CRNA Board Questions with correct answers

Positive end expiratory pressure (PEEP): 1. decreases dead space ases venous return to the heart 3. decreases intrapulmonary shunting 4. decreases extravascular lung water CORRECT ANSWER Positive end expiratory pressure (PEEP): decreases intrapulmonary shunting The major effect of PEEP is to increase FRC and tidal ventilation above the closing capacity. This results in a decrease in intrapulmonary shunting. Neither PEEP nor CPAP decrease extravascular lung water. By increasing intrathoracic pressure, PEEP decreases venous return to the heart. The essential component of cardioplegia solutions is: 1. mannitol 2. magnesium 3. potassium 4. corticosteroid CORRECT ANSWER The essential component of cardioplegia solutions is: potassium High concentrations of potassium (20 - 30 mEq/L) are used in cardioplegia solutions. These solutions result in an increase in extracellular potassium and reduce transmembrane potential. This progressively interferes with the normal sodium currents of depolarization and eventually the sodium channels are completely inactivated. pg. 1092Barash, PG, Cullen, BF, Stoelting, RK, Cahalan, MK, Stock, MC, Ortega, R.,Sharar, SR, and Holt, NF. Clinical Anesthesia. Philadelphia: Lippincott Williams & Wilkins, 2017.