Continuous mediastinal irrigation with
povidone-iodine is used commonly for treating severe postoperative
mediastinitis. However, concurrent
iodine toxicity has been reported, particularly in patients with renal dysfunction (likely because absorbed
iodine is renally excreted). The authors were consulted on a 45-year-old patient with
mediastinitis who had renal and hepatic dysfunction while being treated with mediastinal irrigation of
povidone-iodine. The
povidone-iodine irrigation was discontinued because he had toxic plasma
iodine levels. Despite this, his condition worsened, and the
iodine levels remained elevated. Thus,
hemodialysis (HD) was initiated using high-flux membranes followed by
continuous venovenous hemodiafiltration (
CVVHDF; 2 L/h of
hemofiltration and 2 L/h of HD). Plasma and effluent
iodine levels were measured repeatedly to determine
iodine clearance by these 2 modalities (HD, 120 mL/min;
CVVHDF, 37 mL and 44 mL/min on days 1 and 2, respectively). Hepatic and renal functions improved with decreasing plasma
iodine levels. Based on this experience and after reviewing the literature the authors conclude that: (1)
iodine irrigation can increase blood
iodine levels significantly, especially in the setting of
renal failure, and lead to increased morbidity and mortality; (2) plasma
iodine levels should be monitored in patients with
renal insufficiency; and (3) HD and
CVVHDF are effective at clearing
iodine. The authors suggest that patients that are at high risk or already developing signs of
iodine toxicity should have the
iodine irrigation discontinued and may benefit from
renal replacement therapy (RRT). Alternatively, concomitant RRT during
iodine irrigation may be attempted to maintain the systemic
iodine levels at nontoxic levels.