Volume of blood in liters pumped by heart in one minute?

Appeared in: KPSC Staff Nurse - 2021

Explanation

Cardiac output is the correct term for the total volume of blood the heart pumps in one minute.
It is a crucial indicator of how well the heart is functioning and supplying blood to the body.
The calculation for cardiac output is Stroke Volume (the amount of blood per beat) multiplied by Heart Rate (the number of beats per minute).
A typical resting cardiac output for an adult is between 4 and 8 liters per minute.

Option A: Stroke volume measures the amount of blood pumped with each individual heartbeat, not the total volume over one minute.
Option B: Stroke index is a calculated value that relates stroke volume to the patient's body surface area (BSA). It is not a direct measurement of volume per minute.
Option C: Cardiac index relates the cardiac output to the patient's body surface area (BSA). While it is based on cardiac output, it is an adjusted value, not the primary definition of volume per minute.

Clinical Relevance

Nursing practice connection: Knowing Definition of Cardiac Output and Related Hemodynamic Terms helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Assessing cardiac output is vital in managing critically ill patients, especially those in shock, with heart failure, or after major surgery, as it reflects tissue and organ perfusion.
A low cardiac output can indicate decreased heart function or low blood volume, leading to inadequate oxygen delivery to tissues.
A high cardiac output can be seen in conditions like sepsis or high fever, where the body's metabolic demands are increased.

How to Approach the Question

This is a factual recall question that tests your knowledge of cardiovascular definitions.
First, break down the question stem to identify the key components: 'Volume of blood', 'pumped by heart', and 'in one minute'.
Next, review the definitions of each option.
Stroke Volume is volume per 'beat'.
Cardiac Output is volume per 'minute'.
Cardiac Index and Stroke Index are values adjusted for body size ('index').

Concept Tested & Keywords

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E6 Nursing Fundamentals Potter Perry 12e Part 4 p. 231-233

E6 Physiology Ganong 27e Vol 2 Part 1 p. 91-93

E6 Physiology MindMaps Guyton 4SAE p. 41-43

Practise the full KPSC Staff Nurse - 2021

Attempt every question from this paper in a timed mock, then review the full solution for each one.