Needle aspiration of the lung in complex pneumonias.

In 39 patients with treated unresponsive pneumonia complicated by life-threatening underlying disease, direct needle aspiration of the lung was performed to establish a cause. An infectious agent was detected in 18 patients (46 percent), a nonbacterial cause was found in one, and cure of a recent infection was substantiated in six patients. An incorrect diagnosis was made in seven patients (one false-positive and six false-negative), and an indeterminant answer was obtained by needle aspiration in seven. Serious complications occurred in 11 patients, most commonly in those who had hypoxia or thrombocytopenia, but no morbidity occurred in 22 patients. The diagnostic yield allowed effective rational therapy to be selected for multiple potential pathogens in 12 patients and detected pathogens not suspected in six instances. The technique compares favorably to other invasive techniques for establishing definitive information in this group of seriously ill patients.