Evaluation of Strontium Interference in Calcium Measurement Procedures and Content in Supplements as Measured by ICP-MS.

BACKGROUND: Bone health supplements containing strontium are available without prescription, however, the effects of strontium interference on clinical laboratory calcium measurement procedures are unknown. METHODS: To evaluate strontium interference on total calcium measurements, plasma pools with exogenously added strontium were measured by 3 total calcium measurement procedures. For ionized calcium measurements, whole blood pools prepared with exogenously added strontium were measured by 2 ionized calcium measurement procedures. An inductively coupled plasma mass spectrometry assay (ICP-MS) was validated for research measurements of strontium content in commercially available supplements. RESULTS: Exogenous strontium addition to plasma caused positive bias for total calcium measurements. Strontium concentrations of 1.0 mg/dL (0.114 mmol/L), 2.5 mg/dL (0.284 mmol/L), and 5.0 mg/Dl (0.568 mmol/L) resulted in mean biases of 1.9% to 3.5%, 4.9% to 9.0%, and 10.8% to 19.2%, respectively, for total calcium measurement procedures. Biases for ionized calcium measurements were less than 4.5% for a strontium concentration of 5.0 mg/dL (0.568 mmol/L). An in-house-developed ICP-MS assay for strontium in commercially available supplements exhibited within-laboratory and within-run coefficients of variation of less than 3%, and a linear response was obtained over the assay analytical measurement range of 10 to 100 000 ng/mL (0.0001 to 1.141 mmol/L). Strontium recovery for the ICP-MS assay was 97.1% to 105.3%. The largest amount of strontium measured in dietary supplements was 395 mg in a 1054 mg tablet. CONCLUSIONS: Some dietary supplements contain larger amounts of strontium than indicated on the product label. High concentrations of strontium may cause significant interference for total calcium measurement procedures, but ionized calcium measurement procedures are not significantly affected.

Clinical characteristics and outcomes using dexmedetomidine in nonintubated patients: A poison center observational study.

PURPOSE: Dexmedetomidine is a central α2 agonist commonly used on intubated patients. It is increasingly being used off-label in nonintubated agitated patients. We sought to determine the overall clinical course, adverse effects, and need for subsequent mechanical ventilation in toxicology patients after treatment with dexmedetomidine. METHODS: This was a retrospective cohort study conducted by chart review of electronic records from the Virginia Poison Control Center from January 1, 2019 to February 4, 2022. Inclusion criteria consisted of all poison center cases where dexmedetomidine was used. The primary outcome was the presence or absence of clinical improvement following dexmedetomidine use. Secondary outcomes included adverse effects, subsequent intubation, or death. RESULTS: During this study period, there were 220 cases in which dexmedetomidine was used to treat agitation. After exclusions, 70 cases were analyzed. The categories included antimuscarinic (n = 19), polysubstance (n = 16), sedative withdrawal (n = 10), unknown agitation (n = 7), sympathomimetic (n = 5), baclofen withdrawal (n = 3), unknown ingestion (n = 3), sedative/hypnotic (n = 2), antipsychotic (n = 2), hallucinogenic (n = 2), and opioid withdrawal (n = 1). Clinical improvement occurred in 62 of 70 patients (89%). There were no deaths. A total of 4 patients were intubated after starting dexmedetomidine, 2 for refractory agitation and 2 for hypoxia after aspiration. CONCLUSION: Global clinical improvement was observed in the agitated toxicology patients administered dexmedetomidine. There was one case of intubation secondary to oversedation. Dexmedetomidine could be a useful adjunctive treatment for agitated toxicologic patients but should be studied further before routinely used.

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.

Systemic toxicity from subcutaneous brimonidine injection successfully treated with naloxone.

Brimonidine is a topical ophthalmic alpha-2 adrenergic agonist solution used to treat glaucoma. The toxidrome includes drowsiness, lethargy, hypotension, bradycardia, and respiratory depression when ingested in infants. We report a case of intentional subcutaneous injection of brimonidine in an elderly patient resulting in hypotension and CNS depression that responded to naloxone. A 73-year-old female with a past medical history significant for glaucoma, hypertension, and indwelling pacemaker presented to the emergency department after injecting her brimonidine tartrate ophthalmic solution subcutaneously (SQ). The patient was not taking any antihypertensive medications or opioids. Initial presentation consisted of lethargy, a paced rhythm of 60 bpm, and blood pressure of 91/24 mmHg with a MAP of 46. Due to central nervous system depression, 3 mg of intranasal naloxone was administered. The patient was treated with intravenous fluids and escalating doses of naloxone and required a continuous infusion. Mental status and vital signs subsequently improved. The patient was admitted to the ICU and naloxone was subsequently weaned over 12 h. Systemic central alpha-2 adrenergic agonist toxicity resulted from SQ brimonidine injection. Central alpha-2 adrenergic agonist overdoses present as sympatholytic effects including CNS depression, bradycardia, hypotension, and may mimic the opioid toxidrome. Brimonidine SQ injection has not previously been reported and this case has similar findings to other central alpha-2 adrenergic agonist poisonings. Naloxone has previously shown variable reversal of CNS depression in central alpha-2 overdose. In this case, high-dose naloxone was useful for reversing CNS depression and hemodynamic instability.

Pressure Necrosis Requiring Fasciotomy After Kratom Overdose.

INTRODUCTION: Kratom (Mitragyna speciosa) is a popular plant-based extract that has dose-dependent stimulatory and sedative effects. It has been used for self-treatment of opioid withdrawal and can result in seizures, hepatotoxicity, and infectious complications from bacterial contamination. Reports of morbidity and mortality associated with Kratom may be confounded by coingestants. We report a case of severe rhabdomyolysis and pressure necrosis leading to fasciotomy in a patient who was using Kratom. CASE REPORT: A 31-year-old male with substance use presented to the emergency department after loss of consciousness for 6 hours after smoking Kratom. He was found to have rhabdomyolysis, acute renal and hepatic injury, and electrolyte disturbances. No ethanol was detected, and urine drug screen was negative. Over the next 3 hours, the patient developed signs of compartment syndrome and he was transferred to the operating room for fasciotomy. He required continuous renal replacement therapy for 48 hours and his labs and clinical status improved. He was discharged 18 days later. A serum and urine sample from the first day of presentation were analyzed for mitragynine and 7-hydroxymitragynine using an Ultra Performance Liquid Chromatography-Tandem Mass Spectrometer (UPLC-MSMS) method. The serum mitragynine was 5 ng/mL and the urine mitragynine 6 ng/mL. CONCLUSIONS: Although there are numerous reports of opioids resulting in prolonged periods of immobilization and rhabdomyolysis, this is not commonly reported in Kratom overdoses.This case report highlights the profound sedative effect of Kratom and the potential of pressure necrosis injury resulting in rhabdomyolysis and compartment syndrome requiring fasciotomy.

Skin Necrosis Following Inadvertent Dermal Injection of Extended-release Buprenorphine.

INTRODUCTION: Extended-release subcutaneous buprenorphine injection is a relatively new formulation and clinicians are still gaining experience with its use. There is sparse literature available on adverse events. We describe a case of skin necrosis associated with the injection site of extended-release buprenorphine. CASE REPORT: A 35-year-old reported immediate swelling and eventual skin breakdown near his buprenorphine injection site. He was found to have ulceration down to the subcutis with no evidence of infection. The patient followed up with dermatology and underwent debridement of the site. The injection site healed with scar formation. DISCUSSION: Although mild to moderate adverse events related to the injection site have been reported in Phase 3 studies of extended-release buprenorphine injection, this is a rare case of skin necrosis requiring surgical intervention and excision of the depot. CONCLUSIONS: This case highlights the potential complication of skin necrosis after inadvertent dermal of extended-release buprenorphine and reviews proper administration techniques.

Point-of-care Ultrasound in the Diagnosis of Calciphylaxis.

CASE PRESENTATION: A 63-year-old male with a past medical history of end stage renal disease presented to the emergency department with painful, lower-extremity necrotic ulcerations. Ultrasound and computed tomography imaging showed concerns for calcium deposits. Biopsy confirmed the diagnosis of calciphylaxis, a rare lethal disease. DISCUSSION: Emergency physicians should keep this disease on their differential due to the high mortality rate.