Does using different techniques when sampling CBGs affect results?
Research type
Research Study
Full title
Estimating blood gas pressures from arterialised capillary blood using vasoactive cream and warming techniques: is there a difference?
IRAS ID
245389
Contact name
Blake Marsh
Contact email
Sponsor organisation
Oxford University Hospitals NHS Foundation Trust
Duration of Study in the UK
0 years, 5 months, 0 days
Research summary
Arterial blood gas analysis is a type of test that is regularly performed on patients with lung disease. It is used to measure the amount of oxygen and carbon dioxide in patients’ arterial blood.
There are several methods which can be used to obtain the blood required for a blood gas test. The ‘gold standard’ method is called an Arterial Blood Gas (ABG), and involves taking blood directly from an artery in the patient’s wrist. However, as this method has many risks associated with it, including infection and bleeding, Capillary Blood Gas (CBG) is often used instead. This involves taking blood from the small blood vessels, known as capillaries, in patients’ earlobes.
In order for CBGs to act as a good substitute for ABGs, it is important to first make the patient’s capillary blood reflect their arterial blood, so that there is very little difference in oxygen values between the two. This is known as ‘arterialising’ the capillaries, and can be achieved through two main techniques. The first technique involves applying a vasoactive cream, somewhat like Deep Heat, to the earlobe before sampling the blood. The other technique, however, involves heating the earlobe with warm water.
Currently, no research has been conducted to compare the ‘arterialisation abilities’ of the two techniques used in CBGs. Considering many clinical decisions are based on these tests results, including patient diagnoses and treatment plans, comparative research is invaluable. As such, this research study aims to assess whether these techniques result in a difference in the amount of oxygen measured in the blood, and whether one produces more accurate estimations of arterial blood gas values than the other. This will be achieved through performing both variants of CBG analysis on participants, and then comparing the results with those produced by an ABG.
REC name
London - Westminster Research Ethics Committee
REC reference
19/LO/0523
Date of REC Opinion
29 Mar 2019
REC opinion
Favourable Opinion