Monitoring

Question 1

What is dynamic compliance?

Answer 1

Compliance of the lung and chest wall DURING MOVEMENT

Question 2

What is static compliance?

Answer 2

Lung compliance while there is no airflow. It’s a function of the natural tendency of the lung/chest wall to collapse

Question 3

What is plateau pressure?

Answer 3

Pressure in the small airways and alveoli after the target TV has been delivered.

There is NO airflow at this time, so it’s value is NOT a function of airway resistance. It instead reflects the elastic recoil of lungs and thorax during the inspiratory pause –> at this point the pressures of the lung and chest wall wanting to collapse and the pressure within the lung are equal.

Question 4

Risk of barotrauma exists when plateau pressures are > ____

Answer 4

35cmH2O

Question 5

O2 blood absorbs this wavelength

Deoxygenated blood absorbs this wavelength

Answer 5

O2 = 990nm (near-infrared)
Deox = 660 (red)

Higher O2 content = higher wavelength

Question 6

Pulse oximetry is based on this Law

Answer 6

Beer-Lambert:

- related to the intensity of light trimmed through a solution and the concentration of the solute within the solution.

Question 7

Can pulse ox be used to look at pulse pressure variation (PPV%)?

Answer 7

Yes

Question 8

Does pulse ox account for O2 dissolved in blood?

Answer 8

No

Question 9

Does jaundice affect pulse ox readings?

Answer 9

No

Question 10

Methemoglobin

Answer 10

Fe3+
Absorbs 990 and 660 equally
Thus, it falsely underestimates SpO2 when sat is >85%
Falsely overestimates SpO2 when

Question 11

Carboxyhemoglobin

Answer 11

CO-Hbg (carbon monoxide)

Pulse Ox reads CO-Hgb and O2-Hgb the same. Thus, it overestimates saturation.

Question 12

This is the most common method of analyzing exhaled gas in the OR

Answer 12

Infrared absorption

Question 13

How is O2 analyzed?

Answer 13

O2 does not absorb infrared light, so it must be measured by electrochemical means (Galvanic Cell or Clark Electrodes) or paramagnetic analysis

Question 14

The ideal BP bladder WIDTH is ___% the circumference of the pt’s arm

Answer 14

40%

Question 15

The ideal BP blade LENGTH is ___% the circumference of the pt’s arm

Answer 15

80%

Question 16

Do a-lines measure pressure at the site of insertion or level of transducer?

Answer 16

Level of transducer

Question 17

Most common complication while obtaining CV access

Answer 17

Dysrhythmias

Question 18

This is the classic presentation of PA rupture

Answer 18

Hemopytsis

Question 19

This is the point of phlebostatic access

Answer 19

Mid anteroposterior level at 4th intercostal space

Question 20

Where in the respiratory cycle should CVP be measured?

Answer 20

End expiration

Question 21

Meanings of high and low CVP

Answer 21

Low CVP is easy: either transducer is too high or the pt is hypovolemic.

If CVP is too high, could be a million things related to

1) Hypervolemia
2) Decreased ventricular compliance
3) Increased intrathoracic pressure

Question 22

How to manage Mobitz II heart block

Answer 22

Often unresponsive to atropine.
High risk of progression to Third Degree heart block.

Manage with pacemaker (transcutaneous, transvenous, or implantable)

Question 23

Treatment of third degree heart block

Answer 23

Isoproterenol

Pacing

Question 24

What is the most common pre-excitation syndrome?

Answer 24

WPW

Question 25

Two types of WPW

Answer 25

1) Orthodromic - Most common (90% of cases) - Narrow complex (Goes thru AV node and his-purkinje system, then tract goes back up through atrium to stimulate AV node again) - Treatment: Increase the refractory period of the AV node so it won't be stimulated so frequently by the aberrant pathway. - -> Vagal maneuvers, amiodarone, adenosine, BBs, verapamil, or cardioversion. 2) Antidromic - Less common (10%) - Wide Complex (Abberent pathway goes from SA, accessory pathway, ventricle, AV node, atrium). The his-purkinje system is bypassed, so it's wide complex) - Treatment: Increase the refractory period of the aberrant pathway - -> Procainamide, amiodarone, cardioversion. In this case, DO NO give anything that will prolong AV refractory period --> this will cause the aberrant pathway to be favored and result in Vfib!)

Question 26

Medications to avoid in Antidromic WPW (AVNRT)

Answer 26

AVOID ALL DRUGS THAT BLOCK CONDUCTION THROUGH THE AV NODE - Adenosine - Digoxin - BBs - Verapamil - Lidocaine - Diltiazem

Question 27

What are the two safe options for BOTH orthodromic AND antidromic WPW?

Answer 27

Amiodarone and cardioversion

Question 28

Effect of K+ on the QT interval

Answer 28

Hypokalemia can cause QT prolongation

Question 29

Only narcotic that prolongs QT

Answer 29

Methadone

Question 30

What things cause Torsades des Pointes?

Answer 30

POINTES Phenothiazines (Thorazine) Other meds (meds that are known to lengthen QT --> methadone, droperidol, halloo, zofran, VAs, amiodarone, and quinidine) Intracranial bleed (SAH) No known cause Type 1 antiarrhythmics Electrolyte Disturbances (low K+, Mg+, and Ca+2) Syndromes

Question 31

Those with chronically prolonged QTc will likely be placed on

Answer 31

BBs like metoprolol SNS stimulation and precipitate torsades, and BBs are good at blocking the sympathetic response on the heart

Question 32

Pacemaker designation positions

Answer 32

Position 1 = Chamber paced Position 2 = Chamber sensed Position 3 = Response to sense native cardiac activity Position 4 = Programmability of the pacemaker Position 5 = Indicates that the pacer can pace multiple sites

Question 33

Codes for position III in pacemaker designation

Answer 33

Position III = pacer response to sensed native cardiac activity ``` 0 = None T = Triggered (triggers the pacer to fire) I = Inhibited (tells the pacer NOT to fire) D = Dual (If native activity is sensed, the pacer does NOT fire. If no native activity is sensed, then the pacer WILL fire) ```

Question 34

Codes for position IV in pacers

Answer 34

Position 4 = Programmability ``` 0 = None R = Rate modulation ``` This describes the ability to adjust HR in response to physiologic need

Question 35

Effect of magnet on Pacemaker

Answer 35

Changes it to asynchronous mode

Question 36

Effect of magnet on ICD

Answer 36

Prevents shock delivery

Question 37

Effect of magnet on Pacer/ICD combo

Answer 37

Suspends ICD shock NO EFFECT on pacemaker

Question 38

Elecromagnetic interference (EMI) can interfere with pacer function. EMI can often come from

Answer 38

Electrocautery - Worse with coagulation setting than with cutting setting - Worse with monopolar than bipolar - If surgeon insists on monopolar, tell them to use it in short bursts (

Question 39

Conditions that make the myocardium more resistant to depolarization with pacers

Answer 39

- High and low K+ - Hypocarbia (will cause inward K+ shift) - Hypothermia - MI - Fibrotic tisue buildup around the leads - Antiarrhythmic meds

Question 40

Is lithotripsy contraindicated in those with pacer?

Answer 40

No, but the beam should be directed away from the pulse generator

Question 41

What to do if pacer fails

Answer 41

Have method of backup pacing immediately available Chemical pacing with isoproterenol, epi, and atropine

Question 42

A greater than ___% reduction in cerebral oximeter readings suggests a reduction in cerebral oxygenation

Answer 42

25%

Question 43

Can scalp hypoxia interfere with cerebral oximeter readings?

Answer 43

Yes

Question 44

Do cerebral oximeters detect pulsatile flow?

Answer 44

No

Question 45

Order of EEG waveforms with most awake to deepest

Answer 45

BAT-D ``` Beta Alpha Theta Delta Burst suppression Isoelectric ```

Question 46

Amount of lag in BIS

Answer 46

About 20-30 seconds

Question 47

BIS is less accurate in this population

Answer 47

Children

Question 48

General anesthesia range for PSI

Answer 48

Similar to BIS, but uses different number | GA is 25-50

Question 49

Macroshocks and their effects

Answer 49

``` 1mA = threshold for touch 5 = max harmless 10-20 = Let go current 50 = LOC 100 = Vfib! ```

Question 50

Microshock

Answer 50

``` 10uA = max allowable leak in OR 100uA = Vfib! ```

Question 51

For an electrical shock to occur in the OR, two faults must occur

Answer 51

1) After the first fault, the system becomes grounded | 2) After the second fault, the circuit is complete and shock occurs

Question 52

What is the function of the line isolation monitor (LIM)?

Answer 52

To alert OR staff of the first fault | When the alarm sounds, the last piece of equipment to be plugged in should be unplugged

Question 53

LIM will alarm when ____mA leak current is detected

Answer 53

2-5mA