Arterial Blood Gas Analysis in Acute and Chronic Bronchial Asthma

Arterial blood gas sampling is a very important investigation in the assessment of a patient’s acidbase status and oxygenation in acute and chronic bronchial asthma. It is the gold standard test which measures amounts of oxygen and carbon dioxide as well as the pH of the blood while it also evaluates the effective delivery of oxygen to the blood by the lungs and effective elimination of the carbon dioxide by the lungs. Arterial blood gas analysis is done using a Blood gas analyzer with the blood sample (2 ml heparinized) drawn from the radial or ulnar arteries. The results are obtained within 125 seconds. The present study conducted on 40 patients aims at assessing the blood gas status in individuals with acute and chronic bronchial asthma. The cumulative analysis of all the three parameters considered in this study show a significant variation in pH between acute and chronic asthma with a P value <0.001, a significant variation in PaCO2 with a P value <0.001 showing a tendency to hypercapnoea in severe acute asthma and with a tendency towards hypocapnoea in chronic bronchial asthma. There are very few studies on chronic bronchial asthma. A comparison between severe acute and chronic bronchial asthma showed a variable pH in acute cases depending on the severity of the airways obstruction, showing cases of both respiratory acidosis and alkalosis. While in chronic bronchial asthma the pH was within a narrow range with no cases of acidosis and a moderate number of cases showing respiratory alkalosis.