Hypocapnia: Understanding Low Carbon Dioxide Levels in Blood

The functioning of all body systems and organs depends on maintaining the acid-base balance in body fluids. A low level of carbon dioxide in blood, called hypocapnia, is a red flag signaling that something is upsetting the balance.

Normality

• Regardless of altitude, the normal concentration of CO2 in blood is equivalent to an atmospheric partial pressure at sea level of 35 to 45 mmHg, according to the book ̶0;Medical-Surgical Nursing.̶1;

Imbalance

• A partial pressure of CO2 (PaCO2) lower than 35 mmHg indicates that the blood is no longer sufficiently acidic, observes the book ̶0;Medical-Surgical Nursing.̶1;

Significance

• Metabolic reactions depend on the acid-base balance, observe Professor Arthur Vander and his co-writers in the book ̶0;Human Physiology.̶1; Too little or too much acid in body fluids indicates some underlying condition that, if it persists, will do widespread harm, interfering with nerve impulses and muscle contraction.

Possible Causes

• Low PaCO2 can arise from loss of acidic fluids, such as through vomiting; excessive retention of sodium bicarbonate; or hyperventilation, according to the book ̶0;Understanding Pathophysiology.̶1;

Symptoms

• Symptoms may include weakness; muscle cramps; shallow, slow respirations; confusion; convulsions; abnormally rapid beating of the upper heart chambers (atrial tachycardia); dizziness; tingling of the extremities; or coma, observe the authors Sue Huether, Ph.D. and Kathryn McCance, Ph.D.