Smoking & Effectiveness of Pulse Oximeter Readings

A pulse oximeter measures the percentage of hemoglobin carrying oxygen.

While smoking might reduce the accuracy of pulse oximeter readings by causing blood vessels to narrow, warming usually reverses vessel constriction. Less easy to correct is the actual reduction in oxygenated blood that smoking typically causes.

Definition

A pulse oximeter is a device that passes a beam of light through tissue and measures the amount of light absorbed by oxygen-saturated hemoglobin in blood, according to the book "Medical-Surgical Nursing," by Joyce Black et. al.

Nicotine

Nicotine-constricted vessels can skew pulse oximeter readings by restricting blood flow.

Nicotine causes blood vessels to constrict, notes Richard Lehne in his book "Pharmacology for Nursing Care, Fourth Edition." This phenomenon, called vasoconstriction, reduces oximeter accuracy, note Black et al. Hence, smoking might mar oximeter readings.

Profound Effect

Rather than merely impair oximeter readings, smoking might actually reduce the oxygen saturation of hemoglobin. Evidence shows that it does, notes Pub Med.

Carbon Monoxide's Role

Hemoglobin occupied by carbon monoxide cannot pick up oxygen.

Smoking can directly reduce oxygen saturation through the carbon monoxide in cigarette smoke. Binding to hemoglobin, carbon monoxide prevents it from carrying oxygen, notes Smoking Cessation, an online resource center on smoking.

Emphysema

Emphysema destroys the air sacs by which oxygen enters blood from air.

Smoking can reduce oxygen saturation indirectly because smoking causes emphysema, notes the book "Understanding Pathophysiology, Second Edition," by Sue Huether and Kathryn McCance.

References

• "Medical-Surgical Nursing, Sixth Edition"; Joyce M. Black, Jane Hokanson Hawks, and Annabelle M. Keene; 2001
• "Pharmacology for Nursing Care, Fourth Edition"; Richard A. Lehne; 2001
• Pub Med: Oxygen Saturation
• Smoking Cessation: Smoking and Blood
• "Understanding Pathophysiology, Second Edition"; Sue E. Huether and Kathryn L. McCance; 2000

Resources

• American Lung Association: What's in a Cigarette?