Review of unintentional non-fire-related carbon monoxide poisoning morbidity and mortality in Florida, 1999-2007

The spectrum of presentations of unintentional carbon monoxide poisoning

Carbon monoxide (CO) is an odourless and tasteless gas which can be produced by the incomplete combustion of carbon-containing fuels. Compared to vehicular CO suicides, unintentional cases (excluding those related to fires) are much less common. Increased education surrounding the risks associated with the accumulation of CO in enclosed spaces has contributed to a reduced incidence of unintentional CO poisonings. However, such cases may remain undetected, particularly in domestic and recreational settings where scene findings are often non-specific. The current study of unintentional CO poisonings in South Australia and the Northern Territory, each with a unique climate (Mediterranean and tropical respectively), demonstrated differences in the circumstances of death. Several cases where individuals used carbon-producing fuel sources for heat, both in domestic and vehicular settings and without adequate ventilation, resulted in fatal outcomes. Less common scenarios involved faults in equipment (e.g. a hot water heater), vehicle faults resulting in the accumulation of fatal levels of CO in enclosed spaces, and inadvertent introduction of CO into a diving oxygen supply in a recreational aquatic setting. In ascertaining the cause of death, other considerations include the potential role of underlying chronic cardiovascular and respiratory disease and age which may increase an individual's susceptibility to CO toxicity. Understanding the wide variety of presentations and contributing factors in cases of fatal CO poisoning including consideration of climate-specific differences in domestic and extra-domestic settings may enable improved detection at autopsy.

An urgent health problem of indoor air pollution: results from a 15-years carbon monoxide poisoning observed study in Jinan City

Carbon monoxide (CO) poisoning is a public health concern in developing countries especially in China with a high disease burden. We aimed to focus on non-occupational CO poisoning caused by household coal heating secular trends based on registry data in Jinan, China, and we aim to provide further evidence and suggestions for public health policy. We analyzed the occurrence and development trend and assess the spatial-temporal epidemiological characteristics of non-occupational CO poisoning caused by household coal heating in Jinan between 2007 and 2021. Among total of 6588 CO poisoning, 5616 cases (85.25%) and 180 deaths caused by household coal heating was identified during study period. The cumulative incidence rate was 5.78 per 100,000 person-years and the mortality rate was 0.19 per 100,000 person-years. The incidence in urban areas (6.55 per 100,000 person-years) was higher than rural areas (5.04 per 100,000 person-years), and there was a statistical difference between urban and rural (P < 0.001) (P < 0.001). The poisoning time point mainly occurs in the sleep stage. In Jinan, socioeconomic status, accessibility to health services and rural status are determinants for CO poisoning incidence and mortality. Implementation of urban and rural central heating renovation is an effective way to further reduce the disease burden of CO poisoning in the future.

Urban air pollution and emergency department visits related to central nervous system diseases

Ambient air pollution has been associated with adverse neurological health outcomes. Ambient pollutants are thought to trigger oxidative stress and inflammation to which vulnerable populations, such as elderly may be particularly susceptible. Our study investigated the possible association between concentrations of ambient air pollutants and the number of emergency department (ED) visits for nervous system disorders among people residing in a large Canadian city. A time-stratified case-crossover study design combining data from the National Ambulatory Care Reporting System (NACRS) and the National Air Pollution Surveillance (NAPS) between 2004 and 2015 was used. Two air quality health indices were considered in additional to specific pollutants, including carbon monoxide (CO), nitrogen dioxide (NO₂), sulfur dioxide (SO₂), ozone (O₃) and fine particulate matter (PM_2.5). Weather condition data were included in the models. ED visits with a discharge diagnosis were identified using ICD-10 codes (G00-G99). The analysis was stratified by sex and age, also by seasons. The associations were investigated in arrays organized as 18 strata and 15 time lags (in days) for each pollutant. Overall, 140,511 ED visits were included for the analysis. Most ED visits were related to episodic and paroxysmal diagnoses (G40-G47, 64%), with a majority of visits for migraines (G43, 39%). Among females, an increase of 0.1ppm ambient CO was associated with an increased risk of paroxysmal diagnoses at day 1 (RR = 1.019 (95%CI 1.004–1.033)), day 6 (1.024 (1.010–1.039)) and day 7 (1.022 (1.007–1.036). PM_2.5 and SO₂, and air quality indices were similarly associated with ED visits for episodic and paroxysmal disorders in days 6 and 7. Findings highlight that ambient air pollution is associated with an increased number of ED visits for nervous system disorders, particularly visits for paroxysmal diagnoses.

Temporal trends of carbon monoxide poisoning mortality at the global, regional and national levels: a cross-sectional study from the Global Burden of Disease study, 1990 and 2017

OBJECTIVES

Carbon monoxide (CO) poisoning is one of the most frequent causes of fatal poisoning worldwide. Few studies have explored the mortality trends of CO poisoning grouped by age and gender, at the regional, national and global levels. We therefore aimed to determine the pattern of CO poisoning mortality, as well as temporal trends at all levels.

DESIGN

A cross-sectional survey design was used in this study.

SETTING

CO poisoning data collected from the Global Burden of Diseases (GBDs), from 1990 to 2017, was arranged by sex, age, region and country. In addition, we used human development index data at the national level from the World Bank.

PARTICIPANTS

We collected over 100 000 information on CO poisoning mortality between 1990 and 2017, derived from the GBD study in 2017.

MAIN OUTCOMES AND MEASURES

We have calculated the estimated annual percentage changes in CO poisoning age-standardised mortality rate (ASR), by sex and age at different regions and countries to quantify the temporal trends in CO poisoning ASR.

RESULTS

Globally, death cases of CO poisoning decreased 7.2% from 38 210 in 1990 to 35 480 in 2017. The overall ASR decreased by an average of 1.83% (95% CI 2.10% to 1.56%) per year in this period. This decreasing pattern was heterogeneous across ages, regions and countries. The most pronounced decreases were generally observed in countries with a high sociodemographic index, including Estonia, South Korea and Puerto Rico.

CONCLUSIONS

Current prevention strategies should be reoriented, and much more targeted and specific strategies should be established in some countries to forestall CO poisoning.

Pediatric Carbon Monoxide Poisoning in Southern Israel: A Cross-Sectional Study

OBJECTIVES

This study aimed to describe the epidemiology and clinical burden of unintended carbon monoxide (CO) poisoning among children in the Negev region of southern Israel.

METHODS

This was a cross-sectional retrospective study of CO poisoning patients admitted to Soroka University Medical Center in 2011 through 2015.

RESULTS

Overall, 43 cases of CO poisoning were recorded among children younger than 18 years. Five patients died, all upon admission. Poisoning due to smoke "per se" and due to CO emitted from heating devices were responsible for 28 (65.1%) and 14 (32.6%) cases, respectively. Eight (18.6%) patients suffered from convulsions, and 13 (43.3%) of 30 evaluable patients complained of headaches. Twenty-two (51.2%) were found unconscious in the field, and 7 (16.3%) were unconscious at examination at the emergency department. The average carboxyhemoglobin level on admission was 10.5% ± 10.4% (level ranging from 0.1% to 46.2%). Treatment included oxygen in 34 patients (79%) and hyperbaric oxygen therapy in 8 patients (19%). No differences were found between Bedouin and Jewish children in sex, age, residence area, source of CO poisoning, symptoms severity, and need for hyperbaric oxygen therapy. More patients with exposure to water heating devices were older than 4 years, lived in villages, and were diagnosed as having loss of consciousness in the field compared with those exposed to smoke inhalation.

CONCLUSIONS

Carbon monoxide poisoning in children is frequent in southern Israel. Education about prevention, implementation of safer standards for home heating systems, and government supervision are required management strategies to decrease the CO poisoning incidence in southern Israel.

Smoke Alarms and Carbon Monoxide Alarms in Households With Children, Puerto Rico, 2010

In 2017, Puerto Rico sustained extensive damage from Hurricane Maria, increasing the risk of fires and carbon monoxide (CO) poisonings. Using a population-based, in-person survey of households with children less than 6 years old in Puerto Rico, we collected data in 2010 concerning the presence of smoke alarms and CO alarms in these households. We generated national estimates by extrapolating the number of households in each stratum using data from the 2010 Census. We determined which household characteristics predicted the presence of these alarms. Of 355 households analyzed, 31% had functional smoke alarms, or an estimated 109,773 households territory wide. The presence of smoke alarms was associated with living in multifamily housing and no child in the household receiving government medical insurance. Public housing or publicly subsidized housing, as compared to owner-occupied housing and unsubsidized rental housing, was associated with having a functional smoke alarm in households with children aged less than 6 years. Based on only six houses having CO alarms, we estimated only 7685 (2%) households had CO alarms. The low prevalence of functional smoke or CO alarms 7 years before Hurricane Maria is unfortunate and should be remedied by ensuring that such alarms are widely installed in current rebuilding activities.

The detection of occult CO poisoning through noninvasive measurement of carboxyhemoglobin: A cross-sectional study

OBJECTIVES

Carbon monoxide (CO) poisoning is one of the leading causes of preventable death in the world. Our primary objective was to identify and treat individuals who are unaware of their exposure to carbon monoxide in emergency departments (EDs). Our secondary goal was to reduce the costs of diagnosis and treatment by preventing unnecessary diagnostic testing in EDs.

METHODS

In this cross-sectional study, carboxyhemoglobin (COHb) levels of patients presented with the signs of CO poisoning to the Emergency Department of Kayseri Training and Research Hospital between November 2012 and May 2013 were noninvasively measured during triage. Patients with elevated COHb levels were suspected of CO poisoning and subjected to further investigation.

RESULTS

A total of 4073 patients were enrolled in the study, and 106 (2.6%) of them were diagnosed with CO poisoning. Initial evaluation revealed headache to be the most common presenting complaint in patients with occult CO poisoning. Further evaluations to determine the accuracy of noninvasive measurements showed that noninvasive pulse CO-oxymeter and arterial blood gas (ABG) measurement were compatible.

CONCLUSIONS

The use of noninvasive pulse CO-oxymeter might reduce the morbidity and mortality associated with occult CO poisoning in patients presented with suspected CO poisoning in emergency settings.

Carbon monoxide poisoning surveillance in the Veterans Health Administration, 2010-2017

BACKGROUND

Exposure to carbon monoxide (CO), the odorless, colorless gas resulting from incomplete combustion of hydrocarbons, is preventable. Despite the significant risk of morbidity and mortality associated with CO poisoning, there currently exists no active national CO surveillance system in the United States (U.S.). Our study aims to use electronic health record data to describe the epidemiology of CO poisoning in the Veterans Health Administration healthcare population.

METHODS

We identified unique inpatient and outpatient encounters coded with International Classification of Diseases (ICD) codes for CO poisoning and analyzed relevant demographic, laboratory, treatment, and death data from January 2010 through December 2017 for Veterans across all 50 U.S. states and Puerto Rico. Statistical methods used were 95% CI calculations and the two-tailed z test for proportions.

RESULTS

We identified 5491 unique patients with CO poisoning, of which 1755 (32%) were confirmed/probable and 3736 (68%) were suspected. Unintentional poisoning was most common (72.9%) overall. Age less than 65 years, residence in Midwest U.S. Census region versus South or West, and winter seasonal trend were characteristics associated with confirmed/probable CO poisoning. Twenty-six deaths (1.5%) occurred within 30 days of confirmed/probable CO poisoning and were primarily caused by cardiovascular events (42%) or anoxic encephalopathy (15%).

CONCLUSIONS

Our findings support the use of ICD-coded data for targeted CO poisoning surveillance, however, improvements are needed in ICD coding to reduce the percentage of cases coded with unknown injury intent and/or CO poisoning source. Prevalence of CO poisoning among Veterans is consistent with other U.S. estimates. Since most cases are unintentional, opportunities exist for provider and patient education to reduce risk.

National unintentional carbon monoxide poisoning estimates using hospitalization and emergency department data

Unintentional non-fire-related (UNFR) carbon monoxide (CO) poisoning is a leading cause of poisoning in the US and a preventable cause of death. We generated national estimates of accidental CO poisoning and characterized the populations most at risk. UNFR CO poisoning cases were assessed using hospitalization and emergency department (ED) data from the Healthcare Costs and Utilization Project National Inpatient Sample and Nationwide Emergency Department Sample databases. We used hospitalization data from 2003 to 2013 and ED data from 2007 to 2013. We calculated trends using a linear regression of UNFR CO poisonings over the study period and age-adjusted rates using direct standardization and U.S. Census Bureau estimates. During 2003-2013, approximately 14,365 persons (4.1 cases/million annually) with confirmed or probable UNFR CO poisoning were admitted to hospitals and the annual rate of poisonings showed a weak downward trend (p = 0.12). During 2007-2013, approximately 101,847 persons (48.3 visits/million annually) visited the ED and the annual rate of poisonings showed a significant downward trend (p ≤ 0.01). Most UNFR CO hospital cases involved patients who were older (aged 45-64 years), white, male, or living in the South or Midwest. Overall, the rate of hospitalizations did not change over the study period. Unintentional CO poisoning is preventable and these cases represent the most recent national estimates. ED visits declined over the study period, but the hospitalization rates did not change. This emphasizes the need for prevention efforts, such as education in the ED setting, increased use of CO alarms, and proper use and maintenance of fuel-powered household appliances.

Risk Factors and Outcome Analysis in Children with Carbon Monoxide Poisoning

BACKGROUND

Carbon monoxide (CO) poisoning is one of the common causes of poisoning in patients and can result in significant morbidity and mortality. However, few studies have focused on the pediatric group.

METHODS

We retrospectively reviewed children (age < 18 years) with CO poisoning from nonfire accidents at a tertiary medical center in Taiwan from 2002 to 2010. We analyzed the patients' characteristics, management, and outcome; compared the data of patients who received hyperbaric oxygen (HBO) to those who received normobaric oxygen (NBO) therapy; and identified the ri0sk factors for patients who developed delayed neurological sequelae (DNS) or permanent neurological sequelae (PNS).

RESULTS

A total of 81 children were enrolled. The annual case number increased from five cases in 2002 to 20 in 2010, particularly during the cold months (December to February). The most common source of exposure was an indoor heating system (54.3%). The most common presenting symptoms were vomiting (32.1%) and consciousness changes (30.9%). HBO treatment tended to be administered to patients with a higher initial COHb (%) (p < 0.001), an initial Glasgow coma scale change (p < 0.001), and admission to the hospital (p = 0.002). After multivariate analysis, treatment in the intensive care unit because of prolonged loss of consciousness (p = 0.002) was the only independent risk factor for patients with DNS; only rescue by a ventilator (p < 0.001) was an independent risk factor for patients with PNS. In comparison to the NBO therapy, HBO treatment did not show benefit or harm to patients according to the incidence of inducing DNS or PNS after multivariate analysis.

CONCLUSION

For those with treatment in the intensive care unit because of prolonged loss of consciousness and rescue by a ventilator, special attention should be given and follow-up should be performed to determine whether DNS or PNS occurs, particularly epilepsy and cognitive deficits.

Carbon monoxide poisoning during camping in Korea

OBJECTIVE

The aim of this study was to evaluate the epidemiology and characteristics of unintentional carbon monoxide (CO) poisoning during camping in Korea.

METHODS

We performed a retrospective observational study on patients with unintentional camping-related CO poisoning who were admitted to the emergency department (ED) from 1 January 2010 to 31 December 2014. News reports about incidents of camping-related CO poisoning were collected using news search engines.

RESULTS

A total of 72 patients (29 patients involved in 12 incidents, who were admitted to our ED, and 43 victims involved in 17 incidents reported in the media) were identified. Accidental camping-related CO poisoning occurred most frequently in May, late spring in Korea. Gas stove use and the burning of charcoal for tent heating were responsible for camping-related CO exposure. Seventeen victims (39.5%) were found dead when an ambulance arrived at the scene, in the cases reported in the media. In contrast, all the victims at our hospital were alive on hospital discharge. Twelve of the 17 incidents (70.6%) reported in the media were accidental fatalities. The majority of our patients (83.4%) were not aware of the potential danger of charcoal as a source of CO.

CONCLUSION

Accidental camping-related CO poisoning occurred because of an ongoing lack of awareness about the potential danger of charcoal grills and stoves, and this caused prehospital mortality. Such accidents could be prevented by increasing the awareness of the potential danger of using charcoal grills and stoves during camping, as well as by establishing appropriate safety regulations.

Mortality and hospital admission rates for unintentional nonfire-related carbon monoxide poisoning across Canada: a trend analysis

BACKGROUND

The epidemiology of mortality and morbidity from carbon monoxide poisoning in Canada has received little attention. Our objective was to evaluate trends in mortality and hospital admission rates for unintentional nonfire-related carbon monoxide poisoning across Canada.

METHODS

Age- and sex-standardized mortality (1981-2009) and hospital admission (1995-2010) rates by age group, sex and site of carbon monoxide exposure were calculated for each province and for all of Canada. We quantified the long-term trends by calculating the average annual percent change. Multivariable Poisson regression was used to estimate incidence rate ratios (IRRs) of carbon monoxide poisoning across age groups, sex and month of occurrence.

RESULTS

In Canada, there were 1808 unintentional nonfire-related carbon monoxide poisoning deaths between 1981 and 2009 and 1984 admissions to hospital between 1995 and 2010. Average annual decreases of 3.46% (95% confidence interval [CI] -4.59% to -2.31%) and 5.83% (95% CI -7.79% to -3.83%) were observed for mortality and hospital admission rates, respectively. Mortality (IRR 5.31, 95% CI 4.57 to 6.17) and hospital admission (IRR 2.77, 95% CI 2.51 to 3.03) rates were elevated in males compared with females. Decreased trends in the rates were observed for all sites of carbon monoxide exposure, but the magnitude of this decrease was lowest in residential environments. Deaths and admissions to hospital were most frequent from September to April, with peaks in December and January.

INTERPRETATION

Mortality and hospital admission rates for unintentional nonfire-related carbon monoxide poisoning in Canada have declined steadily. Continued efforts should focus on reducing carbon monoxide poisoning during the cooler months and in residential environments.

Analysis of hospital admissions due to accidental non-fire-related carbon monoxide poisoning in England, between 2001 and 2010

Background

Accidental non-fire-related (ANFR) carbon monoxide (CO) poisoning is a cause of fatalities and hospital admissions. This is the first study that describes the characteristics of ANFR CO hospital admissions in England.

Methods

Hospital Episode Statistics (HES) inpatient data for England between 2001 and 2010 were used. ANFR CO poisoning admissions were defined as any mention of ICD-10 code T58: toxic effect of CO and X47: accidental poisoning by gases or vapours, excluding ICD-10 codes potentially related to fires (X00-X09, T20-T32 and Y26).

Results

There were 2463 ANFR CO admissions over the 10-year period (annual rate: 0.49/100 000); these comprised just under half (48.7%) of all non-fire-related (accidental and non-accidental) CO admissions. There was seasonal variability, with more admissions in colder winter months. Higher admission rates were observed in the north of England. Just over half (53%) of ANFR admissions were male, and the highest rates of ANFR admissions were in those aged >80 years.

Conclusion

The burden of ANFR CO poisoning is preventable. The results of this study suggest an appreciable burden of CO and highlight differences that may aid targeting of public health interventions.

Environmental carbon monoxide related to pregnancy hypertension

Carbon monoxide pollution frequently occurs due to auto exhaust, industrial emissions, and/or cigarette smoke. Exogenous and endogenous carbon monoxide affects blood pressure; however, the relation of carbon monoxide exposure to pregnancy hypertension has not been systematically examined. For the present study the authors recruited a total of 2,707 apparently healthy, non-obese, non-smoking mothers, aged between 15 and 40 years, who had singleton births, and who lived within two miles of the selected air monitoring stations in Tehran, Iran, to study the relation of ambient carbon monoxide to pregnancy hypertension (>140 mmHg systolic and/or >90 mmHg diastolic after the 20th week of gestation). A relatively small but statistically significant elevation in mean postpartum diastolic blood pressure (mean ± SD, 69.5 ± 9.8 mmHg) was observed in the mothers' who were exposed to relatively high ambient carbon monoxide (mean = 14.1 ppm) compared to mothers exposed to lower carbon monoxide (mean = 1.8 ppm) concentrations (mean ± SD, 68.0 ± 8.3 mmHg, p < 0.01). The authors found twice the rate of pregnancy hypertension in the relatively higher carbon monoxide exposed mothers than the mothers with lower exposure (adjusted odds ratio = 2.02, 95% CI 1.35-3.03). Findings of the present study suggest that high level ambient carbon monoxide exposure is associated with pregnancy hypertension.