Which of the following are potential effects of positive-pressure ...

[Wadzanai]

Which of the following are potential effects of positive-pressure ventilation on the cardiovascular system? 1. Decreased venous return 2. Decreased cranial perfusion pressures 3. Increased pulmonary blood flow 4. Decreased ventricular stroke volume
 
  a. 2 and 4 only
  b. 1 and 4 only
  c. 3 and 4 only
  d. 1, 2, 3, and 4

Question 2

Ventricular dysfunction occurs in patients receiving positive-pressure ventilation for which of the following reasons?
 
  1. Hypovolemia
  2. Excessive tidal volume
  3. Receiving more than optimal positive end expiratory pressure (PEEP)
  4. Hypervolemia
  a. 1 and 3 only
  b. 1, 2, and 3 only
  c. 3 and 4 only
  d. 2, 3, and 4 only

[triiciiaa]

Answer to Question 1

ANS: B
Positive pleural pressure compresses the intrathoracic veins and increases central venous and right atrial filling pressures. As these pressures increase, venous return to the heart is impeded and right ventricular preload and stroke volume decrease, as does pulmonary blood flow.

Answer to Question 2

ANS: B
It appears that right or left ventricular dysfunction occurs if the patient is hypovolemic, receiving an excessive tidal volume, or receiving more than optimum PEEP.

[Wadzanai]

Excellent

[helenmarkerine]

Gracias!