Answer to Question 1
ANS: C
A. Incorrect response: See explanation C.
B. Incorrect response: See explanation C.
C. Correct response: For adults, ventilation standards include a frequency of 8 to 10 breaths/minute with a tidal volume of 0.5 to 0.6 liter (6 to 7 ml/kg), and an inspiratory time of 1.0 to 2.0 seconds. This combination corresponds with and inspiratory flow of 30 to 40 L/minute. The use of longer inspiratory times and slower flows is recommended to prevent gastric insufflation.
D. Incorrect response: See explanation C
Answer to Question 2
ANS: B
A. Incorrect response: See explanation B.
B. Correct response: A factor affecting delivered Vt during CPR is esophageal opening pressure. Because airway pressure is increased to deliver volume in the face of increased pulmonary impedance, gastric insufflation results. Based on work by Rueben and associates, esophageal opening pressure is approximately 20 cm H2O. Airway pressures of 30 to 35 cm H2O will likely produce gastric insufflation. The use of longer inspiratory times and slower flows is recommended to prevent gastric insufflation.
C. Incorrect response: See explanation B.
D. Incorrect response: See explanation B