Prospective randomized trial of silver nitrate vs talc slurry in pleurodesis for symptomatic malignant pleural effusions

Study objectives: To compare the efficacy and the safety of talc slurry and silver nitrate (SN) in the treatment of symptomatic malignant pleural effusions. Patients and methods: Sixty patients were enrolled into the study, and all received a chest tube (26F or 28F) that was placed using local anesthesia. The patients were randomized to receive either 5 g talc diluted to a total volume of 50 mL with saline solution or 20 mL 0.5% SN through the chest tube. Patients were clinically evaluated before and after treatment regarding pain, and were evaluated at monthly intervals with respect to the effectiveness of pleurodesis. Eleven patients did not return for their 30-day follow-up visit and were excluded from further analysis. Pleurodesis therapy was considered to be successful if there was no recurrence of the effusion. The patients who did not have a pleurodesis at one visit were excluded from subsequent visits. Results: Forty-nine patients returned at 30 days for follow-up, including 24 patients who received SN and 25 who received talc. The groups were similar in age (p = 0.23), sex (p = 0.70), Karnofsky index (p = 0.94), and pathology (p = 0.68). After the induction of pleurodesis, neither the total mean (+/- SE) fluid drainage (SN, 901 +/- 125 mL; talc, 766 +/- 74 mL; p = 0.36) nor the level of pain (SN, 2.58 +/- 0.26; talc, 2.62 +/- 0.30; p = 0.91) differed significantly between the groups, and no patient in either group developed ARDS. The mean number of days spent in the hospital was nearly identical (SN group, 3.7 +/- 0.15 days; talc group, 3.6 +/- 0.13 days; p = 0.47). Both SN and talc were effective agents. Thirty days after the procedure, 23 of 24 patients (96%) who had received SN and 21 of 25 patients (84%) who had received talc showed an effective pleurodesis (p = 0.35). Similar results were observed after 60 days (SN group, 18 of 18 patients [100%]; talc group, 13 of 13 patients [100%]; p = > 0.99), 90 days (SN group, 16 of 16 patients [100%]; talc, 8 of 9 patients [89%]; p = 0.36), and 120 days (SN group, 4 of 4 patients [100%]; talc group, 4 of 4 patients [100%]; p > 0.99). Conclusions: The present study suggests that SN is an effective agent for producing a pleurodesis. In the present study, SN showed a tendency to be more effective than talc, but the power of the test to detect a significance difference was low in this small group of patients. The side effects of 0.5% SN appear to be minimal, but since only a small number of patients received SN and nearly 20% of the patients were lost to follow-up, significant long-term side effects cannot be excluded. Since SN appears to be as effective as talc, and since there is no evidence that it induces ARDS as has been reported with talc, it should be considered as an alternative to talc for the production of a pleurodesis.