Abstract

We evaluated an incentive spirometer (IS) for monitoring changes in lung function in hospitalized patients. Accuracy and reproducibility of IS measurements of known volumes were adequate (r = 0.87). Flow dependency was demonstrated but was not significant in the clinically useful range. Reproducibility of IS measurements in five normal subjects was good, with a small training effect uncovered. In 15 patients with asthma and chronic obstructive lung disease, change in IS values closely correlated with spirometrically measured changes in volume and flows (best correlation: IS versus FEV1/FVC%, r = 0.98) and in peak flow. The performance of the IS as tested and its availability in most hospitals outweigh its limitations. We advocate its use as an adjunct in monitoring progress of hospitalized patients with obstructive lung disease.