Pulmonary thromboembolism after carbon monoxide poisoning

An artificial intelligence algorithm for analyzing globus pallidus necrosis after carbon monoxide intoxication

Globus pallidus necrosis (GPN) is one of typical neurological imaging features in patients with carbon monoxide (CO) poisoning. Current clinical guideline recommends neurological imaging examination for CO-intoxicated patients with conscious disturbance rather than routine screening, which may lead to undiagnosed GPN. We aimed to develop an artificial intelligence algorithm for predicting GPN in CO intoxication patients. We included CO intoxication patients with neurological images between 2000 and 2019 in Chang Gung Memorial Hospital. We collected 41 clinical and laboratory parameters on the first day of admission for algorithm development. We used fivefold cross validation and applied several machine learning algorithms. Random forest classifier (RFC) provided the best predictive performance in our cohort. Among the 261 patients with CO intoxication, 52 patients presented with GPN. The artificial intelligence algorithm using the RFC-based AI model achieved an accuracy = 79.2 ± 2.6%, sensitivity = 77.7%, precision score = 81.9 ± 3.4%, and F1 score = 73.2 ± 1.8%. The area under receiver operating characteristic was approximately 0.64. Top five weighted variables were Platelet count, carboxyhemoglobin, Glasgow Coma scale, creatinine, and hemoglobin. Our RFC-based algorithm is the first to predict GPN in patients with CO intoxication and provides fair predictive ability. Further studies are needed to validate our findings.

Acute carbon monoxide poisoning with low saturation of carboxyhaemoglobin: a forensic retrospective study in Shanghai, China

Carbon monoxide (CO) poisoning is a common cause of death, leading to morbidity and mortality worldwide. Features of the CO poisoning with low carboxyhemoglobin (COHb) levels remain to be characterized. This study collected a total of 307 CO poisoning cases from Shanghai Public Security Bureau, an official organization that handles the most complicated and life-threatening cases across Shanghai municipality in China, and regrouped these cases into three categories: group 1, 10% < COHb% < 30% (n = 58); group 2, 30% ≤ COHb% < 50% (n = 79); group 3, COHb% ≥ 50% (n = 170). Epidemiological, demographic, and forensic aspects of the CO poisoning cases, particularly those with low COHb levels, were analyzed. Our results showed that group 2 and 3 were mostly observed in younger victims (≤ 30 years), while group 1 equally distributed to all age groups (p = 0.03). All the CO poisoning from group 2 and 3 occurred in enclosed spaces, whereas cases from group 1 died additionally in outdoor spaces (p = 0.01). 81.03% of group 1 cases died in fire circumstances, while only 45.57% from group 2 and 30.59% from group 3 were fire-related (p = 0.00). Accordingly, group 1 was mostly related with fire burns, while group 2 or 3 were largely associated with gas leakage (p = 0.00). A combination with alcohol, but not other psychotropic drugs, associated with significant higher levels of blood COHb% in fire-unrelated (p = 0.021) but not fire-related cases (p = 0.23). Five extremely low COHb% (< 30%)-related poisoning deaths were negative of any cardiopulmonary pathology and psychoactive substances. In conclusion, CO poisoning with low COHb% significantly associates with fire circumstances and outdoor spaces and has no age preference. Further diagnostic markers mandates to be identified in order to avoid disputes in cases of extremely low COHb%-related poisoning.

Risk factors for venous thromboembolism after carbon monoxide poisoning: A nationwide population-based study

Introduction:

The risk of venous thromboembolism increases after acute carbon monoxide poisoning. However, studies on the characteristics of patients who develop venous thromboembolism after carbon monoxide poisoning are rare. The aim of this study was to identify the risk factors for venous thromboembolism within 3 months after carbon monoxide poisoning.

Methods:

This is a population-based study that employed nationwide claims data from South Korea. Among the carbon monoxide poisoning patients (⩾18 years), the characteristics of the groups with and without venous thromboembolism (pulmonary embolism or deep vein thrombosis) were identified. All the significant variables in the univariable analysis were included in the multivariable logistic regression to determine the risk factors for venous thromboembolism occurrence.

Results:

Among the 24,232 carbon monoxide poisoning patients, 130 subjects developed venous thromboembolism within 90 days of their carbon monoxide poisoning diagnosis. The significant risk factors for venous thromboembolism in the multivariable analysis were age (adjusted odds ratio (aOR) = 1.01; 95% confidence interval (CI) = 1.003–1.03), intensive care unit admission (aOR = 3.80; 95% CI = 2.34–6.12), length of stay (aOR = 1.02; 95% CI = 1.0001–1.04), congestive heart failure (aOR = 2.17; 95% CI = 1.36–3.42), and cancer (aOR = 1.94; 95% CI = 1.10–3.22). The adjusted odds ratios for intensive care unit admission for patients with pulmonary embolism and deep vein thrombosis were 3.05 (95% CI = 1.61–5.61) and 5.60 (95% CI = 2.89–10.90), respectively.

Conclusion:

Patients with older age, intensive care unit admission, a longer length of stay, congestive heart failure, or cancer are at greater risk of developing venous thromboembolism after carbon monoxide poisoning. In particular, intensive care unit admission was the strongest risk factor for venous thromboembolism, pulmonary embolism, and deep vein thrombosis. Monitoring and administering prophylactic treatments to prevent venous thromboembolism would be helpful in high-risk in carbon monoxide poisoning patients.

Risk of Venous Thromboembolism After Carbon Monoxide Poisoning: A Nationwide Population-Based Study

STUDY OBJECTIVE

Few studies have investigated the association between carbon monoxide (CO) poisoning and risk of venous thromboembolism. We aim to identify the risk of pulmonary embolism and deep venous thrombosis after CO poisoning.

METHODS

We conducted a nationwide cohort-crossover study using administrative claims data in Korea. We compared the risk of venous thromboembolism (pulmonary embolism or deep venous thrombosis) in the cohort period after CO poisoning to that of the same period 1 year later (crossover period), using conditional logistic regression analysis.

RESULTS

We included 22,699 patients with a diagnosis of CO poisoning during the study period between 2004 and 2015. The risk of venous thromboembolism was significantly elevated during days 0 to 90 after CO poisoning (odds ratio 3.96; 95% confidence interval 2.50 to 6.25). However, this risk was not significantly elevated during subsequent postexposure periods through 360 days. During days 0 to 30 after CO poisoning, the risks of pulmonary embolism (odds ratio 22.00; 95% confidence interval 5.33 to 90.75) and deep venous thrombosis (odds ratio 10.33; 95% confidence interval 3.16 to 33.80) were significantly elevated.

CONCLUSION

We found that the risk of venous thromboembolism persisted for up to 90 days after CO poisoning. The risk was increased 22-fold for pulmonary embolism and 10-fold for deep venous thrombosis, especially in the first month after CO poisoning. Patients should be monitored for venous thromboembolism risk after CO poisoning.

Life-Threatening Acute Pulmonary Thromboembolism Following Severe Carbon Monoxide Poisoning

A 57-year-old man admitted with severe carbon monoxide (CO) poisoning suffered life-threatening pulmonary embolism (PE) after hyperbaric oxygen therapy, in the absence of other risk factors for thromboembolism, and was successfully treated with thrombolysis. CO is a thrombophilic condition predisposing to PE and active surveillance is advisable. (Level of Difficulty: Advanced.)