Clinical Toxicology最新文献

Introduction: Volatile nitrites, such as amyl nitrite, are used recreationally to enhance sexual experience and provide a feeling of euphoria. They are associated with severe adverse reactions including methaemoglobinaemia and maculopathy. The aim of this study was to explore the epidemiology and clinical effects of volatile nitrite exposures reported to the Victorian Poisons Information Centre in Australia over a 10-year period.

Methods: This was a retrospective, observational study of poison centre call records. Data were extracted for all exposures to volatile nitrites reported from 2013 to 2022.

Results: There were 132 calls about volatile nitrites, representing 122 exposures, with a more than five-fold increase in the annual number of exposures (from five in 2013 to 26 in 2022). Ingestion (49.2%) and inhalation (27.9%) were the most common routes of exposure. Seventy-six (62.3%) patients reported one or more symptoms related to volatile nitrite exposure. The most common symptoms were light-headedness/dizziness (20.5%), oro-mucosal irritation (15.6%), ocular irritation (14.8%), nasal irritation (12.3%), and nausea/vomiting (9.8%). Less common, but potentially serious, adverse effects included methaemoglobinaemia (4.1%), hypoxia (1.6%) and hypotension (0.8%). Symptom severity was usually classified as minor (70/76, 92.1%) at the time of the poisons centre call. Fifty-four (44.3%) patients were either in the hospital when the poisons centre was contacted or were referred to the hospital by the poisons centre.

Discussion: The increase in reported volatile nitrite exposures observed in this study aligns with epidemiological data showing an increase in volatile nitrite usage in Australia. The findings about the nature of exposures and symptoms experienced can be used to inform harm reduction and education efforts for community members and health professionals.

Conclusions: Exposures to volatile nitrites reported to an Australian poisons centre increased between 2013 and 2022. More than 40% of exposures resulted in a hospital presentation. Methaemoglobinaemia was reported in 4.1% of cases.

Introduction: Pit viper envenomation causes tissue damage that can persist for weeks to months despite antivenom. Many patients do not receive post-discharge care beyond testing for late coagulopathy and primary care follow-up. The aim of this report is to describe a snake envenomation patient cohort, complications, and management strategies after three years of operation of a specialized outpatient clinic offering post-discharge evaluation and wound care therapy.

Methods: This was an observational study of patients treated in a newly established snakebite follow-up clinic from June 1, 2021 to November 30, 2023. Patient demographics, snake species, and hospital course were abstracted from poison center records. Persistent symptoms upon clinic evaluation were recorded as well as the therapies prescribed by the clinic wound care physicians.

Results: Of the 465 snake envenomations reported to the state poison center, 52 patients presented to the clinic. The median patient age was 29 years (range 5-88 years), and the majority (65.4%) were male. Antivenom was given during hospitalization in 92.3% of cases. Agkistrodon spp. envenomations (including Agkistrodon contortrix and Agkistrodon piscivorus) were most common (n = 33) with a smaller number of Crotalus horridus (n = 7) and 12 unidentified pit viper envenomations. Persistent edema (61.5%) and bullae (38.5%) were common at follow-up. Interventions provided included compression (38.5%), physical therapy referral (32.7%), tissue debridement (9.6%), and antibiotics (5.8%). Rates of edema and bullae were numerically higher in patients envenomated by Agkistrodon spp. compared to those envenomated by Crotalus horridus.

Discussion: In this primarily Agkistrodon spp.-envenomated cohort, persistent edema, wounds, and functional limitations were common in the post-discharge period. Our outpatient snake envenomation clinic leveraged the expertise of wound care physicians and the public health reach of the state poison center to address the significant morbidity seen on follow-up and provide interventions to facilitate recovery.

Conclusion: This snake envenomation wound care clinic addressed a neglected aspect of pit viper envenomation by providing post-discharge management of enduring tissue damage and other complications.

Introduction: Propranolol is a beta-adrenoceptor blocking drug with sodium channel-blocking properties that can cause life-threatening toxicity in overdose. Limited research defines dose thresholds of toxicity. We aimed to investigate propranolol overdose and dose thresholds for severe toxicity.

Material and methods: This is a prospective series of patients with acute propranolol overdose ≥360 mg from August 2014 to December 2023 enrolled through the Australian TOxicology Monitoring (ATOM) collaboration. Severe toxicity was defined as seizure, coma, inotrope therapy, electrocardiographic evidence of sodium channel blockade, or cardiac arrest.

Results: There were 209 presentations in 165 patients (median age 30 years [range 15-80 years]; 117 females, 71%). The median reported dose ingested was 1,000 mg (IQR: 600-2,000 mg; range 360-16,000 mg). Co-ingestion occurred in 155 (74%) patients, most commonly involving benzodiazepines (n = 52). Bradycardia (heart rate <50 beats/min) occurred in 41 (20%), and hypotension (systolic blood pressure <90 mmHg) in 88 (42%). Severe toxicity occurred in 51 patients (24%), with 17 (8%) having a seizure and 29 (14%) developing coma. Forty-one (20%) received inotropes, including 31(15%) who were given epinephrine and 20 (10%) high-dose insulin. Electrocardiographic evidence of sodium channel blockade occurred in 16 (8%). Seven (3%) had a cardiac arrest (reported dose range 2,400-16,000 mg), with two deaths following the ingestion of propranolol 4,000 mg and 16,000 mg. The median length of stay was 17 h (IQR: 11-32 h). In 79 patients who ingested only propranolol, the lowest reported propranolol dose for hypotension was 400 mg and for bradycardia, 800 mg. The lowest reported dose for severe toxicity was propranolol 2,000 mg. In those ingesting propranolol only, 17 of 32 (53%) patients who ingested ≥2,000 mg had severe toxicity.

Discussion: Severe toxicity was common, occurring in a quarter of all propranolol overdoses and half of the isolated propranolol ingestions (≥2,000 mg). The outcome was usually favourable with good supportive care, even in severe toxicity.

Conclusion: The dose threshold for severe toxicity in isolated propranolol overdose appeared to be 2,000 mg.

Introduction: Common recreational drugs and new psychoactive substances pose challenges to public health. This study investigated the feasibility of merging cases of recreational drug poisoning reported to European poison centres.

Methods: Four European poison centres (Freiburg, Germany; the Netherlands; Sweden and Switzerland) collaborated in a retrospective, observational study. We collected aggregated data on poisonings with 11 common recreational drugs and case-by-case data on poisonings with new psychoactive substances in 2021 by using anonymized data from electronic case reports.

Results: In 2021, 2.0% of the poison centre calls involved poisonings with recreational drugs. The poison centres were contacted about 3,705 patients, involving 4,380 drug exposures, of which 3,708 were common recreational drugs, and 672 were new psychoactive substances. Per million inhabitants, the poisoning rate with common recreational drugs varied between 48 (Freiburg) and 145 (Sweden). Poisonings with amfetamine (22%), cocaine (20%), all delta-9-tetra-hydrocannabinol-containing preparations (20%), and 3,4-methylenedioxymetamfetamine (13%) exposures were most frequent. The poisoning rate per million inhabitants with new psychoactive substances varied between two (Switzerland) and 29 (Netherlands). Cathinones (43%), designer benzodiazepines (28%), and phenethylamines (13%) were the most commonly involved new psychoactive substance classes. Symptoms following cathinone poisoning were tachycardia (35%) and hypertension (13%), while following designer benzodiazepines, somnolence was most prominent (38%). The majority of users of new psychoactive substances were male (67%), 55% were between 18 and 30 years, and 8% involved minors (<18 years).

Discussion: This study showed the feasibility of merging data on recreational drug poisoning collected by poison centres in four countries. Despite underestimating the overall incidence of drug-related health incidents, poison centre data offers national coverage, unlike other data sources, such as drug-related emergency department visits.

Conclusion: This multi-centre, multi-national study reported a substantial annual number of recreational drug poisonings, with a variable proportion of new psychoactive substances. It shows that poison centre data offers detailed insights into exposures to common recreational drugs and new psychoactive substances, user characteristics, and symptoms. It can be used for comprehensive monitoring of drug-related health incidents on a multi-national level.

Objective: Early antivenom administration is essential for effective treatment. We investigated the delays in antivenom administration.

Methods: We reviewed snakebites from the Australian Snakebite Project (2006-2021) given antivenom, presenting to hospital within 12 h. We extracted demographics, snake type, time of bite, hospital arrival, blood collection, antivenom treatment and hospital transfer.

Results: There were 2,169 patients recruited to Australian Snakebite Project 1,132 patients received antivenom within 12 h of the bite, and 1,019 of these were envenomated: median age 41 years (IQR: 24-57 years); 738 (72%) males. A pressure bandage was applied in 950 (93%), a median of 15 min (IQR: 5-30 min) post-bite. Specific snakes were identified by venom assays in 855 patients (80%), including 328 brown snakes (32%), 173 tiger snakes (17%), 74 rough-scaled snakes (7%), 85 red-bellied black snakes (8%), 49 taipans (5%) and 26 death adders (3%). Seventy-seven patients (7%) received antivenom without envenomation. The median length of hospital stay was 41 h (IQR: 24-67 h). The median time to hospital was 60 min (IQR: 30-105 min), to first blood tests was 90 min (IQR: 59-154 min) and to antivenom was 235 min (IQR: 155-345 min). There was a median delay in blood tests of 20 min (IQR: 10-37 min) and a median delay to antivenom of 147 min (IQR: 84-249 min). Non-specific systemic symptoms occurred in 641 (63%) patients, which occurred a median of 24 min (IQR: 10-60 min) post-bite, which was at a median of 180 min (IQR: 106 to 275 min) prior to antivenom administration. Time to antivenom in the 314 transferred patients was similar to those not transferred. Time to antivenom was significantly shorter for 189 patients given antivenom prior to transfer, median 183 min (IQR: 110-270 min), compared to 130 patients given antivenom after transfer, median 363 min (IQR: 289-513 min; P <0.001).

Discussion: Antivenom administration was delayed on average by 2.5 h after hospital presentation, despite three-quarters arriving in hospital within 3 h, the optimal time for antivenom administration. Patients requiring transfer received antivenom in a similar time, but earlier if administered prior to transfer, highlighting the possible benefits of pragmatic clinical decision-making prior to blood tests.

Conclusion: We found the leading cause of delays to antivenom administration after patients arrive in hospital was waiting for blood results. Systemic symptoms occurred early in most cases and could be given greater weight in decisions about early antivenom.