Obese and hypoventilation

Mr. April, 24 years of age, is a male patient who was admitted to the surgical unit after a successful repair of an inguinal hernia. Wt. 342lbs, height 5’10. His vital signs are as follows: blood pressure 122/70 mm Hg, respiratory rate 26 breaths/min, heart rate 88 bpm, and temperature 98.6°F. The patient complains of incision pain and rates it on the pain scale as 7 of 10. His family is visiting at the bedside. You administer a dose of morphine as ordered. Fifteen minutes after administering the pain medication, a family member enters the hallway and yells, “We need help in here! John is not breathing.” Upon arrival you find Mr. April having periods of apnea lasting a few seconds followed by a short snorting gasp and then he begins breathing at a rate of 12 breaths per minute. His lips are bluish in coloration and so are his nail beds. He is lying supine in the bed. He awakens as you enter but is very lethargic and somnolent. Describe the correlation between a patient who is obese and hypoventilation? How does atelectasis, and the retention of CO2 play a role? What are your priority interventions with this patient?