UPPER AND MIDDLE LOBE BRONCHOALVEOLAR LAVAGE TO DIAGNOSE PNEUMOCYSTIS-CARINII PNEUMONIA

Pneumocystis carinii pneumonia (PCP) remains the most common lethal op portunistic pulmonary infection in patients infected with the human im munodeficiency virus (HIV). Although the use of prophylactic inhaled p entamidine has effectively reduced the frequency of primary and recurr ent episodes of PCP, the aerosolization of pentamidine may have altere d the localization of active PCP, resulting in more upper lobe disease . The distribution of disease may have also affected the diagnostic ac curacy of standard bronchoalveolar lavage of the middle lobe, with a r eduction in sensitivity from about 90 to 65%. In retrospective surveys of patients from our institution, Steiger and Fahy found that pooled multiple-robe radiographic site-directed bronchoalveolar lavage result ed in diagnostic sensitivities of 91 and 100%, respectively. We perfor med a follow-up prospective study of 38 consecutive patients on aeroso lized pentamidine in whom we lavaged both the middle lobe and an upper lobe. We found that bilobar lavage including routine lavage of an upp er lobe increases the diagnostic sensitivity of bronchoalveolar lavage alone to 95% compared with 65% if lavage is performed only in the mid dle lobe (p < 0.05). Radiographic studies demonstrate a concordant inc rease in exclusive or predominant upper lobe disease in patients on ae rosolized pentamidine, but our results indicate that PCP is recovered more frequently from the upper lobe regardless of the radiographic app earance. We conclude that all patients on prophylactic inhaled pentami dine should undergo bilobar lavage with the inclusion of an upper lobe in the initial evaluation of possible PCP. The diagnostic sensitivity of 95% makes bilobar bronchoalveolar ravage an acceptable sole initia l diagnostic modality without the need for initial transbronchial lung biopsy.