Pre morbid severity of chronic obstructive pulmonary disease as risk factor for carbon dioxide retention during acute exacerbation of chronic obstructive pulmonary disease

This was a case control study done in patients admitted with acute exacerbation of chronic obstructive pulmonary disease (COPD). Patients were grouped into categories, depending upon the arterial blood gas analysis. 30patients with carbon dioxide retention Paco₂ level >46mmHg which was not a compensation for metabolic alkalosis were classified as cases. 30 patients without carbon dioxide retentionPaco₂ level <46mmHg were classified as controls. Pre morbid severity of COPD as per GOLD 2010 was compared between the two groups as risk factor for carbon dioxide retention. The data was entered into the Microsoft Office Excel 2007 and odds ratio was calculated. Patients with severe and very severe COPD showed a risk of having carbon dioxide retention 116 times that of patient with mild and moderate COPD. 50% of cases were in 61-70 years age group. Patients with severe and very severe COPD have a greater risk of carbon dioxide retention during acute exacerbation than patients with mild and moderate COPD. Patients with severe and very severe COPD develop skeletal muscle wasting and skeletal muscle dysfunction, malnutrition, hyperinflation of lungs with poor diaphragm contractility. All these lead to hypoventilation and carbon dioxide retention during acute exacerbation of COPD when ventialtory demand increases.