A 21-year-old man presents to his physician because he has been feeling increasingly tired and short of breath at work. He has previously had these symptoms but cannot recall the diagnosis he was given. Chart review reveals the following results: Oxygen tension in inspired air = 150 mmHg Alveolar carbon dioxide tension = 50 mmHg Arterial oxygen tension = 71 mmHg Respiratory exchange ratio = 0.80 Diffusion studies reveal normal diffusion distance. The patient is administered 100% oxygen but the patient's blood oxygen concentration does not improve. Which of the following conditions would best explain this patient's findings?
ASeptal defect since birth
BUse of opioid medications
CPulmonary fibrosis
DPulmonary embolism
EVacation at the top of a mountain
A 54-year-old man comes to the physician because of excessive daytime sleepiness for 5 months. He wakes up frequently at night, and his wife says his snoring has become louder. He is 180 cm (5 ft 10 in) tall and weighs 104 kg (230 lb); his BMI is 33 kg/m2. His pulse is 80/min and his respiratory rate is 11/min. His jugular venous pressure is 7 cm H2O. He has 2+ pitting edema of the lower legs and ankles. Arterial blood gas analysis on room air shows a pH of 7.42 and a PCO2 of 41 mm Hg. An x-ray of the chest shows normal findings. Which of the following is the most likely underlying cause of this patient's condition?
ADaytime alveolar hypoventilation
BDecreased levels of hypocretin-1
CIncreased medullary ventilatory responsiveness
DImpaired myocardial relaxation
EIntermittent collapse of the oropharynx
A 3-year-old boy is brought to the emergency department with a history of unintentional ingestion of seawater while swimming in the sea. The amount of seawater ingested is not known. There is no history of vomiting. On physical examination, the boy appears confused and is asking for more water to drink. His serum sodium is 152 mmol/L (152 mEq/L). Which of the following changes in volumes and osmolality of body fluids are most likely to be present in this boy?
ADecreased ECF volume, unaltered ICF volume, unaltered body osmolality
BIncreased ECF volume, decreased ICF volume, increased body osmolality
CIncreased ECF volume, unaltered ICF volume, unaltered body osmolality
DIncreased ECF volume, increased ICF volume, decreased body osmolality
EDecreased ECF volume, decreased ICF volume, increased body osmolality
+ 7 more in the PDF
Browse all chapters