What term is described as the amount of blood pumped by each ventricle in one minute?

A. Heart rate:Heart rate refers to the number of cardiac contractions per minute and does not reflect the volume of blood ejected with each beat. While it contributes to overall circulatory performance, it measures frequency rather than total blood flow.

B. Stroke volume:Stroke volume is the amount of blood ejected by one ventricle during a single contraction. Although it is a component of overall cardiac performance, it represents output per beat rather than per minute.

C. Cardiac reserve:Cardiac reserve is the difference between resting cardiac output and the maximum cardiac output achievable during stress or exercise. It reflects the heart’s capacity to increase output above baseline, not the baseline volume pumped each minute.

D. Cardiac output:Cardiac output is the total volume of blood pumped by each ventricle in one minute and is calculated as heart rate multiplied by stroke volume. It represents the overall effectiveness of the heart in delivering oxygenated blood to tissues per unit time.

A. pH 7.48, PaCO2 37 mm Hg, HCO3 30 mEq/L:This ABG shows alkalemia with normal PaCO2 and slightly elevated bicarbonate, consistent with metabolic alkalosis. It does not indicate respiratory acidosis because PaCO2 is within normal limits.

B. pH 7.28, PaCO2 31 mm Hg, HCO3 20 mEq/L:This reflects acidemia with low PaCO2 and low HCO3, suggestive of metabolic acidosis with respiratory compensation. The low CO2 indicates hyperventilation to compensate, not primary respiratory acidosis.

C. pH 7.39, PaCO2 38 mm Hg, HCO3 23 mEq/L:These values are within normal physiologic ranges, representing a normal ABG with no evidence of acid-base disturbance.

D. pH 7.30, PaCO2 50 mm Hg, HCO3 24 mEq/L:This ABG indicates acidemia (low pH) with elevated PaCO2 and normal bicarbonate, which is consistent with respiratory acidosis. The elevated CO2 reflects hypoventilation or impaired gas exchange leading to CO2 retention and decreased pH.