Question

Phil C., a 76-year-old man, was admitted though the ER with difficulty breathing, coughing, and chest pain.

Chemistry Results

	2/18	2/19	Reference Range
Sodium Potassium Chloride CO2 Anion gap Glucose Bilirubin, total Troponin AST ALP Protein BUN Creatinine Calcium Albumin Digoxin CK CK-MB	141 4.4 107 27.0 5.0 95 0.3 <0.3 10 42 65 53 2.0 8.8 3.6 1.06 100 3.1	140 4.7 106 30.0 5.0 112 NT <0.3 NT NT NT 49 1.8 NT NT 0.82 NT 3.2	136-145 mEq/L 3.6-5.0 mEq/L 101-111 mEq/L 24.0-34.0 mEq/L 10-20 mmol/L 80-120 mg/dL 0.2-1.2 mg/dL 0.0-0.4 ng/mL 5-40 IU/L 30-157 IU/L 6.0-8.4 g/dL 7-24 mg/dL 0.5-1.2 mg/dL 8.5-10.5 mg/dL 3.5-5.0 g/dL 0.00-2.00 ng/mL 24-170 IU/L *

*0-3.8 ng/mL = normal; 3.9-10.4 = borderline; >10.4 = significantly elevated.

Abbreviation: NT, not tested.

Questions

1. What are Phil’s abnormal test results?
2. Do the laboratory results rule out a myocardial infarction?
3. What is Phil’s BUN/creatinine ratio? What is a normal BUN/creatinine ratio?
4. What type of azotemia does this indicate?
5. What is digoxin? Is it associated with Phil’s condition?

Answer 1

1, Anion gap, BUN and creatinine are the abnormal test results.

2. Yes, Myocardal infarction can be ruled out since no elevation of cardiac bio-markers troponin, creatine kinase and CK-MB.

3. Phil's BUN/Creatinine ratio:

Date 2/18: 53/2 = 26.5

Date 2/19: 49/1.8 = 27.7

Normal BUN/Creatinine ratio is between 8-15 (Reference: Lyman JL. Blood urea nitrogen and creatinine. Emerg Med Clin North Am 1986; 4, 2: 223-33.)

4. Prerenal azotemia (it is due to absence of enough fluid flow through the kidneys. This low flow of fluid creates high-level concentrations of serum creatinine and BUN).

5. Digoxin is a cardiac glycoside with positive inotropic and antiarrhythmic effects; commonly prescribed for congestive heart failure. Based on symptoms (breathing difficulty and chest pain) and abnormal lab values (elevated BUN/creatinine ratio), Phil may suffer with congestive heart failure. Phil may be prescribed with Digoxin if he experiences congestive heart failure. However, Chest X ray, ECG, Echocardiogram and stress test are required for congestive heart failure diagnosis.