Faculty Bibliography

BACKGROUND: Since intentional overdose with rivaroxaban is expected to lead to significant coagulopathy and bleeding, prophylactic reversal has been suggested. We report a single massive ingestion confirmed by a blood concentration that was managed with expectant therapy alone. CASE REPORT: A 71-year-old man with atrial fibrillation, aortic valve replacement, and congestive heart failure presented to the emergency department after an intentional ingestion of 97 (1940 mg total) rivaroxaban tablets in a suicide attempt. Initial laboratories revealed: PT, 60.2 s; INR 7.2; aPTT, 55.7 s; BUN 28 mg/dL; and creatinine 1.2 mg/dL. A whole-blood rivaroxaban concentration obtained on hospital-day three was 160 ng/mL. The patient was admitted for continued observation and the coagulation markers trended downward with no major bleeding events. No reversal agents or blood products were given during his hospitalization. CONCLUSION: In the setting of a single, acute rivaroxaban overdose, with normal renal function, and no active bleeding, conservative therapy alone may be sufficient.

INTRODUCTION: Synthetic cannabinoid receptor agonists (SCRAs) are heterogeneous compounds originally intended as probes of the endogenous cannabinoid system or as potential therapeutic agents. We assessed the clinical toxicity associated with recent SCRA use in a large cohort of drug overdose patients. METHODS: This subgroup analysis of a large (n = 3739) drug overdose cohort study involved consecutive ED patients at two urban teaching hospitals collected between 2009 and 2013. Clinical characteristics of patients with the exposure to SCRAs (SRCA subgroup) were compared with those from patients who smoked traditional cannabinoids (marijuana subgroup). Data included demographics, exposure details, vital signs, mental status, and basic chemistries gathered as part of routine clinical care. Study outcomes included altered mental status and cardiotoxicity. RESULTS: Eighty-seven patients reported exposure to any cannabinoid, of whom 17 reported SCRAs (17 cases, 70 controls, mean age 38.9 years, 77 % males, 31 % Hispanic). There were no significant differences between SRCA and marijuana with respect to demographics (age, gender, and race/ethnicity), exposure history (suicidality, misuse, and intent), vital signs, or serum chemistries. Mental status varied between SRCA and marijuana, with agitation significantly more likely in SCRA subgroup (OR = 3.8, CI = 1.2-11.9). Cardiotoxicity was more pronounced in the SCRA subgroup with dysrhythmia significantly more likely (OR = 9.2, CI = 1.0-108). CONCLUSIONS: In the first clinical study comparing the adverse effects of SCRA overdose vs. marijuana controls in an ED population, we found that SCRA overdoses had significantly pronounced neurotoxicity and cardiotoxicity compared with marijuana.

CONTEXT: Manganese-associated parkinsonism is well described in occupational settings, in chronic methcathinone users, and in patients receiving long-term total parenteral nutrition. We present a unique case of acute intravenous manganese poisoning with a systematic evaluation of hemodialysis efficacy. CASE DETAILS: A 52-year-old woman was inadvertently administered a single intravenous dose of 800 mg compounded manganese chloride at an outpatient chelation center. In an attempt to minimize central nervous system (CNS) manganese deposition, she underwent urgent hemodialysis followed by five days of therapy with calcium disodium EDTA (1 g/m2 over eight hours daily). Her initial whole blood manganese concentration, obtained six hours after exposure and prior to treatment, was 120 mcg/L (2.19 micromol/L); normal <5 mcg/L (< 0.09 micromol/L). Following the first four-hour hemodialysis session her blood manganese concentration decreased to 20 mcg/L (0.36 micromol/L). Despite the fall in her blood manganese concentration, analysis of dialysate revealed a total elimination of only 604 mcg (11 micromol) manganese ( approximately 1.4% of manganese burden). Although she remained asymptomatic, an MRI on hospital day two revealed T1 hyperintensities within the bilateral globus pallidi, consistent with manganese exposure. DISCUSSION: Manganese poisoning is associated with irreversible neurologic toxicity. Hemodialysis did not appear to significantly enhance elimination in this case of acute intravenous manganese toxicity, beyond supportive care and calcium disodium EDTA chelation.

Caustics are common in household and industrial products, and, when ingested, they can pose a significant public health risk. Caustic exposures in adults typically present in the setting of occupational exposure or suicide attempt; exposures in children occur most often by unintentional ingestion. Caustics cause local damage upon contact with tissue surfaces and can lead to systemic toxicity. Endoscopy is recommended in all intentional ingestions (and many unintentional ingestions) to grade injury severity, determine treatment options, and assess prognosis; however, it is generally best performed within 24 hours post ingestion to avoid risk of perforation. Radiography and computed tomography may also be used to visualize injury in certain cases. This review examines the pathophysiology of caustic exposures, their clinical presentations, and the most current evidence on recommendations for decontamination, surgical consult, treatment, and disposition.