Problem
Pt MC, an 80 yo female was admitted to the hospital for shortness of breath and fluid in her lungs. Upon arrival to the ED, she was treated with nebulized albuterol and strong diuretics. Several hours later, MC complains of muscle cramps and general weakness. Lab data stated the following: Na 138 mEq/L, K 2 mEq/L, Ca 9.3 mg/dL, Mg 2 mEq/L, Phosphate 2.9 mg/L, pH=7.3. EKG findings show depressed ST-waves and sinus bradycardia.
a) What electrolyte disorder is MC presenting here?
b) What specific lab finding/diagnostic test supports your answer?