Suicide by self-administration of a drug mixture (propofol, midazolam, and zolpidem) in an anesthesiologist: the first case report in Italy

Propofol misuse in medical professions: a scoping review

PURPOSE

We aimed to describe the current literature concerning propofol misuse in medical professionals, specifically relating to the individual demographics of those misusing propofol and the outcomes of propofol misuse.

METHODS

We conducted a retrospective scoping review of the literature using a modified PRISMA approach. We used MEDLINE, EMBASE, and PsycINFO databases to identify relevant studies based on search terms. Studies describing individual medical professionals misusing propofol were included.

RESULTS

Twenty-four articles describing 88 individual cases of propofol misuse were included for data charting and analysis. Anesthesiologists and certified registered nurse anesthetists were most commonly identified. Death was a common method of identification of misuse, while rehabilitation and death were common final outcomes associated with propofol misuse.

CONCLUSIONS

Despite knowledge of the pharmacokinetic and pharmacodynamic properties of propofol by those misusing this medication, death was a common outcome reported in the literature. Data related to long-term outcomes including re-entry to clinical practice or success of rehabilitation were limited.

Suicide in anaesthetists: a systematic review

Evidence suggests that healthcare professionals are at an increased risk of dying by suicide, with anaesthetists at particularly high risk. However, much of the data on which this is based are historical. With a focus on the epidemiology and methods used, we conducted a systematic review of evidence regarding suicide and suicidal behaviour among anaesthetists to provide a more contemporary summary. The systematic review process was adapted from a previous similar study in veterinary surgeons and was consistent with recommended guidance. We identified 54 articles published in or after 1990 that had anaesthetist-specific data and met the inclusion criteria. Seven of these reported epidemiological data, of which four were published after 2000. Although none of the more recent studies reported standardised mortality rates specific to suicide in anaesthetists, the proportion of anaesthetists dying by suicide was increased with respect to comparator groups, which is consistent with previous findings. Eleven studies that included information on suicidal behaviour reported suicidal ideation in 3.2-25% of individuals (six studies) and suicide attempts in 0.5-2% (four studies). Studies reporting methods of suicide highlighted the use of anaesthetic drugs, particularly propofol, supporting the suggestion that the increased risk of suicide in anaesthetists may be related to the availability of the means. We discuss our findings in relation to other recently published data and guidance concerning mental health problems in anaesthetists.

Determination of zolpidem phenyl-4-carboxylic acid and zolpidem 6-carboxylic acid in hair using gas chromatography-electron ionization-tandem mass spectrometry

A gas chromatography-electron ionization-tandem mass spectrometric (GC-EI-MS/MS) method was developed and validated for determination of the major metabolites of zolpidem, zolpidem phenyl-4-carboxylic acid (ZPCA) and zolpidem 6-carboxylic acid (ZCA) in human hair. The sample preparation procedure involves decontamination, mechanical pulverization, incubation, extraction and purification prior to instrumental analysis. The extracts were derivatized using hexafluoroisopropanol and heptafluorobutyric anhydride and analyzed by GC-EI-MS/MS. The linear ranges were 8-100 pg/mg for ZPCA and 16-200 pg/mg for ZCA, with the correlation coefficients >0.997. The limits of detection were 1.8 pg/mg for ZPCA and 1.7 pg/mg for ZCA. The recoveries ranged from 77.6 to 111.7%. The intra- and inter-day precisions were within 16.9 and 11.7%, while intra- and inter-day accuracies were -7.0-8.7 and -2.8-7.8%, respectively. The developed method was applied for the analysis of forensic hair samples obtained from suspected zolpidem abusers and the following concentration ranges were monitored: ZPCA 11.9-35.9 pg/mg and ZCA 16.6-21.8 pg/mg. The method proved to be suitable for picogram-level determination of ZPCA and ZCA in human hair.

Application of scanning electron microscopy in the auxiliary diagnosis of death caused by potassium chloride intravenous injection: a case report

To determine the cause of death, in addition to routine autopsy, some assisted techniques are imperative to achieve a definite diagnosis. Herein, we report a case of 36-year-old man who was found dead in his apartment. Medical drug containers (potassium chloride, zolpidem, and propofol) and medical instruments (syringes and indwelling needles) were also found at the scene. An autopsy revealed large amounts of whitish foamy and brown liquid in the trachea and bronchi, and histopathological findings showed remarkable pulmonary congestion and edema. An injection mark with hemorrhage on the right wrist was found on external examination. Results of forensic pathology excluded the presence of mechanical injuries, mechanical asphyxia, embolism, and other fatal diseases. The data of toxicological analysis showed that concentrations of zolpidem and propofol in blood were appreciably higher than the therapeutic dose but they did not reach the absolute lethal dose. Moreover, the level of potassium in the blood and vitreous humor was higher than the expected concentration after death. A scanning electron microscope (SEM) combined with energy-dispersive X-ray microanalyzer (EDX) was subsequently applied to assess the skin samples collected from bilateral wrists. Ultrastructural observation discovered continuous visible interruption of the skin around the injection mark, and energy spectrum analysis revealed statistically significantly higher potassium content of the skin over the right wrist than the left wrist. Comprehensive analysis concluded that the deceased had died of potassium chloride intravenous injection under the zolpidem and propofol effects.

Metabolic Profiles of Propofol and Fospropofol: Clinical and Forensic Interpretative Aspects

Propofol is an intravenous short-acting anesthetic widely used to induce and maintain general anesthesia and to provide procedural sedation. The potential for propofol dependency and abuse has been recognized, and several cases of accidental overdose and suicide have emerged, mostly among the health professionals. Different studies have demonstrated an unpredictable interindividual variability of propofol pharmacokinetics and pharmacodynamics with forensic and clinical adverse relevant outcomes (e.g., pronounced respiratory and cardiac depression), namely, due to polymorphisms in the UDP-glucuronosyltransferase and cytochrome P450 isoforms and drugs administered concurrently. In this work the pharmacokinetics of propofol and fospropofol with particular focus on metabolic pathways is fully reviewed. It is concluded that knowing the metabolism of propofol may lead to the development of new clues to help further toxicological and clinical interpretations and to reduce serious adverse reactions such as respiratory failure, metabolic acidosis, rhabdomyolysis, cardiac bradyarrhythmias, hypotension and myocardial failure, anaphylaxis, hypertriglyceridemia, renal failure, hepatomegaly, hepatic steatosis, acute pancreatitis, abuse, and death. Particularly, further studies aiming to characterize polymorphic enzymes involved in the metabolic pathway, the development of additional routine forensic toxicological analysis, and the relatively new field of ‘‘omics” technology, namely, metabolomics, can offer more in explaining the unpredictable interindividual variability.

Association Between Zolpidem and Suicide: A Nationwide Population-Based Case-Control Study

OBJECTIVE

To evaluate the association between zolpidem and the risk of suicide.

PATIENTS AND METHODS

In this nationwide case-control study, the case group comprised 2199 people who committed suicide or were hospitalized due to suicide attempt between January 1, 2002, and December 31, 2011. To create a control group, we randomly selected 10 people matched to each case according to age, sex, urbanization, and occupation. We measured the risk of suicide/suicide attempt in association with zolpidem exposure by using adjusted odds ratios (ORs) and assessed the dose-response effect of zolpidem.

RESULTS

After adjustment for potential confounders such as the comorbidities of schizophrenia, major depression, bipolar disorder, anxiety, insomnia, substance use, and other mental disorders, the Charlson comorbidity index, and use of benzodiazepine or antidepressants, zolpidem exposure was found to be significantly associated with the risk of suicide/suicide attempt with an OR of 2.08 (95% CIs, 1.83-2.36). The risk increased with the level of zolpidem use. The ORs (95% CIs) for cumulative defined daily doses of less than 90, 90 to 179, and 180 mg or more were 1.90 (1.65-2.18), 2.07 (1.59-2.67), and 2.81 (2.33-3.38), respectively (for trend, P<.001). Subgroup analyses showed that the exposure to zolpidem consistently increased the OR in different age groups, sex, urbanization level, occupation, mental disorders, and Charlson comorbidity index levels and in groups of people with or without the presence of insomnia.

CONCLUSION

This study demonstrated a significant association between using zolpidem and suicide or suicide attempt in people with or without comorbid psychiatric illnesses (all P<.05).