Home > K12 Resources for Teachers > Math in the Workplace: Overview

Math in the Workplace: Overview

print this page
Math in the Work Place

Math in the Workplace - Algebra/Analysis and Probability

BOISE HEART CLINIC

Cardiovascular Care
Cardiovascular Specialist

 
Job Description: Active cath lab and cardiovascular surgeon at the hospitals and clinical physician of primary or secondary heart disease at Boise Heart Clinic, P.A.    
   


Problem:

#1 A man comes to the hospital and needs a medication based on his body size. He weighs 170 lbs. The Doctor prescribes Dobutamine, which stimulates the heart to increase the number of contractions and increases strength of contraction of heart muscle to pump blood more effectively. He needs to be given 10 mg/kg every minute of this medication intravenously.

If we put 500 mg of Dobutamine in one liter of normal saline, how much solution do we need to give per hour?

#2 A 59-year old man comes to the Boise Heart Clinic short of breath. Dr. Lee hears a heart murmur and suspects the patient's aortic valve is tight. He orders an echocardiogram (ultrasound of the heart) to find the valve area of the aortic valve. If it is too tight, he will have surgery to replace the valve.

You must calculate the aortic valve area:
 

CSA = cross sectional area CSA=pr2
AVA = aortic valve area LVOT x CSA/AO
LVOT = minimal flow (before blood goes through the valve)
AO = maximum flow (after blood goes through the valve)
p = 3.14
LVOT = 1.0 m/sec
AO = 5.8 m/sec
LVOT Diameter = 2.5 cm.

solution

 

 

return to top BOISE HEART CLINIC

Solution:  

#1 (Include diagrams as needed)

2.2 lbs. = 1 kg.

170 lbs ÷ 2.2 = 77.3 kg.

77.3 kg x 10 mcg

Kg / min		 x 1 mcg

1,000 mcg		 x 1000 ml

500 mg		 x H2O

Dobutamine		 x = 1.55 liters/min

1.55 l/min x 60 min/hr = 93 l/hr

 

#2 (Include diagrams as needed)
 

CSA = pr2 = 3.14(2.5 cm 2)2
CSA = 4.9 cm2
AVA = LVOT x CSA AO

 

AVA =

(1.0m/sec)(4.9cm)

5.8m/sec
AVA =
.85 cm2

 

  
LVOT

CSA = pr2
 
CSA = 3.14 (2.5 cm 2)2
CSA = 3.14 x 1.56 cm2
CSA = 4.9 cm2 (LVOT)

Aortic valve area ranges:    Normal 
Mild 
Moderate 
Severe 
Critical  		2.6 cm2 to 1.6 cm2
1.6 cm2 to 1.2 cm2
1.2 cm2 to 1.0 cm2
1.0 cm2 to 0.8 cm2
less than 0.75 cm2
aortic illustration
 
AVA = (LVOTvmax)(CSALVOT)

AOvmax
AVA = (1.0 m/s)(4.9 cm2)

5.8 m/s
AVA = .85 cm2 or .9 cm2

This patient has now been diagnosed with severe aortic stenosis. He will have echocardiograms to monitor the tightness of the valve. He will probably have a valve replacement in the near future.