Epidemiology of Hepatitis C infection in pregnancy: Patterns and trends in West Virginia using statewide surveillance data.

BACKGROUND: The increasing rate of Hepatitis C virus (HCV) infection has been attributed to the substance use epidemic. There is limited data on the current rates of the paralleling HCV epidemic. OBJECTIVES: To estimate the prevalence of maternal HCV infection in West Virginia (WV) and identify contributing factors. METHODS: Population-based retrospective cohort study of all pregnant individual(s) who gave birth in WV between 01/01/2020 to 01/30/2024 (N = 69,925). Multiple log-binomial regression models were used to estimate the adjusted risk ratio (ARR) and the 95% confidence intervals (CI). RESULTS: The rate of maternal HCV infection was 38 per 1,000 deliveries. The mean age of pregnant individual(s) with HCV was 29.99 (SD 4.95). The risk of HCV was significantly higher in White vs. minority racial groups [ARR 1.93 (1.50, 2.49)], those with less than [ARR 1.57 (1.37, 1.79)] or at least high school [ARR 1.31 (1.17, 1.47)] vs. more than high school education, those on Medicaid [ARR 2.32 (1.99, 2.71)] vs. private health insurance, those residing in small-metro [ARR 1.32 (1.17, 1.48)] and medium-metro [ARR 1.41 (1.24, 1.61)], vs. rural areas, and those who smoked [ARR 3.51 (3.10, 3.97)]. HCV risk was highest for those using opioids [ARR 4.43 (3.95, 4.96)]; followed by stimulant use [ARR = 1.79 (1.57, 2.04)]. CONCLUSIONS: Our findings highlight that maternal age, race, education, and type of health insurance are associated with maternal HCV infection. The magnitude of association was highest for pregnant individual(s) who smoked and used opioids and stimulants during pregnancy in WV.

Heterogeneity in choice models of addiction: the role of context.

RATIONALE: Theories of addiction guide scientific progress, funding priorities, and policy development and ultimately shape how people experiencing or recovering from addiction are perceived and treated. Choice theories of addiction are heterogenous, and different models have divergent implications. This breeds confusion among laypeople, scientists, practitioners, and policymakers and reduces the utility of robust findings that have the potential to reduce the global burden of addiction-associated harms. OBJECTIVE: Here we differentiate classes of choice models and articulate a novel framing for a class of addiction models, called contextual models, which share as a first principle the influence of the environment and other contextual factors on behavior within discrete choice contexts. RESULTS: These models do not assume that all choice behaviors are voluntary, but instead that both proximal and distal characteristics of the choice environment-and particularly the benefits and costs of both drug use and non-drug alternatives-can influence behavior in ways that are outside of the awareness of the individual. From this perspective, addiction is neither the individual's moral failing nor an internal uncontrollable urge but rather is the result of environmental contingencies that reinforce the behavior. CONCLUSIONS: Contextual models have implications for guiding research, practice, and policy, including identification of novel target mechanisms while also improving existing interventions.

Substance Use Disorder as Risk Factor for Intubation in Angioedema: A Nationwide Cohort Study.

OBJECTIVES: Individuals with angioedema (AE) are at high risk for airway compromise and often require endotracheal intubation. Patient factors predisposing one to airway compromise are not well described. The objective of this study is to examine whether substance use disorder (SUD) in patients with AE is associated with need for airway intervention. METHODS: This population-based retrospective cohort study compared AE patients with SUD versus propensity-matched control groups. Outcomes were hospitalization, intubation, and tracheotomy. Using the TriNetX National Database, this study included 28,931 patients with SUD and 117,509 patients without SUD who presented with AE. RESULTS: Among patients with AE, those with each subtype of SUD (alcohol, cannabis, cocaine, tobacco, and opioids) were found to have higher risk of severe AE compared to propensity-matched non-SUD cohorts. Rate of hospitalization after cohort matching ranged from 20.4% for tobacco use disorder to 30.4% for cocaine use disorder, all significantly higher than the 8.0% in a population without SUD. Each SUD subtype was associated with a higher rate of intubation compared with matched non-SUD groups, with cannabis use disorder having the highest relative risk (RR) of 3.67 (95% CI: 2.69-5.02). Tobacco (RR = 2.45, 95% CI: 1.79-3.34) and alcohol (RR = 2.82, 95% CI: 1.73-4.58) use disorders were both associated with significantly higher risk of tracheotomy. CONCLUSION: These data suggest that patients with SUD, regardless of subtype, and after propensity matching for demographics and comorbidities are at higher risk for adverse outcomes when presenting with AE. This study highlights clinically relevant predictors of airway compromise. LEVEL OF EVIDENCE: Level 3 Laryngoscope, 2024.

Breaking Free From the "War on Drugs": Examples From Three Leader States.

While the federal government continues to pursue a punitive "War on Drugs," some states have adopted evidence-based, human-focused approaches to reducing drug-related harm. This article discusses recent legal changes in three states that can serve as models for others interested in reducing, rather than increasing, individual and community harm.

"Even Though the System Had Failed Him His Entire Life, We Were Failing Him Yet Again": How Clinical, Welfare, and Penal Medicine Interact to Drive Health Inequities and Medical Moral Injury.

Adam, a justice-involved young man, was brought into the emergency department at the county hospital in cardiogenic shock due to a recurring episode of injection-drug-use-related infective endocarditis (IDU-IE). Adam had initiated injection opioid use in prison. He was surgically treated for the previous episodes of IDU-IE but was unable to fully recover due to limitations in care within penal medicine. This case report explores the prison as a determinant of health, interactions between clinical, welfare, and penal medicine, to produce and maintain health inequities, and structural drivers of physician moral injury through an interview with Adam and reflexive writings from emergency medicine physicians. This case demonstrates the need for three types of structural health interventions: (1) restorative justice, community-based reentry programs, and housing as welfare medicine, (2) increased harm reduction services across healthcare, especially penal medicine, and (3) equitable institutional protocols (contrary to ambiguous guidelines) to treat clinical conditions like IDU-IE that disproportionately impact structurally vulnerable patients.

Acute Pain Management in a Multi-site Trauma Patient.

Pain management is often difficult in the setting of multi-site trauma such as that caused by motor vehicle accidents (MVA), which is especially compounded in the setting of polysubstance abuse. This often results in patients with poor pain tolerance requiring escalating doses of opioid therapy, which creates a vicious cycle. The use of peripheral nerve blocks (PNB) has been shown to decrease overall opioid consumption and can be used effectively to manage postoperative pain in this patient population. Our case report aims to highlight the importance of PNBs as part of a multimodal approach to pain management in patients with polytrauma in the setting of polysubstance abuse.

Diagnosing and managing prescription opioid use disorder in patients prescribed opioids for chronic pain in Australian general practice settings: a qualitative study using the theory of Planned Behaviour.

BACKGROUND: Chronic pain is a debilitating and common health issue. General Practitioners (GPs) often prescribe opioids to treat chronic pain, despite limited evidence of benefit and increasing evidence of harms, including prescription Opioid Use Disorder (pOUD). Australian GPs are worried about the harms of long-term opioids, but few are involved in the treatment of pOUD. There is little research on GPs' experiences diagnosing and managing pOUD in their chronic pain patients. METHODS: This qualitative research used semi-structured interviews and a case study to investigate GPs' experiences through the lens of the Theory of Planned Behaviour (TPB). TPB describes three factors, an individual's perceived beliefs/attitudes, perceived social norms and perceived behavioural controls. Participants were interviewed via an online video conferencing platform. Interviews were transcribed verbatim and thematically analysed. RESULTS: Twenty-four GPs took part. Participants were aware of the complex presentations for chronic pain patients and concerned about long-term opioid use. Their approach was holistic, but they had limited understanding of pOUD diagnosis and suggested that pOUD had only one treatment: Opioid Agonist Treatment (OAT). Participants felt uncomfortable prescribing opioids and were fearful of difficult, conflictual conversations with patients about the possibility of pOUD. This led to avoidance and negative attitudes towards diagnosing pOUD. There were few positive social norms, few colleagues diagnosed or managed pOUD. Participants reported that their colleagues only offered positive support as this would allow them to avoid managing pOUD themselves, while patients and other staff were often unsupportive. Negative behavioural controls were common with low levels of knowledge, skill, professional supports, inadequate time and remuneration described by many participants. They felt OAT was not core general practice and required specialist management. This dichotomous approach was reflected in their views that the health system only supported treatment for chronic pain or pOUD, not both conditions. CONCLUSIONS: Negative beliefs, negative social norms and negative behavioural controls decreased individual behavioural intention for this group of GPs. Diagnosing and managing pOUD in chronic pain patients prescribed opioids was perceived as difficult and unsupported. Interventions to change behaviour must address negative perceptions in order to lead to more positive intentions to engage in the management of pOUD.

Assessing Substance Use Disorder Symptoms with a Checklist among Primary Care Patients with Opioid Use Disorder and/or Long-Term Opioid Treatment: An Observational Study.

BACKGROUND: Primary care (PC) offers an opportunity to treat opioid use disorders (OUD). The Substance Use Symptom Checklist ("Checklist") can assess DSM-5 substance use disorder (SUD) symptoms in PC. OBJECTIVE: To test the psychometric properties of the Checklist among PC patients with OUD or long-term opioid therapy (LTOT) in Kaiser Permanente Washington (KPWA). DESIGN: Observational study using item response theory (IRT) and differential item functioning (DIF) analyses of measurement consistency across age, sex, race and ethnicity, and receipt of treatment. PATIENTS: Electronic health records (EHR) data were extracted for all adult PC patients visiting KPWA 3/1/15-8/30/2020 who had ≥ 1 Checklist documented and indication of either (a) clinically-recognized OUD (i.e., documented OUD diagnosis and/or OUD medication treatment) or (b) LTOT in the year prior to the checklist. MAIN MEASURE: The Checklist includes 11 items reflecting DSM-5 criteria for SUD. We described the prevalence of 2 SUD symptoms reported on the Checklist (consistent with mild-severe DSM-5 SUD). Analyses were conducted in the overall sample and in two subsamples (clinically-recognized OUD and LTOT only). KEY RESULTS: Among 2007 eligible patients, 39.9% endorsed ≥ 2 SUD symptoms (74.3% in the clinically-recognized OUD subsample and 13.1% in LTOT subsample). IRT indicated that a unidimensional model for the 11 checklist items had excellent fit (comparative fit index = 0.998) with high item-level discrimination parameters for the overall sample and both subsamples. DIF across age, race and ethnicity, and treatment was observed for one item each, but had minimal impact on expected number of criteria (0-11) patients endorse. CONCLUSIONS: The Substance Use Symptom Checklist measured SUD symptoms consistent with DSM-5 conceptualization (scaled, unidimensional) in patients with clinically-recognized OUD and LTOT and had similar measurement properties across demographic subgroups. The Checklist may support symptom assessment in patients with OUD and diagnosis in patients with LTOT.

Bovine colostrum supplementation as a new perspective in depression and substance use disorder treatment: a randomized placebo-controlled study.

Introduction: This randomized, placebo-controlled, double-blind, parallel study aimed to evaluate the effect of 3-month supplementation of bovine colostrum (BOV-COL; 8x400 mg per day) on the outcomes of depression treatment in hospitalized patients with substance use disorder (SUD). The hypothesis is that BOV-COL supplementation as an add-on treatment results in favorable alternations in selected blood inflammatory markers or neurotransmitters, leading to better depression treatment outcomes compared with placebo (PLA). Methods: Patients with a Minnesota Multiphasic Personality Inventory-2 score ≥60 points were enrolled. Twenty-nine participants (n=18 in the BOV-COL group and n=11 in the PLA group) completed the protocol. Results: The mean Beck Depression Inventory-II score was significantly reduced after supplementation in both groups. However, the mean 17-point Hamilton Depression Rating Scale score was decreased in the BOV-COL group, but not in the PLA group. In the BOV-COL group, there was a reduction in interleukin (IL)-1, IL-6, IL-10, the IL-6:IL-10 ratio, IL-17, and tumor necrosis factor alpha (TNF-α), while in the PLA group only IL-6 decreased. Favorable alternations in the total count and differentials of white blood cell subsets were more pronounced in the BOV-COL. There were no changes in neurotransmitter concentrations. Conclusions: BOV-COL supplementation is a promising add-on therapy in patients with depression and SUD.

Identifying best practices for substance-related intimate partner violence screening and referral: a narrative review.

Introduction: Substance use is strongly associated with intimate partner violence (IPV) and is a modifiable risk factor for IPV. However, lack of comprehensive screening and referral for co-occurring IPV and substance use, along with their psychiatric sequalae, limits the identification and implementation of effective interventions for substance-related IPV. This narrative review (1) investigates the literature on screening and referral practices for IPV, and if these include screening for substance use or other psychiatric comorbidities, (2) provides recommendations for current best practices, and (3) suggests future directions for research and practice aimed at identifying and reducing substance-related IPV. Methods: A narrative literature review examined studies investigating IPV screening and referral programs in clinics. Selected studies were reviewed for: (1) effectiveness, (2) barriers to implementation and sustainability, and (3) responsivity to psychiatric comorbidity, including substance use and substance use disorders (SUD). Results: Findings suggest that effective IPV screening and referral programs have been developed, but disparities in IPV screening exist and many programs only screen for IPV victimization. Barriers to the implementation and sustainability of IPV screening programs include lack of ongoing provider training, funding or institutional support, and direct connection to referral services. Further, many IPV screening programs lack assessment of and referral for comorbid psychiatric conditions, including substance use, and tend not to be routinely implemented in SUD clinics. Discussion: Additional systematic work is needed to develop universal and comprehensive screening and referral programs for substance-related IPV and address issues of long-term sustainability, particularly within SUD treatment settings.

HIV and Substance Use Disorders.

Over 1.2 million Americans aged 13 years and older have been diagnosed with human immunodeficiency virus (HIV). While HIV incidence has been declining since 2017, the risk of HIV acquisition and transmission persists among persons who use drugs via injection drug use and unprotected sexual intercourse associated with substance use. Untreated substance use disorder (SUD) is associated with poor adherence to HIV antiretroviral therapy, poor HIV outcomes, and increased risk for HIV acquisition. Herein, we describe the intertwined syndemic of HIV and SUD, as well as treatment strategies and evidence-based public health efforts to engage and retain persons who use drugs into care.

Empirical assessment of wounds among people who use substances.

BACKGROUND: Wounds are a significant source of morbidity among people who use substances (PWUS). This project sought to identify the incidence and severity of wounds among PWUS in the South Bronx, a region of New York City with one of the highest morbidities of substance use disorder. METHODS: This study recruited PWUS within the past 30 days. Research staff were trained to document the presence and severity of wounds. The primary outcome measure was the incidence of wounds. Acceptability of on-the-street wound care was assessed by the number of participants encountered. The association between participant characteristics and wounds was also evaluated. RESULTS: In total, 586 PWUS were assessed (19.4 % female: 69 % Hispanic; 23 % Black; 5 % White). Heroin (65.7 %) and psychostimulants (58.3 %) were the most commonly used drugs. Approximately 23 % of outreach recipients disclosed a wound. Among those with a wound, 60.9 % reported one wound, 27.8 % had two wounds, and 11.3 % had three or more wounds. Small wounds (approximately the size of a cherry) were the most common (78.6 %). Recent use of stimulants or heroin, along with intravenous use of any substance were significantly associated with having a wound. CONCLUSIONS: This study found that drug-related wounds were common among PWUS. Toxicology data from other sources indicate that xylazine was present in the NYC market at the time, though its prevalence among the current sample is difficult to determine. The occurrence and severity of substance-related wounds in NYC should continue to be monitored as a function of changes in the xylazine adulteration.

Hepatitis C Presenting Like Endocarditis in a Young Patient With Substance Use Disorder: A Case Report.

This case report details a 21-year-old male patient who initially presented with endocarditis-like symptoms but ultimately had hepatitis C in the setting of substance use disorder. It highlights the value of prompt diagnosis and effective treatment. He had a medical history of chronic heroin use over two years and presented inconsistently to the emergency department with generalized body aches. He had generalized body pain and right upper and lower quadrant abdominal pain. He had been unable to tolerate any oral intake and had been vomiting after every meal for the last three weeks. Physical examination was significant only for large, ovoid, erythematous nodules on the left dorsal foot, blanching and slightly painful to touch; diffuse scabs and sores on extremities; and nodules on dorsal interphalangeal joints on the left hand. Urine drug screen was noted to be positive for cannabinoids, methamphetamines, and opioids. The initial electrocardiogram did not show typical T wave flattening changes for hypokalemia. Transthoracic echocardiogram ruled out infective endocarditis, with no valvular vegetation. He was ultimately found to be hepatitis C virus antibody positive. This case illustrates the importance of keeping a wide differential in mind. The patient had hepatitis C despite being asymptomatic throughout presentation-keeping. The patient's history of heroin use was critical while ordering testing.

The methods and baseline characteristics of a multi-site randomized controlled trial evaluating mindfulness-based relapse prevention in conjunction with peer support to improve adherence to medications for opioid use disorders.

Introduction: Medications for opioid use disorders (MOUD) remain the gold standard for treating OUD, but treatment initiation and adherence remain challenging. Exclusive utilization of pharmacotherapy as a treatment modality for OUD is sub-optimal, and a combination of psychotherapies and pharmacotherapies is recommended. General trends indicate the benefits of peer mentoring and MBRP separately. Therefore, we hypothesize that the combined effect of MBRP and Peer mentoring will produce synergistic improvements in MOUD adherence compared to an enhanced twelve-step facilitation (TSF). Methods: This paper describes the methods and baseline characteristics of a multi-site randomized controlled trial evaluating the effectiveness of a combination of MBRP and peer support (MiMP) compared to an enhanced TSF in improving adherence to MOUD. Both MiMP and TSF are 12-week manualized protocols that utilize licensed therapists. The interventions are delivered in weekly group sessions that last about 75-90 minutes per session. The primary outcome is MOUD adherence. Secondary and exploratory outcomes include relapse, cravings, depression, anxiety, stress, quality of life, and pain catastrophizing. Results: The participants' ages ranged from 21 years to 77 years, with a mean age of 44.5 (SD ± 11.5 years). There was an almost equal distribution of gender and place of residence. Overall, 51.9% (n=54) of participants identified as female and 48.1% (n=50) were male. Similarly, 51.9% (n=54) of participants resided in urban areas, while 48.1% (n=50) resided in rural areas. Participants identified as either black or white, with over three-quarters identifying as white (77.9%, n= 81) and 22.1% (n= 23) as black. Most participants randomized to the 12-step facilitation group were white (93.1%). Relationships and employment status were well distributed between categories. Over half of the participants reported some college or higher education. Over 90% of the participants made less than $75,000 per year. Some participants indicated that they had both public and private health insurance. Discussion and conclusion: This study is innovative in several ways including combining MBRP and peer support, addressing comorbid mental health issues among individuals with OUD, utilizing manualized protocols, and evaluating of both physiological and self-reported measures in assessing cortisol reactivity as a predictor of relapse and treatment outcomes.

Considerations when prescribing opioid agonist therapies for people living with HIV.

INTRODUCTION: Medications for opioid use disorder (MOUD) include opioid agonist therapies (OAT) (buprenorphine and methadone), and opioid antagonists (extended-release naltrexone). All forms of MOUD improve opioid use disorder (OUD) and HIV outcomes. However, the integration of services for HIV and OUD remains inadequate. Persistent barriers to accessing MOUD underscore the immediate necessity of addressing pharmacoequity in the treatment of OUD in persons with HIV (PWH). AREAS COVERED: In this review article, we specifically focus on OAT among PWH, as it is the most commonly utilized form of MOUD. Specifically, we delineate the intersection of HIV and OUD services, emphasizing their integration into the United States Ending the HIV Epidemic (EHE) plan by offering comprehensive screening, testing, and treatment for both HIV and OUD. We identify potential drug interactions of OAT with antiretroviral therapy (ART), address disparities in OAT access, and present the practical benefits of long-acting formulations of buprenorphine, ART, and pre-exposure prophylaxis for improving HIV prevention and treatment and OUD management. EXPERT OPINION: Optimizing OUD outcomes in PWH necessitates careful attention to diagnosing OUD, initiating OUD treatment, and ensuring medication retention. Innovative approaches to healthcare delivery, such as mobile pharmacies, can integrate both OUD and HIV and reach underserved populations.

Certified Community Behavioral Health Clinic Services for Clients With Co-occurring Disorders: A Latent Class Approach.

OBJECTIVE: Certified community behavioral health clinics (CCBHCs) are designed to provide comprehensive care for individuals with co-occurring mental and substance use disorders. The authors classified outpatient mental health treatment facilities on the basis of provision of services for clients with co-occurring disorders and assessed whether CCBHCs differed from other outpatient mental health facilities in services provided. METHODS: The authors used latent class analysis to identify distinct services for clients with co-occurring disorders in 5,692 outpatient mental health facilities in the 2021 National Substance Use and Mental Health Services Survey. Nine indicators were included: treatment for clients with substance or alcohol use disorder co-occurring with serious mental illness or serious emotional disturbance, specialized programs or groups for such clients, medication-assisted treatment (MAT) for alcohol use disorder, MAT for opioid use disorder, detoxification, individual counseling, group counseling, case management, and 12-step groups. A multinomial logistic regression was used to estimate whether CCBHCs were associated with any identified classes after analyses controlled for facility characteristics. RESULTS: A four-class solution provided a model with the best fit, comprising comprehensive services (23.4%), case management services (17.7%), counseling and self-help services (58.6%), and professional services (4.3%). Regressing class membership on facility type and covariates, the authors found that compared with community mental health clinics (CMHCs), CCBHCs were more likely to belong to the comprehensive services class than to the case management services, counseling and self-help services, and professional services classes. CONCLUSIONS: CCBHCs were more likely than other outpatient programs to offer comprehensive care, and CCBHC status of a CMHC facilitated enhanced service provisions.

Characteristics of Adolescents with and without a Family History of Substance Use Disorder from a Minority Cohort.

Family history (FH+) of substance use disorder (SUD) is an established risk factor for offspring SUD. The extent to which offspring psychological traits or the family environment, each of which may be relevant to familial transmission of SUD risk, vary by FH+ in socioeconomically disadvantaged populations is less clear. We compared the family/social environmental and psychological characteristics of 73 FH+ and 69 FH- youth ages 12-16, from a study of parental criminal justice system involvement in a primarily low-income, minority urban population. A latent profile analysis (LPA) empirically identified groups of subjects with similar psychological characteristics, which were then compared by FH+. FH+ youths were found to have greater mean household size, greater parental psychological aggression, and a higher mean number of adverse childhood experiences, even without considering parental SUD. FH+ individuals had lower report card grades according to parental report and were more likely to have a history of externalizing disorders than FH- individuals. However, FH+ was not significantly associated with many psychological characteristics or with the class membership from the LPA. In conclusion, among a population of low-income, minority urban youth, FH+ was associated with differences in the family environment and only subtle differences in individual psychological characteristics.

Linkage to Care Outcomes Following Treatment in A Low-Threshold Substance Use Disorder Bridge Clinic.

BACKGROUND: Treatment for substance use disorders (SUD) remains low in the United States. To better meet needs of people who use alcohol and other drugs, low threshold bridge clinics which offer treatment without barrier and harm reduction services have gained prevalence. Bridge clinics work to surmount barriers to care by providing same day medication and treatment for SUD and eventually transitioning patients to community-based treatment providers. In this study, we examine SUD treatment outcomes among patients who transitioned out of a bridge clinic. METHODS: This is a retrospective cohort study of posttreatment outcomes of patients seen at an urban medical center's bridge clinic between 2017 and 2022. The primary outcome was being in care anywhere at time of follow-up. We also examined the proportion of patients who completed each step of the cascade of care following transfer: connection to transfer clinic, completion of a clinic visit, retention in care, and medication use among those remaining in care at the transfer clinic. We examined the association of different bridge clinic services with still being in care anywhere and the association between successful transfer with being in care and taking medication at follow-up. RESULTS: Of 209 eligible participants, 63 were surveyed. Sixty-five percent of participants identified as male, 74% as white, 12% as Hispanic, 6% as Black, and 16% were unhoused. Most participants (78%) reported being connected to SUD treatment from the Bridge Clinic, and 37% remained in care at the same facility at the time of survey. Eighty-four percent reported being in treatment anywhere and 68% reported taking medication for SUD at follow-up, with most participants reporting taking buprenorphine (46%). CONCLUSION: Of those participants who transitioned out of a bridge clinic into community-based SUD care, 78% were successfully connected to ongoing care and 84% were still in care at follow-up.

Clinical signs of nitrous oxide use: case report and review of the literature.

Nitrous oxide is used medically as an anesthetic agent; in the food industry as a propellant for condiments; and recreationally for its euphoric and dissociative effects. We report three cases of nitrous oxide misuse causing severe, symptomatic cobalamin (vitamin B12) deficiency in which signs of nitrous oxide use per se, as well as signs of toxicity, were observed, including characteristic palmar calluses over the metacarpal heads, and frostbite. These signs may assist clinicians in the recognition of nitrous oxide use and the timely diagnosis of nitrous oxide toxicity.