Inverse correlation of expiratory lung flows and sputum eosinophils in status asthmaticus

Seventy-six consecutive patients admitted to Los Angeles County General Hospital with acute asthma were studied. Blood and sputum smears for cell counts were obtained on all patients within 12 hours of admission. Fifty-one (67%) patients were able or willing to perform spirometry and flow/volume curves in the first 24 hours of hospitalization. The severity of airway obstruction as assessed by forced expiratory volume in one second (FEV1), maximum mid-expiratory flow rate (MMFR), and forced vital capacity (FVC) was compared with blood and sputum eosinophil counts. Although there was no relation between the blood eosinophilia and airway obstruction, an inverse relationship between the number of eosinophils in the sputum and airway flow rates was observed. Higher percentages of sputum eosinophils were associated with diminished flow rates. We believe that sputum eosinophils may be helpful in the initial assessment of severe bronchial asthma.