Cardiopulmonary function in pectus excavatum.

Abstract

The results of recent studies clearly support a cardiopulmonary impairment resulting from pectus excavatum, but resolving the apparent discrepancies between studies is necessary. Several factors must be taken into consideration. The severity of the deformity of the chest wall must be defined, whether by the sternovertebral distance or by various means proposed by others. Without some index of the degree of sternal depression, it is impossible to compare patients or results among studies. No study has enrolled a sufficient number of patients to provide an accurate correlation between the severity of the deformity and the extent of the cardiopulmonary deficit, nor has any defined how severe the deformity must be to result in cardiopulmonary dysfunction. The second factor that is important in evaluating results is what controls were used. Studies in which each patient functioned as his own control after surgical repair are preferable. In the pediatric age group where growth and increased pulmonary parameters would be expected, the follow-up studies should be performed at a defined time after surgical treatment. Studies completed years later cannot assess the effect of surgical repair upon cardiopulmonary function. Studies wherein persons matched for age and height to serve as controls are available from the same laboratory are also needed. The degree of co-operation and effort of patients will vary, particularly in the pediatric age group. Constancy of the experimental protocol and personnel is important. Least reliable are reports of experimental findings compared with standardized normal values. In early studies, measurements of vital capacity and total lung capacity produced variable results when compared with normal persons matched for age. The wide range of "normal values" makes statistical comparison difficult, if not impossible. A wide spectrum of cardiopulmonary function exists among individuals, depending upon prior physical training and body habitus. Sufficient physiologic reserve is generally present, such that extensive impairment must exist before patients become symptomatic at rest. Physiologic reserve during exercise is rapidly consumed and differences can be more readily determined. Exercise studies must go beyond the measurement of intracardiac pressures and pulmonary volumes at rest.(ABSTRACT TRUNCATED AT 250 WORDS)