Malignant Pleural Effusions
The estimated annual incidence of malignant pleural effusions in the United States is 150,000 cases. Patients most commonly present with dyspnea, initially on exertion and later at rest. Chemical pleurodesis is the most common modality of therapy for patients with recurrent, symptomatic, malignant pleural effusion. Talc is the most successful pleurodesis agent, and talc poudrage and slurry have equal efficacy. Although a number of cases of acute respiratory failure have been associated with talc pleurodesis, the incidence is < 1% and many of these episodes cannot be clearly attributed to talc alone. Although a low pleural fluid pH is associated with a decreased survival and less successful pleurodesis, pH should not be the sole criterion for recommending or withholding pleurodesis. Other factors that need to be considered before recommending pleurodesis include relief of dyspnea after therapeutic thoracentesis, general health of the patient, performance status, presence of trapped lung, and the primary malignancy. Pleuroperitoneal shunt or chronic indwelling catheter should be considered for patients who fail pleurodesis or who have a trapped lung.

Objectives. Upon completion of this article, the reader should understand the pathogenesis of malignant pleural effusions, the most common causes of malignant pleural effusions, the poor prognosis of these patients, and the therapeutic options that are available for palliation. The reader will also be able to appreciate the importance of trapped lung and have a better understanding about acute respiratory failure associated with talc pleurodesis.

Accreditation. The University of Michigan is accredited by the Accreditation Council for Continuing Medical Education to sponsor continuing medical education for physicians.

Credits. The University of Michigan designates this educational activity for a maximum of 1.0 hour in category one credits toward the AMA Physicians Recognition Award.

Malignant pleural effusions are an important cause of morbidity for the 150,000 patients in the United States who are inflicted with this advanced stage of their illness. It is likely that the incidence of malignant pleural effusions will increase over the next decade due to the virtual epidemic of lung and breast cancer. Malignant pleural effusions remain a therapeutic challenge to the pulmonologist and oncologist. The primary goal of palliation for these patients is relief of dyspnea. Decisions regarding palliative treatment should be determined following a careful, global evaluation of the patient and should not be based on a single factor. This article focuses on the treatment of these patients, and discusses the available therapeutic options and the factors that require consideration before offering palliation.