Shauna is a healthy, fit 28-year-old who decided to go on a 2-week tour of Mexico for young singles. One hot afternoon in a small market community, she grabbed some fruit juice from a street vendor

Question

Several hours later, she developed abdominal cramping and diarrhea. The diarrhea became so severe that she missed 3 days of the tour and stayed in her hotel room. By the end of her illness, she felt weak and tired. Her head ached, but the mild fever had disappeared, and she was able to join her new friends for the rest of the tour.

What is the acid-base imbalance Shauna might have experienced and its etiology?

What are the functions and importance of the bicarbonate buffer system in the body?

Answer 1

Severe diarrhea predisposes an individual to metabolic acidosis. Intestinal secretions are high in bicarbonate, so the loss of these fluids through prolonged or severe diarrhea reduces pH levels. In cases of microbial infection, intestinal secretions of bicarbonate are particularly abundant in an attempt to neutralize the metabolic acids of the pathogen. This situation further contributes to a loss of base and development of metabolic acidosis.

The bicarbonate buffer system uses carbonic acid (H2CO3) to substitute a strong acid and a bicarbonate salt to substitute a strong base in the maintenance of serum pH levels. The bicarbonate/carbon dioxide (HCO3−/CO2) system is particularly efficient in buffering pH levels because of the ability to quickly form these components in the body and eliminate them as needed.