Hemodynamic Pressure Monitoring

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HEMODYNAMIC PRESSURE MONITORING

Dr. Mueen Ullah KhanAssitant professorDepartment of Anaesthesia KKUH

December 2 2009

Lecture series resident 1 and 2 Anaesthesia Lecture series resident 1 and 2 Anaesthesia

A. STANDARD

• Qualified anesthesia personnel shall be present in the room throughout the conduct of all general anesthetics, regional anesthetics and monitored anesthesia care.

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CIRCULATION

• OBJECTIVE: To ensure the adequacy of the patient's circulatory function during all anesthetics.

• METHODS: • (a) Every patient receiving anesthesia shall have the

electrocardiogram continuously displayed from the beginning of anesthesia until preparing to leave the anesthetizing location.

• (b) Every patient receiving anesthesia shall have arterial blood pressure and heart rate determined and evaluated at least every five minutes.

• (c) Every patient receiving general anesthesia shall have, in addition to the above, circulatory function continually evaluated by at least one of the following: palpation of a pulse, auscultation of heart sounds, monitoring of a tracing of intraarterial pressure, ultrasound peripheral pulse monitoring, or pulse plethysmography or oximetry.

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DEFINATIONS

• The arterial pulse is a wave of vascular distention resulting from the impact of the stroke volume of each beat being ejected into a closed system.

• Arterial pressure is the lateral pressure exerted by the contained blood on the walls of thevessels.

• Mean arterial pressure is the product of the cardiac output and the systemic vascular resistance. Mean pressure is about one-third the difference between the systolic and diastolic pressures.

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Arterial pressure• Arterial pressure varies with the respiratory

cycle. • It normally decreases 6 mm Hg or lessREASON: • Increase in venous capacitance during

inspiration • Increase in right-sided heart venous return and

output, thus causing a decrease in left ventricular stroke output and pressure.

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BLOOD PRESSURE MONITORING

• PERIOPERATIVE SYSTEMIC BLOOD PRESSURE MONITORING

• INDIRECTLY using extremity-encircling cuffs

• DIRECTLY By inserting a catheter into an artery and transducing the arterial pressure trace.

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Indirect Measurement of Arterial Blood Pressure

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PREREQUISITES

• The bladder width for indirect blood pressure monitoring should approximate 40% of the circumference of the extremity.

• Bladder length should be sufficient to encircle at least 60% of the extremity.• AUSCULTATION OF THE KOROTKOFF

SOUNDS 8


LIMITATIONS

• Quick deflations underestimate blood pressure.

• Unreliable during conditions of low flow.

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NIBP

• Most current instruments use oscillometric techniques to measure systolic, diastolic, and mean blood pressures.

Automated oscillometry underestimateSystolic blood pressure, with mean errors

reported from -6.9 to -8.6 mm Hg compared with direct radial artery pressure measurements.

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Invasive Measurement of Vascular (Arterial Blood)

Pressure

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Invasive Measurement of Vascular (Arterial Blood) Pressure

• Indwelling arterial cannulation permits the opportunity to monitor arterial blood pressure continuously and to have vascular access for arterial blood sampling.

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INTRAVASCULAR PRESSURE MONITORING

Physiology Monitor

MechanicalMechanicalenergyenergy

TransducerTransducersystemsystem

ElectronicElectronicsignalsignal

Transducer systemTransducer system

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COMPONENTS1. Transducer Change mechanical energy to electronic

signal.

2. Continuos washing system Saline solution in a pressure bag (300mmHg)

or infusion pump (less fluid volume!!!)

3. Proximal stopcock Useful to set “Zero”.

4. Connection to catheter Transfer pressure pulse from caterer to

transducer

5. Distal stopcock Useful to take out blood sample.

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4 5

1

3


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TransducerTransducersystemsystem

Resonance Damping

CONNECTION LINE: SHORTER , LONG and STIFFER!SHORTER , LONG and STIFFER!


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Calibration - “ZERO”

WHY Remove atmospheric pressure interference (~760mmHg)

WHEN connection from transducer to monitor

Not when you change transducer position!!!

TEST Open Proximal Stopcock to connect transducer to air ,monitor must show a Straight line and measure “zero”.

SET: RANGE

Measured pressureis always relative to

a reference point.It’s a difference!


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Level:

Reference pointRIGHT ATRIUM

=“Mean Axillary Line”

Supine position

WHEN: SET LEVEL Every time patient moves (Otherwise measurement is not right!!!)


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RAPID FLUSH TEST

To determinatethe dynamic response

of catheter and transducer system

Overdamped


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Invasive arterial pressureInvasive arterial pressure

WHEN:

• Beat to beat chance in BP•Expecting large fluid shifts•Cardiac arrest• Shock syndrome• Hypertensive crisis• Use of vasoactive drugs• Use on IABP

MULTIPLE BLOOD GAS ANALYSIS• Mechanical Ventilation• Respiratory failure• Sepsis


WHERE:

1. Radial Artery2. Femoral Artery

3. Brachial Artery4. Axillary Artery5. Dorsalis pedis artery

90%

TECHNIQUE OFCANNULATION:

- Use alwaysSeldinger Technique

Invasive arterial pressure - 2Invasive arterial pressure - 2


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MAP = PAd + (PAs-PAd) / 3

Pulse Pressure : PAs-PAd



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NORMAL RANGE SYSTOLIC BLOOD PRESSURE

Age Wt mmHg

Term 3.4kg 40-603 mo 6kg 45-756 mo 7.5kg 50-901 yr 10kg 50-1003yr 14kg 50-1007yr 22kg 60-9010yr 30kg 60-9012yr 38kg 65-9514yr 50kg 65-95

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RESPIRATORY CHANGES IN ARTERIAL WAVE FORM IN

MECHANICALLY VENTILATED PATIENTS

SYSTOLIC PRESSURE VARIATION - SPV

PULSE PRESSURE VARIATION - PPV


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SYSTOLIC PRESSURE VARIATION - SPVThe difference between the maximal and minimal value of systolic blood pressure during one mechanical breath.

SPV can be divided into two components by interposing a brief (5sec) apnea, and using the systolic blood pressure during apnea as a reference value:

down

upThe difference between the maximal systolic value and the systolic blood pressure during apnea.

The difference between the apneic systolic blood pressure and the minimal systolic value.

Invasive arterial pressureInvasive arterial pressureSYSTOLIC PRESSURE VARIATION - SPV

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Down

reflects the expiratory decrease in

LV preload and SV related to the

inspiration decrease in RVSV

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Perel A. et al.-Anesthesiology 1987:67;498-502

Pizov R. et al.-Anesth Analg 1988:67;170-174

Preisman S. et al.-Int Care Med1997:23;651-657

During hypovolemia, as during hemorrage

SPV by Down

The amount of blood loss was closely correlated

with SPV and Down

Volume expansion SPV and Down


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PULSE PRESSUREThe difference between systolic and diastolic arterial pressure

In mechanically ventilated patients:

•PP is maximum at the end of inspiratory period

•PP is minimum during the expiratory period

Respiratory changes in LVSV are reflected by respiratory changes in PP.

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PP (%) = (PPmax- PPmin) / ((Ppmax+Ppmin)/2)*100

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Michard et al.: Am J Resp Crit Care Med 2000; 162:134-138

PPV before volume expansion can accurately predict the effect of volume expansion on CO

PPV is a more reliable indicator of fluid responsiveness than PS

• A patients with a baseline PPV value of more than 13% was very likely to respond to volume expansion by increasing CO by 15% (positive predicted value 94%).

• By contrast, if PPV 13%, the patients was unlikely to respond to fluid challenge (negative predictive value 96%).

Central Venous PressureCentral Venous Pressure

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Central Venous Pressure - 1Central Venous Pressure - 1

WHEN:

• Pre-operative preparation

• Total parenteral nutrition

• Pulmonary artery catheter

• Emergency management

• Use of vasoactive and irritant drugs

• Cardiac arrest

•Neurosurgery


CVP monitoring

• Proponents of CVP monitoring believe that CVP pressures are essentially equivalent to right atrial pressures and serve as a reflection of right ventricular preload

• CVP monitoring is less invasive and less costly than pulmonary artery monitoring and offers unique understanding of right-sided hemodynamic events and the status of vascular volume.

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WHERE:

Depend on surgery plan!!

1. Internal Jugular vein2. Subclavian vein3. Basalic/cephalic veins- long line

2. Femoral vein- long line

TECHNIQUE OFCANNULATION:- Use always

Seldinger Technique


1. 5Kg 4 Fr- 5cm bi-lumen⇒

5,5Fr 5cm triple-lumen

2. 5-10 Kg 4 Fr 8cm triple-lumen⇒

5,5Fr 5cm triple-lumen

3. 10-20 Kg 5,5 Fr 8 cm triple-lumen⇒

4. 20 Kg 5.5 Fr 8 - 13cm triple-⇒lumen

5. Adults 6 Fr 16-18 cm

Central Venous Pressure - 2Central Venous Pressure - 2

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CVP – Central Venous Pressure / Right Atrium waveform

• A wave Atrium Systole

• C wave Tricuspid valve closure

• X wave Atrial relaxation

• V wave Atrial filling with tricuspid valve closed

• Y wave Ventricular filling after ticuspid valve opening


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Spontaneous Breathing Mechanical Ventilation

( = Inspiration)

Central Venous Pressure / Ventilation


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• TRICUSPID REGURGITATION: Elevated CVP

Evident positive V wave

• CARDIAC TAMPONADE: Elevated CVP

Damping or absence of Y waveEqualization of CVP, diastolic PAP and PAWP

CVP – Central Venous Pressure / Right Atrium waveform


Complications

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Superior Vena Cava>Tricuspid Valve

> Right Ventricle> Pulmonary Artery

PULMUNARY ARTERY CATHETER - SWAN-GANZ

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SWAN-GANZ CATHETER

1. Distal lumen

2. Proximal lumen

3. Balloon inflation lumen

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2

3

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WHEN:

• Complicated MI

•Shock (cardiogenic-hypovolemic-Septic)

• Respiratory distress (cardiogenic – noncardiogenic)

• Management post-cardiac surgery patient

• Others


Pulmunary Artery Catheter - 1Pulmunary Artery Catheter - 1

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CONTROINDICATIONS:•Stenosis tricuspid, •LBBB

Inserction:Arrhythmias (TV, FV) 0.3-63 %Right bundle branch (0.1-4.3 %), Total AVB (0-8.5 %)Intracardiac and valve damageTromboembolic complication“Knotting” (loop)

After inserction:Infection (0-22%)SepticemiaEndocarditis (2.2 -100%)Pulmonary infarction (0.1 -7 %)Pulmonary artery perforation (0.06-0.2 %)Balloon rupture

COMPLICATION:



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Insertion technique

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Insertion technique

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MEASUREMENTS:MEASUREMENTS: Cardiac Output

Thermodilution (Fegler G., 1954/Ganz W, 1971) Cold solution in injected into right atrium. The thermistor records blood temperature change on the top of

pulmonary artery catheter.

Stewart-Hamilton formula

CO = Vol injected x (TB-TF)1.08K/ ? ? TB(t)dtCO = Vol injected x (TB-TF)1.08K/ ? ? TB(t)dt

• TB, TF = Blood and cold fliud temperature• ?? TB(t)dt = under-curve area• K = computational constants



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MEASUREMENTS:MEASUREMENTS: Pulmonary Artery Occlusion Pressure (PAOP)



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In Pediatric Cardiac Surgery you can put a catheter direct In Left Atrium

LVEDPLAP

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Error in interpretation – Damped PAP

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Error in interpretation – Overwedging

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Error in interpretation –

Mitral regurgitation

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• Central Venous Line– CVP– Blood gas (ScvO2)

• Arterial line– Continuous Blood Pressure– SPV / PPV

• Pulmonary Artery Catheter (PAC)– Occlusion pressure, PAP– C.O. / SVR / PVR– SvO2– DO2 / VO2 DRUGS?

VOLUME?

• CONTRACTION• PRELOAD• AFTERLOAD

ECHO!!!

CONCLUSIONS

THANK YOU

• QUESTIONS ?

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Education

Hemodynamic Pressure Monitoring