The treatment of lead poisoning from gunshot wounds with succimer (DMSA)

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.

Characteristics of Pediatric Patients With Retained Bullet Fragments and Need for Follow-Up Blood Lead Monitoring

OBJECTIVES

Multiple case reports of lead toxicity related to retained bullet fragments in pediatric patients sustaining gunshot wound have been published. The purpose of the present study was to determine whether the demographic and clinical characteristics of gunshot wounds (GSWs) could be classified high/low risk and whether routine blood lead monitoring is necessary in these patients.

METHODS

A single-center prospective case series of pediatric GSW patients presenting to the emergency department (ED). The data points that were collected and analyzed included age, sex, race, wound location, disposition, and baseline and follow-up lead levels within 6 months post-injury.

RESULTS

Twenty patients were enrolled in the study and the median age was 7.5 years (interquartile range 5.25-10.75); 75% of the patients were African American. A total of 15 patients (75%) had injuries in either a lower or upper extremity, 9 of whom required admission. Almost all of the injuries involving the head, chest, or abdomen required admission. Of the patients, 65% were admitted and 35% were discharged. All of the patients had an initial blood lead level taken, and follow-up lead levels were determined at 6 months post-injury to be <5 μg/dL. Twelve of 20 patients were lost to follow-up.

CONCLUSIONS

Pediatric GSW is common in male African Americans and these patients had baseline and follow-up lead levels below the reference level. These patients were difficult to follow up. Based on the available data, follow-up lead monitoring may not be indicated.

Examination of metal mobilization from a gunshot by scanning acoustic microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and inductively coupled plasma optical emission spectroscopy: a case report

BACKGROUND

Projectile foreign bodies are known to cause chronic heavy metal toxicity due to the release of metal into the bloodstream. However, the local effect around the metallic object has not been investigated and the main goal of our study is to examine the influence of the object in close proximity of the object.

CASE PRESENTATION

A 36-year-old Caucasian woman with one metallic pellet close to her sciatic nerve due to a previous shotgun injury at the gluteal area presented with a diagnosis of recurrent lumbar disk herniation at L4-5 level. A physical examination confirmed chronic neuropathy and she underwent a two-stage surgery. The surgery included removal of the foreign body, followed by discectomy and fusion at the involved level. During the removal of the metallic foreign body, a tissue sample around the pellet and another tissue sample from a remote area were obtained. The samples were analyzed by scanning acoustic microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Lead, chromium, copper, cadmium, iron, manganese, selenium, and zinc elements in tissue, blood, and serum specimens were detected by inductively coupled plasma optical emission spectroscopy.

CONCLUSIONS

An acoustic impedance map of the tissue closer to the metallic body showed higher values indicating further accumulation of elements. Energy-dispersive X-ray spectroscopy results confirmed scanning acoustic microscopy results by measuring a higher concentration of elements closer to the metallic body. Scanning electron microscopy images showed that original structure was not disturbed far away; however, deformation of the structure existed in the tissue closer to the foreign body. Element analysis showed that element levels within blood and serum were more or less within acceptable ranges; on the other hand, element levels within the tissues showed pronounced differences indicating primarily lead intoxication in the proximity of the metallic body. We can state that residues of metallic foreign bodies of gunshot injuries cause chronic metal infiltration to the surrounding tissue and induce significant damage to nearby neural elements; this is supported by the results of scanning acoustic microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and inductively coupled plasma optical emission spectroscopy.

Severe lead toxicity attributed to bullet fragments retained in soft tissue

A man aged 30 years presented to an emergency department with a 1 month history of severe abdominal pain, jaundice, constipation, lower extremity weakness and weight loss. A peripheral blood smear was performed that showed basophilic stippling of erythrocytes prompting a blood lead level (BLL) evaluation. The patient had a BLL of >200 µg/dL. Retained bullet fragments were identified in the left lower extremity from a previous gunshot wound 10 years prior. Lead from the excised bullet fragment was consistent with the patient's blood lead by isotope ratio analysis. This case is a rare example of a severely elevated BLL attributed to bullet fragments in soft tissue. Bullets retained in soft tissue are not often considered a risk factor for a markedly elevated BLL because they become encapsulated within the tissue over time.

Toxicology in the ICU: part 3: natural toxins

This is the third article of a three-part series that reviews the care of poisoned patients in the ICU. This article focuses on natural toxins, such as heavy metals and those produced by plants, mushrooms, arthropods, and snakes. The first article discussed the general approach to the patient, including laboratory testing; the second article focused on specific toxic agents, grouped into categories.

Investigation of lead mobilization from the buckshot residues to the critical organs

Lead exposure causes neurotoxicity, reproductive system dysfunction, renal failure, and blood and endocrine system disorders in human and experimental animals. In this study, we investigated lead mobilization from gunshot fragments to the critical organs (brain, heart, liver, and kidney) and its interaction with essential trace elements on experimental rat model. Thirty-five rats were randomly divided in five groups. The first group was a control and the others were subjected to buckshot implantation in their skeletal muscles (second and third groups) and abdomen (fourth and fifth groups). The control group and the second and fourth groups were sacrificed 1 month after the onset of experiment while the third and fifth groups were followed after 2 months. Blood lead levels were significantly elevated in both 2 month-followed groups and 1 month-followed intraabdominal group. There were significant increases in brain lead levels of both 2 month-followed groups. For the 1 month-followed groups, kidney lead levels were also significantly higher than those of controls. Results show that lead mobilizes from the buckshot residues in distance tissues to the critical organs and interacts with iron, copper, and zinc even though blood lead level sometimes remains unchanged. Our findings are crucial in revealing lead accumulation in critical organs of subjects carrying any gunshot fragments. These subjects and physicians should be in alert for emergence of lead-induced manifestations.

Lead poisoning from a gunshot wound

Lead poisoning from gunshot wounds is unusual. Awareness of this rare but serious complication can guide the physician in making a prompt diagnosis. We present a case of a 30-year-old male who had a remote history of a gunshot wound in the right knee and presented with right knee pain. Plain film showed intrarticular invasion of the bullet fragments. He was also found to have microcytic anemia with high blood lead levels. Chelation therapy was immediately started, followed with surgical removal of the bullet fragments. Lead intoxication is a rare but fatal complication of gunshot wounds. After a timely diagnosis, chelation therapy should be immediately started.

Air gun pellet remaining in the maxillary sinus for 50 years: a relevant risk factor for the patient?

The authors report the case of a 62-year-old man referred to the department of oral and maxillofacial surgery because of a clinical suspicion of palate carcinoma. Incidentally, diagnostic radiology showed a metallic foreign body in the left maxillary sinus. Anamnestic data revealed that a shot from an air gun accidentally hit the patient's left cheek in 1957. The lead-containing air gun pellet was removed by endoscopic antrostomy and the diagnosis of squamous cell carcinoma was confirmed by histopathological examination. 50 years after the pellet's impact, toxicological blood analysis showed no increased blood lead level. It remains unclear whether the air gun pellet has a potential toxicological effect or is related to the development of the patient's oral carcinoma. In this context the article reviews the literature and discusses the necessity of removing metal-containing foreign bodies, the role of lead in chronic toxicity and its possible carcinogenic effect in humans.

Use of oral dimercaptosuccinic acid (succimer) in adult patients with inorganic lead poisoning

BACKGROUND

Chelation therapy has been used as a means of reducing the body burden of lead for five decades. Intravenous sodium calcium edetate has been the preferred agent, but there is increasing evidence that dimercaptosuccinic acid (DMSA) is also a potent chelator of lead.

METHODS

Oral DMSA 30 mg/kg/day was administered to adults with blood lead concentrations > or = 50 microg/dl. The impact of DMSA on urine lead excretion, on blood lead concentrations and on symptoms was observed. The incidence and severity of adverse effects was also recorded.

RESULTS

Thirty-five courses were given to 17 patients. DMSA significantly (P < 0.0001) increased urine lead excretion and significantly (P < 0.0001) reduced blood lead concentrations. Mean daily urine lead excretion exceeded the pre-treatment value by a median of 12-fold with wide variation in response (IQR 8.9-14.8, 95% CI 10.1-14.6). Pre-treatment blood lead concentrations correlated well with 5-day urine lead excretion. Headache, lethargy and constipation improved or resolved in over half the patients within the first 2 days of chelation. DMSA was generally well tolerated, but one course was discontinued due to a severe mucocutaneous reaction. There was a transient increase in alanine aminotransferase (ALT) activity during 14% of chelations. DMSA caused a significant increase in urine copper (P < 0.0001) and zinc (P < 0.05) excretion.

CONCLUSION

Oral DMSA 30 mg/kg/day is an effective antidote for lead poisoning, though there is a wide inter- and intra-individual variation in response.

Lead toxicity in a 14-year-old female with retained bullet fragments

In the past 3 decades, lead levels in North American children have been declining. Despite the decline in lead exposure, lead toxicity remains a significant childhood environmental health hazard. The usual route of lead exposure is through ingestion, but lead toxicity secondary to retained bullet fragments has been well documented in the adult literature. The diagnosis of lead toxicity is often difficult and delayed secondary to vague and transient symptoms. Recognizing high-risk characteristics of bullet fragments can improve clinician awareness to the possibility of lead toxicity. The primary management of patients with continued lead exposure is to remove the source of exposure. However, in the case of retained bullet fragments, initiation of chelation therapy before surgical removal may be essential in preventing systemic toxicity. We present the case of a 14-year-old female with lead toxicity who presented with an 18-month course of chronic abdominal pain, vomiting, and anorexia 2 years after sustaining a gunshot wound to the right leg. The patient was treated with oral succimer and operative removal of bullet fragments.

Surgical issues in the poisoned patient

Some toxicologic emergencies require immediate or urgent surgical intervention in addition to routine medical care. The EP must be familiar with the indications for operative care, even though many of these poisonings and exposures are relatively rare. The EP must also be knowledgeable regarding the various means of surgical decontamination that are available, including temporary cardiopulmonary bypass. Finally, a high level of vigilance must be maintained for patients who have delayed presentation and fulminant organ failure necessitating early involvement of the transplantation team.

A case of lead poisoning due to snooker chalk

A 3 year, 9 month old child with pica presented with a blood lead concentration of 1.74 micromol/l (360 microg/l). The source of poisoning was snooker chalk (lead content 7200 microg/g). She was treated with intravenous calcium disodium edetate chelation. Thirty months later her blood lead was 0.39 micromol/l (80 microg/l). This case illustrates the need to be vigilant for more unusual causes of lead poisoning in the home.

Pellet embolization to the right atrium following double shotgun injury

A 28-year-old man sustained two shotgun injuries of the left inguinal region from a distance of about 1.5 m by simultaneous discharge of both shells from a sawn-off double-barrelled 16-bore shotgun (diameter of the lead pellets, 4 mm). The first X-ray examination carried out soon after hospital admission showed a single embolized pellet near the right margin of the cardiac silhouette. Eight months later, the man committed suicide by drug intoxication. At autopsy, the embolized pellet was found embedded between the pectinate muscles of the right atrium. On the basis of the reported case and with reference to the pertinent literature, the paper points out the medico-legal aspects of venous bullet/pellet embolism and the risk of lead poisoning after shotgun injury.

The effect of 2,3 dimercaptosuccinic acid in the treatment of lead poisoning in adults

Four patients, aged 22-60, belonging to a single family that had been exposed to lead-contaminated food for an unknown period, and nine workers, aged 20-65, who had been exposed to air-borne lead for 6-8 years, were evaluated for lead poisoning in our centres. Blood lead levels were 3.57 +/- 0.39 micromol/L (mean +/- SD) in the family members and 3.46 +/- 0.43 micromol/L (mean +/- SD) in the group of workers. 2,3 dimercaptosuccinic acid (DMSA) therapy was instituted in the four family members while the nine workers were closely monitored after being removed from the contaminated environment without receiving any chelation therapy. DMSA therapy given for the duration of 19 days reduced the blood lead levels to 0.63 +/- 0.44 micromol/L (mean +/- SD), P<0.01, in the four family members. No significant change was observed in the untreated group. The exposure time in the untreated group was probably longer than that in the treated group. Following long-term exposure most of the lead in the body is found in the bones and therefore not easily removed by chelation therapy. No side-effects were reported in the treated group and no rebound elevation of blood lead levels was observed during the therapy period or during the 12-week follow-up period following cessation of therapy. We conclude that 19 days of chelation therapy with DMSA in adults with moderate to severe lead poisoning is effective and safe.

Severe lead poisoning from an imported clothing accessory: "watch" out for lead

CASE REPORT

A case of severe lead poisoning following ingestion of an imported clothing accessory is reported. The child presented with abdominal pain, vomiting, and anemia but did not develop encephalopathy.

RESULTS

Prompt removal of the object in conjunction with whole bowel irrigation and chelation therapy led to a favorable outcome.