Related Experiment Video
Updated: May 23, 2026

Expired CO2 Measurement in Intubated or Spontaneously Breathing Patients from the Emergency Department
Published on: January 29, 2011
Could vital signs predict carbon monoxide intoxication?
1Department of Emergency Medicine, School of Medicine, Hacettepe University, and Department of Emergency Medicine, Ankara Training and Research Hospital, Hasırcılar Street, Sıhhıye, Ankara, Turkey. nmaksu@superposta.com
Objective:
This retrospective study examined the correlation between carboxy haemoglobin (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.
Related Concept Videos
Assessment of Diffusion and Perfusion
The Role of Diffusion in Respiration
Diffusion is the process by which molecules move from an area of higher concentration to an area of lower concentration. In the respiratory system, this principle...
Chemical Factors Affecting Respiration Centers
CO2 has a potent influence on respiration and is strictly regulated. Under...
Introduction to Vital Signs
Vital signs help healthcare professionals assess an individual's well-being and detect any functional changes or...
Diagnosing Acidosis and Alkalosis
First, the pH level is assessed to determine whether the blood pH is normal (7.35–7.45), low (acidosis), or high (alkalosis).
Next, the PCO2 and HCO3− values are examined to...
Acute Respiratory Failure-III
Guidelines For Measuring Vital Signs
Before taking a patient's vital signs, a nurse would consider and assess the patient's comfort level and ensure appropriate equipment is available.

