PBL by chen huangyu https://padlet.com/aldatxnhy/77e8wyocpf88 Limei, Tricia en-us 2016-12-18 14:21:24 UTC 2023-05-18 13:41:14 UTC hello@padlet.com PROBLEM aldatxnhy https://padlet.com/aldatxnhy/77e8wyocpf88/wish/144768333 Cardiac output is the amount of blood that is pumped by the heart per unit time, measured in litres per min. adult 4.7

main vein has dye, into right side of heart. 

healthy resting patient, 10mg of dye

time in seconds x axis
dye conc mg/L y axis]]> 2016-12-24 17:03:32 UTC https://padlet.com/aldatxnhy/77e8wyocpf88/wish/144768333 Question 1: About cardiac output, not more than 400 words (ALDA) aldatxnhy https://padlet.com/aldatxnhy/77e8wyocpf88/wish/144768408 Cardiac output is the blood pumping rate per minute of the heart and litre/minute is the usual unit. Cardiac output is calculated by multiplying heart rate with stroke volume. Stroke volume is maintained by sympathetic effect, which releases norepinephrine will be increasing the contraction. Moreover, aortic pressure decreases the blood supply that flows into the aorta. Most importantly, Frank-Starling mechanism causes heart muscle fibers to react to expansion by contracting more vigorously which in turn increases the end-diastolic volume and thus increases the stroke volume. The pressure of the large veins entering the right atrium is known as central venous pressure.  The position of our body will affect the stroke volume as the end-diastolic volume is directly proportionate to stroke volume. In summary, cardiac output is determined by the heart rate, contraction, preload and afterload. Some effects of cardiac output change is when muscles are used. Muscles affects the blood rate in the vein as the rate will increase when muscles are in use. Frank-Starling mechanism plays a pivotal role in balancing the pump of the left and right ventricles which will help to ensure that the end-diastolic volume is similar to stroke volume which will result in equal blood rate and thus having a normal cardiac output in a body.

Dye Dilution (Tricia)
The dye dilution method for measuring cardiac output is based on injecting rapidly a known quantity of a dye into the circulatory system at a certain point in the body's circulatory system. Many different types of dyes can be used but the most successful dye is the indocyanine green as it allows the curve to be measured by light absorption. However the dye is very expensive and if it the process is repeated continuously would cause the patient to turn green due to the pigment. Also, the process is very time consuming. The dye is inserted as a bolus at a point where the blood flows downstream. The concentration of dye in the blood is recorded in a graph where the concentration would increase to a rounded peak before reducing the amount of concentration in the blood as it is being washed out. The blood is withdrawn for the calibration of the individual's dye dilution curve using a photoelectric earpiece.

https://en.wikipedia.org/wiki/Cardiac_output
https://courses.washington.edu/conj/heart/cardiacoutput.htm

JL Vincent, 22 August 2008
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2575587/

http://www.sciencedirect.com/science/article/pii/000287035890098X

http://foxlinton.org/cardiac_output/LDCOpages/indicator_dilution.html]]> 2016-12-24 17:08:07 UTC https://padlet.com/aldatxnhy/77e8wyocpf88/wish/144768408 Q5 (LIMEI) limei0106 https://padlet.com/aldatxnhy/77e8wyocpf88/wish/146699154 CARDIAC OUTPUT (F) FORMULA:



where the amount of dye injected
is known, and the integral can be determined using the concentration readings.

The integral = area under the graph

FINAL ANSWER: 6.20 litre/minute

]]> 2017-01-12 06:39:57 UTC https://padlet.com/aldatxnhy/77e8wyocpf88/wish/146699154 Q3 (LIMEI) limei0106 https://padlet.com/aldatxnhy/77e8wyocpf88/wish/146964784 Using Simpson's Rule, we will be able to find the area under the curve. 

In order to evaluate each ordinate (y0, y1...), we have to estimate the y values from the graph given.]]> 2017-01-13 05:04:56 UTC https://padlet.com/aldatxnhy/77e8wyocpf88/wish/146964784 Q3 (cont.) limei0106 https://padlet.com/aldatxnhy/77e8wyocpf88/wish/146965571 2017-01-13 05:30:24 UTC https://padlet.com/aldatxnhy/77e8wyocpf88/wish/146965571 Q3 (cont.) limei0106 https://padlet.com/aldatxnhy/77e8wyocpf88/wish/146965787 2017-01-13 05:36:15 UTC https://padlet.com/aldatxnhy/77e8wyocpf88/wish/146965787 Q6a (TRICIA) guitarensembleforever https://padlet.com/aldatxnhy/77e8wyocpf88/wish/147172192 When read at intervals of 1 second the accuracy of the answer would be much higher as there there would be more readings for us to use and further analyse the graph and the patient's cardiac output.]]> 2017-01-14 02:12:18 UTC https://padlet.com/aldatxnhy/77e8wyocpf88/wish/147172192 Q6b (TRICIA AND LIMEI) guitarensembleforever https://padlet.com/aldatxnhy/77e8wyocpf88/wish/147220140 Yes as y is operating on x as the amount of time taken for the dye to flow all the way through the blood stream depends on how much dye was injected into the patient's circulatory system.]]> 2017-01-15 08:17:04 UTC https://padlet.com/aldatxnhy/77e8wyocpf88/wish/147220140 limei0106 https://padlet.com/aldatxnhy/77e8wyocpf88/wish/152372967 http://www.intmath.com/applications-integration/2-area-under-curve.php

https://www.montereyinstitute.org/courses/Algebra1/COURSE_TEXT_RESOURCE/U03_L2_T1_text_final.html

]]> 2017-02-08 07:21:45 UTC https://padlet.com/aldatxnhy/77e8wyocpf88/wish/152372967 Q2 (TRICIA AND LIMEI) limei0106 https://padlet.com/aldatxnhy/77e8wyocpf88/wish/152678480 -GRAPH EXPLANATION
-SIMILARITIES BETWEEN RESEARCH AND PROBLEM GIVEN]]> 2017-02-09 05:43:37 UTC https://padlet.com/aldatxnhy/77e8wyocpf88/wish/152678480