Retained Bullet Fragments Can Lead to Toxic Elevated Blood Lead Levels
February 28th, 2017
ATLANTA – A young man presents to your emergency department with nonspecific symptoms, such as fatigue, abdominal pain, and memory loss, but no cause is obvious. The next question you might ask? Has the patient has ever suffered a gunshot wound?
The national Centers for Disease Control and Prevention notes that, as of 2004, fewer than 100 cases of lead toxicity caused by retained bullet fragments (RBFs) had been reported in the medical literature, but, during 2003-2012, elevated blood lead levels (BLLs) associated with RBFs made up 0.3% of all elevated BLLs and 4.9% of BLLs exceeding 80 μg/dL.
The article in the Morbidity & Mortality Weekly Report points out that elevated BLLs associated with RBFs usually occurred in men 16-24 years old in non-occupational settings.
“The population identified in this study differs from the population exposed to lead in occupational settings, where cases are identified through a mechanism of routine lead exposure screening,” the researchers write. “However, adult males without an occupational exposure, including those with RBFs, would likely only be screened if they seek care for symptoms related to elevated BLLs, or as part of routine care for other purposes, if suspicion is raised by a medical provider. In addition, a low index of suspicion of lead toxicity by medical providers might result in a delay in diagnosis, and patients might receive multiple incorrect diagnoses before receiving correct assessment and treatment.”
Part of the problem, they add, is that BLLs can fluctuate in those with RBFs: Someone with a low BLL at the time of testing can have an increase and become symptomatic when RBFs migrate, such as into a joint space.
The problem is increasingly recognized, the CDC notes, because an estimated 115,000 firearm injuries occur annually in the United States, with about 70% nonfatal. As emergency physicians well know, bullet removal is not routinely indicated for victims of gunshot injuries with RBFs unless they are a cause of immediate morbidity.
During the nine-year study period, 145,811 Americans ages 16 years and older were reported to Adult Blood Lead Epidemiology and Surveillance (ABLES) programs in 41 states. Among these, 457 RBF-associated cases were identified with a maximum RBF-associated BLL of 306 μg/dL.
Even at BLLs exceeding 10 μg/dL, hypertension, kidney dysfunction, possible subclinical neurocognitive deficits, and adverse reproductive outcomes – including spontaneous abortion and reduced birthweight – can occur. Decreased renal function has been documented in association with BLLs greater than 5 μg/dL, and an increased risk for hypertension and essential tremor at BLLs greater than 10 μg/dL.