A 20-year-old man presents with obtundation. Past medical history is unobtainable. Blood pressure is 120/70 without orthostatic change, and he is well perfused peripherally. The neurological examination is nonfocal. His laboratory values are as follows: Na: 138 mEq/L K: 4.2 mEq/L HCO3: 5 mEq/L Cl: 104 mEq/L Creatinine: 1.0 mg/dL BUN: 14 mg/dL Ca: 10 mg/dL Arterial blood gas on room air: PO2 96, PCO2 15, pH 7.02 Blood glucose: 90 mg/dL Urinalysis: normal, without blood, protein, or crystals. Which of the following is the most likely acid-base disorder? 

1.  A 42-year-old male is found unconscious in a subway station. He is brought to the emergency department where cardio-pulmonary resuscitation (CPR) is done and IV glucose and thiamine are given. His lab profile shows: 
Blood pH 7.20 PaO2 90mmHg PaCO2 30mmHg HCO3· 12 mEq/L Which of the following is the best next step in the diagnosis of this patient's acid-base status? 

1.  A 56-year-old male comes to the emergency room because of a 2-day history of fever, chills, shortness of breath and productive cough. He also threw up once in the emergency room. He has been smoking for several years and occasionally drinks alcohol. On admission, his BP was 90/60, but with one liter of normal saline it improved to 120/80 mm Hg. His temperature is 38.8C (102F). His arterial blood gas (ABG) analysis is as follows:   Blood pH 7.53 PaO2 70 mmHg PaCO2 30 mmHg HCO3- 22 mEq/L Which of the following best describes his primary acid-base status? 

1.  . A 44-year-old obese female undergoes an open cholecystectomy for a complicated acute cholecystitis. On her third post-operative day, her temperature is 36.7C (98.2F), blood pressure is 110/80 mm Hg and pulse is 92/min. Her arterial blood gas shows the following: Blood pH 7.28 PaO2 62 mmHg PaCO2 54 mmHg HCO3- 30 mEq/L What is the most likely cause of acidosis in this patient? 

1.  A 56-year-old male comes to the emergency room because of increasing shortness of breath for the last 3 days. He had a cold recently, and since then his symptoms have been worse. He has a mild productive cough but denies fever or chills. He has a several year history of smoking and has been diagnosed with emphysema. He also has a history of diabetes, hypertension, hyperlipidemia, and hypothyroidism. He takes glipizide, metformin, lisinopril, furosemide, aspirin, atorvastatin and levothyroxine. Physical examination shows trace bilateral lower extremity edema and a diffuse decrease in breath sounds along with wheezing. Heart sounds are distant. His arterial blood gas shows the following: Blood pH 7.23 PaO2 88mm Hg PaCO2 40 mm Hg HCO3- 16mEq/L Which of the following best describes the acid-base status of this patient? 

1.  A 56-year-old diabetic male is brought to the emergency department due to nausea and vomiting. While you are examining the patient, a nurse asks if determination of the patient's acid-base status will help ascertain the etiology and subsequent management of the patient's primary problem. Which of the following pairs of laboratory values will help get the best picture of the patient's acid-base status? 

1.  As you are walking across the hospital lobby, you stumble upon the arterial blood gas (ABG) results of a patient. The ABG (on room air) results are shown below:   Blood pH 7.43 PaO2 100 mm Hg PaCO2 25 mm Hg HCO3- 16 mEq/L Which of the following patients is most likely to have these laboratory values?