10 ECG, CO2 Elimination, & ETCO2 Flashcards Preview

AS - N927 Chem/Physics > 10 ECG, CO2 Elimination, & ETCO2 > Flashcards

Flashcards in 10 ECG, CO2 Elimination, & ETCO2 Deck (46)
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1

Einthoven's Triangle

Discovered ECG mechanism

2

Electrocardiogram

Potential difference across the membrane (voltage)
Each cardiomyocyte can create potential difference across the heart

3

Vector

Mean potential difference
Direction & magnitude
Length correlates to magnitude
(-) → (+)

4

Lead I

R arm (-) → L arm (+)

5

Lead II

R arm (-) → L leg (+)
60°

6

Lead III

L arm (-) → L leg (+)
120°

7

Mean Electrical Axis (MEA)

Average all depolarization waves = resultant vector

8

Normal

-30° to 60° MEA
Lead I positive (upward deflection)
Lead II positive
aVF positive

9

Left Axis Deviation

-30° to -90°
Causes: L ventricular enlargement, R side MI, R side tension pneumo, normal variant (diaphragm elevation

10

Right Axis Deviation

90° to 180°
Causes: R ventricular enlargement, L side MI, L side tension pneumo, pediatrics variant

11

aVR

Augmented voltage right
R arm set to positive
Sum L arm + L leg
(-) starting point at chest center
-150°

12

aVL

Augmented voltage left
L arm set to positive
Sum R arm + L leg
(-) starting point at chest center
-30°

13

aVF

Augmented voltage foot
Foot set to positive
Sum R arm + L arm
(-) starting point at chest center
60°

14

V Leads

Transverse plain
V1 = 120°
V2 = 90°
V3 = 75°
V4 = 60°
V5 = 30°
V6 = 0°

15

Anteroseptal

V1
V2

16

Anteroapical

V3
V4

17

Anterolateral

V5
V6

18

Lateral

I, aVL, V5, V6
Left circumflex artery

19

Inferior

Apical
II, III, aVF
R coronary artery

20

Anterior

V1 - V4
L anterior descending

21

Beer-Lambert Law

Amount energy absorbed or transmitted by solution directly proportional to solution molar absorption and solute concentration
More concentrated solution absorbs more light than more dilute solution

22

Beer-Lambert Application

↑ path-length
↑ absorbance
↓ transmission

23

Absorbance

Measure quantity of light absorbed by sample
Light passes through sample and none absorbed = 0
100% transmission
Therefore solution would be pure solvent

24

CO2 Absorber (Scrubber)

Chemical reaction
Function to remove CO2 from circle system
Neutralization reaction (acid/base)
Able to rebreathe exhaled gas possible

25

CO2 End Products

Carbonates (CaCO3)
H2O
Heat

26

Fresh Gas Flow

Normal 4.2L/min

0.3-0.5L/min near total rebreathing
Complete reliance on absorbent to prevent CO2 rebreathing

4-5/min little to no reliance on absorbent
No rebreathing
Costly $

27

CO2 Absorbent

Soda Lime NaOH
Sodium hydroxide (base)
Base neutralizes volatile acid (CO2)

Calcium Hydroxide Lime
Ca(OH)2
Skips additional step

28

Scrubber Issues

Tunneling porous granules line up inside (unable to see)
Channeling visible from outside
Not enough surface area to scrub the gas to remove CO2
Gas takes the path of least resistance

29

Soda Lime

4% NaOH
80% CaOH2
15% H2O
Large & small irregular granules mixtures
4-8 mesh
Moisture added to prevent drying
Silica added to increase hardness

30

Mesh

1/8 inch
1/4 inch
Resistance