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

Sponsor
Radboud University Medical Center (Other)
Overall Status
Completed
CT.gov ID
NCT00294879
Collaborator
(none)
10
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Study Details

Study Description

Brief 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.

Condition or Disease Intervention/Treatment Phase
  • Procedure: pressure support ventilation at 0, 5, and 10% IRT
N/A

Detailed 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.

Study Design

Study Type:
Interventional
Anticipated Enrollment :
10 participants
Allocation:
Randomized
Intervention Model:
Crossover Assignment
Masking:
Single
Study Start Date :
Feb 1, 2006
Actual Study Completion Date :
Mar 1, 2008

Outcome Measures

Primary Outcome Measures

  1. Work of breathing []

Secondary Outcome Measures

  1. patient comfort []

Eligibility Criteria

Criteria

Ages Eligible for Study:
18 Years and Older
Sexes Eligible for Study:
All
Accepts Healthy Volunteers:
No
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

Contacts and Locations

Locations

Site City State Country Postal Code
1 Radboud University Nijmegen Medical Centre Nijmegen Netherlands 6500 HB

Sponsors and Collaborators

  • Radboud University Medical Center

Investigators

  • Principal Investigator: Cornelia WE Hoedemaekers, MD PhD, Radboud University Medical Center

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.
Responsible Party:
, ,
ClinicalTrials.gov Identifier:
NCT00294879
Other Study ID Numbers:
  • LBCH 0601
First Posted:
Feb 22, 2006
Last Update Posted:
Jun 2, 2008
Last Verified:
May 1, 2008

Study Results

No Results Posted as of Jun 2, 2008