Aspiration Pneumonia in Carbon Monoxide Poisoning Patients with Loss of Consciousness: Prevalence, Outcomes, and Risk Factors.

BACKGROUND: Aspiration pneumonia is associated with significant morbidity and mortality; however, little is known about aspiration pneumonia in patients with carbon monoxide intoxication, which is the leading cause of poisoning-related death. This study aimed to evaluate the prevalence, clinical impacts, and risk factors for developing aspiration pneumonia in patients with carbon monoxide poisoning with loss of consciousness.

METHODS: A retrospective analysis of a carbon monoxide poisoning registry was performed at our emergency department for the period January 2008 to December 2015. All adult carbon monoxide poisoning patients with loss of consciousness were included.

RESULTS: Aspiration pneumonia developed in 103 (19.2%) of 537 patients. It was associated with increased ventilator use (52.4% vs 3.2%), length of hospital stay (median [interquartile range], 3.6 [2.1-5.1] vs 1.3 [0.6-2.1] days), and in-hospital mortality (5.8% vs 0.0%) (all P < .001). Altered mental status on emergency department arrival, white blood cell count, and increased exposure duration were the independent factors associated with development of aspiration pneumonia; odds ratios were 9.46 (95% confidence interval [CI] 4.92-18.19; P < .001), 1.19 (95% CI 1.13-1.26; P < .001), and 1.12 (95% CI 1.06-1.19; P < .001), respectively. For painful or unresponsive mental status and white blood cell count >12,000/mm3 , the odds ratio increased up to 17.75 (95% CI 10.65-29.59; P < .001).

CONCLUSIONS: The prevalence of aspiration pneumonia was 19.2% in carbon monoxide poisoning patients with loss of consciousness and was associated with poor outcomes. Additionally, altered mental status on emergency department arrival, white blood cell count, and increased exposure duration were independently associated with the development of aspiration pneumonia.