CASE LEARNING OBJECTIVES
Correctly interpret ABG values
Identify risk factors for acid–base and electrolyte disorders
Develop an appropriate treatment and monitoring plan for a patient with metabolic alkalosis and critical hypokalemia
Understand the clinical implications of hypophosphatemia
Integrate magnesium repletion into the care plan of a patient with hypokalemia that is refractory to conventional correction
History of Present Illness
Helen Baker is a 78-year-old woman transferred from a local nursing home for weakness and confusion. For several days she has had "the flu" according to the nursing home staff. The patient is delirious and unable to provide any history: nursing notes show at least 3 days of N/V/D, and poor oral intake. Several other residents at the nursing home have been ill with similar symptoms. A review of the patient's records shows that she was recently discharged from another hospital after being treated for pneumonia for 7 days. Although she was previously living independently, she had agreed to a temporary stay in the nursing home's acute care area to complete an additional 7 days of intravenous ciprofloxacin and gentamicin for a resistant Pseudomonas strain. Her current symptoms began within the first 24 hours of hospital discharge. The hospital discharge note indicates that the only other change to her medications during that hospitalization was the addition of 40 mEq (40 mmol) of oral potassium supplementation taken twice daily for persistent hypokalemia.
MI (1999, 2005); three-vessel CABG (2001)
Angioplasty with stent placement (2009)
Ischemic cardiomyopathy with a left ventricular ejection fraction of 20% (0.20)
CKD: baseline serum creatinine 1.5 mg/dL (133 μmol/L)
Unknown, as the patient was adopted
The patient is a lifelong resident of a rural Iowa farming community. She is a widow and lives with her son. She was employed as a bank teller for 19 years before retiring 5 years ago for health reasons. She has no recent travel history.
The patient is a lifelong nonsmoker. Although she denied alcohol consumption to medical staff during her recent hospitalization and at the time of nursing home admission, her son reports ingestion of a pint of vodka daily for the past 25 years. Her recent hospital records document moderate alcohol withdrawal, requiring short-term benzodiazepine therapy.
Allergies/Intolerances/Adverse Drug Events