Temperature in the stability of blood gases.

We read with interest in the April 1993 issue of Chest the artide by Liss and Payne’ on “Stability of Blood Gases in Ice and at Room Temperature.” Although some authors would agree that the small changes observed in Pco , and pH when the arterial blood samples were kept at room temperature make it unnecessary to maintain arterial blood in ice if gas analysis is done within 30 mm, several comments should be pointed out. In a previous paper,2 we analyzed the samples obtained from 23 patients breathing ambiental air and from 20 patients with chronic respiratory failure receiving supplementary oxygen to determine variations in the values of arterial blood gases depending on the preservation procedure and on the characteristics of the syringe used. Arterial blood from the same puncture was placed in glass and plastic syringes at room temperature and under ice. Samples were analyzed at baseline and after 15, 30, 60, and 120 mm. Because similar results were obtained in both groups, Figure 1 only shows changes observed in patients with chronic respiratory failure. From this data we can see thatsignificant changes