Related Experiment Video
Updated: Aug 11, 2026

Expired CO2 Measurement in Intubated or Spontaneously Breathing Patients from the Emergency Department
Published on: January 29, 2011
Carbon monoxide blood levels and reported cessation of smoking
Abstract:
The carboxyhemoglobin (COHb) level was estimated in patients attending an anti-smoking clinic. A surprisingly large fraction of patients that reported "no smoking" were found to have abnormally high COHb. We believe that this discrepancy is due to the patients not reporting their smoking habits correctly. This phenomenon is further evidence that smoking should be regarded as a form of drug addiction in some persons. Some early relapses in stop-smoking programs can apparently be explained by the patient's admitting previously concealed smoking. For scientific purposes the results of stop-smoking cures should be evaluated by other means than the patient's own reports.
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...
Oxygen Transport in the Blood
Carbon Dioxide Transport in the Blood
Forms of CO2 Transport
1. Dissolved in plasma: A small percentage (7-10%) of CO2 is transported and dissolved directly in the plasma.
2. Carbaminohemoglobin: Just over 20% of CO2 is chemically bound to...
Hypoxia
Types of Hypoxia
There are four primary types of hypoxia, each resulting from a different cause:
1. Anemic hypoxia: This type occurs due to insufficient oxygen delivery caused by a lack of red blood cells (RBCs) or RBCs with abnormal or...
Chemical Factors Affecting Respiration Centers
CO2 has a potent influence on respiration and is strictly regulated. Under...
Chronic Obstructive Pulmonary Disease-IV: Assessement and Diagnostic Studies
Medical History

