Could Vital Signs Predict Carbon Monoxide Intoxication?

Abstract

OBJECTIVE: This retrospective study examined the correlation between carboxyhaemoglobin (COHb) levels and vital signs in patients with carbon monoxide (CO) intoxication. METHODS: Over a 10-year period, patients > 16 years of age who presented to the emergency department due to CO intoxication were included. Age, gender, comorbidities, month/year of presentation, presenting symptoms, vital signs, blood pH, COHb level, treatment and outcome were recorded. RESULTS: In total, 476 patients were included. The mean +/- SD age was 36.22 +/- 13.65 years; 96.4% of the patients had a normal Glasgow Coma Scale score, 91.0% had normal blood pressure and 80.0% had a normal heart rate. COHb levels were stratified into three groups: < 10% (n = 39), 10 - 20% (n = 106) and > 20% (n = 205); levels could not be obtained in the remaining 126 patients. In patients with COHb levels > 20%, 34 (16.6%) had alkalosis and nine (4.4%) had acidosis. Among patients with COHb levels > 20%, 140 (68.3%) had normal vital signs. CONCLUSIONS: Vital signs cannot be used as a prognostic marker of CO intoxication and, therefore, patients must be monitored closely.