Pagana: Mosby’s Manual of Diagnostic and Laboratory Tests, 5th Edition

Adolescent with Diabetes Mellitus (DM)

Case Study

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. 240 1100 mg/dL (normal: 60-120 mg/dL)

Arterial blood gases (ABGs) test (on admission),

p. 110

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. 364 440 mOsm/kg (normal: 275-300 mOsm/kg)

Serum glucose test, p. 240 250 mg/dL (normal: 70-115 mg/dL)

2-hour postprandial glucose test (2-hour PPG), p.

244

500 mg/dL (normal: <140 mg/dL)

Glucose tolerance test (GTT), p. 248

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. 252 9% (normal: <7%)

Diabetes mellitus autoantibody panel, p.196

Insulin autoantibody Positive titer >1/80

Islet cell antibody Positive titer >1/120

Glutamic acid decarboxylase antibody Positive titer >1/60

Microalbumin, p. 931 <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 self-blood 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 be switched eventually to an oral hypoglycemic agent? 3. How do you anticipate this adolescent social life is going to be affected? 4. How could you help this patient to be compliant with his treatment?