8. Monitoring Anesthesia

Question 1

The big 5s

Answer 1

ECG, pulsox, capnograph, BP, temperature

Question 2

main causes of complications of anesthetic death

Answer 2

respiratory and CV

50% in post-op period

Question 3

which palpebral do you loose first?

Answer 3

lateral

Question 4

Guedel’s classification

Answer 4

clinical assessment of CNS, eyes mostly, old school

Question 5

BIS bispectral index

Answer 5

0-100 100 = awake
indicates level of consciousness
results controversial in dogs, used in humans

Question 6

why monitor BP?

Answer 6

indicates tissue perfusion

Question 7

hypotension

Answer 7

MAP <65mmHg
range of pressure where range of perfusion to organ is preserved, below 65 autoregulation is not preserved and adequate perfusion will not happen

Question 8

measuring BP

Answer 8

Indirect v. Direct

*pulse does not indicate BP its just difference between systolic and diastolic

Question 9

Oscillometic method

Answer 9

indirect, cuff inflates above systolic and deflates in stepwise fashion, when the P = systolic the vessell starts vibrating, when vibrating the most thats the MAP.

Question 10

cuff width

Answer 10

40-60% circumference of extremity, between ELBOW AND CARPUS is best!

Question 11

inaccurate BP because?

Answer 11

wrong size cuff!! (too big cuff -> lower BP, vice versa) And put cuff at level of the heart

Question 12

Doppler method

Answer 12

emits US, signal becomes sound indicating blood flow. First audible sound = systolic AP.

• does NOT give diastolic or mean!!!!!!!
• **sortof inaccurate, portela doesn’t like it.

Question 13

Direct monitoring

Answer 13

gold standard. continuous monitoring*

Question 14

which artery for direct BP?

Answer 14

dorsopedal artery (dorsal metatarsal) most often
(lingual, radial/carpal, coccygeal, femoral, auricular) 
*Flush regularly to avoid clotting

Question 15

inaccuracies of direct bp monitoring?

Answer 15

1. overdamping - air bubble, systolic lower than real

2. underdamping - systolic higher than real number

Question 16

Fluid responsiveness

Answer 16

increase in volume causes inc. left ventricle, inc. preload, inc. stroke volume.
- doesn’t work if in FLUID OVERLOAD

Question 17

Pulse pressure variation must be ____ for patient to be responsive to fluids

Answer 17

above 15%

Question 18

what measures Tidal volume

Answer 18

wright respirometer

Question 19

What is capnography

Answer 19

indirectly measures ventilation, espimates PaCO2

• differences between PaCO2 and end tidal CO2 due to dead space ventilation
• can indicate, problem in circuit, obstruction, cardiogenic shock

Question 20

What happens when hypoventilating?

Answer 20

• if hypoventilating, theyre moving mostly deadspace, end tidal CO2 would be low
• if ET CO2 is low, give a big breath and see if it goes up (if it doesn’t they may be hyperventilating)

Question 21

two types of capnography monitoring

Answer 21

1. side stream:
   - monitor is away from patient, sampling continuously, delayed response every time it aspirates
   - in small animals doesn’t work
   - sample is contaminated in nonrebreathing system
2. main stream:
   - monitor in connector, in real time, more accurate, big awkward thing connected to tube

Question 22

low ET CO2 indicates?

high ET CO2 indicates?

Answer 22

hyperventilation/deadspace

hypoventilation

Question 23

Ventilating Deadspace indicates what on capnography??

Answer 23

Low end tidal CO2
** Know this, he kept saying it**
Check by giving big breath!!

Question 24

Cardiac oscillations

Answer 24

normal, heart pushing on lung parynchyma

Question 25

/| alpha angle increased?

Answer 25

obstruction! kink in ET, bronchoconstriction

Question 26

|\ shark fin? (swimming towards you)

Answer 26

Leak, or washing out with high flow O2

Question 27

inspiration doesn’t go down to 0 on capnograph?

increased baseline

Answer 27

rebreathing CO2

exhausted exorbant, or unidirectional valves not working.

Question 28

gradual decrease in ET CO2

Answer 28

sudden bp drop, or CO drop, cardiac arrest, PTE

Question 29

Sudden disappearance of capnograph waveform?

Answer 29

apnea, disconnection

Question 30

90 Hb saturation indicates ____ PaO2

Answer 30

60 mmHg

Question 31

uses absorbance of infared light for O2 saturation?

- affected by?

Answer 31

pulsox

- ambient light, motion, skin pigment

Question 32

vasoconstriction during anesthesia affects temperature mostly during the _______. Loose heat via skin

Answer 32

first hour.
Preheat if you predict your animal will get hypothermic
(skinny, small dogs)

Question 33

hypothermia causes

Answer 33

marked CNS depression, little or no anesthetic req, unresponsive bradycardia