Deliberate Self-poisoning with a Lethal Dose of Pentobarbital with Confirmatory Serum Drug Concentrations: Survival After Cardiac Arrest with Supportive Care

A Case of Barbiturate Poisoning From Pentobarbital in a Young Japanese Patient

Concomitant prescriptions of psychotropic drugs such as sleeping pills, antidepressants, and anti-anxiety medications are common. The relationship between the number of psychotropic drug prescriptions and the incidence of drug overdose has not been reported. However, efforts have been made to reduce the number of concomitant prescriptions hoping that fewer prescriptions of multiple drugs will lower the incidence of drug overdoses. Furthermore, among sleeping pills, prescriptions of barbiturates have been gradually decreasing due to the risk of severe side effects and addiction. This report features a case of an overdose of pentobarbital tablets that caused the classic medical triad (impaired consciousness, hypotension, and hypothermia) of barbiturate intoxication under the characteristics of borderline personality disorder.

Comparison of Low and High Doses of Pentobarbital or Thiopental for Euthanasia of Isoflurane-anesthetized Pigs

Barbiturate overdose is a common method for euthanizing pigs. However, barbiturates can cause tissue damage and may affect experimental results, so the minimal dose should be used. The minimal dose of barbiturate for euthanasia in pigs under isoflurane anesthesia has not yet been determined. In this study, we compared the effect of low and high doses of 2 barbiturates (pentobarbital, 30 or 60 mg/kg; thiopental, 20 and 40 mg/kg) on hemodynamic parameters and time to cardiac arrest in female pigs maintained on isoflurane. Acute decreases in blood pressure and end-tidal CO₂ occurred in all pigs shortly after administration of the barbiturate. However, these changes were not different between either of the high- and low dose groups. Cardiac arrest occurred significantly faster for high dose as compared with low dose thiopental groups, but this parameter was different between the 2 pentobarbital groups. The bispectral index fell immediately after dosing, in all pigs, but no significant differences were observed in the time needed to achieve 0 for the high or low-doses of either drug. In pigs maintained on isoflurane, a low dose of barbiturates is adequate for euthanasia and may result in less tissue damage.

Successful resuscitation and neurological monitoring of a dog with out-of-hospital cardiopulmonary arrest due to pentobarbital overdose

OBJECTIVE

To describe the clinical signs, electroencephalographic (EEG) findings, treatment, and outcome in a dog after successful resuscitation from out-of-hospital cardiopulmonary arrest (OHCA) induced by pentobarbital intoxication.

CASE SUMMARY

A 10-year-old, male intact Jack Russell Terrier was referred for management of refractory status epilepticus and presented dead on arrival. After 7 minutes of cardiopulmonary resuscitation, return of spontaneous circulation was achieved, but the dog remained comatose, apneic, and lacked brainstem reflexes on neurological examination 6 hours following resuscitation. Magnetic resonance imaging showed polioencephalomalacia consistent with prolonged epileptiform activity, and EEG was initially concerning for electrocerebral inactivity. Following supportive care that included short-term mechanical ventilation, the dog made a full recovery and was discharged from the hospital alive 7 days postresuscitation. It was later revealed that the dog had been administered an unknown amount of pentobarbital during transportation, which likely contributed to the OHCA, clinical, and EEG findings.

NEW INFORMATION PROVIDED

This is the first report to describe the full recovery and hospital discharge of a dog suffering OHCA and the first description of EEG findings in a clinical veterinary patient following cardiopulmonary arrest and successful resuscitation. Factors likely contributing to successful patient outcome and potential benefits and limitations of EEG in monitoring postcardiac arrest patients are discussed.

Barbiturate-related hospitalisations, drug treatment episodes, and deaths in Australia, 2000-2018

OBJECTIVES

To determine the characteristics and population rates of barbiturate-related hospitalisations, treatment episodes, and deaths in Australia, 2000-2018.

DESIGN, SETTING

Analysis of national data on barbiturate-related hospitalisations (National Hospital Morbidity Database, 1999-2000 to 2017-18), drug treatment episodes (Alcohol and Other Drug Treatment Services National Minimum Data Set, 2002-03 to 2017-18), and deaths (National Coronial Information System, 2000-01 to 2016-17).

MAIN OUTCOME MEASURES

Population rates directly age-standardised to the 2001 Australian standard population; average annual percentage change (AAPC) in rates estimated by Joinpoint regression.

RESULTS

We identified 1250 barbiturate-related hospitalisations (791 cases of deliberate self-harm [63%]), 993 drug treatment episodes (195 cases with barbiturates as the principal drug of concern [20%]), and 511 deaths during the respective analysis periods. The barbiturate-related hospitalisation rate declined from 0.56 in 1999-2000 to 0.14 per 100 000 population in 2017-18 (AAPC, -6.0%; 95% CI, -7.2% to -4.8%); the declines in hospitalisations related to accidental poisoning (AAPC, -5.8%; 95% CI, -9.1% to -2.4%) and intentional self-harm (AAPC, -5.6%; 95% CI, -6.9% to -4.2%) were each statistically significant. Despite a drop from 0.67 in 2002-03 to 0.23 per 100 000 in 2003-04, the drug treatment episode rate did not decline significantly (AAPC, -6.7%; 95% CI, -16% to +4.0%). The population rate of barbiturate-related deaths increased from 0.07 in 2000-01 to 0.19 per 100 000 population in 2016-17 (AAPC, +9.3%; 95% CI, +6.2-12%); the rate of intentional self-harm deaths increased (AAPC, +11%; 95% CI, +7.4-15%), but not that of accidental deaths (AAPC, -0.3%; 95% CI, -4.1% to +3.8%).

CONCLUSIONS

While prescribing and community use of barbiturates has declined, the population rate of intentional self-harm using barbiturates has increased. The major harm associated with these drugs is now suicide.

Low temperature exerts protective effects by inhibiting mitochondria-mediated apoptosis pathway following pressure injury to rat muscle

OBJECTIVE

We aimed to determine the effect of different low-temperature range interventions at different time-points in a rat model of pressure injury (PI) produced by Ischemia/Reperfusion (I/R) injury.

METHODS

Sprague-Dawley rats were randomly assigned to blank control, injury control, and temperature intervention groups. Rats in the injury control and temperature intervention groups (involving exposure to different temperature range at different time-points) were subjected to three cycles of I/R injury with 2-h ischemia and 0.5-h reperfusion to induce PI.

RESULTS

The muscle tissues exhibited degenerative changes after compression. Low temperature intervention of 16-18°C in the ischemia period resulted in the lowest degree of tissue damage and significantly decreased levels of Bcl-2-associated X protein (Bax), caspase-9, and caspase-3. Moreover, it resulted in the highest expression level of B-cell lymphoma 2 (Bcl-2) and lowest expression levels of Bax, caspase-9, and caspase-3 in muscle tissues among all intervention groups.

CONCLUSION

Low-temperature intervention at 16-18°C during the ischemia period showed optimal effects on the expressions of apoptotic factors during the development of PI with I/R-induced tissue damage.

Recent trends in barbiturate detection in medicolegal deaths

A study was undertaken of 51 cases where barbiturates were detected in post-mortem blood samples from 2000 to 2019 at Forensic Science South Australia, Adelaide, Australia. The cause of death was drug toxicity in only 27 (53%) (M:F = 19:8; age range 19-74yrs, mean 46yrs). In 17 cases, barbiturate toxicity was the primary cause of death, 14 due to pentobarbitone and 3 to phenobarbitone. All were suicides. Barbiturates were obtained by online purchase from overseas sources in 9 cases (33%), and through veterinary practice in 2 cases (7%). Drug toxicity deaths where barbiturates were detected rose from 1 in 2000-2004 to 11 in 2015-2019, and those where deaths were primarily due to barbiturate toxicity rose from 1 in 2000-2004 to 9 in 2015-2019. However, the mere detection of barbiturates in post mortem samples did not equate with illicit use, as 23 of the deaths (45%) were due to natural causes in individuals prescribed barbiturates for epilepsy. The usefulness of examining subset populations separate from accrued national data is also demonstrated in the significantly younger age of decedents in South Australia dying from deliberately administered barbiturates (46 yrs) compared to the national average of 57.9 yrs. The reasons for this difference will require further investigation as this may impact upon local suicide prevention strategies.

Old and Cold: A Novel Case of Combined Secobarbital and Pentobarbital Poisoning in an Elderly Woman

A 94-year-old woman was found unresponsive in her room at an independent living facility. Upon paramedic arrival, the patient had a Glasgow Coma Scale of 3, and she was transported to the emergency department (ED). In the ED, she was unresponsive but spontaneously breathing, bradycardia, and hypothermia. Serum concentrations of both secobarbital (3.3µg/mL; therapeutic 1.0-2.0µg/mL) and pentobarbital (9.5µg/mL; therapeutic < 5.0µg/mL) were detected and elevated. This type of poisoning is quite rare and should be considered in patients presenting with hypothermia and coma, even in patients showing brain death signs. The use of hemodialysis for refractory pentobarbital poisoning may be helpful.

Toxicologic Confounders of Brain Death Determination: A Narrative Review

The aim of this narrative review is to describe the toxicologic confounders of brain death currently reported in the literature to offer guidance for physicians assessing brain death after a toxic exposure. We established an a priori definition of a “brain death mimic” as an unresponsive, intubated patient missing some, but not all brainstem reflexes. We completed a review of the literature utilizing MEDLINE and EMBASE to find case reports of patients of all ages in English, French, and Spanish meeting the criteria and hand searched the references of the results. We recorded xenobiotic dose, duration of physical exam suggesting brain death, and how the cases failed to meet full brain death criteria, when available. Fifty-six cases representing 19 different substances met the a priori definition of brain death mimic. Xenobiotic toxicities included: snake envenomation (13), baclofen (11), tricyclic antidepressants (8), bupropion (7), alcohols (4), antiepileptic agents (3), barbiturates (2), antidysrhythmics (2), organophosphates (2), and one case each of magnesium, succinylcholine, tetrodotoxin, and zolpidem. All patients except one survived to discharge and the majority at their baseline physical health. The most common means by which the cases failed brain death examination prerequisites was via normal neuroimaging. The xenobiotics in this review should be considered in cases of poisoning resulting in loss of brainstem reflexes and addressed before brain death determination. Brain death diagnosis should not be pursued in the setting of normal cerebral imaging or incomplete evaluation of brain death prerequisites.

Sudden unresponsive patient with normal vital signs: what is going on?

PURPOSE OF REVIEW

To summarize the differential diagnosis and diagnostic approach of sudden unresponsiveness with normal vital signs in various settings, including the ICU.

RECENT FINDINGS

Sudden unresponsiveness may be either transient or persistent, and may result from primary brain diseases or nonstructural systemic conditions. Life-threatening causes should always be discriminated from those more benign. Regional epidemiology, for example regarding intoxications, and evolving therapeutic management, for example for ischemic stroke, should always be taken into account for optimal opportunity for rapid diagnosis and best management.

SUMMARY

Sudden unresponsiveness with normal vital signs should trigger immediate and focused diagnostic evaluation to find or exclude those conditions requiring urgent, and possibly life-saving, management.