Safety and systemic consequences of pleurodesis with three different doses of silver nitrate in patients with malignant pleural effusion.

BACKGROUND Silver nitrate (SN) is an alternative to talc pleurodesis in patients with malignant pleural effusion (MPE). Nevertheless, SN complications have not been thoroughly investigated so far. OBJECTIVE To evaluate frequent adverse events (AE) of SN treatment at three different doses for pleurodesis in patients with MPE. The secondary objective was to evaluate systemic inflammation, efficacy and quality of life in these patients. METHODS A double-blind, randomized, clinical trial was conducted in patients with recurrent MPE at a tertiary university hospital. The study patients underwent pleural catheter insertion and were randomly assigned to one of the three pleurodesis groups treated with 30 ml 0.3%, 30 ml 0.5% or 60 ml 0.3% SN. Patients were discharged 3 days after the procedure, and returned to follow-up visits on days 10 and 30. During follow-up, AE, inflammatory markers, quality of life and CT scans were systematically assessed and documented. RESULTS Sixty patients (11 males and 49 females, median age 62.13 years) were included. Overall, 199 AE were observed, including 23 serious AE. Grade 1/2 metabolic AE, such as increases in creatinine and liver enzymes, were the most frequent. Grade 3/4 hypoxia was observed in 13 patients. Four patients died, 3 due to disease progression and in 1 patient death was possibly related to pleurodesis. C-reactive protein levels increased in a dose-dependent manner and peaked 48 h after pleurodesis. No significant difference was observed among groups regarding quality of life or clinical/radiological recurrence. CONCLUSION Hypoxia was the most significant AE following SN pleurodesis; mild metabolic events were very common. SN instillation causes substantial dose-dependent systemic inflammatory responses.