Author Question: Which of the following physiologic changes would the therapist expect a patient to experience as a ... (Read 32 times)

mcmcdaniel · **on:** Jul 16, 2018

Which of the following physiologic changes would the therapist expect a patient to experience as a result of being mechanically ventilated with positive pressure? I. increased right ventricular afterload II. decreased left ventricular afterload III. decreased pulmonary vascular resistance IV. increased systemic vascular resistance

A. I, II only
B. I, III only
C. II, IV only
D. III, IV only

Question 2

How do the positive and negative effects of positive-pressure ventilation (PPV) on stroke volume influence the pulse pressure of a fully hypervolemic patient receiving mechanical ventilation? The pulse pressure will ___________________ .

A. increase
B. decrease
C. remain constant
D. fluctuate significantly

AaaA · **Reply #1 on:** Jul 16, 2018

Answer to Question 1

ANS: A
A. Correct response: For a relaxed patient receiving a positive-pressure breath, nearly all of the individual mechanical effects are invoked with each inspiration. Pleural pressure increases would tend to (1) decrease venous return, (2) decrease left ventricular afterload, (3) increase lung volume, (4) increase right ventricular afterload, (5) increase pulmonary vascular resistance, and (6) increase or decrease blood flow into the left atrium depending on the overall fluid volume status.
B. Incorrect response: See explanation A.
C. Incorrect response: See explanation A.
D. Incorrect response: See explanation A.

Answer to Question 2

ANS: C
A. Incorrect response: See explanation C.
B. Incorrect response: See explanation C.
C. Correct response: In patients who are fully volume replete or hypervolemic, positive and negative effects of ventilation on stroke volume tend to balance each other, so that the pulse pressure remains relatively constant.
D. Incorrect response: See explanation C