Download Basic Hemodynamics for the Cath Lab and ICU

Basic Hemodynamics
Ailin Barseghian El-Farra, MD
Cath Lab Essentials
January 23, 2016
Pressure is created by blood within the
heart or vessels.
• First cardiac catheterization and pressure
measurement performed on a living animal
– English physiologist Stephen Hales early in the 1700s
– “By accessing the internal jugular vein and carotid
artery of a horse, Hales performed his experiments
using a brass pipe as the catheter connected by a
flexible goose trachea to a long glass column of fluid.
The pressure in the white mare’s beating heart raised
a column of fluid in the glass tube over 9 feet high.”
Reported in the book Haemastaticks in 1733
Right Heart Catheterization
INDICATIONS
Indications
Diagnostic and therapeutic indications:
– Differentiate cause of shock or pulmonary edema
– Evaluation for pulmonary hypertension
– Differentiation of pericardial tamponade from
constrictive and restrictive cardiomyopathy
– Diagnosis of left to right shunt
– Guide fluid management and hemodynamic
monitoring after surgery, complicated MI, shock,
etc..
CONTRAINDICATIONS
Contraindications
• No absolute contraindications
• CAUTION in patients with pulmonary
hypertension and elderly
• Left bundle branch block
EQUIPMENT
Equipment
• Catheter
• Transducer
• Fluid-filled tubing to connect the catheter to
the transducer
• Physiologic recorder to display, analyze, print
and store the hemodynamic waveforms
Equipment
TECHNIQUE
A Systematic Approach to
Hemodynamic Interpretation
1. Establish the zero level and balance transducer.
2. Confirm the scale of the recording.
3. Collect hemodynamics in a systematic method
using established protocols.
4. Critically assess the pressure waveforms for
proper fidelity.
5. Carefully time pressure events with the ECG.
6. Review the tracings for common artifacts
Precautions
• Always record pressures at end-expiration
(unless on PEEP)
• During inspiration, pressures will be lower due
to decrease in intrathoracic pressure
(assuming normal conditions)
• Always zero and reference the system
Components of a Routine Complete
Right- and Left-Heart Catheterization
1. Position pulmonary artery (PA) catheter.
2. Position aortic (AO) catheter.
3. Measure PA and AO pressure.
4. Measure thermodilution cardiac output.
5. Measure oxygen saturation in PA and AO blood samples to determine Fick output and
screen for shunt.
6. Enter the left ventricle (LV) by retrograde crossing of the AO valve.
7. Advance PA catheter to pulmonary capillary wedge position (PCWP).
8. Measure simultaneous LV-PCWP.
9. Pull back from PCWP to PA.
10. Pull back from PA to right ventricle (RV) to screen for pulmonic stenosis and record RV.
11. Record simultaneous LV-RV.
12. Pull back from RV to right atrium (RA) to screen for tricuspid stenosis and record RA.
13. Pull back from LV to AO to screen for aortic stenosis.
Once the catheter was in place, all lights in the
room were turned off, and the Hamilton
manometer (which focused a light on sensitive
paper to record the pressure contour) was
attached to the catheter and manipulated in
absolute darkness so that its light output could
be captured with a handheld mirror and
adjusted to strike the paper. Researchers could
then record intravascular pressures.
Enson Y, Chamberlin MD. Cournand and Richards and the Bellevue Hospital Cardiopulmonary Laboratory. Columbia Magazine, Fall 2001.0000
CARDIAC CYCLE
Phase 1: atrial contraction
Phase 2: isovolumic contraction
TV/MV closure
to PV/AV opening
Phase 3: rapid ejection
Phase 4: reduced ejection
PV/AV opening to
PV/AV closure
Phase 5: isovolumic relaxation
PV/AV closure to
TV/MV opening
Phase 6: rapid ventricular filling
Phase 7: reduced ventricular
filling
TV/MV opening to
TV/MV closure
PRESSURE WAVE INTERPRETATION
LEFT HEART CATHETERIZATION
PITFALLS
ARTIFACTS
CARDIAC OUTPUT
Cardiac Output
• Thermodilution
• Fick Method
Thermodilution
• Bolus injection of liquid
– Saline
– Proximal port
• Change in temperature is
measured by thermistor in
the distal portion of the
catheter
Fick Principle
• Described in 1870
• Assumes rate of O2
consumption is a
function of rate of
blood flow times the
rate of O2 pick up by
the RBC
Cardiac
Output
(L/min)
Direct Fick: Vo2
measurement
Indirect Fick: Vo2
estimate (3.5 mL/Kg)
Limitations
Thermodilution
Fick
• Not accurate in TR
• Overestimated cardiac
output at low output
states
• VO2 is often estimated by
body weight (indirect
method) rather than
measured directly
• Large errors possible with
small differences in
saturations and
hemoglobin.
• Measurements on room
air
THANK YOU
Normal Pressures
Site
Normal Value Mean
(mmHg)
Pressure
(mmHg)
0-5
Right Atrium
(or CVP)
Right Ventricle 25/5
Pulmonary
Artery
PCWP
LV
Aorta
25/10
7-12
120/10
120/80
Saturation
75%
75%
10-20
75%
95-100%
95-100%
95-100%
Normal Values
Site
Value
Sv02
0.60-0.75
Stroke Volume
60-100 ml/beat
Stroke Index
33-47 ml/beat/m2
Cardiac Output
4-8 L/min
Cardiac Index
2.5-4.0 L/min/m2
SVR
800-1200 dynes sec/-cm5
PVR
<250 dynes sec/-cm5
MAP
70-110 mmHg
References
• Bangalore and Bhatt. Right heart catheterization,
coronary angiography and percutaneous
coronary intervention. Circulation, 2011; 124:
e428-e433.
• Kern, Morton J. The Cardiac Catheterization
Handbook. Philadelphia, PA: Saunders Elsevier,
2011. Print.
• Ragosta, Michael. Textbook of Clinical
Hemodynamics. Philadelphia, PA:
Saunders/Elsevier, 2008. Print.