Case:
A 73-year-old woman with medical problems of hypertension,
hyperlipidemia, and coronary artery disease underwent left CEA for
asymptomatic carotid artery stenosis. Preoperative computed tomography
(CT) angiogram showed severe calcification of the aortic arch and the
proximal left common carotid artery. Her preoperative laboratory workup
was unremarkable with a baseline sodium of 139 mmol/L (Table 1). The
operation was performed under regional anesthesia with sedation and
there were no intraoperative complications. The patient was discharged
on postoperative day (POD) one in a stable condition.
On POD four, the patient presented to the emergency room with a
three-day history of lethargy, confusion, nausea, and emesis. Given the
patient’s altered mentation, the initial history was provided by her
family. On examination, the patient was somnolent and lacked orientation
to person, place or time. No other focal neurological deficits were
appreciated. There was no peripheral edema, and the skin turgor was
normal. Initial laboratory evaluation showed severe hyponatremia (109
mmol/L), hypokalemia, and normal renal function (Table 2).