. Why was this patient in metabolic acidosis?

Pagana: Mosby’s Manual of Diagnostic and Laboratory Tests, 6th Edition Adolescent With Diabetes Mellitus (DM) Case Studies The patient, a 16-year-old high-school football player, was brought to the emergency room in a coma. His mother said that during the past month he had lost 12 pounds and experienced excessive thirst associated with voluminous urination that often required voiding several times during the night. There was a strong family history of diabetes mellitus (DM). The results of physical examination were essentially negative except for sinus tachycardia and Kussmaul respirations. Studies Results Serum glucose test (on admission), p. 227 1100 mg/dL (normal: 60–120 mg/dL) Arterial blood gases (ABGs) test (on admission), p. 98 pH 7.23 (normal: 7.35–7.45) PCO2 30 mm Hg (normal: 35–45 mm Hg) HCO2 12 mEq/L (normal: 22–26 mEq/L) Serum osmolality test, p. 339 440 mOsm/kg (normal: 275–300 mOsm/kg) Serum glucose test, p. 227 250 mg/dL (normal: 70–115 mg/dL) 2-hour postprandial glucose test (2-hour PPG), p. 230 500 mg/dL (normal: <140 mg/dL) Glucose tolerance test (GTT), p. 234 Fasting blood glucose 150 mg/dL (normal: 70–115 mg/dL) 30 minutes 300 mg/dL (normal: <200 mg/dL) 1 hour 325 mg/dL (normal: <200 mg/dL) 2 hours 390 mg/dL (normal: <140 mg/dL) 3 hours 300 mg/dL (normal: 70–115 mg/dL) 4 hours 260 mg/dL (normal: 70–115 mg/dL) Glycosylated hemoglobin, p. 238 9% (normal: <7%) Diabetes mellitus autoantibody panel, p. 186 insulin autoantibody Positive titer >1/80 islet cell antibody Positive titer >1/120 glutamic acid decarboxylase antibody Positive titer >1/60 Microalbumin, p. 872 <20 mg/L Diagnostic Analysis The patient’s symptoms and diagnostic studies were classic for hyperglycemic ketoacidosis associated with DM. The glycosylated hemoglobin showed that he had been hyperglycemic over the last several months. The results of his arterial blood gases (ABGs) test on admission indicated metabolic acidosis with some respiratory compensation. He was treated in the emergency room with IV regular insulin and IV fluids; however, before he received any insulin
levels, insulin antibodies were obtained and were positive, indicating a degree of insulin
resistance. His microalbumin was normal, indicating no evidence of diabetic renal disease, often
a late complication of diabetes.
During the first 72 hours of hospitalization, the patient was monitored with frequent serum
glucose determinations. Insulin was administered according to the results of these studies. His
condition was eventually stabilized on 40 units of Humulin N insulin daily. He was converted to
an insulin pump and did very well with that. Comprehensive patient instruction regarding selfblood glucose monitoring, insulin administration, diet, exercise, foot care, and recognition of the
signs and symptoms of hyperglycemia and hypoglycemia was given.
Critical Thinking Questions
1. Why was this patient in metabolic acidosis?
2. Do you think the patient will eventually be switched to an oral hypoglycemic agent?
3. How would you anticipate this life changing diagnosis is going to affect your patient
according to his age and sex?
4. The parents of your patient seem to be confused and not knowing what to do with this
diagnoses. What would you recommend to them?