Abstract

Asthma is serious global health problem affecting all age groups with increasing prevalence in many countries. This main function of gas exchange and thus acid-base balance is affected by diseases of the lung. So it is expected that asthma also lead to respiratory acid-base disorders. In addition, the resulting hypoxemia can reduce tissue oxygenation causing lactic acidosis. Also chronic hypocapnia can lead to compensatory reduction in plasma bicarbonate resulting in metabolic acidosis. Thus functional compromise measurement reflects severity of that pathology and its outcome. Similarly measurement of blood oxygen, carbon dioxide and pH may help in assessing severity of respiratory pathology. So this prospective study was aimed to study arterial blood gas analysis with severity and outcome of asthma. 43 patients of asthma were selected randomly. During treatment of patient periodical ABG was tested to assess the management. We found that in asthma patient respiratory alkalosis i.e. hypocapnia (48.83%) was most common acid base abnormality followed by normal ABG (46.5%). Respiratory acidosis i.e. hypercapnia was seen only in 4.65%.patients. Hypercapnia and metabolic acidosis in asthma was associated with severity of disease. Significant fall in PaO₂ and increase in alveolar-arterial gradient is seen in very severe asthma. 

Keywords: Bronchial asthma, PaO₂, PaCO₂, pH value, arterial blood gases.