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NURA 641 Intro to Nurse Anesthesia > Week 2 Hemodynamic Monitoring > Flashcards

Week 2 Hemodynamic Monitoring Flashcards

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1
Q

T of F: The distribution of ST depression type ischemia correlates exactly with the specific location of CAD.

A

False;

ST segment depression correlates poorly with location of demand.

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2
Q

How does mechanical ventilation affect CVP?

A

Increases CVP about 3-5 mmHg

(Think of positive pressure and increased thoracic pressure)

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3
Q

Describe the “a” wave of the CVP waveform.

A
  • caused by atrial contraction
    • (follows the P-wave on ECG)
  • represents end diastole
  • corresponds with “atrial kick” which causes filling of the right ventricle
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4
Q

For the 5-lead ECG system, which lead is the preferred lead for special arrhythmia monitoring?

A

V1

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5
Q

Normal cardiac output and stroke volume.

A

CO: 4.0-6.5 L/min (average: 5 L/min)

SV: 60 - 90 mL (average: 75 mL)

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6
Q

The increase in left ventricular preload and decrease in left ventricular afterload (from positive pressure ventilation) produce what hemodynamic effects?

A
  • increase in left ventricular stroke volume
  • increase in cardiac output
  • increase in systemic arterial pressure (in the absense of changes in peripheral resistance)
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7
Q

What is CVP monitoring and what are normal values?

A

Central Venous Pressure

Gives estimation of right atrial pressure and RV preload

Normal: ~2-7 mmHg in a spontaneous breathing patient

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8
Q

Describe ST segment depression and when are we likely to see it?

A

ST segment: flat or downslope of > or = to 1 mm

***This is a demand issue***

Demands of the patient are exceeding the cardiac output.

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9
Q

Name a few other causes of ST depression besides myocardial ischemia.

A
  • drugs (most notably digitalis)
  • temperature changes
  • hyperventilation
  • position changes
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10
Q

According to the AANA Standard 9: Monitoring and Alarms, when a physiological monitoring device is used…..

A

pitch and threshold alarms are turned on and audible.

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11
Q

Name 4 major sources of artifact for pulse oximetry reading and describe how we can remedy them?

A
  • Ambient light (remedy by covering pulse ox)
    • Cover the the sensor with an opaque shield
  • low perfusion (weak pulse, low AC to DC signal ratio)
    • **Significantly erroneous reductions in SpO2 readings may be observed for systolic blood pressures lower than 80 mmHg**
    • Whenever you have a lot of noise from low perfusion, it’s usually equal in the red and the infared signals and the ratio of the two is usually at a 1:1 ratio with that, you might see an SpO2 that reads 85% which is inaccurate obviously
  • venous blood pulsation (caused by patient motion, among other things)
    • The pulse oximeter makes the assumption that whatever is pulsing must be arterial blood. In most cases, this is true, but in some situations (patient motion) there can be large venous pulsations that can produce erroneously low saturation values
    • If the device averages its measurements over a longer period of time, then the effect of an intermittent artifact is usually less. HOWEVER, this longer averaging period also slows the response time to an acute change in SaO2, and it may result in “frozen” SpO2 values being displayed when the true saturation is changing
      • ​The purpose of the delay is using the averaging time to compensate for the motion artifact, but what it means is you’ll see a decline in the patient before you see a drop in your SpO2 or an improvement in your patient before you see an increase in SpO2 back to normal
  • additional light absorbers in the blood (IV dyes, dyshemoglobins)

**All these sources of artificats produce a low signal-to-noise ratio, resulting in either erroneous SpO2 values or no value at all**

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12
Q

Describe ST segment elevation.

A

ST segment: elevation > or = 1 mm

***This is a supply issue***

Think endothelial plaque rupture and complete occlusion of a coronary artery

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13
Q

For NIBP cuffs, bladder width should be approximately ___% of the circumference of the extremity. Bladder length should be sufficient to encircle at least ___% of the extremity. What else do we need to do to ensure proper fitting of NIBP cuff?

A

40; 80

Apply snuggly with bladder centered over the arter_y* and *_residual air removed

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14
Q

Describe the “x” descent of the CVP waveform.

A
  • systolic decrease in atrial pressure due to atrial relaxation
  • atria are in diasole, tricuspid valve remains closed
  • mid-systolic event
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15
Q

Define overdamped waveform and list potential causes of an overdamped waveform.

A

Waveform shows diminished pulse pressure, flattened, low amplitude

Potential causes:

  • loose connections
  • air bubbles
  • kinks
  • blood clots
  • arterial spasm
  • narrow tubing
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16
Q

Septal Ischemia: Which leads will show ST elevation and which coronary artery is likely affected?

A

Left descending coronary artery (per slide)

Left anterior descending (LAD)

Leads: V1, V2

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17
Q

Describe oscillometry as a measurement of NIBP.

A

**Typically what is used in the OR**

Automated cuff - measure changes in oscillatory amplitude electronically, derives MAP, SBP, DBP by using algorithms.

  • 1st oscillation correlates with SBP
  • MAP = maximal degree of detectable pulsation
  • Oscillations cease at DBP
    • DBP most unreliable oscillometric measurement
    • DBP is mathematically inferred from the SBP & MAP
    • when BP is low, DBP becomes more unreliable

***In general, oscillometric pressures underestimate SBP and overestimate DBP → significantly underestimate pulse pressure calculation***

***During periods of hypertension, tend to underestimate***

***During periods of hypotension, tend to overestimate***

Errors in cuff measurement:

  • too small/too large cuff
  • stiff atherosclerotic arteries are restant to compression
  • external compression by patient motion
  • surgeon leaning on BP cuff
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18
Q

Aortic regurgitation can show which types arterial waveform abnormalities?

A

Bisferians pulse (double peak)

wide pulse pressue

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19
Q

List uses of TEE in the OR.

A
  • unusual causes of acute hypotension
  • pericardial tamponade
  • pulmonary embolism
  • aortic dissection
  • myocardial ischemia
  • valvular dysfunction
  • valvular function
  • wall motion abnormalities
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20
Q

Name 3 methods of verification for intubation of the trachea or placement of other artificial airway device.

A
  1. auscultation
  2. chest rise/chest excursion
  3. confirmation of expired carbon dioxide/end tidal CO2
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21
Q

Describe the components of an arterial pressure waveform.

A

Peak: ejection of blood from the left ventricle into the aorta during systole

Dicrotic notch: closure of the aortic valve

Followed by peripheral runoff during diastole

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22
Q

What is pulse oximetry?

A
  • Method of measuring hemoglobin oxygen saturation (SpO2)
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23
Q

Why is there a delay of 120 - 180 milliseconds between the R wave (on EKG) and the upstroke of systole (on arterial waveform)?

A

Represents the delay between actual ventricular depolarization and the arrival of the signal to the pressure transducer.

OR (from slide, way more detailed)

Interval reflects totaly time required for depolarization of the ventricular myocardium, isovolumetric left ventricular contraction, opening of the aortic valve, left ventricular ejection, propagation of the aortic pressure wave, and finally, transmission of the singal to the pressure transducer.

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24
Q

Describe a PA catheter, including french size, length, and lumens.

A
  • 7 french (introducer is 8.5 french)
  • 110 cm length marked at 10 cm intervals
  • 4 lumens
    • distal port - PAP
    • second port - 30 cm more proximal - CVP
    • third lumen - balloon
    • fouth wire for temp thermistor
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25
Q

Cardiac Tamponade - CVP waveform

A

Dominant x descent

attenuated y descent

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26
Q

Describe proper placement of the tip of the CVC.

A
  • tip within the SVC, just above the junction of the vena cava and the RA
  • parallel to the vessel walls
  • positioned below the inferior border of the clavicle
  • above the level of 3rd rib at T4/T5 interspace, the carina, or takeoff of the right main bronchus
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27
Q

What is diastolic blood pressure?

A

trough pressure during diastolic ventricular relaxation

***changes in DBP reflect coronary perfusion pressure***

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28
Q

Indications for central venous cannulation

A
  • CVP monitoring
  • PA catheterization and monitoring
  • transvenous cardiac pacing
  • temporary HD
  • Drug administration
    • concentrated vasoactive drugs
    • hyperalimentation (i.e. TPN)
    • chemotherapy
    • prolonged antibiotic therapy (i.e. endocarditis)
  • Rapid infusion of fluids (via large cannulas)
    • trauma
    • major surgery
  • aspiration of air emboli
  • inadequate peripheral IV access
  • sampling site for repeated blood testing
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29
Q

List the 4 types of hemoglobin in adult blood.

A
  • oxygenated hemoglobin
  • deoxygenated hemoglobin
  • carboxyhemoglobin (concentrations 1%-3%)
  • methemoglobin (<1%)
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30
Q

How do we meausure perfusion pressure (pressure difference) for the systemic circulation? Pulmonary circulation?

A

Systemic circulation: MAP - CVP

Pulmonary circulation: Mean pulmonary artery pressure (MPAP) minus the left atrial pressure (usually estimated by a pulmonary artery wedge pressure) (PAWP)

MPAP - PAWP

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31
Q

Insertion of a PA Catheter: distances from the R IJ to distal structures.

A

Structure Distance inserted from skin (cm)

Vena cave and RA junction 15

Right atrium 15-25

Right ventricle 25-35

Pulmonary artery 35-45

Wedged in pulmonary capillary. 40-50

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32
Q

What is subendocardial ischemia and how does it present on ECG?

A

Ischemia confined to subendocardial area

Presents at ST segment depression

***typically occurs during episodes of symptomati or asymptomatic (silent) stable angina pectoris***

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33
Q

Inferior wall ischemia: Which leads will show ST elevation and which coronary artery is likely affected?

A

RCA - right coronary artery

Leads: II, III, aVF

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34
Q

Pulse Pressure

A

SBP - DBP

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35
Q

Right ventricular ischemia - CVP waveform

A

Tall a and v waves

steep x and y descents

M or W configuration

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36
Q

What is systolic blood pressure?

A

peak pressure generated during systolic ventricular contraction

**changes in SBP correlate with changes in myocardial O2 requirements**

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37
Q

Pulsus paradoxus (exaggerated decrease in systolic blood pressure during spontaneous inspiration) may be indicative of?

A

cardiac tamponade

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38
Q

What is the normal electrical axis of the heart?

A

“The main vector of the QRS complex in the front plane serves to calculate the electrical axis of the heart.”

Normal: between -30 and +90 degrees

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39
Q

True of False: The Allen Test has a poor predictive value of ischemic injuries following a line insertion.

A

True;

Ischemic injuries seen even in patients with normal Allen test

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40
Q

True of False: The continuous flush device of a transducer system provides a continuous, slow infusion of saline at about 1-3 ml/hr.

A

True;

The continuous, slow flush of 1-3 ml/hr prevents thrombus formation within the arterial catheter.

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41
Q

Describe doppler as a measurement of NIBP.

A
  • based on shift in frequency of sound waves that is reflected by RBCs moving through an artery
  • **measures only SBP reliably**
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42
Q

As the pressure wave travels from the central aorta to the periphery, how does the morphology of the arterial waveform change?

A
  • arterial upstroke becomes steeper
  • systolic peak increases
  • dicrotic notch appears later
  • diastolic wave becomes more prominent
  • end-diastolic pressure decreases
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43
Q

What is the most common complication of placing a subclavian line?

A

Pneumothorax

(although, unintended arterial puncture may actually be more frequent)

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44
Q

Filtering capacity should be set to _________ mode.

A

diagnostic

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45
Q

Describe finger readings as a measurement of NIBP.

A
  • **subject to significant limitations**
  • disadvantages: finger arteries are prone to spasm with the potential for distal ischemia, hand position will influence pressure values
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46
Q

Extreme wrist dorsiflexion following establishment of an A line should be avoided to prevent injury to the _______ nerve.

A

median

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47
Q

Name scenarios you may obtain a falsely high BP.

A
  • cuff to small
  • cuff too loose
  • extremity below level of heart
  • arterial stiffness (atherosclerotic change) - HTN, PVD
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48
Q

List complications of transesophageal echocardiography.

A
  • esophageal trauma
  • dysrhythmias
  • hoarseness
  • dysphagia
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49
Q

How will the SpO2 read when you have a methemoglobinemia? Why?

A

SpO2 will approach and remain at ~85%

  • MetHb absorbs a significant amount of light at both 660 and 940 nm.
  • As a result, in its presence, the ratio of light absorption approaches unity. An R value of 1 represents the presence of equal concentrations of O2Hb and deO2Hb and corresponds to an SpO2 of 85%.
  • In a patient with methemoglobinemia, the SpO2 is 80% to 85% irrespective of the SaO2.
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50
Q

Which precordial leads are the preferred leads for ischemia monitoring?

A

V3-V5

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51
Q

What is the preferred site for CVC insertion? Why?

A

Right Internal Jugular Vein (R IJ)

  • predictable anatomical location
  • palpable surface landmarks
  • straight course to the SVC
  • really accessible
  • high success rate of placement, >90%
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52
Q

Contraindications for placement of CVC.

A
  • R atrial tumor
  • contralateral pneumothorax
  • infection at site
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53
Q

INFO CARD

Proper ECG Placement: 3 leads

A
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54
Q

If you plan to insert an a line, and you’re concerned about your patient’s stability during induction, when should you insert the art line?

A

PRIOR to induction.

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55
Q

Lateral wall ischemia: Which leads will show ST elevation and which coronary artery is likely affected?

A

Circumflex branch of LCA

Leads: I, aVL, V5, V6

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56
Q

Pulmonary artery catheter complications

A
  • arrhythmias
    • V fib, RBBB, complete heart block
  • catheter knotting
  • balloon rupture
  • thromboembolism; air embolism
  • pneumothorax
  • PA rupture
    • ​most dangerous complication of insertion
  • infection (endocarditis)
  • damage to cardiac structures (valves, etc.)
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57
Q

Should we suspect ischemia in the OR, is obtaining a 12 lead ECG likely going to be our first line of assessment?

A

No, with draping and the sterile surgical field, we can obtain a 12 lead, but this may be difficult.

**More likely to drop a TEE probe and assess for wall motion abnormalities as well as work on supply and demand**

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58
Q

Actions to remedy a damped waveform.

A
  • pressure bag inflated to 300 mmHg
  • reposition extremity or patient
  • verify appropriate scale
  • flush or aspirate line
  • check or replace module or cable
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59
Q

5 (but actually 6) principle indicators for ECG ischemia detection:

A
  1. ST segment elevation, > or = 1 mm
  2. T wave flattening or inversion
  3. Development of Q waves
  4. ST segment depression, flat or downslope > or = 1 mm
  5. Peaked T waves
  6. Arrhythmias
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60
Q

Is the 3 lead ECG placement adequate as standard ECG monitoring in the OR?

A

NO, usually adequate for tracking HR, detecting R waves for synchronized direct-current shock in cardioversion, and detecting ventricular fibrillation.

INADEQUATE for diagnosing more complex arrhythmias or for ST segement monitoring.

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61
Q

Summary of CVP Waveform.

A

Waveform Componenent Phase of Cardiac Cycle Mechanical Event

a wave end - diastole atrial contraction

c wave early systole isovolumetric contraction

x descent mid systole atrial relaxation

v wave late systole systolic filling of atrium

y descent. early diastole. early ventricular filling

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62
Q

Anterior wall ischemia: Which leads will show ST elevation and which coronary artery is likely affected?

A

LCA - left coronary artery (per slide)

More specifically, LAD

Leads: V3, V4

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63
Q

INFO CARD

Proper ECG Placement and Vectors

A
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64
Q

Triscuspid stenosis - CVP waveform

A

Tall a wave

attenuation of y descent

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65
Q

Respiratory variation during spontaneous or positive pressure ventilation - CVP waveform

A

measure pressures at end - expiration

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66
Q

SpO2 accuracy is really reduced at a level lower than ______?

A

70-75%

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67
Q

If you have a sudden drop in ETCO2, what should you do immediately?

A

Check for a pulse!

**An acute drop in ETCO2 in the most accurate and the quickest method of assessing perfusion**

68
Q

Axis deviation more negative than -30 degrees.

A

Left axis deviation

69
Q

According to the AANA Standard 9: Monitoring and Alarms, how often do we document blood pressure, heart rate, and respiration for all anesthetics?

A

at least every 5 minutes

**Note: Dr. OG states vitals are often pulled over more frequently with the use of computer charting nowadays**

70
Q

How many views of the heart can we get using the 5-lead ECG system?

A

7 views of the heart (adds anterior view)

Leads: I, II, III, aVR, aVL, aVF, V lead

71
Q

When clinically significant changes in body temperature are intended, anticipated, or suspected, we monitor and facilitate what?

A

Monitor body temperature

**Use active measures to facilitate normothermia**

72
Q

Name a common hemodynamic event in which we can commonly see ST segment depression, especially in patients with significant, but stable coronary artery disease (CAD)?

A

tachycardia

73
Q

List complications of a line monitoring.

A
  • nerve damage
  • hemorrhage/hematoma
  • infection
  • thrombosis
  • air embolus
  • skin necrosis
  • loss of digits
  • vasospasm
  • arterial aneurysm
  • retained guide wire
  • peripheral neuropathy
  • misinterpretation of data
  • misuse of equipment
74
Q

Describe a few ways to maintain vigilance in a long case when vital signs look like train tracks?

A

Remain engaged with the surgery/status of surgery.

Continuously scan the room, monitors, patient, tubes/drains, and anesthesia machine.

75
Q

How does positive pressure ventilation increase left ventricular preload and reduce left ventricular afterlaod?

A

Positive pressure ventilation increases lung volumes, displacing blood contained within the pulmonary venous resevoir into the left heart chambers → increasing left ventricular preload.

Simultaneously, the increase in intrathoracic pressure reduces left ventricular afterload.

76
Q

What is the MAP? How do we calculate?

A

Time weighted average of arterial pressure during a pulse cycle

SBP + 2(DBP)/3

OR

DBP + 1/3 (SBP-DBP)

77
Q

Which two leads are the most sensitive leads to detect exercise-induced ischemia?

A

V4 and V5 (90 to 100% sensitivity)

78
Q

Cardiac blood flow review: just for funzys.

A
79
Q

Why do we use two wavelengths of light, 660 and 940 nm, for pulse oximetry?

A

At 660 nm, light absorption is greater by dexoxygenated hemoglobin than oxygenated hemoglobin.

At 940 nm, light absorption is greater by oxygenated hemoglobin than by deoxygenated hemoglobin.

80
Q

Gain should be set at standardization. 1 mV signal produces…

A

10 mm calibration pulse.

Therefore, a 1 mm ST segment change is accurately assessed

81
Q

The cornerstones of monitoring are in our physical assessment. Describe the 3 types of key physical assements and give examples of important uses in the OR.

A

Inspection, palpation, auscultation

  • Observing chest rise and fall & ausculation of breath sounds pre-op, after intubation, and when ventilatory parameters change
  • direct palpation of a pulse when a monitor value is questionable
  • direct observation of a beating heart during cardiac surgery or palpation of the aorta by the surgeon
  • inspecting the surgical field for blood loss
    • noting real time changes on the surgical field (i.e. color change of blood)
  • observing urine output
  • inspection of mucous membranes, skin color, and turgor
    • hydration, oxygenation, and perfusion
  • evaluating JVD
  • pupillary response
82
Q

What is transmural ischemia?

A

ENTIRE wall thinkness is involved from the occlusion, endocardium to epicardium.

83
Q

Describe common uses of precordial or esophageal stethoscopes.

A

Pediatric setting, especially when there will be airway manipulation and the tube could become kinked or dislodged.

Also, common in monitoring for venous air embolism in high risk cases (neuro anesthesia, exposing dural sinuses, per Dr. OG)

**very sensitive monitor for bronchospasm, airway obstruction, changes in HR/rhythm, continual assessment of heart tones and breath sounds**

84
Q

Describe the “v” wave of the CVP waveform.

A
  • ventricular ejection
    • which drives venous filling of the atrium
  • occurs in late systole
    • tricuspid valve still closed
  • occurs just after T wave on ECG
85
Q

The 3 lead EKG is inadequate for diagnosing more complex arrhythmias for which a _*true* V1 lead is necesarry,_ to distinguish between:

A
  • RBBB vs LBBB
  • VT
  • SVT with aberrant venricular conduction
86
Q

What is the purpose of electrocardiogram?

A
  • detect arrhythmias
  • monitor heart rate
    • via both EKG (heart rate) and pulse oximetry pleth (pulse rate)
    • heart rate on EKG monitoring is detected by R-R intervals, updated/calibrated every 5-15 seconds → can get a lot of inaccuracies on heart rate because of these calculations by monitor → further emphasizes importance of relating pulse oximetry pulse rate to EKG heart rate.
  • detect ischemia
  • detect electrolyte changes
  • monitor pacemaker function

**Be mindful of all factors in the OR that could have electrical interference with our EKG monitoring**

87
Q

Name some underlying abnormalities that may hinder ST segment analysis.

A
  • hypokalemia
  • digitalis
  • Wolff - Parkinson - White sydrome
  • LVH
  • acute pericarditis
88
Q

Because of the disadvantages known to placing left IJ catheters, how should we confirm placement in these scenarios?

A

Obtain xray to confirm tip placement

89
Q

Describe the relationship between oxygen and hemoglobin with a left shift of the oxyhemoglobin dissociation curve. What are some conditions that would cause a left shift?

A

With a left shift, hemoglobin is going to bind more tightly to oxygen and be less likely to release oxygen to the tissues.

Conditons

  • alkalosis
  • hypocarbia
  • hypothermia
  • decreased 2,3 BPG
  • carboxyhemoglobin
  • fetal hemoglobin
90
Q

Indications for PAP monioring.

A
  • LV dysfunction
  • valvular disease
  • pulmonary HTN
  • CAD
  • ARDS/resp failure
  • shock/sepsis
  • ARF
  • surgical procedure: cardia, aortic, OB (rare)
91
Q

Is a CVC alone sufficient for large, volume fluid resuscitation?

A

No, large bore peripheral IVs are more sufficient for rapid, large volume fluid resuscitation

CVC can be used as adjunct for other purposes obviously

92
Q

What conditions are needed to measure PPV (pulse pressure variation) accurately?

A
  • mechanical ventilation with tidal volumes of 8-10 ml/kg
  • PEEP > or = 5 mmHg
  • regular cardiac rhythm
  • normal intraabdominal pressure
  • closed chest
93
Q

When neuromuscular blocking agents are administered, what do we monitor and assess?

A

neuromuscular response to assess depth of blockade and degree of recovery

94
Q

How do we measure pulse oximetry?

A
  • Spectroscopy
  • probe is composed of a light emitter and a photodetector
  • Measures transmission of light through a solution to the concentration of the solute in the solution
  • Application of Beer - Lambert Law
  • Provides an estimate of SaO2 by differentiating light absorption by arterial blood from light absorption by other components
95
Q

Which conditions/scenarios may preclude accurate pressure monitoring from affected sites?

A
  • atherosclerosis
  • arterial dissection
  • stenosis
  • embolism
  • unusual patient positions during surgery
    • may produce regional arterial compression
  • surgical retraction
    • can compromise perfusion and monitoring to a localized area
96
Q

What is the most imporatnt life-threatening vascular complication of central venous catheterization?

A

Cardiac tamponade resulting from perforation of the intrapericardial super vena cava, right atrium, or right ventricle

  • **Injury was the 2nd most common complication related to central catheters reported in the American Society of Anesthesiologists Closed Claims Project in 2004**
  • 81% mortality in these claims
    • often had delayed pressentation (1-5 days!)
97
Q

Pericardial constriction - CVP waveform

A

Tall a and v waves

Steep x and y descents

M or W configuration

98
Q

Describe palpation as a measurement of NIBP.

A
  • palpating the return of arterial pulse while an occluded cuff is deflated
  • advantages: simple, inexpensive
  • disadvantages: meausures only SBP, underestimates SBP
  • **likely use this as a quick method when someone is hypotenisve**
99
Q

Name some causes of inaccurate pulse oximetry readings.

A
  • malposition of probe
  • dark nail polish
  • different hemoglobin
  • dyes
  • electrical interference
  • shivering
100
Q

Name a few mechanisms in which we can improve accuracy and system dynamics of our transducer set up.

A
  • minimize tube length
  • limit stop cocks
  • no air bubbles
  • using non compliant stiff tubing
  • calibration at level of heart (mid-axillary line/right atrium)
  • calibration at meatus of ear/circle of Willis if concerned about cerebral perfusion as in sitting patient
101
Q

INFO CARD

Square wave test

A
102
Q

In the 5-electrode system, which two leads do we usually monitor and why?

A

Lead II - HR, and arrhythmia detection

V5 - ischemia detection

103
Q

A majority of modern patient monitoring systems do not simultaneously monitor all 12 ECG leads, how can we use our 5 lead system to benefit us, particularly in noncardiac surgery?

A

Intentionally select chest leads to monitor for potential ischemia in particular leads if there is a known blockage or % blockage in a particular coronary artery.

104
Q

Describe the relationship between oxygen and hemoglobin with a right shift of the oxyhemoglobin dissociation curve. What are some conditions that would cause a right shift?

A

With a right shift, hemoglobin is more likely to release oxygen to the tissues, so the tissues will be more oxygenated

Conditions

  • acidosis
  • hypercarbia
  • hyperthermia
  • increased 2,3 BPG
105
Q

Complications of central venous catheters (CVC)

A
  • More serious complications include:
    • perforation into the pleural space of mediastinum
      • hydrothorax
      • hemothorax
      • hydromediastinum
      • hemomediastinum
106
Q

List patient types that may be more vulnerable to complications of NIBP measurement and how can we mitigate these complications?

A

Patients with:

  • peripheral neuropathies
  • arterial or venous insufficiency
  • severe coagulopathies
  • recent use of thrombolytic therapy

*Be mindful of where we place the BP cuff as well as frequency of inflation - someone who is stable probably does not need q1 or q3 min NIBP like they may have need for induction. Can switch back to q5min*

107
Q

Give a brief overview of the CVP waveform. How many phasic events? Peaks? Descents?

A
  • 5 phasic events
  • 3 peaks (a, c, v)
  • 2 descents (x, y)
108
Q

Complications of NIBP measurement.

A
  • pain
  • petechiae and ecchymoses
  • limb edema
  • venous stasis and thombophlebitis
  • peripheral neuropathy
  • compartment syndrome
109
Q

What is your first duty as an anesthesia provider?

A

Vigilance

110
Q

List insertion sites for CVCs

A
  • left internal jugular vein
  • right internal jugular vein
  • subclavian veins
  • external jugular veins (difficult to place)
  • femoral veins
111
Q

INFO CARD

Arterial Waveform Detail

A
112
Q

1 square on the horizontal axis of ECG recording = ? sec and ? mV

A

.04 sec

.1 mV

113
Q

Triscuspid regurgitation - CVP waveform

A

tall systolic c-v wave

loss of x descent

114
Q

Define Vigilance.

A

Sustained attention.

The ability of the observer to maintain their focus of attention and to remain alert to stimuli for prolonged periods of time.

115
Q

Describe the disadvantages of placing a CVC or any catheters through the left side of the neck.

A
  • the cupula (tip of the pleura) is higher on the left side than on the right → theoretically, increased risk of pneumothorax
  • Thoracic duct may be injured as catheter enters the venous system at the junction of the left IJ and subslavian veins
  • left IJ is often smaller
  • more overlap with adjacent carotid
  • has to traverse the inominate vein and enter the SVC perpendicular
    • catheter tip may impinge on right, lateral wall of SVC, which can increase risk of vascular injury
116
Q

In general, do we confirm placement of a CVC in the OR?

A

No

  • we aspirate blood from all ports
  • obtain XRAY after surgery

**Likely will obtain XRAY in OR if catheter was placed on left**

117
Q

Which leads are the precordial leads?

A

V1-V6

118
Q

Describe the “y” descent of the CVP waveform.

A
  • diastolic decrease in atrial pressure
    • due to flow across the open tricuspid valve into the ventricle
119
Q

Where do we place precordial and esophageal stethoscopes?

A

Precordial: placed ON the chest surface (can be taped)

Esophageal: 28-30 cm INTO esophagus

120
Q

Name 5 methods of cardiac output monitoring and note which one is the most widely used clinical technique.

A
  • Thermodilution
    • **Most common method**
    • can have some measurement errors based on rapid IV administration of fluid, shunts, and tricuspid regurgitation
  • Continuous thermodilution
  • Mixed venous oximetry
  • Ultrasound
  • Pulse Contour
121
Q

Describe auscultation as a measurement of NIBP.

A
  • Obtain using a sphygmomanometer, cuff, and stethoscope; Korotkoff sounds heard due to turbulent flow within an artery created by mechanical deformation from BP cuff
  • advantages: permits estimation of SBP and DBP
  • disadvantages: unreliable in patients with HTN - usually lower
122
Q

Which electrode monitoring system is currently the standard for monitoring patients with suspected perioperative myocaridal ischemia?

A

5-electrode monitoring system

123
Q

Name 5 different types of Non-Invasive Blood Pressure Management

A
  • Palpation
  • Doppler
  • Auscultation
  • Oscillometry
  • Coninuous NIBP finter readings
124
Q

Define underdamped waveform and list potential causes.

A

Systolic pressure overshoot and additional small, nonphysiologic pressure waves distort the waveform making it hard to discern the dicrotic notch.

Potential causes:

  • catheter whip or artifact
  • stiff non compliant tubing
  • hypothermia
  • tachycardia or dysrhythmia
125
Q

Describe lead placment for 3-Lead ECG.

A

Electrodes: RA, LA, LL

Leads: I, II, III

3 views of heart (no anterior view)

126
Q

Describe pulsus parvus and pulsus tardus and they’re associated condition.

A

pulsus parvus: narrow pulse pressure

pulsus tardus: delayed upstroke

aortic stenosis

127
Q

The overall complication risk for a radial a line is low. Which kinds of scenarios put patients at increased risk for complications?

A
  • vasospastic arterial disease
  • previous arterial injury
  • thrombocytosis
  • protracted shock
  • high dose vasopressor administration
  • prolonged cannulation
  • infection
128
Q

Systolic left ventricular failure will have an arterial waveform characteristic of?

A

pulsus alternans: alternating pulse pressure amplitude

129
Q

When we have unreliable or inaccurate pulse oximetry readings (SpO2), what else can we use to obtain accurate SaO2 readings as well as measures of other hemoglobins?

A

Co-oximetry

**Co-oximetry is consdiered the gold standard for SaO2 measurements and is relied on when pulse oximetry readings are inaccurate or unobtainable**

130
Q

In a patient with an underlying ECG abnormality that makes ST segment analysis difficult, what is another modality for diagnosis of myocardial ischemia?

A

Transesophageal echocardiography (TEE)

131
Q

Relate Ohm’s law (V=IR) to blood pressure.

A

V (blood pressure) = blood flow (cardiac output) multiplied by resistance (systemic vascular resistance)

132
Q

On the vertical axis of EKG recording, ? mm = ? mV.

A

10 mm = 1 mV

133
Q

Explain in detail, why it is important to assess baseline ST segments and set ST segment alarms accordingly, especially in patients with CAD.

A

Many patients with CAD do not have perfectly isoelectric ST segments (they’re baseline is already off!)

Tailoring the ST segment alarm paramters to the patient’s baseline ST segment level is important becasuse if alarm parameters are set 1 - 2 mm around isoelectric (0 mV) line rather than at the patient’s baseline ST segment level, false alarms will frequently occur.

i.e. A patient may alarm at 4 mm ST depression. While concerning, this makes a huge difference if they’re baseline was already 3 mm depression vs. baseline 0 mm.

134
Q

Indications for arterial cannulation for BP monitoring.

A
  • continuous, real time blood pressure monitoring
  • planned pharmacologic or mechanical cardiovascular manipulation
  • repeated blood sampling
  • failure of indirect arterial blood pressure measurement
  • supplementary diagnostic information from the arterial waveform itself
  • elective deliberate hypotension
  • wide swings of intra-op BP
  • risk of rapid changes in BP
  • rapid fluid shifts
  • titration of vasoactive drugs
  • end organ disease
135
Q

How will your SpO2 levels read when you have carboxyhemoglobinemia (carbon monoxide poisoining)? Why?

A

Falsely high;

Carboxyhemoglobin and oxygenated hemoglobin absorb light at the same frequency (660 nm). At 940 nm, COHb absorbs virtually no light. Thus, in a ptient with carbon monoxide poisoning, the SpO2 is falsely elevated.

However, patient will be hypoxic if you draw an ABG.

136
Q

If you do infact have ST segment elevation related to coronary artery thrombosis, you are likely to see reciprocal ST segment depression in which leads?

A

contralateral leads

137
Q

INFO Card

Standard Chest Lead Electrode Placement

A
138
Q

In an arterial waveform, spike and dome (mid systolic obstruction) is associated with which type of condition?

A

HCM-hypertrophic cardiomyopathy

139
Q

Why should we use diagnositc mode on our EKG filtering capacity?

A

Filtering out the low end of frequency bandwidth can distort ST segment.

“We see more ‘noise,’ but have a better diagnositic”

*Other modes include filter mode and monitor mode*

140
Q

Relative contraindicaitons of PA cath insertion

A
  • Wolff Parkinson White syndrome
  • LBBB
141
Q

Normal oxygen consumption (mL/min)

A

200 - 250 mL/min (average: 225 mL/min)

142
Q

Name the 5 types of monitoring required according to the AANA Documenting Standards: Monitors.

A
  • Electrocardiogram (EKG) (Cardiovascular)
  • Blood Pressure (Cardiovascular)
  • Temperature (Thermoregulation)
  • Pulse Oximeter (Oxygenation)
  • End-tidal CO2 (Ventilation)
143
Q

INFO CARD

Table of Normal Values

A
144
Q

A fib - CVP waveform abnormality

A

loss a wave (no atrial kick)

prominent c wave

145
Q

Compared with central aortic pressure, peripheral arterial waveforms have:

A
  • higher systolic pressure
  • lower diastolic pressure
  • wider pulse pressures
146
Q

Why is the 3 lead EKG system inadequate for ST-segment monitoring?

A

Does not provide multilead monitoring or precordial leads, which are often most sensitive for detecting ischemia.

147
Q

How does decreasing HR help to remedy ST segment depression related to tachycardia?

A

Increases time in diastole (ventricular relaxation/filling) → improves coronary perfusion pressures

148
Q

Describe the “c” wave of the CVP waveform.

A
  • atrial pressure decreases after the “a” wave as a result of atrial relaxation
  • the “c” wave is due to isovolumetric contraction; tricuspid valve closes, bulging back into the right atrium
  • occurs in early systole (after the QRS on ECG)
149
Q

Describe the PCWP (pulmonary capillary wedge pressure) waveform.

A
  • “a” wave
    • respresents contraction of the left atrium
    • normall a small deflection UNLESS there is resistant in moving blood into the left ventricle (i.e mitral stenosis)
  • “c” wave”
    • due to a rapid rise in the left ventricular pressure in early systole, causing the mitral valve to bulge backward into the left atrium, so that the atrial pressure increases momentarily
    • (mitral valve bulges back with isovolumetric contration)
  • “v” wave
    • ​produced when blood enters the left atrium during late systole
    • prominent “v” wave reflects mitral insufficiency causing large amounts of blood to reflux into the left atrium during systole
      • ​can have mitral regurge and have a lot of reflux into the left atrium
150
Q

What is a pulmonary artery catheter and what data can we gather PAP monitoring?

A
  • right sided heart catheter used for direct bedside assessment of:
    • intracardiac pressures
      • CVP, PAP, PCWP/PAWP
    • estimate LV filling pressures
    • Assess LV function
    • CO
    • Mixed venous oxygen saturation
    • PVR and SVR
  • Pacing options
151
Q

List 2 uses of pulse oximetry and appropriate sites.

A

Uses

  1. detection of hypoxemia
  2. detection of perfusion

Sites

  • fingers
  • toes
  • nose
  • ear
  • tongue
  • cheek
152
Q

Describe an arterial line.

A

Percutaneous arterial catheter transduced to convert the generated pressure into an electrical signal to provide a waveform.

  • generates real - time beat to beat BP
  • allows access for arterial blood samples
  • measurement of CO/CI/SVR (based on algorithms)
153
Q

Axis deviation higher than +90 degrees

A

Right axis deviation

154
Q

Which two arterial waveforms more closely resemble aortic pressure than do waveforms from peripheral sites?

A

Axillary and femoral

155
Q

How does transmural ischemia present on EKG and what are two primary causes?

A

ST elevation with OR without positive (hyperacute) T waves.

Result of acute coronary artery occlusion by:

(1): coronary thrombosis

(2): vasospasm (Prinzmetal variant angina)

156
Q

List the 5 electrodes for the 5 lead ECG system and the leads monitored.

A

Electrodes: RA, LA, LL, RL, chest lead

Leads: I, II, III, aVR, aVL, aVF, V lead

157
Q

Name some ways that we can decrease O2 demand when we notice ST depression in the OR?

A

Decrease HR

Increase BP

Decrease catecholamines

158
Q

For which cases do we monitor end tidal CO2?

A

ALL anesthesia cases including moderate sedation, deep sedation or general anesthesia.

159
Q

Normal mixed venous oxygen saturation

A

70 - 80% (average: 75%)

160
Q

What is the phlebostatic axis and what positions is it relevant for?

A

4th intercostal space, mid axillary line

relevant for supine and up to 60 degrees of head up tilt

161
Q

Name scenarios where you may obtain falsely low BP.

A
  • cuff too large
  • extremity above level of heart
  • poor tissue perfusion
  • too quick deflation
162
Q

When performing transesophageal echocardiography, what

7 cardiac parameters are observed?

A
  • ventricular wall characteristics and motion
  • valve structure and function
  • estimation of end-diastolic and end-systolic pressures and volumes (EF)
  • CO
  • blood flow characteristics
  • Intracardiac air (look for)
  • Intracardiac massess (look for)
163
Q

What is perfusion pressure?

A

Pressure difference across the circulation of any organ → the pressure on the upstream side of that system minus the pressure on the downstream side

164
Q

How do we typically define intraoperative hypotension for adults? Why?

A

MAP of 55-60 mmHg

MAPs < ~50 mmHg and < 60 mmHg for as short as 5 and 10 minutes, respectively, were associated with an increased 30 day postop mortaility rate.

165
Q

What does the ST segment represent on ECG?

A

myocardial repolarization (relaxation)

ECG component most sensitive to acute myocardial ischemia.

166
Q

Normal values for systemic vascular resistance and pulmonary vascular resistance.

A

SVR: 800-1600 (average: 1200 dynes-sec-cm-5)

PVR: 40-180 (average: 80 dynes-sec-cm-5)

167
Q

Atrioventricular dissociation - CVP waveform

A

cannon a wave

NURA 641 Intro to Nurse Anesthesia (10 decks)

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