Test Bank 5th_Ed Pilbeam’s Mechanical Ventilation by Cario
Sample Chapter No 19
Chapter 19; Basic Concepts of Noninvasive Positive Pressure Ventilation
- Negative pressure ventilators cause air to enter the lungs by increasing ______________ pressure.
Transpulmonary pressure maintains alveolar inflation due to the decrease in pleural pressure caused by the negative pressure surrounding the chest wall. Positive pressure ventilators cause air to move into the lungs by increasing the pressure in the upper airways and in the conductive airways. Changes in transpulmonary pressure result in corresponding changes in alveolar volume. The transairway pressure is the gradient that produces airway movement in the conductive airways and represents the pressure caused by resistance to gas flow in the airways. The transrespiratory pressure is responsible for gas flow into and out of the alveoli during breathing. The transthoracic pressure is the pressure across the chest wall. It represents the pressure necessary to expand or contract the lungs and chest wall together.
DIF: 1 REF: pg. 379
- A patient with acute cardiogenic pulmonary edema (ACPE), as evidenced by pink, frothy secretions, arrives in the emergency department (ED) by ambulance with a nonrebreather mask (NRM) at 15 L/min. An arterial blood gas sample is drawn in the ED while the patient is on the NRM; the values are: pH = 7.50, PaCO2 = 28 mm Hg; PaO2 = 43 mm Hg; SaO2 = 84%; HCO3– = 24 mEq/L. After evaluating the situation, the respiratory therapist should suggest which of the following therapies?
|a.||IPPB with supplemental oxygen|
|b.||Mask CPAP with supplemental oxygen|
|c.||Postural drainage to clear the secretions|
|d.||NPPV via nasal mask with postural drainage|
The current recommendation for ACPE is for CPAP to be used initially. NPPV should be used only in patients who were hypercapnic and continue to be hypercapnic in spite of the CPAP. This patient is not hypercapnic at this time; therefore, mask CPAP is the appropriate therapy. IPPB is not appropriate because the positive effects of the therapy will be lost after a few minutes off the therapy.
DIF: 3 REF: pg. 381
- A patient has acute pulmonary edema from left-sided heart failure and acute hypoxemic respiratory failure that has not responded to conventional pharmacologic and oxygen therapy. As the next line of therapy, the respiratory therapist should recommend which of the following?