Critical values for carbon monoxide in cases admitted to the emergency department in a local hospital

Abstract Carbon monoxide (CO) poisoning has been an important concern in winter particularly due to malfunctioning coal stoves, in many developing countries, including Turkey. Winter months, especially February, were the most dangerous periods for CO exposure. Carbon monoxide has no color or smell so has known as the silent killer. Brain, heart, and other organs are under risk in CO poisoning. Because patients usually present with non-specific symptoms, CO poisoning should be considered in the differential diagnosis of unexplained nausea and vomiting, neurological or cardiac signs and symptoms. Carboxyhemoglobin (COHb) is a reliable marker to monitor the patient. Lactate is also important as a measure of impaired systemic oxygen delivery. Fifteen patients with a diagnosis of CO poisoning were included in the study. This is the number of all cases admitted to the emergency in the last one and a half months in our local hospital located in a town with almost 48.918 residents. Blood gas analysis was performed by ABL90 FLEX, Radiometer. Reference for COHb was 0.6-1.5 % and for lactate was 0.5-1.6 mmol/L. Troponin I levels were also analyzed in some patients to assess possible myocardial ischemia. Troponin levels were analyzed by ARCHITECT i2000, Abbott and reference range was <16 ng/mL in woman, <34 ng/mL in men. Graph Pad Prism program was used for statistical analysis of the data. We had 15 cases aged between 4-56 years with COHb values with panic values (> 20%) except two of the cases with values 16.5% and 19%. The female-male ratio was 6/9. On admission to the Emergency Department, 46.6% of patients (n=7) had headache and vomiting, 40% of patients (n=6) had headache, 6.6% (n=1) fatigue and 6.6% of patients (n=1) had syncope. Median value of COHb % was 23.7(16.5-40.8), lactate was 1.9 (0.8-4.8), pH was 7.39 (7.30-7.47). Excluding three patients as outliers, lactate levels had a good correlation with carboxyhemoglobin values (R2=0.9413). It was notable that 1 patient had a higher-than-normal Troponin I level (24.9 ng/mL) who has highest lactate level (4.8 mmol/L). Four of the patients, from the same family was admitted for suspected food poisoning for the symptoms of nausea, vomiting, diarrhea. A diagnosis of CO poisoning was made after a COHb value between 16.5-25.7% for these patients. This was very critical for the accurate treatment given to those patients being hyperbaric oxygen treatment in CO poisoning cases. CO poisoning should be considered in patients admitting to the emergency department with complaints of headache, dizziness, weakness, nausea, and vomiting. Reporting panic values is a means of alerting the clinician for the right diagnosis.