A patient has a long history of smoking. He has blood studies done because he is very tired, short of breath, and does not feel well. His blood gases reveal the following findings: pH 7.3, HCO3- 25 mEq/L, PaCO2 48 mmHg. What is the interpretation of these gases?

Select all that apply:

Normal range:

• pH: 7.35-7.45
• PaCO2: 36-44 mmHg
• HCO3-: 22-26 mEq/L

Choice A Reason:

Increased neuromuscular excitability is not typically associated with respiratory acidosis. Instead, respiratory acidosis can lead to symptoms such as confusion, fatigue, and shortness of breath due to the buildup of carbon dioxide in the blood. Neuromuscular excitability is more commonly associated with conditions like hypocalcemia.

Choice B Reason:

This is the correct answer. Respiratory acidosis occurs when the lungs cannot remove enough carbon dioxide (CO2) from the body, leading to an accumulation of CO2 in the blood. This increase in CO2 results in the formation of carbonic acid, which lowers the pH of the blood. The elevated levels of carbonic acid are a hallmark of respiratory acidosis.

Choice C Reason:

Increased pH is not associated with respiratory acidosis. In fact, respiratory acidosis is characterized by a decrease in blood pH due to the accumulation of carbon dioxide and the subsequent increase in carbonic acid. Therefore, this choice is incorrect.

Choice D Reason:

Hypokalemia, or low potassium levels, is not typically associated with respiratory acidosis. Instead, respiratory acidosis can sometimes lead to hyperkalemia (high potassium levels) due to the shift of potassium out of cells in response to the acidotic state. Therefore, this choice is incorrect.

Choice A Reason:

An increase in HCO3- (bicarbonate) is not typically associated with diarrhea and lower intestinal fluid losses. In fact, the opposite is true. Diarrhea often leads to a loss of bicarbonate, which can result in metabolic acidosis. Therefore, this choice is incorrect.

Choice B Reason:

This is the correct answer. Diarrhea and other lower intestinal fluid losses lead to a decrease in HCO3- levels. The loss of bicarbonate from the body results in a lower pH, contributing to metabolic acidosis. This condition occurs because bicarbonate is a key buffer that helps maintain the acid-base balance in the blood.

Choice C Reason:

An increase in the chance of alkalosis is not typically associated with diarrhea. Alkalosis refers to a condition where the pH of the blood is higher than normal, which can occur due to a loss of hydrogen ions or an increase in bicarbonate. However, diarrhea usually causes a loss of bicarbonate, leading to acidosis rather than alkalosis.

Choice D Reason:

Saying that diarrhea has no effect on the pH of the blood is incorrect. Diarrhea can significantly impact the acid-base balance in the body by causing a loss of bicarbonate, leading to metabolic acidosis. Therefore, this choice is incorrect.