Chapter 9: Ventilatory Assistance Test Bank

1. A patient has coronary artery bypass graft surgery and is transported to the surgical intensive care unit at noon. He is placed on mechanical ventilation. Interpret his initial arterial blood gas levels: pH 7.31 PaCO2 48 mm Hg Bicarbonate 22 mEq/L PaO2 115 mm Hg O2 saturation 99% a. Normal arterial blood gas levels with a high oxygen level b. Partly compensated respiratory acidosis, normal oxygen c. Uncompensated metabolic acidosis with high oxygen levels d. Uncompensated respiratory acidosis; hyperoxygenated ANS: D The high PaO2 level reflects hyperoxygenation; the PaCO2 and pH levels show respiratory acidosis. The respiratory acidosis is uncompensated as indicated by a pH of 7.31 (acidosis) and a normal bicarbonate level. No metabolic compensation has occurred. DIF: Cognitive Level: Analysis REF: pp. 178-179 | Box 9-2 | Box 9-3 OBJ: Describe methods for assessing the respiratory system, including physical assessment, interpretation of arterial blood gases, and noninvasive techniques