Experience of carbon monoxide poisoning and the outcome predicting score: A multicenter retrospective study

Abstract

Background: Carbon monoxide poisoning (COP), resulting from accidental and intentional exposure, is a leading cause of fatal poisoning worldwide. Except for early death, neurological sequelae are common and impose a large burden on patients, caregivers, and the society.

Materials and methods: This retrospective study included patients who visited the emergency departments (EDs) of the medical institutes of Chang Gung Memorial Hospital after COP with a carboxyhemoglobin level > 10% between January 2009 and October 2018. Patients who experienced out-of-hospital cardiac arrest (OHCA) were excluded. Poor outcome was defined as mortality or a Glasgow coma scale (GCS) <13 at discharge. Stepwise regression analysis was performed, and a receiver operating characteristic (ROC) curve was applied to analyze our newly created scoring system for prognosis prediction.

Results: This study enrolled 1171 patients. Fire scene (F) (aOR, 20.635; 95% CI, 8.345-51.023), intentional CO exposure (I) (aOR, 2.634; 95% CI, 1.335-5.196), respiratory failure (R) (aOR, 9.944; 95% CI, 5.533-17.873), every point of reduced GCS (E) (aOR, 1.253; 95% CI, 1.186-1.323), and diabetes mellitus (D) (aOR, 2.749; 95% CI, 1.201-6.292) were identified as predictors of poor outcomes. The FIRED score was created.

Conclusion: The FIRED score could predict the outcomes of non-OHCA patients with a carboxyhemoglobin level > 10% after COP using five factors that can be obtained by history taking and basic examination. An FIRED score ≥ 10 was associated with a poor outcome (sensitivity, 89.6%; specificity, 82.4%; AUC0.930).

Keywords: Carbon monoxide poisoning; Hyperbaric oxygen therapy; Outcome; Score; mini-mental state examination.