The primary purpose of this study is to determinate the degree of chest pain on patients with malignant pleural effusion submitted to pleurodesis with silver nitrate in three different dosages and concentrations ( 30ml 0.5% ; 30ml 0.3% ; 60ml 0.3%). Our secondary purpose is to evaluate the efficacy and occurence of adverse effects in the usage of silver nitrate for pleurodesis in the aforementioned dosages/concentrations.

Malignant pleural effusion is a frequent complication in advanced neoplasia. Pleurodesis is the procedure of choice for symptomatic control, with talc as the sclerosing agent of choice. However, the occurrence of severe adverse effects associated with its use has led to the search for other agents.

Silver nitrate poses an option, presenting excellent results in animal models and having successful usage in pleurodesis in the past. Although important, the current literature on the effective use of silver nitrate for pleurodesis is still too scarce, and a deeper knowledge on the occurrence of adverse side effects, especially pain, is still necessary to allow the substance to be considered as an effective alternative to talc, as well as for the definition of an adequate dosage.

Inclusion Criteria:

• Malignant pleural effusion confirmed by cytologic analysis of the fluid and/or pleural biopsy.
• Recurrent and symptomatic malignant pleural effusion.
• Full pulmonary expansion (>90%) post thoracocentesis, confirmed via chest x-ray.
• Karnofsky Performance Status >30
• Agreement to participate of the study by signing of the Informed Consent Term.

Exclusion Criteria:

• Coagulopathies (prothrombin activity <50%) and/or thrombocytopenia (<80000 count).
• Active pleural or systemic infection.
• Massive skin neoplastic infiltration.
• Inability of understanding the pain scale.
• Previous pleural procedures (except for thoracocentesis and/or pleural biopsy).
• Refusal to participate of the study.