Question

A 59 year-old post CABG patient has a C(a-v)O2 that has increased from 5 mL/dL to 8 mL/dL. The respiratory therapist should report to the physician that the patient's ________.

1) hemoglobin is increasing.
2) cardiac output is decreasing.
3) VD/VT ratio has increased.
4) oxygen consumption has decreased.

Answer 1

An increase in C(a-v)O2 from 5 mL/dL to 8 mL/dL in a post-CABG patient indicates a likely decrease in cardiac output, which is the correct answer the respiratory therapist should report to the physician.

Step-by-step explanation:

The question refers to a change in a measure known as C(a-v)O2, which stands for arteriovenous oxygen content difference. An increase in C(a-v)O2 from 5 mL/dL to 8 mL/dL in a post coronary artery bypass grafting (CABG) patient suggests a change in the patient's cardiovascular or respiratory function. The correct interpretation of this change is that the patient's cardiac output is likely decreasing.

This is because the arteriovenous oxygen difference reflects the amount of oxygen extracted by tissues; when this value rises, it typically indicates that tissues are extracting more oxygen due to a reduced blood flow, pointing to a reduced cardiac output.