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 60-year-old woman is brought to the emergency department by her husband because of worsening shortness of breath over the past 2 days. Last week, she had a sore throat and a low-grade fever. She has coughed up white sputum each morning for the past 2 years. She has hypertension and type 2 diabetes mellitus. She has smoked 2 packs of cigarettes daily for 35 years. Current medications include metformin and lisinopril. On examination, she occasionally has to catch her breath between sentences. Her temperature is 38.1°C (100.6°F), pulse is 85/min, respirations are 16/min, and blood pressure is 140/70 mm Hg. Expiratory wheezes with a prolonged expiratory phase are heard over both lung fields. Arterial blood gas analysis on room air shows: pH 7.33 PCO2 53 mm Hg PO2 68 mm Hg An x-ray of the chest shows hyperinflation of bilateral lung fields and flattening of the diaphragm. Which of the following additional findings is most likely in this patient?
ADecreased urinary bicarbonate excretion
BDecreased urinary chloride concentration
CIncreased serum anion gap
DIncreased urine osmolar gap
EIncreased urinary pH
A 27-year-old woman is admitted to the emergency room with dyspnea which began after swimming and progressed gradually over the last 3 days. She denies cough, chest pain, or other respiratory symptoms. She reports that for the past 4 months, she has had several dyspneic episodes that occurred after the exercising and progressed at rest, but none of these were as long as the current one. Also, she notes that her tongue becomes ‘wadded’ when she speaks and she tires very quickly during the day. The patient’s vital signs are as follows: blood pressure 125/60 mm Hg, heart rate 92/min, respiratory rate 34/min, and body temperature 36.2℃ (97.2℉). Blood saturation on room air is initially 92% but falls to 90% as she speaks up. On physical examination, the patient is slightly lethargic. Her breathing is rapid and shallow. Lung auscultation, as well as cardiac, and abdominal examinations show no remarkable findings. Neurological examination reveals slight bilateral ptosis increased by repetitive blinking, and easy fatigability of muscles on repeated movement worse on the face and distal muscles of the upper and lower extremities. Which arterial blood gas parameters would you expect to see in this patient?
APaCO2 = 51 mm Hg, PaO2 = 58 mm Hg
BPaCO2 = 37 mm Hg, PaO2 = 46 mm Hg
CPaCO2 = 34 mm Hg, PaO2 = 61 mm Hg
DPaCO2 = 31 mm Hg, PaO2 = 67 mm Hg
EPaCO2 = 43 mm Hg, PaO2 = 55 mm Hg
+ 7 more in the PDF
Browse all chapters