Treatment of chronic lead toxicity with succimer: a case series of 2 adults with retained lead shotgun fragments

Succimer chelation does not produce lasting reductions of blood lead levels in a rodent model of retained lead fragments

Retained lead fragments from nonfatal firearm injuries pose a risk of lead poisoning. While chelation is well-established as a lead poisoning treatment, it remains unclear whether chelation mobilizes lead from embedded lead fragments. Here, we tested whether 1) DMSA/succimer or CaNa2EDTA increases mobilization of lead from fragments in vitro, and 2) succimer is efficacious in chelating fragment lead in vivo, using stable lead isotope tracer methods in a rodent model of embedded fragments. DMSA was > 10-times more effective than CaNa2EDTA in mobilizing fragment lead in vitro. In the rodent model, succimer chelation on day 1 produced the greatest blood lead reductions, and fragment lead was not mobilized into blood. However, with continued chelation and over 3-weeks post-chelation, blood lead levels rebounded with mobilization of lead from the fragments. These findings suggest prolonged chelation will increase fragment lead mobilization post-chelation, supporting the need for long-term surveillance in patients with retained fragments.

Retained bullets and lead toxicity: a systematic review

INTRODUCTION

Lead toxicity secondary to retained bullet(s) (RB) after a penetrating gunshot wound is a rare but likely underdiagnosed condition, given the substantial number of firearm injuries in the United States. There is currently no consensus on the indications for surveillance, chelation, or surgical intervention.

OBJECTIVE

The purpose of our review is to summarize the literature on systemic lead toxicity secondary to RBs to help guide clinicians in the management of these patients.

METHODOLOGY

The primary literature search was conducted in Medline (PubMed), EMBASE, Cochrane, and CENTRAL using the following MESH terms: "chelation" and "lead poisoning" or "lead toxicity" or "lead" and "bullet" or "missile" or "gunshot", or "bullet".

RESULTS

The search identified 1,082 articles. After exclusions, a total of 142 articles were included in our final review, the majority of which were case reports. Several factors appear to increase the risk of developing lead toxicity including the location of the RB, the presence of a fracture or recent trauma, number of fragments, hypermetabolic states, and bullet retention duration. Particularly, RBs located within a body fluid compartment like an intra-articular space appear to be at a substantially higher risk of developing lead toxicity. Even though patients with lead toxicity from RBs will have similar symptoms to patients with lead toxicity from other sources, the diagnosis of lead poisoning may occur months or years after a gunshot wound. Symptomatic patients with high blood lead levels (BLLs) tended to improve with a combination of chelation and surgical removal of RBs.

CONCLUSIONS

We suggest surveillance with serial BLLs should be performed. Patients with intra-articular RBs appear to be at increased risk of lead toxicity and if possible, early surgical removal of the RBs is warranted, especially given that signs of toxicity are vague, and patients may not have access to follow-up. Long-term chelation should not be used as a surgical alternative and management should be multidisciplinary.

A systematic review of clinical and laboratory findings of lead poisoning: lessons from case reports

Lead is one of the most toxic heavy metals in the environment. The present review aimed to highlight hazardous pollution sources, management, and review symptoms of lead poisonings in various parts of the world. The present study summarized the information available from case reports and case series studies from 2009 to March 2020 on the lead pollution sources and clinical symptoms. All are along with detoxification methods in infants, children, and adults. Our literature compilation includes results from 126 studies on lead poisoning. We found that traditional medication, occupational exposure, and substance abuse are as common as previously reported sources of lead exposure for children and adults. Ayurvedic medications and gunshot wounds have been identified as the most common source of exposure in the United States. However, opium and occupational exposure to the batteries were primarily seen in Iran and India. Furthermore, neurological, gastrointestinal, and hematological disorders were the most frequently occurring symptoms in lead-poisoned patients. As for therapeutic strategies, our findings confirm the safety and efficacy of chelating agents, even for infants. Our results suggest that treatment with chelating agents combined with the prevention of environmental exposure may be an excellent strategy to reduce the rate of lead poisoning. Besides, more clinical studies and long-term follow-ups are necessary to address all questions about lead poisoning management.

Nausea, Vomiting, and Weight Loss in a Young Adult Patient With a History of a Gunshot Wound

Assessing victims of gunshot wounds with retained bullets/bullet fragments for lead toxicity is not always considered until the patient develops signs and symptoms of toxicity. We discuss the case of a 19-year-old young man who received a diagnosis of chronic lead toxicity (serum lead concentration 51 μg/dL) 5 weeks after a hunting accident. Extensive wound debridement occurred following the accident; however, lead toxicity was not diagnosed until after his fourth emergency department visit. Oral chelation therapy was required for the management of his lead toxicity.