The approach to the patient with an unknown overdose

Cardiac Arrest in Special Populations

Best practices in cardiac arrest depend on continuous high-quality chest compressions, appropriate ventilatory management, early defibrillation of shockable rhythms, and identification and treatment of reversible causes. Although most patients can be treated according to highly vetted treatment guidelines, some special situations in cardiac arrest arise where additional skills and preparation can improve outcomes. Situations covered in this section involve cardiac arrest in context of electrical injuries, asthma, allergic reactions, pregnancy, trauma, electrolyte imbalances, toxic exposures, hypothermia, drowning, pulmonary embolism, and left ventricular assist devices.

Clinical and Epidemiological Study of Poisoning Cases Presenting to the Emergency Department of a Tertiary Care Center in Central India

Objective To analyze the clinical and epidemiological characteristics of acute cases of poisoning and the pre-hospital measures that the patient receives before seeking care in an emergency department at a tertiary care center in Central India. Methods An observational prospective study was carried out over 18 months, and the relevant findings were documented using a predesigned data collection form. All patients who presented to the emergency department and were 18 years of age or older were recruited, and consent was sought. Data analysis was performed using the SPSS software. Results A total of 102 patients diagnosed with poisoning were taken for this study, and data were collected and analyzed. The mean age was 32.8 ± 13.75 years. Of the study population, 63 (61.8%) patients were males. In our study, the most common cause of poisoning was impulsive intake of poison (n = 22, 21.5%) and suicidal ingestion in patients with depression (n = 18, 17.6%). In the emergency department, 61 patients (59.8%) received gastric lavage, and 37 patients (36.3%) received an antidote. The most common agent of poisoning was pesticide ingestion, accounting for 45 (44%) of the total cases. Prescribed drugs were the second-largest group (n = 19, 18.6%). Other common poisoning agents were rodenticides (n = 12, 11.7%), corrosives (n = 8, 7.8%), and aluminum phosphide (n = 3, 2.9%). Out of 102 patients, 82 patients survived, 15 patients died, and five patients left against medical advice (LAMA). One patient had residual comorbidity and was discharged with jejunostomy. The maximum mortality (22.5%) was due to organophosphorus compounds. Conclusions While accidental encounters are also common, intentional self-harm accounts for the majority of poisonings; homicidal motives are less likely. Pesticides were the most often used poisoning agents, followed by prescribed and over-the-counter drugs, rodenticides, corrosive agents, and aluminum phosphide. Of the poisoned cases, 69.6% had a full recovery, 22.54% of them died, and eight (7.84%) among them left against medical advice (LAMA). Organophosphorus chemicals were the cause of the highest mortality (22.5%).

Cardiac Arrest in Special Populations

Best practices in cardiac arrest depend on continuous high-quality chest compressions, appropriate ventilatory management, early defibrillation of shockable rhythms, and identification and treatment of reversible causes. Although most patients can be treated according to highly vetted treatment guidelines, some special situations in cardiac arrest arise where additional skills and preparation can improve outcomes. Situations covered in this section involve cardiac arrest in context of electrical injuries, asthma, allergic reactions, pregnancy, trauma, electrolyte imbalances, toxic exposures, hypothermia, drowning, pulmonary embolism, and left ventricular assist devices.

Deep learning neural network derivation and testing to distinguish acute poisonings

INTRODUCTION

Acute poisoning is a significant global health burden, and the causative agent is often unclear. The primary aim of this pilot study was to develop a deep learning algorithm that predicts the most probable agent a poisoned patient was exposed to from a pre-specified list of drugs.

RESEARCH DESIGN & METHODS

Data were queried from the National Poison Data System (NPDS) from 2014 through 2018 for eight single-agent poisonings (acetaminophen, diphenhydramine, aspirin, calcium channel blockers, sulfonylureas, benzodiazepines, bupropion, and lithium). Two Deep Neural Networks (PyTorch and Keras) designed for multi-class classification tasks were applied.

RESULTS

There were 201,031 single-agent poisonings included in the analysis. For distinguishing among selected poisonings, PyTorch model had specificity of 97%, accuracy of 83%, precision of 83%, recall of 83%, and a F1-score of 82%. Keras had specificity of 98%, accuracy of 83%, precision of 84%, recall of 83%, and a F1-score of 83%. The best performance was achieved in the diagnosis of single-agent poisoning in diagnosing poisoning by lithium, sulfonylureas, diphenhydramine, calcium channel blockers, then acetaminophen, in PyTorch (F1-score = 99%, 94%, 85%, 83%, and 82%, respectively) and Keras (F1-score = 99%, 94%, 86%, 82%, and 82%, respectively).

CONCLUSION

Deep neural networks can potentially help in distinguishing the causative agent of acute poisoning. This study used a small list of drugs, with polysubstance ingestions excluded.Reproducible source code and results can be obtained at https://github.com/ashiskb/npds-workspace.git.

Alcohol use in adolescence as a risk factor for overdose in the 1986 Northern Finland Birth Cohort Study

Background

Overdoses and poisonings are among the most common causes of death in young adults. Adolescent problem drinking has been associated with psychiatric morbidity in young adulthood as well as with elevated risk for suicide attempts. There is limited knowledge on adolescent alcohol use as a risk factor for alcohol and/or drug overdoses in later life.

Methods

Here, data from The Northern Finland Birth Cohort 1986 study with a follow-up from adolescence to early adulthood were used to assess the associations between adolescent alcohol use and subsequent alcohol or drug overdose. Three predictors were used: age of first intoxication, self-reported alcohol tolerance and frequency of alcohol intoxication in adolescence. ICD-10-coded overdose diagnoses were obtained from nationwide registers. Use of illicit drugs or misuse of medication, Youth Self Report total score, family structure and mother’s education in adolescence were used as covariates.

Results

In multivariate analyses, early age of first alcohol intoxication [hazard ratios (HR) 4.5, 95% confidence intervals (CI) 2.2–9.2, P < 0.001], high alcohol tolerance (HR 3.1, 95% CI 1.6–6.0, P = 0.001) and frequent alcohol intoxication (HR 1.9, 95% CI 1.0–3.4, P = 0.035) all associated with the risk of overdoses. Early age of first intoxication (HR 5.2, 95% CI 1.9–14.7, P = 0.002) and high alcohol tolerance (HR 4.4, 95% CI 1.7–11.5, P = 0.002) also associated with intentional overdoses.

Conclusions

Alcohol use in adolescence associated prospectively with increased risk of overdose in later life. Early age of first intoxication, high alcohol tolerance and frequent alcohol intoxication are all predictors of overdoses.

Comment on Lionte et al. Association of Multiple Glycemic Parameters at Hospital Admission with Mortality and Short-Term Outcomes in Acutely Poisoned Patients. Diagnostics 2021, 11, 361

We have read with great interest the article by Lionte et al., "Association of multiple glycemic parameters at hospital admission with mortality and short-term outcomes in acutely poisoned patients", recently published in your journal [...].

Changes in Diagnosis of Poisoning in Patients in the Emergency Room Using Systematic Toxicological Analysis with the National Forensic Service

BACKGROUND

It is difficult to diagnose patients with poisoning and determine the causative agent in the emergency room. Usually, the diagnosis of such patients is based on their medical history and physical examination findings. We aimed to confirm clinical diagnoses using systematic toxicological analysis (STA) and investigate changes in the diagnosis of poisoning.

METHODS

The Intoxication Analysis Service was launched in June 2017 at our hospital with the National Forensic Service to diagnose intoxication and identify toxic substances by conducting STA. Data were collected and compared between two time periods: before and after the initiation of the project, i.e., from June 2014 to May 2017 and from June 2017 to May 2020.

RESULTS

A total of 492 and 588 patients were enrolled before and after the service, respectively. Among the 588 after-service patients, 446 underwent STA. Among the 492 before-service patients, 69.9% were diagnosed clinically, whereas the causative agent could not be identified in 35 patients. After starting the service, a diagnosis was confirmed in 84.4% of patients by performing a hospital-available toxicological analysis or STA. Among patients diagnosed with poisoning by toxins identified based on history taking, only 83.6% matched the STA results, whereas 8.4% did not report any toxin, including known substances. The substance that the emergency physician suspected after a physical examination was accurate in 49.3% of cases, and 12% of cases were not actually poisoned. In 13.4% of patients who visited the emergency room owing to poisoning of unknown cause, poisoning could be excluded after STA. Poisoning was determined to be the cause of altered mental status in 31.5% of patients for whom the cause could not be determined in the emergency room.

CONCLUSION

A diagnosis may change depending on the STA results of intoxicated patients. Therefore, appropriate STA can increase the accuracy of diagnosis and help in making treatment decisions.

Epidemiology and regional differences of acute poisonings of eight cities in Gyeonggi-do province in Korea using data from the National Emergency Department Information System of Korea

OBJECTIVE

We aimed to analyze the differences in epidemiological aspects and clinical courses of acute poisonings in each region of the Gyeonggi-do province in Korea.

METHODS

This retrospective study analyzed data from the National Emergency Department Information System of Korea. We retrospectively reviewed cases of acute poisonings between April 2006 and March 2015 recorded at 13 emergency departments in eight different cities of Gyeonggi-do province in Korea. The differences in the incidence, age distribution, causative agent, and clinical course of poisonings among regions were the main outcomes measured.

RESULTS

The proportion of poisonings in the ≤9 age group was high in Yongin (17.44%) and that in ≥65 age group was high in Gwangmyeong (21.76%). The proportion of cases involving carbon monoxide was high in Ansan (8.82%) in patients hospitalized and the proportion of cases involving pesticides was high in Pyeongtaek (52.78%) in patients admitted to the intensive care unit. The admission rate of poisoned patients was high in Osan (36.02%).

CONCLUSION

In this study, differences in the characteristics of poisoned patients between 8 cities were noted. Therefore, hospitals need to arrange treatment resources for poisoned patients according to the characteristics of the specific region. The.

RESULTS

of this study may serve as evidence for new strategies to prepare for the acute poisonings in hospitals.

Changes in thallium distribution in the scalp hair after an intoxication incident

In cases of criminal thallium poisoning, forensic investigation is required to identify the amount and time of thallium exposure. Usually, blood and urine thallium levels are respectively used as biomarkers. Additionally, hair has the unique potential to reveal retrospective information. Although several studies have attempted to clarify how thallium is distributed in hair after thallium poisoning, none have evaluated the time course of changing thallium distribution. We investigated changes in the distribution of thallium in hair at different time points after exposure in five criminal thallotoxicosis patients. Scalp hair samples were collected twice, at 2.6 and 4.2-4.5months after an exposure incident by police. Results of our segmented analysis, a considerable amount of thallium was detected in almost all hair sample segments. The thallium exposure date estimated from both hair sample collections matched the actual exposure date. We found that determination of thallium amounts in hair samples divided into consecutive segments provides valuable information about exposure period even if a considerable time passes after exposure. Moreover, when estimating the amount of thallium exposure from a scalp hair sample, it is necessary to pay sufficient attention to individual differences in its decrease from hair.

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.

New Psychoactive Substances in Pediatric Patients

New psychoactive substances (NPS), namely cannabinoids, cathinones, and opioids, have surged in popularity among school-age children, resulting in serious morbidity and mortality globally. In the last decade, there has been a rapid evolution of NPS resulting in hundreds of new compounds. Little to no evidence for humans is available on most compounds. The clinical presentations of patients intoxicated with cannabinoids and cathinones are highly variable but most commonly present with a sympathomimetic toxidrome, for example, agitation, delirium, and tachycardia. Those with opioids present with a classic opioid toxidrome: coma, dilated pupils, and respiratory failure.

A Young Adult with Unintended Acute Intravenous Iron Intoxication Treated with Oral Chelation: The Use of Liver Ferriscan for Diagnosing and Monitoring Tissue Iron Load

Acute iron intoxication (FeI) in humans has not been adequately studied. The manifestation of FeI, defined as a serum iron concentration >300 μg/dL (55 μmol/L) within 12 hours of ingestion, include various symptoms appearing in progressive stages. Systemic toxicity is expected with an intake of 60 mg/kg. A 27-year-old female nurse presented with unintended acute intravenous iron intoxication (FeI) a week after self-injecting herself with 20 ampoules of IV iron (4,000 mg elemental iron, 60 mg/kg). She had stable vital signs and mild hepatic tenderness. Hepatic MRI (Ferriscan^®) showed a moderate/severe liver iron content (LIC: 9 mg/g dry tissue). Her hemogram, electrolytes, hepatic and renal functions were normal. Based on the high dose of iron received and her elevated LIC, chelation therapy was advised. She accepted only oral therapy and was started on deferasirox at a dose of 30 mg/kg daily. This oral chelation proved to be effective in clearing her hepatic iron overload after six months (LIC: 2 mg/g dry tissue), without side effects. This case also proved the value of Ferriscan^® in diagnosing the degree of hepatic FeI and monitoring therapy to achieve a safe level of LIC.

The Pharmacologic and Clinical Effects of Illicit Synthetic Cannabinoids

This article presents information on illicitly used synthetic cannabinoids. Synthetic cannabinoids are structurally heterogeneous and commonly used drugs of abuse that act as full agonists of the cannabinoid type-1 receptor but have a variety of additional pharmacologic effects. There are numerous cases of patient harm and death in the United States, Europe, and Australia with many psychological, neurological, cardiovascular, pulmonary, and renal adverse events. Although most users prefer using cannabis, there are convenience, legal, and cost reasons driving the utilization of synthetic cannabinoids. Clinicians should be aware of pharmacologic and clinical similarities and differences between synthetic cannabinoid and cannabis use, the limited ability to detect synthetic cannabinoids in the urine or serum, and guidance to treat adverse events.

Asystolic Cardiac Arrest of Unknown Duration in Profound Hypothermia and Polysubstance Overdose: A Case Report of Complete Recovery

BACKGROUND

Opioid addiction and overdose is a serious problem worldwide. Fatal overdoses from opioids are responsible for numerous deaths and are increasing, especially if taken in combination with other psychoactive substances. Combined with environmental exposure, opioid overdose can cause profound hypothermia. Opioid abuse and other drugs of abuse impair thermoregulation, leading to severe hypothermia. Both drug overdose and severe hypothermia can cause cardiac arrest.

CASE REPORT

We report a case of 20-year-old man with history of polysubstance abuse presenting with severe hypothermia and asystole of unknown duration with return of spontaneous circulation (ROSC) achieved after 28 minutes of cardiopulmonary resuscitation (CPR). Urine toxicology was positive for cocaine, heroin, and benzodiazepine, along with positive blood alcohol level. The patient was rewarmed using non-invasive techniques. Hospital course was complicated by acute renal failure (ARF), severe rhabdomyolysis, severe hyperkalemia, ST-elevation myocardial infarction (STEMI), shock liver, coagulopathy, and aspiration pneumonia.

CONCLUSIONS

Survival with full cardiovascular and neurologic recovery after a cardiac arrest caused by drug overdose in the setting of severe hypothermia is still possible, even if the cardiac arrest is of unknown or prolonged duration. Patients with severe hypothermia experiencing cardiac arrest/hemodynamic instability can be rewarmed using non-invasive methods and may not necessarily need invasive rewarming techniques.

New drugs of abuse

Drug abuse is a common problem and growing concern in the United States, and over the past decade, novel or atypical drugs have emerged and have become increasingly popular. Recognition and treatment of new drugs of abuse pose many challenges for health care providers due to lack of quantitative reporting and routine surveillance, and the difficulty of detection in routine blood and urine analyses. Furthermore, street manufacturers are able to rapidly adapt and develop new synthetic isolates of older drugs as soon as law enforcement agencies render them illegal. In this article, we describe the clinical and adverse effects and purported pharmacology of several new classes of drugs of abuse including synthetic cannabinoids, synthetic cathinones, salvia, desomorphine, and kratom. Because many of these substances can have severe or life-threatening adverse effects, knowledge of general toxicology is key in recognizing acute intoxication and overdose; however, typical toxidromes (e.g., cholinergic, sympathomimetic, opioid, etc.) are not precipitated by many of these agents. Medical management of patients who abuse or overdose on these drugs largely consists of supportive care, although naloxone may be used as an antidote for desomorphine overdose. Symptoms of aggression and psychosis may be treated with sedation (benzodiazepines, propofol) and antipsychotics (haloperidol or atypical agents such as quetiapine or ziprasidone). Other facets of management to consider include treatment for withdrawal or addiction, nutrition support, and potential for transmission of infectious diseases.

The toxic trio: valproic acid, lithium, and carbamazepine

Patients with altered mental status and seizure or psychiatric disease often present with an unclear medication history. Commonly prescribed medications include valproic acid (VPA), lithium (Li), or carbamazepine (CZN) of which the regional poison center (RPC) often recommends obtaining these serum concentrations. Regularly ruling out supratherapeutic concentrations without a known history of ingestion may help direct care. Cases from the RPC coded as VPA, Li, and CZN, from January 1, 2006 to December 31, 2008, were searched. All patients with supratherapeutic concentrations (VPA >100 μg/mL, Li >1.2 mEq/L, and CZN >12 μg/mL) were evaluated for the following criteria: (1) those with altered mental status and an unclear history of seizure or psychiatric disorder and (2) a mediation profile not including VPA, Li, or CZN. Twenty-six patients met the inclusion criteria: 8 patients in the VPA group (113-247 μg/mL; mean, 158), 9 patients in the Li group (1.9-5.2 mEq/L; mean, 2.9), and 9 patients in the CZN group (13.4-38.8 μg/mL; mean, 23.2). All patients survived and were treated with supportive care; however, 1 patient had a Li level of 5.2 mEq/L and received hemodialysis. In altered patients potentially being treated for seizure or psychiatric disorders and unknown ingestions or medication lists, obtaining concentrations of VPA, Li, and CZN may help direct care and provide clinically relevant information. The RPC detected 26 patients with supratherapeutic VPA, Li, or CZN concentrations in patients with potential indications for the agent but no available history of drug ingested or medication list. A prospective study is warranted to evaluate the usefulness of obtaining these concentrations in this patient population.

Toxidromes

The critical care physician is often called to care for poisoned patients. This article reviews the general approach to the poisoned patient, specifically focusing on the utility of the toxidrome. A toxidrome is a constellation of findings, either from the physical examination or from ancillary testing, which may result from any poison. There are numerous toxidromes defined in the medical literature. This article focuses on the more common toxidromes described in clinical toxicology. Although these toxidromes can aid the clinician in narrowing the differential diagnosis, care must be exercised to realize the exceptions and limitations associated with each.

Utility of serum lactate to predict drug-overdose fatality

CONTEXT

Poisoning is the second leading cause of injury-related fatality in the United States. An elevated serum lactate concentration identifies medical and surgical patients at risk for death; however, its utility in predicting death in drug overdose is controversial and unclear.

OBJECTIVE

We aimed to evaluate the prognostic utility of serum lactate concentration for fatality in emergency department (ED) patients with acute drug overdose.

MATERIALS AND METHODS

This was a case-control study at two urban university teaching hospitals affiliated with a regional poison control center. Data were obtained from electronic medical records, poison center data, and the office of the chief medical examiner. Controls were consecutive acute drug overdoses over a 1-year period surviving to hospital discharge. Cases were subjects over a 7-year period with fatality because of drug overdose. Serum lactate concentration was obtained from the initial blood draw in the ED and correlated with fatality.

RESULTS

During the study period, 873 subjects were screened with 50 cases and 100 controls included. Drug exposures and baseline characteristics were similar between groups. Mean lactate concentration (mmol/L) was 9.88 ± 6.7 for cases and 2.76 ± 2.9 for controls (p < 0.001). The receiver operating characteristic area under the curve for prediction of fatality was 0.87 (95% CI: 0.81-0.94). The optimal lactate cutpoint was 3.0 mmol/L (84% sensitivity, 75% specificity), which conferred a 15.8-fold increase in odds of fatality (p < 0.001).

CONCLUSION

In this derivation study, serum lactate concentration had excellent prognostic utility to predict drug-overdose fatality. Prospective validation in the ED evaluation of drug overdoses is warranted.

Management of the critically poisoned patient

BACKGROUND

Clinicians are often challenged to manage critically ill poison patients. The clinical effects encountered in poisoned patients are dependent on numerous variables, such as the dose, the length of exposure time, and the pre-existing health of the patient. The goal of this article is to introduce the basic concepts for evaluation of poisoned patients and review the appropriate management of such patients based on the currently available literature.

METHODS

An unsystematic review of the medical literature was performed and articles pertaining to human poisoning were obtained. The literature selected was based on the preference and clinical expertise of authors.

DISCUSSION

If a poisoning is recognized early and appropriate testing and supportive care is initiated rapidly, the majority of patient outcomes will be good. Judicious use of antidotes should be practiced and clinicians should clearly understand the indications and contraindications of antidotes prior to administration.