THE EFFECT OF A TIME-DELAY ON THE MEASUREMENT OF CAPILLARY BLOOD-GASES

Patients using domiciliary nasal ventilation, or long-term oxygen, req uire regular assessment which could be carried out in the home. Blood gas analysis may be regarded as an essential part of the assessment. T he present study investigated the effect of a 1-h time delay on the me asurement of capillary blood gases. Four samples of arterialized earlo be blood were collected from 15 outpatients. One sample was analysed i mmediately, the other three were stored on crushed ice and analysed at intervals of 30, 45, and 60 min post-collection. In order to examine any range effect, a wide range of PaO2 values were examined. The delay , at all levels, resulted in minor changes in the measurement of PaO2, which would be unlikely to alter clinical management. The technique m ight be used for the reliable assessment of patients in the home.