Assessing Gas Exchange in Intensive Care Patients on a Ventilator

NCT02599350 | Completed

• 1 other identifier: 09/MRE00/32
• Study Type: observational
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

In an attempt to standardise the degree of impairment of gas exchange in the lungs of ICU patients a number of indices of oxygen exchange have been developed. These include: the arterial-alveolar oxygen tension ratio (a/APO2), the arterial oxygen tension-inspired oxygen concentration ratio (PaO2/FIO2), the respiratory index (RI), \[A-a)DO2/PaO2) and the alveolar-arterial oxygen tension difference \[A-a)DO2). These are used clinically despite the fact that they do not accurately predict gas exchange particularly with changing the amount of inspired oxygen or when there is mixing of oxygenated blood with unoxygenated blood in the patient (called shunt). None of the indices reliably reflect the behaviour of the physiological shunt. In a pilot study as inspired oxygen (FIO2) was increased incrementally from 0.30 to 1.00, up to 55 per cent of the measured changes in these indices were opposite in direction to the corresponding changes in the physiological shunt. The investigators have developed a computer algorithm and a slide rule to try and improve on these clinical measures. The investigators wish to test their slide rule on ventilated patients by altering the inspired oxygen to see if it will predict what the actual change in oxygen will be.

Conditions

Mechanical Ventilation Complication

Keywords

Ventilation; Gas exchange; V/Q ratio; Requirement for mechanical ventilation

Study Arms (1)

1

Patients receiving mechanical ventilation

Eligibility Criteria

• Age: 16 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)
• Sampling Method: Probability Sample

Study Population

30 adult patients admitted to Aberdeen Royal Infirmary ICU, requiring invasive mechanical ventilation and with impaired gas exchange will be recruited.

You may qualify if:

• FIO2 on enrollment = 0.4-0.6, PEEP 5cm H2O, "Stable" respiratory failure - same or less FIO2 for 2 hours prior to enrollment.

You may not qualify if:

• Age \< 16 years
• Pregnancy
• Known intracranial disease
• Prone position
• Nitric oxide therapy
• Pneumothorax/bronchopleural fistula/intercostal drain in situ
• Severe respiratory failure (FIO2 0.7), OR
• Severe haemodynamic instability (escalating inotrope requirements, fluid resuscitation \> 1 litre/hour in 2 hours prior to commencing intervention, mean arterial blood pressure \< 65 mmHg).

Sponsors & Collaborators

• University of Aberdeen: lead

Study Sites (1)

Aberdeen Royal Infirmary

Aberdeen, Aberdeenshire, AB25 2ZD, United Kingdom

Location

MeSH Terms

Conditions

Respiratory Aspiration

Condition Hierarchy (Ancestors)

Respiration Disorders; Respiratory Tract Diseases; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Study Officials

• Nigel R Webster, MB PhD

  University of Aberdeen

  PRINCIPAL INVESTIGATOR

Study Design

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

Study Record Dates

• First Submitted: April 30, 2009
• First Posted: November 6, 2015
• Study Start: May 1, 2009
• Primary Completion: July 1, 2012
• Study Completion: August 1, 2012
• Last Updated: November 6, 2015

Record last verified: 2015-11

Locations

GB (1)