A 39 - year - old , 178 - cm ( 5 - ft 10 - in ) , 120 - kg ( 265 - ) male is in the recovery room following an appendectomy . The patient wakes easily and follows commands , but continues to exhibit somnolence and snoring . Arterial blood gas analysis while receiving 40 % oxygen by face mask during sleep reveals 7.31 55 torr PaCO₂ HCO₃ BE 75 torr 28 mEq / L mEq / L Which of the following is MOST likely contributing to this patient's current condition ?
a. Obstructive sleep apnea
b. Congestive heart failure
c. Pulmonary embolus
d. COPD