Cardiac Clinical Monitorin Flashcards
Normal CVP aka MRAP (mean right atrial pressure) range
1-10 mmHG
Where should the CVP line sit in the heart
At the most distal part of the SVC but not in the RA
Normal RV range
15-30 / 0-8 mmhg
25/5 average (quarter over a nickel)
Normal PA range
15-30 / 5-15 mmhg
25/10 average (quarter of a dime)
Normal mean PA range
10-20mmhg
15 avg
Normal PAOP (wedge) range
5-15mmhg
10 avg
Normal LVEDP (left ventricular end-diastolic pressure) range
4-12 mmHg
Avg 8 mmHg
CVP port on PAC is used to estimate?
RVEDP
right ventricular end diastolic pressure
Distal tip of PAC is used to estimate?
RV systolic pressure via the PA systolic reading.
The upstroke of the PA tracing is produced by?
The opening of the pulmonic valve and is followed by RV ejection.
The downstroke of the PA waveform, which contains the dicrotic notch, is produced by?
Sudden closure of the pulmonic valve leaflets (the beginning of diastole)
Similarities and differences between PAOP and CVP waveform/readings
Both have a,c,v waves.
PAOP (5-15) is less likely to see c wave. Waveform as a whole should be at a higher baseline pressure because you are measuring LV pressures.
CVP measurements will be 0-10
PAOP waveform - what do a, c, and v represent
a = LA systole
c = closure of mitral valve
v = filling of LA as well as volume displacement of mitral valve closure during LV systole
The a wave on the cvp will correlate with what EKG event
a wave will follow the P wave (atrial depolarization, contraction)
The c and v wave on the cvp will correlate with what EKG event
the c and v waves occur after the beginning of the ventricular contraction (QRS)
the v wave may not occur until shortly after the T wave
What factors can create giant a waves aka cannon a waves?
Junctional rhythms
complete AV block
PVCs
ventricular pacing asynchronous
tricuspid or mitral stenosis
diastolic dysfunction
myocardial ischemia
ventricular hypertrophy
What are 2 factors that can create large v waves?
Tricuspid or Mitral Regurg
Acute increase in intravascular volume
What are two factors that can cause a loss of a waves or only v waves?
atrial fibrillation
ventricular pacing in the setting of asystole
is the CVP a reliable measurement for fluid volume responsiveness?
No. But it still has value to it, just not for evaluating fluid responsiveness.
What are better measures of fluid responsiveness than CVP?
Dynamic values such as SVV and PPV
stroke volume variant and pressure volume variation
What change in SVV indicates fluid responsiveness
Small volume bolus and assess SVV. If there is less SVV occurs after bolus (ex 17% to 15%) the reduction indicates the patient will respond/require further preload augmentation
What criteria must be met for SVV and PPV measurements to be accurate?
Patients must be mechanically vented with at least 7-6mL/kg tidal volume with no spontaneous respiratory effort and patients must be in sinus rhythm.
In mechanically vented patients, the normal SVV? Above what % implies fluid admin should be given?
range for normal is 10-13%. Values higher than 12-13% imply patients will respond positively to an increase in preload.
Goal PPV range?
10-15%. greater than 12% likely fluid responsive.
Potential causes of elevated CVP
RV failure
Tricuspid stenosis or regurg
Cardiac Tamponade
Constrictive pericarditis
volume overload
Pulm HTN
chronic LV failure
catheter whip
catheter coiling
Potential causes of elevated PAP
LV failure
Mitral stenosis or regurg
L to R Shunt
ASD or VSD
Volume overload
Pulm HTN
“catheter whip”
Potential causes of elevated POAP
LV failure
Mitral stenosis or regurg
Cardiac tamponade
Constrictive pericarditis
volume overload
ischemia
The mean or diastolic PA pressure should always be measured when? Why?
At the end of expiration.
this the time when pleural pressures are most closely equal to atmospheric pressure (except when PEEP is being used)
LVEDP should be measured at what point the PAP recording?
Lowest most point after dicrotic notch. just before the upstroke of the v wave, or c wave if present
What are some circumstances PADP poorly correlates with PAOP?
When Pulm Vasc Resistance (PVR) is elevated (COPD, HPV, PE, ARDS, Hypercarbia)
HR > 130bpm
Severe Mitral or Aortic Regurg
When lung zone III has changed to II or I (hypovolemia or PEEP)
Normal SVRI values
1760-2600 dynes
Normal SVR values
800-1200 dynes
Normal PVRI values
45-225 dynes
Normal PVR values
40 -225 dynes
Normal svo2
65-77%
Normal ScVo2
~70%
BP cuff that is too small can produce a ?
Falsely elevated BP
BP cuff that is too big can produce a ?
Falsely low BP
Transducer below the level of the heart can produce a?
Falsely elevated BP
Transducer above the level of the heart can produce a?
Falsely low BP
Which of the following conditions are associated with large ‘v’ waves on the central venous pressure waveform?
tricuspid regurg
A condition in which individuals exhibit reduced recognition of auditory alarms when subjected to a high visual workload is known as
inattentional deafness
The degree of ST elevation or depression on an ECG is measured between the isoelectric line and the
J point
For optimal positioning in an adult, an esophageal temperature probe sensor should be positioned about ______ cm from the nose.
45cm
Which of the following corresponds to the opening of the tricuspid valve on a central venous pressure waveform?
The y descent represents the opening of the tricuspid valve.
Most common and required diagnostic tool
ECG
what two leads to monitor for accurate ST segments
V2 and V3
where is the J point
end of QRS complex and beginning of ST
Incidence of perioperative ischemia in patients with CAD
20-80%
If the pateints Preop EKG was unremarkable, what leads should you monitor intraop?
V3-V5, III and aVF
What lead monitors narrow WRS rhythms best
Lead II
Which leads detects ischemia earliest and most frequently
V3 (86%), V4 (79%), V5 (65%)
What is the gain setting
The amplitude at which the ECG monitor is set
SVV or PPV more accurate for predicting fluid responsiveness?
PPV with the use of an arterial catheter
Normal cardiac INdex
2.8-3.6 L/min
When might you have tricuspid regurg but not have a large v wave on CVP tracing?
When RA has become very compliant (large/expanded) due to long term tricuspid regurg.
What does the a wave represent in the CVP tracing?
Atrial Contraction - End of Ventricular Diastole. P wave on EKG.
When the ventricle is FULLY relaxed - it can receive the remainder of blood in the RA.
The size of the a wave on the CVP tracing is dependent on?
- The volume of blood moving into the atrium
- The compliance of the atrium
What does compliance of a heart chamber mean?
The ease with which the heart expands when filled with blood—the inverse of stiffness.
High compliance = stretchy
Low compliance = small/stiff
The x wave on the CVP tracing represents?
Start of atrial diastole. Pressure starts to decrease as RA begins to relax.
What does the c wave on the CVP tracing represent?
Tricuspid valve CLOSURE. the onset of early ventricular contraction. R wave on QRS complex.
What is one condition that may result in the loss of the c wave into the a wave?
Tachycardia
What does the x1 descent represent in a CVP tracing?
Downslope represents mid-ventricular systole. R-S EKG.
The tricuspid valve and septum descend towards the apex of the heart as the ventricle squeezes, creating a bigger volume and less pressure in RA.
What does the v wave represent on the CVP tracing?
Late ventricular systole. T-wave on EKG.
Blood enters RA, hits the CLOSED TV (which is pushing back due to RV contraction). v wave is measuring the back pressure.
When might you see a large v wave on a CVP tracing?
Suggestive of tricuspid regurg.
What is the amplitude of the v wave dependent on?
- Compliance of RA
- Volume filling the RA
What does the y descent on the CVP tracing represent?
Open tricuspid valve - volume leaving the RA, filling a relaxing RV, thus a drop in RA pressure.
Diastolic EKG trace - after T-wave before P-wave.
Describe the arterial line response to this square wave test
Normal. 2 oscillations, quick up and downstroke
Describe the arterial line response to this square wave test
Under damped. too much energy, More than 2 oscillations
Describe the arterial line response to this square wave test
Over damped. Not enough energy. No oscillations
Stroke volume is calculated as
end diastolic volume minus the end systolic volume
MAP Calculation
MAP = DP + [1/3(SP-DP)] AKA
MAP = DP + [1/3(PP)]
MAP Calculation
MAP = DP + [1/3(SP-DP)] AKA
MAP = DP + [1/3(PP)]
What percent of patients scheduled for noncardiac surgery are at risk for CAD?
33%
What is happening in this arterial waveform? Why might this happen?
overdamped. Air bubbles in tubing, thrombus on catheter, catheter kinking, flexed wrist, loss of dicrotic notch. Underestimation of BP
What is happening in this arterial waveform? Why might this happen?
underdamped - overestimation of SBP. Decreased arterial compliance.
An underdamped arterial transducer system produces ?
An artificially high systolic BP - overestimated BP
Underestimated DBP
Describe where to place your 5 precordial leads for EKG
V1: RSB, 4th ICS
V2: LSB, 4th ICS
V3: Equal distance between V2 and V4
V4: Midclavicular line at 5th ICS
V5: Next to V4 along Anterior Axillary Line
V6: Next to V5 along midaxillary line
How would you interpret:
CVP - low
PADP - low
PAOP - low
hypovolemia
Or transducer not at phlebostatic axis
How would you interpret:
CVP - Normal or High
PADP - High
PAOP - High
LV Failure
PADP and PAOP correlate poorly when?
Pulmonary Vascular Resistance is elevated (COPD, PE, ARDS, Hypercarbia)
HR > 130s
Severe MR or AR
When Pulmonary Zone III has changed to Zone II or I due to hypovolemia or PEEP)
How would you interpret:
CVP - High
PADP - Normal or Low
PAOP - Normal or Low
RV Failure,
TR or TS
How would you interpret:
CVP - High
PADP - High
PAOP - Normal or Low
PE
How would you interpret:
CVP - High
PADP - High
PAOP - Normal
Pulmonary HTN
How would you interpret:
CVP - High
PADP - High
PAOP - High
Cardiac Tamponade
Transducer not leveled
How would you interpret:
CVP - Normal
PADP - Normal or High
PAOP - High
LV myocardial Ischemia or MR
How would you interpret:
CVP - Low
PADP - High
PAOP - Normal
ARDS
What things can increase SvO2
Left to Right Shunt
Hypothermia
Sepsis
Cyanide Toxicity
Wedged PAC
Increased CO
What things can decrease SvO2?
Hyperthermia
Shivering
Seizures
Hemorrhage
Decreased CO
