A patient with CAD is asking the nurse about the mechanisms of the heart.
It would be appropriate for the nurse to respond that when the left ventricle contracts, it pushes blood through the semilunar valve to the:

Choice A rationale:

Hyperventilation is a compensatory mechanism for metabolic acidosis, not a cause. It helps to eliminate carbon dioxide, a weak acid, to balance the pH.

Choice B rationale:

Diarrhea causes loss of bicarbonate, a base, from the body. This can lead to metabolic acidosis as there is an excess of acids.

Choice C rationale:

Salicylate intoxication can cause both respiratory alkalosis and metabolic acidosis. However, it is not the most common cause of metabolic acidosis.

Choice D rationale:

Vomiting leads to loss of gastric acid, a strong acid. This usually results in metabolic alkalosis, not acidosis.

Choice A rationale:

Metabolic alkalosis is incorrect because it would present with a high pH and high HCO3. This client’s pH is low, indicating acidosis, not alkalosis.

Choice B rationale:

Respiratory acidosis is correct. It is characterized by a low pH and high PaCO2, as seen in this client’s results. This condition occurs when the lungs can’t remove enough CO2, causing it to build up in the blood and lower the pH.

Choice C rationale:

Metabolic acidosis is incorrect because it would present with a low pH and low HCO3. This client’s HCO3 is normal.

Choice D rationale:

Respiratory alkalosis is incorrect because it would present with a high pH and low PaCO2. This client’s pH is low and PaCO2 is high.