visual analogue scale (VAS) ranging from 1 to 10. WOB and patient comfort will be measured (in random order) at 0, 5, and 10% IRT. For statistical analysis the two-way analysis of variance will used. A p value of < 0.05 will be considered statistically significant.

Description:

Introduction Pressure Support Ventilation is widely used in patients in the ICU. Matching the patient's respiratory needs with adequate ventilator settings is necessary to ensure a low work of breathing (WOB) and maximal patient comfort. The inspiratory rise time (IRT) determines the time to reach the selected airway pressure. A short IRT results in a high peak inspiratory flow and a short time to reach that peak, but is also associated with the development of turbulent flow, resulting in increased WOB. Aim of this study is to investigate the effects of different IRT settings on WOB and patient comfort during pressure support ventilation.

Methods We will performed a prospective, single blind cohort study in patients on Pressure Support Ventilation. 10 healthy adult patients admitted to the ICU after elective facial or neck surgery will be included. All patients will be ventilated in pressure support mode using a Servo 300 ventilator (Siemens. Elema, Solna, Sweden), with a positive end expiratory pressure of 5 cm H2O, pressure support level of 12 cm H2O above PEEP and an inspiratory oxygen fraction of 0.40. Patients have to be awake and cooperative (Ramsay 2). WOB will be measured with an esophageal balloon, and miniature flowmeter (Bicore system). Breathing comfort will be evaluated using a visual analogue scale (VAS) ranging from 1 to 10. WOB and patient comfort will be measured (in random order) at 0, 5, and 10% IRT. For statistical analysis the two-way analysis of variance will used. A p value of < 0.05 will be considered statistically significant.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 10
• Est. completion date: March 2008
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• awake and cooperative patient

• ICU admission following surgery of head or neck

Exclusion Criteria:

• coagulopathy

• inability to sit

• hypoxemia and/or hypercapnia and /or hypocapnia

• Pain score > 5 (on scale 1-10)

• esophageal abnormalities

• Pregnancy

• COPD

Study Design

Allocation: Randomized, Intervention Model: Crossover Assignment, Masking: Single Blind

Related Conditions & MeSH terms

• Mechanical Ventilation

Intervention

Procedure:
• pressure support ventilation at 0, 5, and 10% IRT

Locations

Country	Name	City	State
Netherlands	Radboud University Nijmegen Medical Centre	Nijmegen

Sponsors (1)

Lead Sponsor	Collaborator
Radboud University

Country where clinical trial is conducted

Netherlands, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Work of breathing
Secondary	patient comfort