Learning Issues :
Case 3

1. What is a CABG 

Coronary Artery Bypass Graft is a triple bypass surgery in the heart using an artery from 
another part of the body. In this case, the femoral artery of the patient is being used for 
the bypass.  (Merck Manual )

2. Why would calcium levels go down in terms of the interactions of calcium with 
biochemicals in the body?

In the body, calcium can bind with cholesterol to form plaques in the artery which could 
result in hardening of the arteries. This calcium binding could cause calcium levels to 
drop in the body. However, the lab values do not provide any information regarding 
increased cholesterol levels. 
Between admission day and post operative day, serum albumin decreased below the 
normal range and calcium decreased as well. This is not surprising because a lowered 
serum albumin can cause calcium to decrease artificially.  (RD Notebook)

3. What kinds of medications is the patient on? 
	Hygroton is an antihypertensive drug and a thiazide diruetic. The patient has a 
medical history of HTN. 

	Nitrobid is an antianginal and vasodilator medication. The patient most likely was 
placed on this medication due to his unstable angina.

	Propranol Ð anti-HTN, anti-anginal, anti-migraine, anti-dysrythmic, post MI and 
antiglaucoma. The patient presents with hx of HTN, MI, and current unstable angina. 

	Propulsid (cisapride) Ð for the prevention of acid reflux

	Lasix (furosemide) Ð potent diuretic that causes water and electrolyte depletion in 
the body. It is used to treat excessive fluid retention and edema caused by heart failure, 
cirrhosis, and kidney failure. It is a strong K diuretic. 
(RD Notebook Ð Medications section)

4. What is Angina? 
	Angina pectoris is caused by coronary artery obstruction due to artherosclerosis. 
Symptoms include chest discomfort and pressure precipitated by exertion. The pain 
occurs because the oxygen demands exceed the ability of the body.  (Merck Manual)

5. What does unstable angina at rest mean and what are itÕs implications?
	Angina at rest is known as angina decubitus and is accompanied by increased 
heart rate and a rapid rise in blood pressure. 
	Unstable angina is caused by a coronary artery obstruction and is a medical 
emergency that must be controlled immediately in a cardiac unit. The patient is 
presenting with unstable angina at rest which makes him highly at risk for an MI if it is 
not controlled or relieved in some way. 
 (Merck Manual On-Line, Mayo Health Clinic On-Line site, and RD Notebook 
Links)

6. What is hemodynamic stability and what does it mean for feeding?
Hemodynamic stability is the ability of the pt. To maintain adequate blood volume 
and pressure.  It can be affected through parenteral nutrition and should be monitored 
carefully 
(Krauss Ð Therapeutic Nutrition Text)

7. Calculation of serum osmolality : 
2 (Na+) + (glucose / 20) + (BUN / 2.8) 

2 (125 mEq/L) + (140 mg/dl / 20) + (19 mg/dl  / 28) = 250+7+0.68 = 257.7

Normal serum osmolality range : 280-300 mOsm / kg
Elevated range: 			> 300 mOsm/kg
Decreased range:			< 280 mOsm/kg

Decreased serum osmolality can occur with excess fluid intake, adrenal disease, and 
inappropriate ADH secretion.  
(RD Notebook)

8. What are the implications of respiratory failure in this patient?
Respiratory failure is caused by various acute pulmonary injuries and is characterized 
by non-cardiogenic pulmonary edema, respiratory distress and hypoxemia. 
(Merck Manual)

9. What is the insulin sliding scale?
The insulin sliding scale is used in times of stress

Insulin Sliding Scale:
200-250  mg/dl  glucose	5	doses for stress
251-300  mg/dl glucose	10	doses for stress
301-350  mg/dl glucose 	15	doses for stress
351-400 mg/dl glucose	20 	doses for stress

(Skipper Ð DietitianÕs Handbook)