CASE 1 :
Twenty-four hours after colon resection, urine
output in a 70-year-old man is 10 mL/h. Blood
chemistry analysis reveals sodium, 138 mEq/L;
potassium, 6 mEq/L; chloride, 100 mEq/L; bicarbonate,
14 mEq/L. His metabolic abnormality
is characterized by which of the following?
(A) Abdominal distension
(B) Peaked T waves
(C) Narrow QRS complex
(D) Cardiac arrest in systole
(E) J wave or Osborne wave
(B) Hyperkalemia can manifest by GI or
cardiovascular signs. GI symptoms include
nausea, vomiting, intestinal colic, and diarrhea.
Abdominal distension as a result of paralytic
ileus is due to hypokalemia. An ECG is useful
to monitor potassium levels. Hyperkalemia
is characterized by peaked T waves. ECG
changes also include ST-segment depression,
widened QRS complex, and heart block.
Cardiac arrest occurs in diastole with increasing
levels of potassium. Osborne (J) wave is
seen in hypothermia.