Elevated Methemoglobin Levels in a Patient Treated with Hydroxocobalamin After Suspected Cyanide Exposure.

BACKGROUND: Cyanide (CN) toxicity commonly occurs during enclosed-space fires. Historically, the first step in treating CN toxicity utilized amyl nitrite and sodium nitrite to induce methemoglobinemia, which can be dangerous in this population. Hydroxocobalamin (OHCob), which binds to CN to form the nontoxic metabolite cyanocobalamin, is now the first-line antidote for CN toxicity, and has the advantage of not inducing methemoglobinemia. CASE REPORT: A 62-year-old man presented to the Emergency Department (ED) after a house fire. He was intubated for respiratory distress and hypoxia with an initial carboxyhemoglobin of 1.3%, methemoglobin 0.3%, and anion gap 19. Eleven hours after presentation, his serum lactic acid was 9 mmol/L. Given his continued deterioration, 14 h after arrival he received OHCob 5 g i.v. for presumed CN toxicity. Methemoglobin concentration 4 min prior to OHCob administration was 0.7%, and 2 h after administration was 4.2%. This subsequently increased to 14.3% (16 h after OHCob administration) and peaked at 16.3% (47 h after OHCob administration), at which time he was administered a dose of methylene blue 50 mg i.v., 60 h after ED arrival. His methemoglobin concentrations fluctuated until a consistent downward trend starting at 92 h from ED arrival. He continued to deteriorate and expired on hospital day 5 with a methemoglobin concentration of approximately 6.0%. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: CN toxicity requires immediate recognition and treatment. The antidote, OHCob, is believed to not induce methemoglobinemia. However, this potential side effect must be considered by emergency physicians when treating suspected CN toxicity, especially if the patient does not improve after antidotal therapy.

Retrospective Review of a Novel Approach to Buprenorphine Induction in the Emergency Department.

BACKGROUND: The Emergency Department (ED) frequently treats patients with drug overdoses and is an important resource for individuals with opioid use disorder who are seeking treatment. Initiating medication-assisted treatment (MAT) in the ED seems to be an effective way to link patients with opioid use disorder (OUD) to treatment programs. There is ongoing discussion on the best approach to MAT in the ED setting. OBJECTIVE: Describe a new model for managing OUD in the ED. METHOD: Information was obtained retrospectively from the electronic medical records of patients seen in a large county tertiary care center's Clinical Decision Unit (CDU) for OUD between September 1, 2017 and February 6, 2018. Data were summarized descriptively. RESULTS: There were 18 different patients placed in the CDU during the study period. Ninety-five percent were induced with buprenorphine-naloxone in the CDU. The median initial Clinical Opioid Withdrawal Scale score at the time of induction was 10. The median total dose of buprenorphine-naloxone that was administered was 8/2 mg. The median amount of time spent in the CDU and ED combined was 23 h. Approximately (12/19) 63% of subjects went to their initial follow-up appointment in clinic. Nine were still active in clinic at 30 days and 4 were active at 6 months. CONCLUSIONS: This retrospective chart review shows promising preliminary data for managing OUD in an ED CDU. Such strategies have the potential to increase access to care in a vulnerable patient population.

Elevated methemoglobin levels in patients treated with hydroxocobalamin: a case series and in-vitro analysis.

BACKGROUND: Historically, the first step in treating cyanide (CN-) toxicity utilized antidotes to induce methemoglobinemia. This is concerning in patients who are already hypoxemic or have elevated carboxyhemoglobin. Hydroxocobalamin (OHCbl) is now the first-line antidote for CN- toxicity and is not known to induce methemoglobinemia. We observed elevated methemoglobin (MetHb) levels in several patients treated with OHCbl and sought to investigate the incidence of MetHb formation following administration of OHCbl. METHODS: Chart review: A single-center, retrospective case series of patients who received 5 or 10 g of hydroxocobalamin from 01/01/2011 through 04/30/2019. Data was analyzed using descriptive statistics. In-vitro study: Discarded blood was separated into whole blood and plasma samples. OHCbl and normal saline was added to reach 0×, 1×, 2×, and 4× peak therapeutic concentrations and analyzed at times 0, 2, and 4 h after administration. RESULTS: Chart review: Twenty-seven cases of OHCbl administration were identified. The median age was 53 years (IQR 38 - 64) and 20 (74.1%) were male. Exposure to a house fire or smoke inhalation was the reason for OHCbl administration in 21 (77.8%) patients. Five (18.5%) patients received 10 g of OHCbl while the rest received 5 g. Six (22.2%) patients developed methemoglobinemia, all after 5 g OHCbl administration; four had been exposed to fire and smoke, two received the medication for severe acidosis of unknown etiology not related to fire or smoke. The median peak level was 7.1% (IQR 2.2 - 16.4%) at a median time of 11.4 h post-administration. Two patients received methylene blue (MB), neither responded. Death occurred in 17 (63%) cases. In-vitro study: We observed a dose dependent elevation in total hemoglobin but did not detect any increase in MetHb. CONCLUSION: We observed a noteworthy temporal association between the formation of methemoglobinemia and the administration of hydroxocobalamin. This does not appear to be an artifact of the CO-oximeters. This could have profound implications for patients who are already hypoxemic or have impaired oxygen carrying capacity from carboxyhemoglobin.

Poisonings due to storage in a secondary container reported to the National Poison Data System, 2007-2017.

BACKGROUND: Transfer of xenobiotics from their original container to an unlabeled or secondary container is a well-identified risk factor for poisoning. Nonetheless, recent large-scale data on the practice are unavailable. The objective of this study is to describe the incidence and features of poisonings in the United States due to xenobiotics stored in a secondary container. METHODS: This was a retrospective review of the National Poison Data System (NPDS) from 2007 to 2017. Non-suicidal exposures associated with the scenario "container transfer involved (product transferred from original container to unlabeled container, incorrectly labeled container, or food container for use or storage and patient accessed product from second container)" were included. RESULTS: Forty-five thousand five hundred and twelve cases were included. The median age of subjects was 30 years (interquartile range: 6-53); 52% were female. Cleaning products (38.2%), disinfectants (17.3%), and hydrocarbons (5.0%) were the most common xenobiotics reported. The annual incidence of cases increased over the study period. There were 9369 (20.6%) ED visits and 1856 (4.1%) hospital admissions. Most cases (72%) were deemed nontoxic or resulted in no effects; 4.4% resulted in serious outcomes (moderate effects, major effects, or death), including 23 deaths. Morbidity was highest for pesticides, prescription medications, and herbicides, with 10.3%, 9.8%, and 7.6% of cases resulting in serious outcomes, respectively. Hydrofluoric acid and herbicides were associated with the most deaths (13/23 [57%]). CONCLUSIONS: Transfer of xenobiotics to a secondary container is a scenario increasingly reported to U.S. poison centers. Although most exposures do not result in significant toxicity, ED visits are common and substantial morbidity can occur. This represents an opportunity for public health intervention to curb the practice.

Seizures in tramadol overdoses reported in the ToxIC registry: predisposing factors and the role of naloxone.

Importance: Tramadol prescriptions have increased as fewer schedule II and III drugs are prescribed. There has been a concomitant increase in overdoses and adverse events recorded in the National Poison Data System. Seizure activity after tramadol overdose or therapeutic use is a well-documented adverse event. The primary objective is to evaluate the characteristics associated with seizures following single agent tramadol ingestion. Secondarily we aim to compare the rate of seizures in individuals treated, and not treated, with naloxone. Methods: We searched the Toxicology Investigators Consortium data registry for all cases of single agent tramadol ingestions from 01/01/2014 through 12/31/2017. Descriptive statistics were used to evaluate characteristics associated with increased risk of seizures. Binary logistic regressions were used to evaluate the associations between seizures and age, race, acuity, intent, toxidromes, symptoms, and treatments. Results: There were 80 single ingestion tramadol cases entered into the registry. Seizures developed in 42 (52.5%) patients. Asian patients (OR = 7.2, 95% CI: 1.9-27.3, p = .004) and patients abusing or misusing tramadol (OR = 3.2, 95% CI: 1.2-8.3, p = .02) more likely to develop seizures. Patients exhibiting an opioid toxidrome were significantly less likely to develop seizures (OR = 0.12, 95% CI: 0.03-0.60). Ingestion of tramadol as a means of self-harm and age were not associated with an increased risk of seizures. There was no significant association between naloxone administration and seizures (OR = 0.30, 95% CI 0.07-1.25). Conclusions: Based on data from the ToxIC registry, tramadol induced seizures are more likely in Asian patients and those abusing or misusing the medication. There was no association found between the development of seizures and the use of naloxone.

Pneumonitis and Respiratory Failure Secondary to Civilian Exposure to a Smoke Bomb in a Partially Enclosed Space.

Smoke grenades are used during drills, police and military exercises, and crowd control. We report on a 25-year-old man who was exposed to a Superior 3C smoke bomb. He was initially stable but developed respiratory distress after 3 days and ultimately developed pulmonary fibrosis with marked loss in pulmonary function. The Superior 3C smoke bomb is similar in composition to the British Military's L83A1/2 and L132A1 and the US M18 smoke grenades, all commonly used as multipurpose smoke-producing devices for combat and training. They are primarily composed of zinc oxide and hexachlorethane, the combustion of which produces zinc chloride. These devices are safe when used properly in open air but can cause significant morbidity in an enclosed space. This case emphasizes the potential hazards of using smoke bombs even in semienclosed spaces and the potential delay in the development of significant pulmonary complications.