2023 American Heart Association Focused Update on the Management of Patients With Cardiac Arrest or Life-Threatening Toxicity Due to Poisoning: An Update to the American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care.

In this focused update, the American Heart Association provides updated guidance for resuscitation of patients with cardiac arrest, respiratory arrest, and refractory shock due to poisoning. Based on structured evidence reviews, guidelines are provided for the treatment of critical poisoning from benzodiazepines, ß-adrenergic receptor antagonists (also known as ß-blockers), L-type calcium channel antagonists (commonly called calcium channel blockers), cocaine, cyanide, digoxin and related cardiac glycosides, local anesthetics, methemoglobinemia, opioids, organophosphates and carbamates, sodium channel antagonists (also called sodium channel blockers), and sympathomimetics. Recommendations are also provided for the use of venoarterial extracorporeal membrane oxygenation. These guidelines discuss the role of atropine, benzodiazepines, calcium, digoxin-specific immune antibody fragments, electrical pacing, flumazenil, glucagon, hemodialysis, hydroxocobalamin, hyperbaric oxygen, insulin, intravenous lipid emulsion, lidocaine, methylene blue, naloxone, pralidoxime, sodium bicarbonate, sodium nitrite, sodium thiosulfate, vasodilators, and vasopressors for the management of specific critical poisonings.

Extracorporeal treatment for ethylene glycol poisoning: systematic review and recommendations from the EXTRIP workgroup.

Ethylene glycol (EG) is metabolized into glycolate and oxalate and may cause metabolic acidemia, neurotoxicity, acute kidney injury (AKI), and death. Historically, treatment of EG toxicity included supportive care, correction of acid-base disturbances and antidotes (ethanol or fomepizole), and extracorporeal treatments (ECTRs), such as hemodialysis. With the wider availability of fomepizole, the indications for ECTRs in EG poisoning are debated. We conducted systematic reviews of the literature following published EXTRIP methods to determine the utility of ECTRs in the management of EG toxicity. The quality of the evidence and the strength of recommendations, either strong ("we recommend") or weak/conditional ("we suggest"), were graded according to the GRADE approach. A total of 226 articles met inclusion criteria. EG was assessed as dialyzable by intermittent hemodialysis (level of evidence = B) as was glycolate (Level of evidence = C). Clinical data were available for analysis on 446 patients, in whom overall mortality was 18.7%. In the subgroup of patients with a glycolate concentration ≤ 12 mmol/L (or anion gap ≤ 28 mmol/L), mortality was 3.6%; in this subgroup, outcomes in patients receiving ECTR were not better than in those who did not receive ECTR. The EXTRIP workgroup made the following recommendations for the use of ECTR in addition to supportive care over supportive care alone in the management of EG poisoning (very low quality of evidence for all recommendations): i) Suggest ECTR if fomepizole is used and EG concentration > 50 mmol/L OR osmol gap > 50; or ii) Recommend ECTR if ethanol is used and EG concentration > 50 mmol/L OR osmol gap > 50; or iii) Recommend ECTR if glycolate concentration is > 12 mmol/L or anion gap > 27 mmol/L; or iv) Suggest ECTR if glycolate concentration 8-12 mmol/L or anion gap 23-27 mmol/L; or v) Recommend ECTR if there are severe clinical features (coma, seizures, or AKI). In most settings, the workgroup recommends using intermittent hemodialysis over other ECTRs. If intermittent hemodialysis is not available, CKRT is recommended over other types of ECTR. Cessation of ECTR is recommended once the anion gap is < 18 mmol/L or suggested if EG concentration is < 4 mmol/L. The dosage of antidotes (fomepizole or ethanol) needs to be adjusted during ECTR.

Extracorporeal Treatment for Gabapentin and Pregabalin Poisoning: Systematic Review and Recommendations From the EXTRIP Workgroup.

Toxicity from gabapentin and pregabalin overdose is commonly encountered. Treatment is supportive, and the use of extracorporeal treatments (ECTRs) is controversial. The EXTRIP workgroup conducted systematic reviews of the literature and summarized findings following published methods. Thirty-three articles (30 patient reports and 3 pharmacokinetic studies) met the inclusion criteria. High gabapentinoid extracorporeal clearance (>150mL/min) and short elimination half-life (<5 hours) were reported with hemodialysis. The workgroup assessed gabapentin and pregabalin as "dialyzable" for patients with decreased kidney function (quality of the evidence grade as A and B, respectively). Limited clinical data were available (24 patients with gabapentin toxicity and 7 with pregabalin toxicity received ECTR). Severe toxicity, mortality, and sequelae were rare in cases receiving ECTR and in historical controls receiving standard care alone. No clear clinical benefit from ECTR could be identified although major knowledge gaps were acknowledged, as well as costs and harms of ECTR. The EXTRIP workgroup suggests against performing ECTR in addition to standard care rather than standard care alone (weak recommendation, very low quality of evidence) for gabapentinoid poisoning in patients with normal kidney function. If decreased kidney function and coma requiring mechanical ventilation are present, the workgroup suggests performing ECTR in addition to standard care (weak recommendation, very low quality of evidence).

Confirmed Grayanotoxin Poisoning with Bradycardia from a Gift of Imported Honey.

BACKGROUND: Human grayanotoxin poisoning is distinctly uncommon in North America, as the predominant source of human exposure is honey made by bees pollinating rhododendron species in the Mediterranean. We present a case of confirmed grayanotoxin poisoning from honey imported from Turkey. CASE REPORT: A 61-year-old man developed nausea, lightheadedness, and lost consciousness. Onset was 30 min after the ingestion of honey that was brought to the United States from Turkey. Emergency medical services found him bradycardic, hypotensive, and unresponsive. He was treated with atropine, saline, and oxygen, at which point his heart rate and blood pressure improved, and he regained consciousness. A similar episode several days earlier was followed by a brief unrevealing hospitalization. He was again hospitalized, and had a normal echocardiogram, telemetric monitoring, and complete laboratory studies. Grayanotoxins I and III were subsequently identified in the patient's blood, urine, and honey. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Grayanotoxins are diterpenoids found in rhododendron species, whose clinical effects span multiple organ systems including gastrointestinal, cardiac, and neurologic. Treatment is largely supportive, and a good response to atropine and intravenous fluids has been described. Laboratory confirmation of grayanotoxins is not available in a short enough turnaround time to be clinically useful during immediate management, but confirmatory testing may obviate further unnecessary evaluation. Grayanotoxins are likely to remain a rare source of poisoning in North America, but recurrent bradycardia without alternative etiology should prompt a thorough exposure history, which may reveal, as in this case, a treatable toxicologic etiology.

Detectable Digoxin Concentrations in 3 Patients with Ramps Misadventure.

Allium tricoccum (commonly known as "ramps") is an edible plant known for its strong garlic-like odor and onion flavor. Unfortunately, A tricoccum mimics such as Lily of the Valley (Convallaria majalis) and False Hellebore (Veratrum viride) can lead to foraging errors and subsequent patient harm/toxicity. We describe 3 adults who foraged and ate what they believed were A tricoccum and then subsequently became symptomatic with detectable digoxin concentrations. A 41-y-old woman, 41-y-old man, and a 31-y-old man presented to the emergency department after ingesting an unknown plant that was believed to be A tricoccum. On arrival to the emergency department, the patients were hypotensive and bradycardic. They had detectable digoxin concentrations ranging from 0.08 ng·mL-1 to 0.13 ng·mL-1. One patient received 20 vials of digoxin antibody fragments. All 3 patients recovered without complication. Laboratory analysis of plant specimen was positive for cyclopamine, a teratogenic alkaloid found in Veratrum californicum. A tricoccum foraging errors can be a source of morbidity given their similarity in appearance to plants like C majalis and V viride. C majalis causes a detectable digoxin concentration via its cardiac steroid compound (convallatoxin) that is similar to digoxin. V viride contains alkaloid compounds (such as veratridine) that can cross react with digoxin assays and lead to a falsely elevated digoxin concentration. Clinicians should be prompted to think about ingestion of C majalis or Veratrum spp. when patients present with bradycardia, gastrointestinal symptoms, and detectable digoxin concentrations after plant ingestion and/or foraging for A tricoccum.

Recommendations from the EXTRIP workgroup on extracorporeal treatment for baclofen poisoning.

Baclofen toxicity results from intentional self-poisoning (acute baclofen poisoning) or accumulation of therapeutic dose in the setting of impaired kidney function. Standard care includes baclofen discontinuation, respiratory support and seizure treatment. Use of extracorporeal treatments (ECTRs) is controversial. To clarify this, a comprehensive review of the literature on the effect of ECTRs in baclofen toxicity was performed and recommendations following EXTRIP methods were formulated based on 43 studies (1 comparative cohort, 1 aggregate results cohort, 1 pharmacokinetic modeling, and 40 patient reports or series). Toxicokinetic data were available for 20 patients. Baclofen's dialyzability is limited by a high endogenous clearance and a short half-life in patients with normal kidney function. The workgroup assessed baclofen as "Moderately dialyzable" by intermittent hemodialysis for patients with normal kidney function (quality of evidence C) and "Dialyzable" for patients with impaired kidney function (quality of evidence C). Clinical data were available for 25 patients with acute baclofen poisoning and 46 patients with toxicity from therapeutic baclofen in kidney impairment. No deaths or sequelae were reported. Mortality in historical controls was rare. No benefit of ECTR was identified in patients with acute baclofen poisoning. Indirect evidence suggests a benefit of ECTR in reducing the duration of toxic encephalopathy from therapeutic baclofen in kidney impairment. These potential benefits were balanced against added costs and harms related to the insertion of a catheter, the procedure itself, and the potential of baclofen withdrawal. Thus, the EXTRIP workgroup suggests against performing ECTR in addition to standard care for acute baclofen poisoning and suggests performing ECTR in toxicity from therapeutic baclofen in kidney impairment, especially in the presence of coma requiring mechanical ventilation.

Comparison of the EXtracorporeal TReatments In Poisoning (EXTRIP) and Paris criteria for neurotoxicity in lithium poisoned patients.

AIMS: Two guidelines for haemodialysis in lithium poisoning, one from the Extracorporeal TReatments in Poisoning (EXTRIP) workgroup and a single centre retrospective one (Paris) differ. We compared outcomes in lithium poisoning based on these criteria with a primary outcome of worsening neurological symptoms in patients for whom EXTRIP and Paris criteria were discordant. METHODS: Poison centre data were queried for lithium poisoned patients for whom haemodialysis was either recommended or performed. Patients were categorized according to EXTRIP and Paris criteria and excluded if the peak lithium concentration was <1.2 mmol/L or if neurological follow-up was unavailable. Comparative analyses were only performed when both criteria could be assessed. RESULTS: In total, 219 patients were analysed. Paris criteria were met in 70 and EXTRIP criteria in 178. Forty two patients were excluded because Paris criteria could not be evaluated. When Paris and EXTRIP both supported haemodialysis, 50/57 (88%) of patients who received haemodialysis improved, as did all 3 who did not receive haemodialysis. When Paris and EXTRIP did not support haemodialysis, all nondialysed patients did well. Among the 86 patients for whom EXTRIP supported haemodialysis but Paris did not, 4/19 (21%) patients not dialysed deteriorated (P = .02; odds ratio = 8.7, 95% confidence interval = 1.5-51.8), 1 of whom died. All 8 patients for whom Paris criteria supported haemodialysis but EXTRIP did not were dialysed and improved. CONCLUSIONS: When the EXTRIP and Paris criteria are discordant, EXTRIP criteria outperforms the Paris criteria at identifying potentially ill patients who might benefit from haemodialysis.

Extracorporeal treatment for poisoning to beta-adrenergic antagonists: systematic review and recommendations from the EXTRIP workgroup.

BACKGROUND: ß-adrenergic antagonists (BAAs) are used to treat cardiovascular disease such as ischemic heart disease, congestive heart failure, dysrhythmias, and hypertension. Poisoning from BAAs can lead to severe morbidity and mortality. We aimed to determine the utility of extracorporeal treatments (ECTRs) in BAAs poisoning. METHODS: We conducted systematic reviews of the literature, screened studies, extracted data, and summarized findings following published EXTRIP methods. RESULTS: A total of 76 studies (4 in vitro and 2 animal experiments, 1 pharmacokinetic simulation study, 37 pharmacokinetic studies on patients with end-stage kidney disease, and 32 case reports or case series) met inclusion criteria. Toxicokinetic or pharmacokinetic data were available on 334 patients (including 73 for atenolol, 54 for propranolol, and 17 for sotalol). For intermittent hemodialysis, atenolol, nadolol, practolol, and sotalol were assessed as dialyzable; acebutolol, bisoprolol, and metipranolol were assessed as moderately dialyzable; metoprolol and talinolol were considered slightly dialyzable; and betaxolol, carvedilol, labetalol, mepindolol, propranolol, and timolol were considered not dialyzable. Data were available for clinical analysis on 37 BAA poisoned patients (including 9 patients for atenolol, 9 for propranolol, and 9 for sotalol), and no reliable comparison between the ECTR cohort and historical controls treated with standard care alone could be performed. The EXTRIP workgroup recommends against using ECTR for patients severely poisoned with propranolol (strong recommendation, very low quality evidence). The workgroup offered no recommendation for ECTR in patients severely poisoned with atenolol or sotalol because of apparent balance of risks and benefits, except for impaired kidney function in which ECTR is suggested (weak recommendation, very low quality of evidence). Indications for ECTR in patients with impaired kidney function include refractory bradycardia and hypotension for atenolol or sotalol poisoning, and recurrent torsade de pointes for sotalol. Although other BAAs were considered dialyzable, clinical data were too limited to develop recommendations. CONCLUSIONS: BAAs have different properties affecting their removal by ECTR. The EXTRIP workgroup assessed propranolol as non-dialyzable. Atenolol and sotalol were assessed as dialyzable in patients with kidney impairment, and the workgroup suggests ECTR in patients severely poisoned with these drugs when aforementioned indications are present.

Extracorporeal Treatment for Chloroquine, Hydroxychloroquine, and Quinine Poisoning: Systematic Review and Recommendations from the EXTRIP Workgroup.

BACKGROUND: Although chloroquine, hydroxychloroquine, and quinine are used for a range of medical conditions, recent research suggested a potential role in treating COVID-19. The resultant increase in prescribing was accompanied by an increase in adverse events, including severe toxicity and death. The Extracorporeal Treatments in Poisoning (EXTRIP) workgroup sought to determine the effect of and indications for extracorporeal treatments in cases of poisoning with these drugs. METHODS: We conducted systematic reviews of the literature, screened studies, extracted data, and summarized findings following published EXTRIP methods. RESULTS: A total of 44 studies (three in vitro studies, two animal studies, 28 patient reports or patient series, and 11 pharmacokinetic studies) met inclusion criteria regarding the effect of extracorporeal treatments. Toxicokinetic or pharmacokinetic analysis was available for 61 patients (13 chloroquine, three hydroxychloroquine, and 45 quinine). Clinical data were available for analysis from 38 patients, including 12 with chloroquine toxicity, one with hydroxychloroquine toxicity, and 25 with quinine toxicity. All three drugs were classified as non-dialyzable (not amenable to clinically significant removal by extracorporeal treatments). The available data do not support using extracorporeal treatments in addition to standard care for patients severely poisoned with either chloroquine or quinine (strong recommendation, very low quality of evidence). Although hydroxychloroquine was assessed as being non-dialyzable, the clinical evidence was not sufficient to support a formal recommendation regarding the use of extracorporeal treatments for this drug. CONCLUSIONS: On the basis of our systematic review and analysis, the EXTRIP workgroup recommends against using extracorporeal methods to enhance elimination of these drugs in patients with severe chloroquine or quinine poisoning.

Incidence and risk factors for hyperlactatemia in ED patients with acute metformin overdose.

INTRODUCTION: The goals of this study are to describe clinical characteristics and risk factors for metabolic acidosis with hyperlactatemia in emergency department (ED) patients with acute metformin overdose. METHODS: This was a secondary analysis of data from a retrospective observational cohort of adult ED patients presenting with acute drug overdose at two tertiary care hospitals over 5 years. The primary outcomes were: (1) hyperlactatemia, defined as a lactate concentration ≥ 2 mmol/L at any point during hospital admission and, (2) metformin associated lactic acidosis (MALA), defined as a lactate concentration ≥ 5 mmol/L and pH <7.35 at any point during hospital admission. RESULTS: We screened 3739 acute overdoses; 2872 met eligibility, 56 self-reported metformin overdose (57% female, mean age 55.8). Of these, 39 had measured lactate values. There was a high incidence of hyperlactatemia (56.4%); MALA was less frequent (17.9%). There were no deaths. Low serum bicarbonate was an independent clinical risk factor for hyperlactatemia (adjusted p < 0.05). Acetaminophen co-exposure was an independent clinical risk factor for MALA (OR 24.40, 95% CI 1.6-376.4). CONCLUSIONS: In ED patients with acute metformin overdose, initial hyperlactatemia is common but MALA is unusual. Acetaminophen co-exposure is a novel independent risk factor for the occurrence of MALA that deserves further investigation.

Toxicokinetics of hydroxychloroquine following a massive overdose.

BACKGROUND: We report a patient with a massive hydroxychloroquine overdose manifested by profound hypokalemia and ventricular dysrhythmias and describe hydroxychloroquine toxicokinetics. CASE REPORT: A 20-year-old woman (60 kg) presented 1 h after ingesting 36 g of hydroxychloroquine. Vital signs were: BP, 66 mmHg/palpation; heart rate, 115/min; respirations 18/min; oxygen saturation, 100% on room air. She was immediately given intravenous fluids and intubated. Infusions of diazepam and epinephrine were started. Activated charcoal was administered. Her initial serum potassium of 5.3 mEq/L decreased to 2.1 mEq/L 1 h later. The presenting electrocardiogram (ECG) showed sinus tachycardia at 119 beats/min with a QRS duration of 146 ms, and a QT interval of 400 ms (Bazett's QTc 563 ms). She had four episodes of ventricular tachydysrhythmias requiring cardioversion, electrolyte repletion, and lidocaine infusion. Her blood hydroxychloroquine concentration peaked at 28,000 ng/mL (therapeutic range 500-2000 ng/mL). Serial concentrations demonstrated apparent first-order elimination with a half-life of 11.6 h. She was extubated on hospital day three and had a full recovery. CONCLUSION: We present a massive hydroxychloroquine overdose treated with early intubation, activated charcoal, epinephrine, high dose diazepam, aggressive electrolyte repletion, and lidocaine. The apparent 11.6 hour half-life of hydroxychloroquine was shorter than previously described.

Antipsychotics for the treatment of sympathomimetic toxicity: A systematic review.

OBJECTIVE: Benzodiazepines are often recommended first-line for management of cocaine and amphetamine toxicity while antipsychotic treatment is discouraged due to the potential for lowering seizure threshold, prolonging the QT interval, and decreasing heat dissipation. We performed a systematic review including animal and human studies to elucidate the efficacy and safety of antipsychotics in managing sympathomimetic toxicity specifically evaluating the effect of treatment on mortality, seizures, hyperthermia, and cardiovascular effects. METHODS: We searched MEDLINE, Embase, BIOSIS Previews, Web of Science, Scopus, CENTRAL and gray literature from inception to 31 May 2017 to answer: Can antipsychotics be used safely and effectively to treat cocaine or amphetamine toxicity? Citations were screened by title and abstract. Additional citations were identified with citation tracking. Data were extracted from full-texts. RESULTS: 6539 citations were identified; 250 full-text articles were assessed. Citation tracking identified 2336 citations; 155 full texts were reviewed. Seventy-three papers were included in this review. In 96 subjects with cocaine toxicity treated with an antipsychotic, there were three deaths, two cardiac arrests, two seizures, and one episode of hyperthermia. In 330 subjects with amphetamine toxicity treated with an antipsychotic, there were two episodes of coma and QT prolongation and one episode of each: hypotension, NMS, cardiac arrest, and death. CONCLUSION: This systematic review represents an exhaustive compilation of the available evidence. There is neither a clear benefit of antipsychotics over benzodiazepines nor a definitive signal of harm noted. We encourage clinicians to adapt treatment based on specific circumstances and characteristics of their individual patients.

Use of extracorporeal treatments in the management of poisonings.

Historically, the clinical application of extracorporeal treatments (ECTRs), such as hemodialysis or hemoperfusion, was first intended for poisoned patients. With time, ECTRs were used almost indiscriminately to facilitate the elimination of many poisons, albeit with uncertain clinical benefit. To determine the precise role of ECTRs in poisoning situations, multiple variables need to be considered including a careful risk assessment, the poison's characteristics including toxicokinetics, alternative treatments, the patient's clinical status, and intricacies of available ECTRs, all of which are reviewed in this article. Recently, evidence-based and expert opinion-based recommendations from the EXTRIP workgroup were also published to help minimize the knowledge gap in this area.

Prognostic Utility of Initial Lactate in Patients With Acute Drug Overdose: A Validation Cohort.

STUDY OBJECTIVE: Previous studies have suggested that the initial emergency department (ED) lactate concentration may be an important prognostic indicator for inhospital mortality from acute drug poisoning. We conduct this cohort study to formally validate the prognostic utility of the initial lactate concentration in a larger, distinct patient population with acute drug overdose. METHODS: This observational, prospective, cohort study was conducted during 5 years at 2 urban teaching hospitals. Consecutive adult ED patients with acute drug overdose had serum lactate levels tested as part of clinical care. The primary outcome was inpatient fatality. Receiver operating characteristics were plotted to determine optimal cut points, test characteristics, area under the curve, odds ratios, and 95% confidence intervals (CIs). RESULTS: Of 3,739 patients screened, 1,406 were analyzed (56% women; mean age 43.1 years) and 24 died (1.7%). The difference in mean initial lactate concentration was 5.9 mmol/L (95% CI 3.4 to 8.1 mmol/L) higher in patients who died compared with survivors. The area under the curve for prediction of fatality was 0.85 (95% CI 0.73 to 0.95). The optimal lactate cut point for fatality was greater than or equal to 5.0 (odds ratio 34.2; 95% CI 13.7 to 84.2; 94.7% specificity). Drug classes for which lactate had the highest utility were salicylates, sympathomimetics, acetaminophen, and opioids (all area under the curve ≥0.97); lowest utility was for diuretics and angiotensin-converting enzyme inhibitors. CONCLUSION: Initial lactate concentration is a useful biomarker for early clinical decisionmaking in ED patients with acute drug overdose. Studies of lactate-tailored management for these patient populations are warranted.

Low dose intramuscular methadone for acute mild to moderate opioid withdrawal syndrome.

STUDY OBJECTIVE: To assess the efficacy of 10mg intramuscular (IM) methadone in patients with opioid withdrawal syndrome (OWS). METHODS: This was a prospective observational, convenience sample of patients presenting to the ED with mild to moderate OWS. Evaluations included the Clinical Opiate Withdrawal Scale (COWS), Withdrawal Symptoms Scale (WSS), Altered Mental Status Scale (AMSS) and a physician assessment of the patient's WSS (MDWSS). After enrollment, 10mg of IM methadone was administered and patients were reassessed at 30min post-methadone administration. The primary outcome was the change in COWS at baseline and after methadone administration. Secondary outcomes were the differences between AMSS, and WSS post-methadone. RESULTS: Fifty-seven patients had COWS scores recorded at baseline and 30min. Fifty-six had mild to moderate OWS. The COWS improved a mean of 7.6 after methadone administration (P<0.001). The improvement was greater among patients presenting with moderate versus mild withdrawal (mean decrease=-9.1 vs. -5.5, P<0.001). Patients were more likely to self-score themselves as having withdrawal compared to MDs (93.6% vs. 76.6% respectively, P=0.027). Of the 62 patients with baseline and follow-up WSS by self-assessments, 69% improved post-methadone administration. In addition, the AMSS score remained the same or improved among 86% of cases with measurements at baseline and follow-up. CONCLUSION: A single IM dose of 10mg methadone in the ED reduces the severity of acute mild to moderate OWS by 30min. Larger prospective, randomized controlled, and blinded studies would be needed to confirm these results.

Endotracheal Intubation after Acute Drug Overdoses: Incidence, Complications, and Risk Factors.

BACKGROUND: Drug overdose is the leading cause of injury-related fatality in the United States, and respiratory failure remains a major source of morbidity and mortality. OBJECTIVES: We aimed to identify the incidence and risk factors for endotracheal intubation after acute drug overdose. METHODS: This secondary data analysis was performed on a 5-year prospective cohort at two urban tertiary-care hospitals. The present study analyzed adult patients with suspected acute drug overdose to derive independent clinical predictors of endotracheal intubation. RESULTS: We analyzed 2497 patients with acute drug overdose, of whom 87 (3.5%) underwent endotracheal intubation. Independent clinical risk factors for endotracheal intubation were: younger age (odds ratio [OR] 0.97, 95% confidence interval [CI] 0.96-0.98), and history of obstructive lung disease (OR 6.6, 95% CI 3.5-12.3); however, heart failure had no association. Patients with obstructive lung disease had significantly more hypercapnia (mean difference 6.8 mm Hg, 95% CI 2.3-11.3) and a higher degree of acidemia (mean pH difference 0.04, 95% CI 0.01-0.07) than patients without obstructive lung disease. Lack of rapid sequence sedative/paralytic was associated with in-hospital fatality. Early complications of endotracheal intubation itself included desaturation (3.4%) and bradycardia (1%). CONCLUSIONS: Endotracheal intubation was infrequently performed on patients with acute drug overdose, and complications were rare when performed. Risk factors associated with endotracheal intubation included younger age and prior obstructive lung disease.