Maya Chen, age 63, has rheumatoid arthritis and takes predni…

Maya Chen, age 63, has rheumatoid arthritis and takes prednisone and methotrexate. A lower-leg laceration has become red, swollen, painful, and purulent. Maya is admitted with a temperature of 102.56°F, heart rate of 118/min, blood pressure of 88/52 mm Hg, sodium of 129 mEq/L, potassium of 3.0 mEq/L, and elevated lactate. The arterial blood gas shows pH 7.29 and bicarbonate of 17 mEq/L.