A 70-year-old man presents to his primary care physician for a general checkup. He states that he has been doing well and taking his medications as prescribed. He recently started a new diet and supplement to improve his health and has started exercising. The patient has a past medical history of diabetes, a myocardial infarction, and hypertension. He denies any shortness of breath at rest or with exertion. An ECG is performed and is within normal limits. Laboratory values are ordered as seen below. Serum: Na+: 139 mEq/L Cl-: 100 mEq/L K+: 6.7 mEq/L HCO3-: 25 mEq/L Glucose: 133 mg/dL Ca2+: 10.2 mg/dL Which of the following is the most likely cause of this patient's presentation?
AMedication
BAcute renal failure
CHemolysis
DDietary changes
ERhabdomyolysis
A 45-year-old man presents to the emergency department with complaint of dizziness and nausea for the past hour. He says that he can feel his heartbeat racing. He also reports of generalized weakness that began in the morning. He was diagnosed with end-stage renal disease 2 years ago and currently on dialysis, but he missed his last dialysis session. He has also been diabetic for the past 15 years and managed with insulin, and was also diagnosed with celiac disease 8 years ago. He does not smoke or drink alcohol. The family history is insignificant. The temperature is 36.7°C (98.0°F), blood pressure is 145/90 mm Hg, pulse is 87/min, and respiratory rate is 14/min. On physical examination, the patient looks fatigued and exhausted. The muscle strength in the lower limbs is 4/5 bilaterally. An ECG is ordered which shows peaked and narrow T waves and prolongation of PR interval. The lab test results are as follows: Serum Sodium 132 mEq/L Serum Potassium 8 mEq/L Serum Creatinine 5 mg/dL Blood urea nitrogen (BUN) 25 mg/dL What is the mechanism of action of the most likely initial treatment for the patient's condition?
APrevents platelet aggregation
BBlocks beta adrenergic receptors
CAntagonizes the membrane action of hyperkalemia
DIncrease potassium loss from the gastrointestinal tract
EBlocks Na+/K+ ATPase
A 32-year-old man with a history of chronic alcoholism presents to the emergency department with vomiting and diarrhea for 1 week. He states he feels weak and has had poor oral intake during this time. The patient is a current smoker and has presented many times to the emergency department for alcohol intoxication. His temperature is 97.5°F (36.4°C), blood pressure is 102/62 mmHg, pulse is 135/min, respirations are 25/min, and oxygen saturation is 99% on room air. On physical exam, he is found to have orthostatic hypotension and dry mucus membranes. Laboratory studies are ordered as seen below. Serum: Na+: 139 mEq/L Cl-: 101 mEq/L K+: 3.9 mEq/L HCO3-: 25 mEq/L BUN: 20 mg/dL Glucose: 99 mg/dL Creatinine: 1.1 mg/dL Ca2+: 9.8 mg/dL The patient is given normal saline, oral potassium, dextrose, thiamine, and folic acid. The following day, the patient seems confused and complains of diffuse weakness and muscle/bone pain. An ECG and head CT are performed and are unremarkable. Which of the following is the most likely explanation for this patient's new symptoms?
AHypomagnesemia
BHyponatremia
CHypoglycemia
DHypophosphatemia
EHypocalcemia
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