A Man With Hypokalemia, Sleep Apnea, and Resistant Hypertension

Minh Chung; Eric Warren, DO; Darshan Rola; Brian Zacharias; Jennifer Broyles, MD


July 20, 2022

Physical Examination and Workup

The patient's vital signs on his initial visit showed a blood pressure of 170/88 mm Hg and a repeat blood pressure of 162/80 mm Hg, a temperature of 98.8°F (37.1°C), a heart rate of 77 beats/min, a respiration rate of 18 breaths/min, and an oxygen saturation of 99% on room air. His height was 65 in (165.1 cm), his weight was 176 lb (79.8 kg), and his body mass index was 29.5 kg/m2.

Upon physical examination, the patient is well developed, well nourished, and in no acute distress. His head shows no trauma; his conjunctiva are clear. The skin is warm, with no rashes. His neck is supple, and the trachea is in midline. The lungs are clear to auscultation bilaterally. Heart rate and rhythm are regular, with no audible murmurs. Bowel sounds are normal, and no abdominal distention is noted. No focal neurologic deficits are detected. The patient does not have a shuffling or wide-based gait. His affect is normal, and he is oriented to person, place, and time.

A routine comprehensive metabolic panel (CMP), complete blood cell (CBC) count, albumin level, random urine sample with creatinine measurement, and lipid panel are ordered. The patient's CBC count is within the normal range. The CMP reveals the following values:

  • Calcium: 9.6 mg/dL (reference range, 8.5-10.5 mg/dL)

  • Glucose: 93 mg/dL (reference range, 65-110 mg/dL)

  • Blood urea nitrogen (BUN): 13 mg/dL (reference range, 8-24 mg/dL)

  • Total protein: 7.4 g/dL (reference range, 6-8.3 g/dL)

  • Albumin: 4.7 g/dL (reference range, 3.4 to 5.4 g/dL)

  • Total bilirubin: 0.3 mg/dL (reference range, 0.1-1.2 mg/dL)

  • Alkaline phosphatase: 76 IU/L (reference range, 44-147 IU/L)

  • Aspartate aminotransferase: 19 IU/L (reference range, 6-34 IU/L)

  • Alanine aminotransferase: 17 IU/L (reference range, 20-60 IU/L)

  • Potassium: 3.4 mmol/L (reference range, 3.5-5.5 mmol/L)

  • Sodium: 140 mmol/L (reference range, 135-147 mmol/L

  • Chloride: 99 mmol/L (reference range, 96-106 mmol/L)

  • Creatinine: 0.79 mg/dL (reference range, 0.9-1.3 mg/dL)

  • Total carbon dioxide: 27 mmol/L (reference range, 23-29 mmol/L)

  • BUN/creatinine ratio: 16 (reference range, 10-20)

  • Total globulin: 2.7 g/dL (reference range, 2.0-3.9 g/dL)

  • Albumin/globulin ratio: 1.7 (reference range, 1.1-2.5)

  • Estimated glomerular filtration rate (non–African American): 98 mL/min/1.73 m2 (reference range, > 90 mL/min/1.73 m2)

The patient's potassium level (3.4 mmol/L) is low despite potassium chloride supplementation. The urine albumin/creatinine ratio is elevated at 47 mg/g (reference range, < 30 mg/g). The lipid panel shows an elevated total cholesterol level of 203 mg/dL (reference range, < 200 mg/dL), a high triglyceride level of 183 mg/dL (reference range, < 150 mg/dL), and a high low-density lipoprotein cholesterol level of 126 mg/dL (reference range, < 100 mg/dL). The aldosterone-to-renin ratio is elevated at 75.5 (reference range, 0-30), as is the aldosterone level at 13.9 ng/dL (reference range, 2-9 ng/dL).


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