Managing a Mass CO Poisoning: Critical Issues and Solutions From the Field to the Hyperbaric Chamber

Carbon monoxide poisoning: A problem uniquely suited to a medicinal inorganic chemistry solution

Carbon monoxide poisoning is one of the most common forms of poisoning in the world. Although the primary mode of treatment, oxygen therapy, is highly effective in many cases, there are instances in which it is inadequate or inappropriate. Whereas oxygen therapy relies on high levels of a low-affinity ligand (O2) to displace a high-affinity ligand (CO) from metalloproteins, an antidote strategy relies on introducing a molecule with a higher affinity for CO than native proteins (Kantidote,CO > Kprotein,CO). Based on the fundamental chemistry of CO, such an antidote is most likely required to be an inorganic compound featuring an electron-rich transition metal. A review is provided of the protein-, supramolecular complex-, and small molecule-based CO poisoning antidote platforms that are currently under investigation.

Evaluation of a Portable Blood Gas Analyzer for Prehospital Triage in Carbon Monoxide Poisoning: Instrument Validation Study

BACKGROUND

Carbon monoxide (CO) poisoning is an important cause of morbidity and mortality worldwide. Symptoms are mostly aspecific, making it hard to identify, and its diagnosis is usually made through blood gas analysis. However, the bulkiness of gas analyzers prevents them from being used at the scene of the incident, thereby leading to the unnecessary transport and admission of many patients. While multiple-wavelength pulse oximeters have been developed to discriminate carboxyhemoglobin (COHb) from oxyhemoglobin, their reliability is debatable, particularly in the hostile prehospital environment.

OBJECTIVE

The main objective of this pilot study was to assess whether the Avoximeter 4000, a transportable blood gas analyzer, could be considered for prehospital triage.

METHODS

This was a monocentric, prospective, pilot evaluation study. Blood samples were analyzed sequentially with 2 devices: the Avoximeter 4000 (experimental), which performs direct measurements on blood samples of about 50 µL by analyzing light absorption at 5 different wavelengths; and the ABL827 FLEX (control), which measures COHb levels through an optical system composed of a 128-wavelength spectrophotometer. The blood samples belonged to 2 different cohorts: the first (clinical cohort) was obtained in an emergency department and consisted of 68 samples drawn from patients admitted for reasons other than CO poisoning. These samples were used to determine whether the Avoximeter 4000 could properly exclude the diagnosis. The second (forensic) cohort was derived from the regional forensic center, which provided 12 samples from documented CO poisoning.

RESULTS

The mean COHb level in the clinical cohort was 1.7% (SD 1.8%; median 1.2%, IQR 0.7%-1.9%) with the ABL827 FLEX versus 3.5% (SD 2.3%; median 3.1%, IQR 2.2%-4.1%) with the Avoximeter 4000. Therefore, the Avoximeter 4000 overestimated COHb levels by a mean difference of 1.8% (95% CI 1.5%-2.1%). The consistency of COHb readings by the Avoximeter 4000 was excellent, with an intraclass correlation coefficient of 0.97 (95% CI 0.93-0.99) when the same blood sample was analyzed repeatedly. Using prespecified cutoffs (5% in nonsmokers and 10% in smokers), 3 patients (4%) had high COHb levels according to the Avoximeter 4000, while their values were within the normal range according to the ABL827 FLEX. Therefore, the specificity of the Avoximeter 4000 in this cohort was 95.6% (95% CI 87%-98.6%), and the overtriage rate would have been 4.4% (95% CI 1.4%-13%). Regarding the forensic samples, 10 of 12 (83%) samples were positive with both devices, while the 2 remaining samples were negative with both devices.

CONCLUSIONS

The limited difference in COHb level measurements between the Avoximeter 4000 and the control device, which erred on the side of safety, and the relatively low overtriage rate warrant further exploration of this device as a prehospital triage tool.

Chemical, Biological, Radiological, or Nuclear Response in Queensland Emergency Services: A Multisite Study

A disaster overwhelms the normal operating capacity of a health service. Minimal research exists regarding Australian hospitals' capacity to respond to chemical, biological, radiological, or nuclear (CBRN) disasters. This article, and the research supporting it, begins to fill that research gap. We conducted a descriptive quantitative study with 5 tertiary hospitals and 1 rural hospital in Queensland, Australia. The study population was the hospitals' clinical leaders for disaster preparedness. The 25-item survey consisted of questions relating to each hospital's current response capacity, physical surge capacity, and human surge capacity in response to a CBRN disaster. Data were analyzed using descriptive statistics. The survey data indicated that over the previous 12 months, each site reached operational capacity on average 66 times and that capacity to respond and create additional emergency, intensive care, or surgical beds varied greatly across the sites. In the previous 12 months, only 2 sites reported undertaking specific hospital-wide training to manage a CBRN disaster, and 3 sites reported having suitable personal protective equipment required for hazardous materials. There was a noted shortfall in all the hospitals' capacity to respond to a radiological disaster in particular. Queensland hospitals are crucial to CBRN disaster response, and they have areas for improvement in their response and capacity to surge when compared with international preparedness benchmarks. CBRN-focused education and training must be prioritized using evidence-based training approaches to better prepare hospitals to respond following a disaster event.

État de connaissance des médecins urgentistes sur la prise en charge des intoxications au monoxyde de carbone en région Auvergne-Rhône-Alpes

Objectif : L’intoxication au monoxyde de carbone (ICO) est un diagnostic souvent difficile en urgence. Son incidence restant faible, les médecins urgentistes (MU) y sont rarement confrontés mais la pertinence de leur prise en charge est essentielle pour limiter la morbi-mortalité. L’objectif principal de cette étude était d’évaluer le niveau de connaissance des MU sur la prise en charge des ICO dans une région française de 8,1 millions d’habitants. L’objectif secondaire était d’individualiser les facteurs associés à une bonne connaissance de la prise en charge en urgence de cette pathologie.

Matériel et méthodes : Étude descriptive multicentrique et déclarative, réalisée auprès de MU travaillant au sein de cette région à l’aide d’un questionnaire en ligne.

Résultat : 246 MU ont répondu à l’enquête, représentant 82 % des structures de médecine d’urgence de la région. Parmi eux, 27 % estimaient prendre en charge moins de deux ICO par an. Le protocole territorial était connu par 59 % des répondeurs. La médiane de réponses justes au questionnaire de connaissance était de 43 [40-47] sur 60. Un taux de réponses justes plus faible (< 70 %) était retrouvé sur les questions traitant du diagnostic (65 %) et des indications et contre-indications de l’oxygénothérapie hyperbare (61 %). Les facteurs associés à un meilleur taux de réponses justes étaient : la connaissance du protocole territorial (63 vs 46 %, p = 0,035), une ancienneté d’exercice ≥ 5 ans (60 vs 40 %, p = 0,014), une formation complémentaire à la médecine hyperbare (85 vs 53 %, p = 0,018), un nombre estimé de prise en charge d’ICO ≥ 2 (60 vs 43 %, p = 0,022) et une auto-évaluation de ses connaissances > 7/10 (68 vs 50 %, p = 0,007).

Conclusion : Cette étude a montré un niveau de connaissance perfectible des MU sur cette pathologie en rapport avec un faible nombre de prise en charge annuel. La création d’un consensus national est à encourager pour améliorer les pratiques.

Maintaining Preparedness to Severe Though Infrequent Threats-Can It Be Done?

Background: A mass casualty incident (MCI) caused by toxicological/chemical materials constitutes a potential though uncommon risk that may cause great devastation. Presentation of casualties exposed to such materials in hospitals, if not immediately identified, may cause secondary contamination resulting in dysfunction of the emergency department. The study examined the impact of a longitudinal evaluation process on the ongoing emergency preparedness of hospitals for toxicological MCIs, over a decade. Methods: Emergency preparedness for toxicological incidents of all Israeli hospitals were periodically evaluated, over ten years. The evaluation was based on a structured tool developed to encourage ongoing preparedness of Standard Operating Procedures (SOPs), equipment and infrastructure, knowledge of personnel, and training and exercises. The benchmarks were distributed to all hospitals, to be used as a foundation to build and improve emergency preparedness. Scores were compared within and between hospitals. Results: Overall mean scores of emergency preparedness increased over the five measurements from 88 to 95. A significant increase between T1 (first evaluation) and T5 (last evaluation) occurred in SOPs (p = 0.006), training and exercises (p = 0.003), and in the overall score (p = 0.004). No significant changes were found concerning equipment and infrastructure and knowledge; their scores were consistently very high throughout the decade. An interaction effect was found between the cycles of evaluation and the hospitals’ geographical location (F _(1,20) = 3.0, p = 0.056), proximity to other medical facilities (F _(1,20) = 10.0 p = 0.005), and type of area (Urban vs. Periphery) (F _(1,20) = 13.1, p = 0.002). At T5, all hospitals achieved similar high scores of emergency preparedness. Conclusions: Use of accessible benchmarks, which clearly delineate what needs to be continually implemented, facilitates an ongoing sustenance of effective levels of emergency preparedness. As this was demonstrated for a risk that does not frequently occur, it may be assumed that it is possible and practical to achieve and maintain emergency preparedness for other potential risks.

Hospitals preparedness using WHO guideline: A systematic review and meta-analysis

Background:

Hospitals play a critical role in providing communities with essential medical care during disasters.

Objectives:

In this article, the key components and recommended actions of WHO (World Health Organization) Hospital emergency response checklist have been considered to identify current practices in disaster/emergency hospital preparedness in actual or potential incidents.

Methods:

Articles were obtained through bibliographic databases, including ISI Web of Science, PubMed, Science Direct, Scopus, Google Scholar, and SID: Scientific information database. Keywords were “Disaster,” “Preparedness,” “Emergency Preparedness,” “Disaster Planning,” “Mass Casualty Incidents,” “Hospital Emergency Preparedness,” “Health Emergency Preparedness,” “Preparedness Response,” and “Emergency Readiness.” Independent reviewers (F.R. and M.H.Y.) screened abstracts and titles for eligibility. STROBE (STrengthening the Reporting of OBservational studies in Epidemiology) checklist was used to qualifying the studies for this review.

Results:

Of 1545 identified studies, 26 articles were implied inclusion criteria. They accounted for nine key components and 92 recommended actions. The majority of principles that had been rigorously recommended at any level of the hospital emergency preparedness were command and control and post-disaster recovery. Surge capacity was considered less frequently.

Conclusion:

We recommend considering the proposed disaster categories by FEMA (Federal Emergency Management Agency). In this framework, different weights for nine components can be considered based on disaster categories. Thus, a more valid and reliable preparedness checklist could be developed.

Mass Casualty Triage in the Case of Carbon Monoxide Poisoning: Lessons Learned

ABSTRACTCarbon monoxide (CO) can cause mass intoxication, but no standard triage algorithm specifically addresses CO poisoning. The roles of some recent diagnostic tools in triage as well as treatment with hyperbaric oxygen are controversial. We describe a mass casualty case of CO poisoning involving 77 patients, with a focus on the triage and treatment options decided on-site. The reasons for choosing these options are reviewed, and the pitfalls that occurred and the lessons learned from this major incident are described. We discuss the potential to improve the management of such an event and strategies to accomplish this, including simplifying triage and administering oxygen to all exposed persons for 6 h. (Disaster Med Public Health Preparedness. 2018; 12: 373-378).