Extracorporeal Cardiopulmonary Resuscitation After Diphenhydramine Ingestion

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, β-adrenergic receptor antagonists (also known as β-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.

Diphenhydramine overdose detected early by integration of toxidrome and electrocardiography and treated with venoarterial extracorporeal membrane oxygenation: a case report

Drug overdose can lead to a range of symptoms, including potentially life-threatening cardiac arrhythmias. However, identifying the specific causative drug upon admission can be challenging in many cases. The toxidrome approach is a method that utilizes toxidromes, which are collections of findings obtained from physical examination and ancillary tests, that may be caused by a specific toxin. In this particular case, a man presented with an unknown drug overdose that caused symptoms indicative of anticholinergic effects and abnormal electrocardiogram (ECG) findings. The ECG revealed an R wave in lead aVR, S waves in leads I and aVL, and wide QRS tachycardia with a Brugada pattern. Shortly after arrival, the patient developed cardiac arrest due to a lethal arrhythmia. Prompt initiation of venoarterial extracorporeal cardiopulmonary membrane oxygenation (VA-ECMO) was performed. Fortunately, the patient achieved full neurological recovery, and the overdosed drug was identified as diphenhydramine. When diagnosing and treating drug overdose caused by an unidentified substance, diphenhydramine toxicity should be considered when an anticholinergic toxidrome is present and a Brugada pattern is observed on the ECG. VA-ECMO demonstrates potential as a viable treatment option when initial interventions prove ineffective.

Extracorporeal cardio-pulmonary resuscitation in poisoning: A scoping review article

Background

Extracorporeal cardiopulmonary resuscitation (ECPR) represents last-line salvage therapy for poisoning-induced cardiac arrest but no review has focused on this specific area.

Objective

This scoping review sought to evaluate the survival outcomes and characteristics of published cases of ECPR for toxicological arrest, with the aim of highlighting the potential and limitations of ECPR in toxicology.Eligibility Criteria.We searched PubMed and Cochrane for eligible papers from database inception to October 1, 2022 using the keywords "toxicology", "ECLS" and "CPR". References of included publications were searched to identify additional relevant articles. Qualitative synthesis was used to summarize the evidence.

Results

85 articles were chosen: 15 case series, 58 individual cases and 12 other publications that were analyzed separately due to ambiguity. ECPR may improve survival outcomes in selected poisoned patients, although the extent of benefit is unclear. As ECPR for poisoning-induced arrest may have better prognosis compared to from other aetiologies, it is likely reasonable to apply ELSO ECPR consensus guideline recommendations to toxicological arrest.Out-of-hospital cardiac arrest alone may not be sufficient grounds to deny ECPR if effective resuscitation had been promptly instituted. Poisonings involving membrane-stabilizing agents and cardio-depressive drugs, and cardiac arrests with shockable rhythms appear to have better outcomes. ECPR may permit excellent neurologically-intact recovery despite prolonged low-flow time of up to four hours. Early ECLS activation and pre-emptive catheter placement can significantly shorten time-to-ECPR and possibly improve survival.

Conclusion

As effects of poisoning may be reversible, ECPR can potentially support poisoned patients through the critical peri-arrest state.

An unusual case of fatal hypothermia involving topical diphenhydramine

PURPOSE

Diphenhydramine is an antihistamine drug widely used to alleviate symptoms caused by allergies and the common cold. Diphenhydramine-involved fatalities have been reported in the past but usually involving overdose by ingestion. We report a peculiar case of fatal hypothermia during non-winter season involving topical diphenhydramine.

METHODS

A 23-year-old male with no known preexisting medical conditions was found dead in the bathroom of his apartment with a small amount of running water on his back. Postmortem examinations and toxicological analysis on blood and urine were performed.

RESULTS

Color difference was apparent between the right and left cardiac blood. Wischnewski spots were observed in the gastric mucosa. Histological examination revealed no obvious findings that could attribute to serious cardiovascular events. Drug screening by gas chromatograph-tandem mass spectrometry (GC/MS/MS) detected diphenhydramine in blood and urine. Further quantification revealed the postmortem concentrations to be 0.44 μg/mL in blood and 2500 μg/mL in urine.

CONCLUSIONS

The cause of death was determined to be hypothermia. Diphenhydramine-induced drowsiness and possible intrinsic cardiac factor may have led to prolonged impaired consciousness, preventing his ability to escape from the running cold water leading to hypothermia and death.

Efficacy of lipid emulsion therapy in treating cardiotoxicity from diphenhydramine ingestion: a review and analysis of case reports

INTRODUCTION

Lipid emulsion therapy (LET) has been most thoroughly studied to reverse local anesthetic systemic toxicity (LAST). Case reports suggest that LET can successfully rescue cardiovascular collapse from bupropion, amitriptyline, and propranolol. The efficacy of LET against refractory hypotension and dysrhythmias from diphenhydramine, a commonly ingested lipophilic cardiotoxic agent, is less well described.

OBJECTIVE

Summarize the evidence that LET rescues cardiac ion channel blockade (QRS, QTc widening) or hypotension attributable to diphenhydramine overdose.

METHODS

We searched MEDLINE, EMBASE, and Google Scholar for English-language full-length case reports of diphenhydramine (DPH) intoxication in patients 17 years of age or older. We extracted data with a PRISMA-compliant protocol, dividing the case reports into two groups, one that received LET and one that did not. We performed a pooled analysis to compare the change in mean arterial pressure (MAP), QRS duration, and QTc duration between the two groups.

RESULTS

We identified 23 reports (25 patients). Lipid emulsion therapy (LET) was used in 6 cases because the patient suffered from hypotension refractory to traditional resuscitation. Those who received LET and those who did not were comparable in age, gender, amount ingested, and frequency of seizures. The mean arterial pressure (MAP) decreased by 4.5 ± 11.5 mm Hg in those who did not receive LET compared to an increase in MAP 37 ± 17.5 mm Hg in those who did receive LET. The QRS narrowed by 29 ± 33.9 ms (no LET group) vs 68 ± 49.5 ms (LET group) and QTc by 168.5 ± 126.75 ms (no LET group) vs 134 ± 88 ms (LET group). All values are expressed as median ± interquartile range. One out of the 6 patients who received LET died after withdrawal of care. In the group that did not receive LET 4 out of 19 died and 3 had no outcome reported.

DISCUSSION

LET may improve MAP in patients with hypotension refractory to vasopressors due to diphenhydramine toxicity. We found no significant effect of LET on QRS or QTc duration. These results are limited by a small sample size, reporting bias of case reports, incomplete data, and heterogeneity.

CONCLUSION

An analysis of pooled case reports suggests that LET may rescue hypotension when other methods have failed in patients with hypotension attributable to diphenhydramine overdose.

Unexpected survival after deliberate phosphine gas poisoning: An Australian experience of extracorporeal membrane oxygenation rescue in this setting

Phosphine poisoning is responsible for hundreds of thousands of deaths per year in countries where access to this pesticide is unrestricted. Metal phosphides release phosphine gas on contact with moisture, and ingestion of these tablets most often results in death despite intensive support. A 36-year-old woman presented to a regional hospital after ingesting multiple aluminium phosphide pesticide tablets and rapidly developed severe cardiogenic shock. In this case, serendipitous access to an untested Extracorporeal Membrane Oxygenation (ECMO) service of a regional hospital effected a successful rescue and prevented the predicted death. We discuss the toxicology, management and the evidence for and against using ECMO in this acute poisoning.

Central histaminergic signalling, neural excitability and epilepsy

Epilepsy is a common neurological disorder characterized by repeated and spontaneous epileptic seizures and is not well controlled by current medication. Traditional theory suggests that epilepsy results from an imbalance of excitatory glutamate neurons and inhibitory GABAergic neurons. However, new evidence from clinical and preclinical research suggests that histamine in the CNS plays an important role in the modulation of neural excitability and in the pathogenesis of epilepsy. Many histamine receptor ligands have achieved curative effects in animal epilepsy models, among which the histamine H₃ receptor antagonist pitolisant has shown anti-epileptic effects in clinical trials. Recent studies, therefore, have focused on the potential action of histamine receptors to control and treat epilepsy. In this review, we summarize the findings from animal and clinical epilepsy research on the role of brain histamine and its receptors. We also identify current gaps in the research and suggest where further studies are most needed.

Cardiac Arrest Following the Administration of Intravenous Diphenhydramine for Sedation to an Infant With Congenital Heart Disease

Diphenhydramine (Benadryl) is a first-generation antihistamine that is used primarily to treat allergic reactions including anaphylaxis, urticaria, and allergic rhinitis. Despite its availability as an over-the-counter medication, toxicity may occur with its use especially when administered in large doses or via the intravenous route. We present a 3-month-old infant with Trisomy 21 who suffered a cardiac arrest immediately following administration of a single 1.25 mg/kg dose of intravenous diphenhydramine, prescribed for sedation in the Pediatric ICU setting. The potential cardiovascular and respiratory effects of diphenhydramine are presented, previous reports of life-threatening adverse effects reviewed, and options to limit these effects discussed.

Clinical and patient characteristics associated with severe outcome in diphenhydramine toxicity

BACKGROUND

Diphenhydramine is frequently misused and ingested recreationally for its antihistaminergic and antimuscarinic effects and is often involved in both serious and fatal poisonings, either in isolation or in combination with other xenobiotics.

OBJECTIVE

This analysis sought to determine which patient and encounter characteristics were associated with severe outcome after diphenhydramine overdose.

METHODS

This is an analysis of the multi-center ToxIC registry (2010-2016). Descriptive analysis of all cases with diphenhydramine listed as the "primary agent" contributing to toxicity were included. Analysis sought to determine which patient and encounter characteristics were associated with severe outcome, defined as occurrence of seizure, ventricular dysrhythmia, or intubation. To determine which patient and encounter characteristics were individually associated with severe outcome, we performed chi-square tests. Fisher's exact tests were used in the case of sparse data. We also performed multivariable logistic regression to further determine independent risk factors for severe outcome in diphenhydramine overdose.

RESULTS

Eight hundred and sixty-three cases remained after exclusion with 15.6% (n = 135) of all patients having one or more severe outcome. The most common severe outcome was seizures which occurred in 98 (11.6%) of all ingestions. Females comprised 59.1% (n = 510) of all ingestions. Most ingestions were intentional (86.0%, n = 742) with the most common known reason for an intentional ingestion being self-harm, accounting for 37.5% (n = 324) of all ingestions. Self-harm ingestions and ingestions in males were more commonly associated with intubation. When examining outcomes by age, there were no significant differences overall or in any individual outcome except intubation in which children 0-12 were less likely to be intubated as compared to teens and adults. Signs and symptoms most strongly associated with a severe outcome included acidemia (pH < 7.2), QRS prolongation (QRS > 120 ms), and elevated anion gap (AG > 20).

DISCUSSION

Acidemia, QRS prolongation, and elevated anion gap are associated with severe outcomes in diphenhydramine toxicity. Further research is warranted to determine their predictive characteristics.

A Bitter Taste in Your Heart

The human genome contains ∼29 bitter taste receptors (T2Rs), which are responsible for detecting thousands of bitter ligands, including toxic and aversive compounds. This sentinel function varies between individuals and is underpinned by naturally occurring T2R polymorphisms, which have also been associated with disease. Recent studies have reported the expression of T2Rs and their downstream signaling components within non-gustatory tissues, including the heart. Though the precise role of T2Rs in the heart remains unclear, evidence points toward a role in cardiac contractility and overall vascular tone. In this review, we summarize the extra-oral expression of T2Rs, focusing on evidence for expression in heart; we speculate on the range of potential ligands that may activate them; we define the possible signaling pathways they activate; and we argue that their discovery in heart predicts an, as yet, unappreciated cardiac physiology.

Clinical and Forensic Aspects of Pharmacobezoars

BACKGROUND

Pharmacobezoars are specific types of bezoars formed when medicines, such as tablets, suspensions, and/or drug delivery systems, aggregate and may cause death by occluding airways with tenacious material or by eluting drugs resulting in toxic or lethal blood concentrations.

OBJECTIVE

This work aims to fully review the state-of-the-art regarding pathophysiology, diagnosis, treatment, and other relevant clinical and forensic features of pharmacobezoars.

RESULTS

Patients of a wide range of ages and of both sexes present with signs and symptoms of intoxications or more commonly gastrointestinal obstructions. The exact mechanisms of pharmacobezoar formation are unknown but are likely multifactorial. The diagnosis and treatment depend on the gastrointestinal segment affected and should be personalized to the medication and the underlying factor. A good and complete history, physical examination, image tests, upper endoscopy, and surgery through laparotomy of the lower tract are useful for diagnosis and treatment.

CONCLUSION

Pharmacobezoars are rarely seen in clinical and forensic practice. They are related to controlled or immediate-release formulations, liquid, or non-digestible substances, in normal or altered digestive motility/anatomy tract, and in overdoses or therapeutic doses, and should be suspected in the presence of risk factors or patients taking drugs which may form pharmacobezoars.