Which of the following factors can directly affect cardiac output?
Respiratory rate
Stroke volume
Heart rate
Blood pressure
Correct Answer : B,C
B. stroke volume is the amount of blood ejected from the left ventricle with each contraction (systole) of the heart. Changes in stroke volume directly affect cardiac output. An increase in stroke volume leads to an increase in cardiac output, while a decrease in stroke volume results in a decrease in cardiac output. Factors that can affect stroke volume include preload, afterload, and contractility of the heart.
C. Heart rate refers to the number of heartbeats per minute. Heart rate directly affects cardiac output by determining how frequently the heart contracts and pumps blood. An increase in heart rate (tachycardia) leads to an increase in cardiac output, while a decrease in heart rate (bradycardia) results in a decrease in cardiac output. Factors such as sympathetic and parasympathetic nervous system activity, hormones, and medications can influence heart rate.
A. Respiratory rate does not directly affect stroke volume or heart rate but changes in respiratory rate can indirectly impact cardiac output through their effects on venous return and preload.
D. Blood pressure represents the force exerted by the blood against the walls of the arteries. While blood pressure does not directly affect cardiac output, it is influenced by cardiac output and systemic vascular resistance (SVR).
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is A
Explanation
A. The insertion of a pulmonary artery catheter can help in assessing hemodynamic parameters and distinguishing between these two conditions. It provides direct measurement of pulmonary artery pressures, which can be elevated in the case of heart failure.
B. A ventilation-perfusion (V/Q) scan is used to evaluate ventilation and perfusion in the lungs. While it can help identify areas of ventilation-perfusion mismatch, it may not be the most appropriate initial test for distinguishing between ARDS and pulmonary edema.
C. Drawing blood for arterial blood gases is also a critical step as it helps in assessing the severity of hypoxemia and respiratory failure.
D. A chest x-ray can show the presence of bilateral opacities, which are indicative of ARDS when cardiac failure or fluid overload is not the primary cause. However, transthoracic echocardiography (TTE) is often performed to seek evidence of cardiac dysfunction when cardiogenic pulmonary edema cannot be excluded by clinical evaluation, laboratory findings, or imaging.
Correct Answer is B
Explanation
B. A client who is postoperative with shallow respirations at a rate of 9/min is likely not adequately eliminating carbon dioxide from their body due to hypoventilation. This retention of carbon dioxide can lead to an increase in the partial pressure of CO2 in the blood, causing an acidotic state.
A. Metabolic acidosis results from an accumulation of acids in the body or a loss of bicarbonate. Hypoventilation leading to respiratory acidosis does not directly cause metabolic acidosis.
C. Respiratory alkalosis occurs when there is excessive elimination of CO2 from the body, leading to decreased arterial carbon dioxide levels (hypocapnia) and an increase in pH. Shallow respirations and decreased respiratory rate are more consistent with hypoventilation and respiratory acidosis rather than hyperventilation and respiratory alkalosis.
D. Metabolic alkalosis results from excessive loss of acids or increased bicarbonate levels in the body. Hypoventilation leading to respiratory acidosis does not directly cause metabolic alkalosis.

Whether you are a student looking to ace your exams or a practicing nurse seeking to enhance your expertise , our nursing education contents will empower you with the confidence and competence to make a difference in the lives of patients and become a respected leader in the healthcare field.
Visit Naxlex, invest in your future and unlock endless possibilities with our unparalleled nursing education contents today
Report Wrong Answer on the Current Question
Do you disagree with the answer? If yes, what is your expected answer? Explain.
Kindly be descriptive with the issue you are facing.