What is ejection fraction?
Percentage of blood that leaves the heart in a minute
Percentage of blood that leaves the heart with each beat
Amount of blood that leaves the heart with each beat
Amount of blood that leaves the heart in a minute
The Correct Answer is B
Choice A reason: This is not the definition of ejection fraction. The percentage of blood that leaves the heart in a minute is related to the cardiac output, which is the product of the heart rate and the stroke volume.
Choice B reason: This is the correct definition of ejection fraction. It is the ratio of the stroke volume (the amount of blood pumped by the left ventricle) to the end-diastolic volume (the amount of blood in the left ventricle at the end of diastole). It is a measure of the efficiency of the heart and reflects the contractility of the cardiac muscle.
Choice C reason: This is not the definition of ejection fraction. The amount of blood that leaves the heart with each beat is the stroke volume, which is one of the factors that determine the ejection fraction.
Choice D reason: This is not the definition of ejection fraction. The amount of blood that leaves the heart in a minute is the cardiac output, which is influenced by the ejection fraction, but not equivalent to it.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is D
Explanation
Choice A reason: Potassium is not restricted in the management of high blood pressure. In fact, potassium can help lower blood pressure by balancing the effects of sodium and relaxing the blood vessel walls.
Choice B reason: Magnesium is not restricted in the management of high blood pressure. Magnesium can also help lower blood pressure by regulating the calcium channels and improving the endothelial function.
Choice C reason: Calcium is not restricted in the management of high blood pressure. Calcium can also help lower blood pressure by inhibiting the renin-angiotensin system and reducing the vascular resistance.
Choice D reason: Sodium is restricted in the management of high blood pressure. Sodium can increase blood pressure by retaining water in the body and increasing the blood volume and pressure.
Correct Answer is D
Explanation
Choice A reason: This is not a correct statement. LABAs stand for long-acting beta2-agonists, which are a class of medications that relax the smooth muscles of the airways and improve the airflow in patients with asthma or COPD. However, LABAs do not reduce the risk of asthma-related deaths, and may even increase it if used alone without an inhaled glucocorticoid, which is a type of anti-inflammatory medication.
Choice B reason: This is not a correct statement. LABAs cannot be used on an as-needed basis to treat symptoms, as they have a slow onset of action and a long duration of effect. LABAs are meant to be used as a maintenance therapy to prevent asthma exacerbations, not to relieve acute symptoms. For quick relief of symptoms, patients should use a short-acting beta2-agonist, such as albuterol or salbutamol.
Choice C reason: This is not a correct statement. LABAs are not safer than short-acting beta2 agonists, as they have similar side effects, such as tachycardia, tremors, and hypokalemia. LABAs also have a black box warning that they may increase the risk of asthma-related deaths if used without an inhaled glucocorticoid.
Choice D reason: This is the correct statement. LABAs should be combined with an inhaled glucocorticoid, as this combination has been shown to improve the asthma control, reduce the frequency and severity of exacerbations, and decrease the inflammation and airway hyperresponsiveness. The inhaled glucocorticoid also reduces the risk of adverse effects and mortality associated with LABAs.
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