Poisoning with illicit substances: toxicology for the anaesthetist

Perioperative Considerations for Patients Exposed to Psychostimulants

Concerns regarding the perioperative management of acute psychostimulant intoxication have been recognized for decades, but novel and diverse substances in this class continue to be developed. Despite the similarities in mechanisms of action among psychostimulants, each subclass within this broad category has unique receptor specificity and different mechanisms that play a role in patient clinical presentation. These issues present challenges to anesthesia providers when caring for patients with either acute or chronic exposure to psychostimulants during the perioperative period. Challenges result from both physiological and psychological effects that influence the action of the primary anesthetic agent, adjuvant anesthetics, and analgesics used for perioperative management of pain. The epidemiology, pharmacology, and perioperative implications of psychostimulant use are presented for amphetamines and similar acting nonamphetamines, cocaine, and, finally, the mixed-action drugs known as entactogens that share stimulant and psychedelic properties. This information is then used as the foundation for safe and effective perioperative management of patients exposed to psychostimulants.

Acute poisoning in children: Etiology, structure, treatment tactics and outcomes

Introduction: Acute poisoning is often observed in children and can have serious consequences since it is characterized by rapid development of symptoms and obvious disfunction of vital organs.

Materials and methods: Retrospective analysis of the case histories of the children with acute poisoning admitted to Voronezh Regional Children’s Clinical Hospital No. 1 in 2016–2019 was carried out. Anamnesis, clinical and laboratory studies and effective treatment criteria were entered into electronic spreadsheets and served as the basis for a database on children’s poisoning.

Results and discussion: Analysis of 183 case histories of children with intoxication aged 4 months to 17 years old was performed. Distribution per age showed bimodal peaks at 1–2 years and 13–14 years. Poisoning was accidental in 96.2% of the cases, and 3.8% of the adolescents reported suicide cases. In the group of young children, acute drug poisoning is more frequent in girls (P < 0.05). In the older groups, there is no gender difference in frequency of poisoning cases.

Early call for medical help is typical for the adolescent age group. Correlation between time of help-seeking and children’s age is statistically significant (correlation coefficient r = 0.38, P < 0.05).

Conclusion: Study of poisoning issue in children will allow to carry out targeted preventive measures to reduce the number of poisoning cases, prevent their consequences and to determine the most rational modus operandi for medical personnel for effective and safe pharmacotherapy.

Graphical abstract

In pediatric practice, intoxication by poisons and drugs is among the most common reasons for seeking medical help and hospitalization in intensive care units. It is important to study and record dynamics, structure and frequency of acute poisoning with subsequent development of prevention and treatment methods.

Intravenous Lipid Emulsion for the Treatment of Perioperative Cocaine Intoxication

Symptomatic cocaine intoxication in the preoperative period is a potentially life-threatening condition, especially before emergent surgery. The anesthesiologist is faced with a dilemma where the patient is deemed unsafe for induction of general anesthesia but also in need of immediate surgical intervention. Cocaine is a local anesthetic and, as such, has been proposed to respond to lipid emulsion treatment as other local anesthetics would. We present a case supporting this statement and review the relevant published literature on the topic.

Anesthesia for Patients Who Self-Report Cannabis (Marijuana) Use Before Esophagogastroduodenoscopy: A Retrospective Review

Increasing numbers of patients are using cannabis before procedures that require anesthesia. This study set out to examine the impact of cannabis use on anesthetic agent requirements, associated cardiac and respiratory morbidity, and overall satisfaction levels in patients undergoing esophagogastroduodenoscopy (EGD). This involved a retrospective review of patients undergoing EGD at a single center. Fortyseven, self-reported cannabis users were identified and 23 were successfully cross-matched with control participants for comparison purposes. The Wilcoxon signed rank test was used to evaluate differences in propofol administration between the 2 groups, and the McNemar test was used to test for differences in fentanyl and ketamine administration. No statistically significant differences were observed in propofol, fentanyl, or ketamine administration in the cannabis group compared with the control group. No adverse cardiac or respiratory events were reported within 30 days for either group. This study was specific to EGD procedures of short duration, and larger studies are needed to confirm results of no consequence in cannabis users undergoing anesthesia. Future studies should consider cannabis users who undergo anesthesia for diverse procedure types of various durations.

A review of the anesthetic implications of marijuana use

Marijuana, derived from plants of the genus Cannabis, is the most commonly used illicit drug in the United States. Marijuana is illegal at the federal level and remains a Drug Enforcement Agency Schedule 1 substance. Nevertheless, most states have passed less stringent legislation related to its use, ranging from decriminalization of possession to allowing medical or even recreational use, and some county and municipal law enforcement agencies have refrained from prosecuting personal possession and/or use even when statute would require such action. Therefore, as use of marijuana becomes more common in the larger population, more patients who are chronic and/or heavy users of marijuana present for surgical procedures, raising the question of best practices to care for these patients in the perioperative period. This review summarizes the known physiologic effects of marijuana in humans, discusses potential implications of marijuana use that the anesthesiologist should consider at each phase of the perioperative period, and outlines recommendations for future study.

Phantom menace: novel psychoactive substances and the UK Armed Forces

Novel psychoactive substances (NPS) encompass a large group of synthesised compounds specifically designed to mimic traditional recreational drugs. Current UK Armed Forces compulsory drug testing does not screen for these substances, making them tempting to the small proportion of UK Armed Forces personnel who indulge in recreational drug use. The acute and chronic sequelae of NPS misuse are widely variable and associated with high morbidity. In this paper, we discuss NPS pharmacology and clinical presentation. We describe toxidromes and management of patients who have misused NPS.Finally, we reflect on the legal, ethical and military consequences of NPS misuse for both the service person misusing NPS and the Military Physician providing their care.

Anesthetic implications of recreational drug use

PURPOSE

As the use of recreational drugs increases, the likelihood of an anesthesiologist perioperatively encountering patients using or addicted to these drugs will also increase.

PRINCIPAL FINDINGS

Addicted patients may present for anesthetic care in a variety of circumstances in everyday elective surgeries or in acute or life-saving situations, such as emergency Cesarean delivery or trauma surgery. Therefore, it is important for anesthesiologists to know about the most common illicit drugs being used, their clinical presentation and side effects, and the anesthetic options that are beneficial or detrimental to these patients. The most frequently used illicit substances, apart from alcohol and tobacco, are cannabis, cocaine, heroin, prescription opioids, methamphetamine, and hallucinogens. When planning anesthetic care, it is important for anesthesiologists to understand the effects of these agents, including various drug interactions, to predict tolerance to some anesthetic agents, to recognize drug withdrawal signs and symptoms, and to be prepared to manage all these factors in the perioperative period.

CONCLUSIONS

For optimal patient care through the perioperative period, it is critical to obtain information about patient drug use and other associated treatment in order to construct an appropriate anesthetic plan, including specific considerations during surgery, emergence, and in the postanesthesia care unit.

Role of cannabis in cardiovascular disorders

The growing popularity of medical and recreational consumption of cannabis, especially among the youth, raises immediate concerns regarding its safety and long-terms effects. The cardiovascular effects of cannabis are not well known. Cannabis consumption has been shown to cause arrhythmia including ventricular tachycardia, and potentially sudden death, and to increase the risk of myocardial infarction (MI). These effects appear to be compounded by cigarette smoking and precipitated by excessive physical activity, especially during the first few hours of consumption. Cannabinoids, or the active compounds of cannabis, have been shown to have heterogeneous effects on central and peripheral circulation. Acute cannabis consumption has been shown to cause an increase in blood pressure, specifically systolic blood pressure (SBP), and orthostatic hypotension. Cannabis use has been reported to increase risk of ischemic stroke, particularly in the healthy young patients. The endocannabinoid system (ECS) is currently considered as a promising therapeutic target in the management of several disease conditions. Synthetic cannabinoids (SCs) are being increasingly investigated for their therapeutic effects; however, the value of their benefits over possible complications remains controversial. Despite the considerable research in this field, the benefits of cannabis and its synthetic derivatives remains questionable even in the face of an increasingly tolerating attitude towards recreational consumption and promotion of the therapeutic complications. More efforts are needed to increase awareness among the public, especially youth, about the cardiovascular risks associated with cannabis use and to disseminate the accumulated knowledge regarding its ill effects.

Parenteral emulsions and liposomes to treat drug overdose

Drug overdoses from both pharmaceutical and recreational drugs are a major public health concern. Although some overdoses may be treated with specific antidotes, the most common treatment involves providing supportive care to allow the body to metabolize and excrete the toxicant. In many cases, supportive care is limiting, ineffective, and expensive. There is a clear medical need to improve the effectiveness of detoxification, in particular by developing more specific therapies or antidotes for these overdoses. Intravenous lipid emulsions (ILEs) have been investigated as a potential treatment for overdoses of local anesthetics and other hydrophobic drugs. While ILE therapy has been successful in several cases, its use beyond local anesthetic systemic toxicity is controversial and its mechanism of detoxification remains a subject of debate. ILEs were not originally developed to treat overdose, but clarifying the mechanisms of detoxification observed with ILE may allow us to design more effective future treatments. Liposomes are highly biocompatible and versatile formulations, thus it was a natural step to explore their use for drug overdose therapy as well. Several researchers have designed liposomes using a variety of approaches including surface charge, pH gradients, and inclusion of enzymes in the liposome core to optimize the formulations for detoxification of a specific drug or toxicant. The in vitro results for drug sequestration by liposomes are very promising and animal trials have in some cases shown comparable performance to ILE at reduced lipid dosing. This narrative review summarizes the current status and advances in the use of emulsions and liposomes for detoxification and also suggests several areas in which studies are needed for developing future therapies.

A Comparison of Dexmedetomidine, Moxonidine and Alpha-Methyldopa Effects on Acute, Lethal Cocaine Toxicity

Background:

The treatment of cocaine toxicity is an important subject for emergency physicians. We investigated the effects of dexmedetomidine, moxonidine and alpha-methyldopa on acute cocaine toxicity in mice.

Objectives:

The aim of this study was to evaluate the effects of dexmedetomidine, moxonidine and alpha-methyldopa in a mouse model of acute cocaine toxicity.

Materials and Methods:

We performed an experiment consisting of four groups (n = 25 each). The first group received normal saline solution, the second group received 40 µg/kg of dexmedetomidine, the third group received 0.1 mg/kg of moxonidine and the fourth group received 200 mg/kg of alpha-methyldopa, all of which were intraperitoneally administered 10 minutes before cocaine hydrochloride (105 mg/kg). All animals were observed for seizures (popcorn jumping, tonic-clonic activity, or a loss of the righting reflex) and lethality over the 30 minutes following cocaine treatment.

Results:

The ratio of animals with convulsions was lower in all treated groups when compared to the control (P < 0.001). Furthermore, 68% (n = 17) of animals in the dexmedetomidine group, 84% (n = 21) of the alpha-methyldopa group, 92% (n = 23) of the moxonidine group and 100% (n = 25) of the control group showed evidence of seizure activity (P = 0.009). Cocaine-induced lethality was observed in 12% (n = 3) of the dexmedetomidine group, 48% (n = 12) of the alpha-methyldopa group, 52% (n = 13) of the moxonidine group, and 72% (n = 18) of the control group (P < 0.001). All treatments prolonged the time to seizure, which was longest in the dexmedetomidine group (P > 0.05). In addition, the time to lethality was also longer in the same group (P < 0.001).

Conclusions:

The present study provides the first experimental evidence in support of dexmedetomidine treatment for cocaine-induced seizures. Premedication with dexmedetomidine reduces seizure activity in a mouse model of acute cocaine toxicity. In addition, while dexmedetomidine may be effective, moxonidine and alpha-methyldopa did not effectively prevent cocaine-induced lethality.

Perioperative management in the patient with substance abuse

Drug and alcohol use is a pervasive problem in the general population and in those requiring anesthesia for an operation. History and screening can help delineate those who may be acutely intoxicated or chronic drug and alcohol users. Both acute intoxication and chronic abuse of these substances present challenges for anesthetic management during and after an operation. The clinician should be aware of problems that may be encountered during any part of anesthesia or postoperative care.

Potential diversion of local anesthetics from dental offices for use as cocaine adulterants

BACKGROUND

Reports of lidocaine and benzocaine in the bloodstreams of people who abuse cocaine with accompanying reports of seizures and methemoglobinemia indicate that there is a potential that local anesthetics are being diverted from dental offices and being used as cocaine adulterants. These adulterants augment the nasal numbness produced by inhaling cocaine.

METHODS

The authors conducted a PubMed search by using the following terms: "adulterants," "benzocaine," "cocaine," "lidocaine" and "methemoglobinemia."

RESULTS

The authors identified two case reports as a result of their PubMed search. Each case involved a patient with symptoms of both cocaine overdose and methemoglobinemia who sought treatment at an emergency department. The results of urine samples from each patient, as well as the results from an analysis of a sample of one patient's cocaine, revealed the presence of many adulterants, including lidocaine and benzocaine.

CONCLUSIONS

Injectable lidocaine and topical benzocaine are cheap and readily available substances found in dental offices that may be diverted by anyone-including dentists, office staff members or patients-to adulterate cocaine.

PRACTICAL IMPLICATIONS

Additional research is needed to identify whether dental offices are a common source of cocaine adulterants. The authors recommend that dentists keep track of their local anesthetic supplies.

Overdose of drugs for attention-deficit hyperactivity disorder: clinical presentation, mechanisms of toxicity, and management

The prevalence of attention-deficit hyperactivity disorder (ADHD) in the USA is estimated at approximately 4-9% in children and 4% in adults. It is estimated that prescriptions for ADHD medications are written for more than 2.7 million children per year. In 2010, US poison centers reported 17,000 human exposures to ADHD medications, with 80% occurring in children <19 years old and 20% in adults. The drugs used for the treatment of ADHD are diverse but can be roughly separated into two groups: the stimulants such as amphetamine, methylphenidate, and modafinil; and the non-stimulants such as atomoxetine, guanfacine, and clonidine. This review focuses on mechanisms of toxicity after overdose with ADHD medications, clinical effects from overdose, and management. Amphetamine, dextroamphetamine, and methylphenidate act as substrates for the cellular monoamine transporter, especially the dopamine transporter (DAT) and less so the norepinephrine (NET) and serotonin transporter. The mechanism of toxicity is primarily related to excessive extracellular dopamine, norepinephrine, and serotonin. The primary clinical syndrome involves prominent neurological and cardiovascular effects, but secondary complications can involve renal, muscle, pulmonary, and gastrointestinal (GI) effects. In overdose, the patient may present with mydriasis, tremor, agitation, hyperreflexia, combative behavior, confusion, hallucinations, delirium, anxiety, paranoia, movement disorders, and seizures. The management of amphetamine, dextroamphetamine, and methylphenidate overdose is largely supportive, with a focus on interruption of the sympathomimetic syndrome with judicious use of benzodiazepines. In cases where agitation, delirium, and movement disorders are unresponsive to benzodiazepines, second-line therapies include antipsychotics such as ziprasidone or haloperidol, central alpha-adrenoreceptor agonists such as dexmedetomidine, or propofol. Modafinil is not US FDA approved for treatment of ADHD; however, it has been shown to improve ADHD signs and symptoms and has been used as an off-label pharmaceutical for this diagnosis in both adults and children. The mechanism of action of modafinil is complex and not fully understood. It is known to cause an increase in extracellular concentrations of dopamine, norepinephrine, and serotonin in the neocortex. Overdose with modafinil is generally of moderate severity, with reported ingestions of doses up to 8 g. The most common neurological effects include increased anxiety, agitation, headache, dizziness, insomnia, tremors, and dystonia. The management of modafinil overdose is largely supportive, with a focus on sedation, and control of dyskinesias and blood pressure. Atomoxetine is a selective presynaptic norepinephrine transporter inhibitor. The clinical presentation after overdose with atomoxetine has generally been mild. The primary effects have been drowsiness, agitation, hyperactivity, GI upset, tremor, hyperreflexia, tachycardia hypertension, and seizure. The management of atomoxetine overdose is largely supportive, with a focus on sedation, and control of dyskinesias and seizures. Clonidine is a synthetic imidazole derivative with both central and peripheral alpha-adrenergic agonist actions. The primary clinical syndrome involves prominent neurological and cardiovascular effects, with the most commonly reported features of depressed sensorium, bradycardia, and hypotension. While clonidine is an anti-hypertensive medication, a paradoxical hypertension may occur early with overdose. The clinical syndrome after overdose of guanfacine may be mixed depending on central or peripheral alpha-adrenoreceptor effects. Initial clinical effects may be drowsiness, lethargy, dry mouth, and diaphoresis. Cardiovascular effects may depend on time post-ingestion and may present as hypotension or hypertension. The management of guanfacine overdose is largely supportive, with a focus on support of blood pressure. Overdose with ADHD medications can produce major morbidity, with many cases requiring intensive care medicine and prolonged hospital stays. However, fatalities are rare with appropriate care.