A patient has been diagnosed with heart failure and cardiac output is decreased. Which formula can the nurse use to calculate cardiac output?
Ventricular filling time/diastolic filling time
Stroke volume x heart rate
Myocardial contractility x myocardial blood flow
Preload/afterload
The Correct Answer is B
A. Ventricular filling time and diastolic filling time are not formulas used to calculate cardiac output; they pertain to the phases of the cardiac cycle.
B. Cardiac output is calculated by multiplying stroke volume (the amount of blood ejected by the heart with each beat) by heart rate (the number of beats per minute). This formula accurately reflects the overall volume of blood the heart pumps in one minute.
C. Myocardial contractility and myocardial blood flow are important factors in cardiac function but do not directly provide a formula for calculating cardiac output.
D. Preload and afterload are factors that affect stroke volume but are not used to calculate cardiac output directly.
Free Nursing Test Bank
- Free Pharmacology Quiz 1
- Free Medical-Surgical Quiz 2
- Free Fundamentals Quiz 3
- Free Maternal-Newborn Quiz 4
- Free Anatomy and Physiology Quiz 5
- Free Obstetrics and Pediatrics Quiz 6
- Free Fluid and Electrolytes Quiz 7
- Free Community Health Quiz 8
- Free Promoting Health across the Lifespan Quiz 9
- Free Multidimensional Care Quiz 10
View Related questions
Correct Answer is B
Explanation
A. A patient with hypercapnia requires monitoring, but wearing an oxygen mask indicates some level of intervention is in place.
B. A patient with a chest tube should never ambulate with the chest tube unclamped, as this can lead to a collapsed lung and respiratory distress; thus, this patient should be prioritized.
C. While a patient with thick secretions may need suctioning, this is not as critical as ensuring the safety of a patient with an unclamped chest tube.
D. A patient with a new tracheostomy requires monitoring, but the presence of the obturator indicates readiness for emergencies; this does not take priority over the safety of the patient with the chest tube.
Correct Answer is A
Explanation
A. The P wave represents atrial depolarization, which is initiated by the SA node, the heart's natural pacemaker.
B. The AV node is responsible for conducting impulses from the atria to the ventricles but does not initiate the P wave.
C. The Bundle of His transmits the electrical impulses to the ventricles but is not directly associated with the P wave.
D. Purkinje fibers are involved in ventricular depolarization, which corresponds to the QRS complex, not the P wave.