Hydroxocobalamin is not associated with methemoglobinemia in patients with inhalation injury and suspected cyanide toxicity and a proposed algorithm for hydroxocobalamin administration.

BACKGROUND: Cyanide poisoning poses a significant threat to burn patients exposed to smoke in residential or workplace fires, leading to central nervous system dysfunction, hemodynamic instability, cardiovascular collapse, and death. Prompt administration of an effective antidote is critical. Hydroxocobalamin, a form of vitamin B12, is the gold standard treatment for cyanide toxicity, by binding to cyanide molecules and converting them into non-toxic cyanocobalamin that is eliminated by the kidneys. This mechanism is distinct from previous cyanide antidotes, which induce the formation of methemoglobin to bind to cyanide. Recent case studies have reported elevated methemoglobin levels after hydroxocobalamin administration, raising concerns regarding its safety. The current study investigates smoke inhalation patients treated with hydroxocobalamin at a single institution Burn Unit in hopes of enhancing our understanding of the complexities surrounding cyanide antidote therapy. METHODS: After Institutional Board Approval, a retrospective cohort study was conducted. Our sample comprised burn patients with inhalation injury admitted to a single institution from 2013 to 2023 and treated with hydroxocobalamin for suspected cyanide toxicity. We also analyzed a matched control cohort of similar patients with inhalation injury not treated with hydroxocobalamin. We analyzed changes and peaks in methemoglobin levels, lactate levels, blood urea nitrogen (BUN) and creatinine, ventilator days, % total body surface area (TBSA), various types of medications and dressings, and mortality. Statistical analyses included t-tests, chi-square, linear and logistic regressions, and correlation analysis. RESULTS: In the study, 36 patients with suspected inhalation injury were treated with hydroxocobalamin at the Los Angeles General (LAG) Burn Unit from 2013 to 2023, who were matched to 32 control patients with inhalation injury who were not treated with hydroxocobalamin. Demographic and baseline characteristics showed no statistically significant differences between the groups, including age, gender, BMI, and %TBSA. No significant differences were found in initial, final, peak, or change in methemoglobin levels. The study also revealed no significant disparities in initial lactate levels, mortality, kidney function tests, ventilator days, surgeries, or use of medications/treatments (e.g., Silvadene dressings, Vitamin C) between the two groups. When controlling for covariates, multiple linear regression analysis (age, gender, and %TBSA) indicated that hydroxocobalamin administration was not significantly associated with changes in methemoglobin or mortality. Increased %TBSA, however, was linked to elevated lactate levels. CONCLUSIONS: Our investigation sought to assess the potential risks associated with hydroxocobalamin administration in burn patients with concomitant inhalation injury. Contrary to our initial hypothesis, we found no statistically significant differences in methemoglobinemia, lactate levels, mortality, or kidney function. The influence of other factors, such as methemoglobinemia-inducing drugs or hydroxocobalamin's interference with co-oximetry, adds complexity. Although elevated methemoglobin levels were observed in some cases, their clinical significance was limited. However, this study's limitations, particularly the rarity of inhalation injury cases with concern for cyanide toxicity, warrant consideration. Further research is required to comprehensively elucidate the impact of hydroxocobalamin administration on burn patients' outcomes.

A Case of Status Epilepticus and Transient Stress Cardiomyopathy Associated with Smoking the Synthetic Psychoactive Cannabinoid, UR-144.

BACKGROUND Synthetic cannabinoids have a higher affinity for the cannabinoid receptors CB1 and CB2 than natural cannabinoids. Their use can be associated with cardiovascular disease and neurological complications. A case is reported of status epilepticus and stress cardiomyopathy following the recreational use of the synthetic cannabinoid, UR-144. CASE REPORT A 19-year-old woman presented to the emergency department in status epilepticus after smoking the synthetic cannabinoid known as 'space'. Recurring seizure activity was controlled after three hours. On hospital day 3, the patient developed severe biventricular failure. Cardiac magnetic resonance imaging (MRI) confirmed the diagnosis of stress cardiomyopathy. A comprehensive urine drug screen was performed using gas chromatography-mass spectrometry (GC-MS), which was positive for UR-144, or (1-pentyl-1H-indol-3-yl)(2,2,3,3-tetramethylcyclopropyl)-methanone, and negative for all other illicit recreational drugs. The patient improved at one week following admission, with a left ventricular ejection fraction (LVEF) of 40%. She was discharged home on hospital day 10. CONCLUSIONS The use of the synthetic cannabinoid, UR-144, may be associated with prolonged status epilepticus and stress cardiomyopathy. Physicians should be aware of these potentially lethal complications associated with the recreational use of this and other illicit synthetic cannabinoids.

Hemorrhagic complications associated with dabigatran use.

OBJECTIVE: Dabigatran is a direct thrombin inhibitor approved for anticoagulation in non-valvular atrial fibrillation and, in some countries, for thromboembolism prophylaxis following select orthopedic surgeries. Despite decreased rates of thromboembolism, bleeding remains a risk due to the inability to conveniently monitor anticoagulant effect and the lack of a reversal agent. CASE SERIES: We present four cases of dabigatran-related bleeding. A 79-year-old man on aspirin, clopidogrel, and dabigatran presented with rectal bleeding and epistaxis. He died despite transfusion and administration of prothrombin complex concentrate. A 73-year-old woman on dabigatran and aspirin survived after transfusion and an emergent sternotomy for cardiac tamponade. An 86 year-old man with kidney disease and thrombocytopenia received packed red blood cells, platelets, and fresh frozen plasma for rectal bleeding while on dabigatran. An 80 year-old man on dabigatran had a subdural hematoma after falling and hitting his head. Serial imaging showed no progression. CONCLUSION: The absence of a reversal agent for dabigatran raises concern for uncontrollable bleeding and death. Dabigatran's listed contraindications include active bleeding and a history of dabigatran hypersensitivity reaction. Wider use may result in bleeding rates higher than anticipated from clinical trials. Risks factors that may have contributed to bleeding in these patients include concomitant bleeding diathesis, antiplatelet agent use, renal insufficiency, advanced age, and fall risks.

Poisoning and suicide by cyanide jewelry cleaner in the US Hmong community: a case series.

Over 200 000 persons of Hmong ethnicity live in the United States. The majority of this Southeast Asian ethnic group live in California, Minnesota and Wisconsin. Tradition plays a strong role in the Hmong population, and difficulty in assimilation into "Western ways" has been reported to result in depression and suicide attempts. Some products sold at Southeast Asian ethnic markets are well-known within the Hmong community to be lethal but are essentially unknown to the outside community. We describe eight cases in which cyanide-containing products were ingested by Hmong patients. Seven cases were suicide attempts involving the ingestion of a locally-purchased substance intended for cleaning metal, coins, or jewelry. One case involved the fatal ingestion of a cyanide-containing "herbal" cure. In the majority of the cases, cyanide was not initially suspected, and treatment was delayed due to lack of information regarding the product ingested. In the two patients who survived, the cyanide antidote kit (sodium nitrite, amyl nitrite, and sodium thiosulfate) was administered early. Clinicians should be aware that unusual and potentially lethal products are easily available at ethnic markets. Cyanide toxicity should be suspected, and empiric antidote therapy initiated early, in patients of Hmong or Southeast Asian descent who present with sudden and unexplained cardiovascular collapse and metabolic acidosis, especially in the setting of a suspected suicidal ingestion.

Have advances in extracorporeal removal techniques changed the indications for their use in poisonings?

During the past 25 years, numerous changes have taken place in the use of hemodialysis as a therapeutic modality. Advances in technologies and a progression in our collective understanding of the pharmacokinetics of certain xenobiotics have resulted in alterations in the indications, effectiveness, and safety of hemodialysis. However, these changes have not necessarily been reflected in the current published data regarding treatment of intoxications. Reported clearance rates often reflect what was achievable in the 1970s and 1980s, and more recent reports are frequently lacking. Our goal in this review is to summarize the changes in hemodialysis and in other extracorporeal removal technologies and highlight the effects of these changes on the current indications for hemodialysis of the poisoned patient. Changes in dialysis performance that are reviewed in this article include the use of high-efficiency and high-flux dialysis membranes, improved hemodynamic stability because of ultrafiltration control, and the use of bicarbonate as a source of base. We review the indications for hemodialysis for removal of specific toxins, including vancomycin, methotrexate, carbamazepine, and valproic acid.