Hemodynamic Monitoring and Volume Management€¦ · Hemodynamic Monitoring and Volume Management ... 121:2000–2008 ... •Tousignant CP, Anesth Analg 2000;

Hemodynamic Monitoring and

Volume Management

Lakhmir S. Chawla, MD

Division of Renal Diseases and Hypertension

DIVISION OF CRITICAL CARE MEDICINE GWUMC

Overview

• Blood Pressure Monitoring

• Assessment of Intravascular Volume

• Volume Responsiveness

– Where are you on the Starling Curve?

• Cardiac Output Monitoring


Measurement of Blood Pressure

• Stethescope plus BP Cuff

• Dinamap

• Arterial line


Old School

•Advantages

– Accurate systolic and

diastolic measurement

– Individual validation not

needed

•Disadvantages

– Cumbersome

– Operator variability


Oscillometric Blood

Pressure Measurement

•Advantages

– Easy to use

– Faster than manual

– Measures MAP, not SBP or DBP

•Disadvantages

– Does not measure systolic or

diastolic directly; uses ratio

formula to estimate SBP and

DBP

– Assumes NSR

– Motion Artifact


Overestimate Underestimate

(Too much pressure to occlude) (Too little pressure to occlude)



Skipped Values in the

DINAMAP algorithm

• Skipped SBP

– 89, 119, 120, 124, 125, 130, 140, 141, 150,

160, 170, 180, 190, and 200 mm Hg

• Skipped HR

– 95, 99, 103, 106, and 109 bpm.

Skip Patterns in DINAMAP-Measured Blood Pressure in 3 Epidemiological Studies

Kathryn M. Rose. (Hypertension. 2000;35:1032.)


Invasive Arterial BP Monitoring



Central Peripheral

Effects of Systolic and Diastolic

BP

• SBP rises (approx 20-30 mm Hg)

• DBP falls

• Pulse Pressure Widens




Quality Assurance with Arterial

Lines

• Square Root Test

• Waveform assessment


Overdamped

decreased SPB, increased DPB

Check for clot, large air bubbles, soft tubing

Underdamped

Increased SPB, ringing artifacts in waveform

Remove bubbles, often small, replace tubing with larger bore,

add damping device

Hemodynamic monitoring : invasive and noninvasive clinical application 3rd ed.

Gloria Oblouk Darovic. Philadelphia : W.B. Saunders Co., 2002.


Summary of Arterial Pressure

Assessment

• If you are not measuring the BP yourself, think prescribe in MAP terms, not SBP or DBP

• When using an arterial line, know its location, evaluate its wave form

• As we become more and more technology dependent

Trust, BUT Verify


Assessment of Intravascular

Volume

• Bedside- Physical Exam

– JVP

– Orthostatics

• Central Venous Pressure

• Pulmonary Artery Wedge Pressure

• Stroke Volume

• Stroke Volume Variation


Physical Exam

• Jugular Venous Pressure

– Observer Variability

– Difficult in obese and edematous patients

– Trending problematic

• Orthostatics

– Can be helpful

– Difficult to do in critically ill patients

– Specific but not sensitive

– Result Binary; Following trend difficult


Physical Exam

• Does not reliably predict intravascular

volume status

• Classic Triad - Jugular venous

distension, crackles on auscultation,

and peripheral edema

•Crit Care Med 2001; 29: 1502-1512

•N Engl J Med 1983; 308:263–267

•Crit Care Med 1984; 12:107–112

•Crit Care Med 2001; 29:1635–1636

•Intensive Care Med 2001; 27:1238


Portable CXR

• The classic radiographic signs of volume overload (pleural effusions, septal lines, peribronchial cuffing, or distribution of lung densities) are poor predictors of LVEDP

•Crit Care Med 2001; 29: 1502-1512

•Crit Care Med 2001; 29:1635–1636


Central Venous Pressure (CVP)

• Advantages

– Can be trended

– Objective Measure

• Disadvantages

– Not helpful in the absence of cardiac output measure

– Significantly affected by respiration and PEEP

Michard F et al Chest 2002; 121:2000–2008

Kumar A et al Crit Care Med 2004; 32:691–699

Shippy CR et al Crit Care Med 1984; 12:107–112


Central Venous Pressure

• Does NOT predict cardiac

preload or volume status

•Michard F et al Chest 2002; 121:2000–2008

•Kumar A et al Crit Care Med 2004; 32:691–699

•Shippy CR et al Crit Care Med 1984; 12:107–112


Pulmonary Capillary Wedge

(Occlusion ) Pressure

• Value generated by right sided heart catheterization (typically balloon guided)

• Under idealized conditions, PCWP (PAOP) represents left ventricular end diastolic pressure (LVEDP)

• LVEDP is a surrogate for LV end diastolic volume which should represent pre-load



Pulmonary Capillary Wedge Pressure

• Advantages

– Measures left sided pressures as

compared CVP

• Disadvantages

– Somewhat invasive & more side effect than

CVP

– Accuracy dependent on optimal placement

– Wedge pressure must be read by

experienced operator


Pulmonary Capillary Wedge Pressure

Contrary to expectations

• PCWP fails to correlate with LVEDV or

stroke volume

• The wedge is NOT a good measure of intravascular volume status.


The Evidence

•Kumar A et al Crit Care Med 2004 Vol. 32, No. 3

• Sakka SG, Intensive Care Med 1999; 25:

•843–846

• Jardin F, Intensive Care Med 1994; 20:550–554

•Calvin JE, Crit Care Med 1981; 9:437–443

•Calvin JE,. Surgery 1981; 90:61–76

•Diebel L, J Trauma 1994; 37:

•950–955

•Martyn JA,. J Trauma 1981; 21:

•619–626

• Lichtwarck-Aschoff M,. Intensive

•Care Med 1992; 18:142–147

•Tousignant CP, Anesth Analg 2000; 90:351–355

•Thys DM,. Anesthesiology 1987; 67:630–634

•Ellis RJ, J Thorac Cardiovasc Surg 1979; 78:605–613

• Hoeft A, Anesthesiology 1994; 81:76–86

•Douglas PS, Ann Thorac Surg 1987; 44:31–34

•Hansen RM, Anesthesiology 1986; 64:764–770

•Tuman KJ, J Cardiothorac Vasc Anesth 1995; 9:2–8

•Buhre W, Eur J Anaesthesiol 1999; 16:11–17

•Dennis JW, J Vasc Surg 1992; 16:372–377


A, Initial CVP

and SVI

B, Δ in CVP and

SVI in response to

saline

C, Initial PWP and SVI

D, Δ in PWP and SVI

in response to saline.

Pulmonary artery occlusion

pressure and central venous

pressure fail to predict ventricular

filling volume, cardiac

performance, or the response to

volume infusion in normal

subjects

Kumar, Anand MD; Critical Care

Medicine: Volume 32(3) March

2004 pp 691-699


•2-D echo LVEDVI compared to SVI


Volume Responsiveness

Increase in cardiac output with

volume bolus

CO = HR x SV

•Stroke Volume corrected for BSA = SVI



Renal Considerations

• Pre-renal (low FeNa)

– Not necessarily volume depleted

– Decreased Renal Perfusion Pressure

RPP = CO x RVR

CO = cardiac output

RVR = Renal Vascular Resistance

Optimize RPP

Flow is preferable to resistance

Dobutamine versus phenylephrine


If Physical Exam, CVP, and

PCWP do not determine volume

status, how do we optimize our

patients?

Build a Starling curve one patient at a time

Assess the effect of volume infusion on stroke volume


Volume seeking versus room for diuresis


Stroke Volume Variation

• Based on clinical observation that respi-

phasic variation of arterial pressure in

intra-vascular volume depletion

• Quantitative Measure

• Available on Pulse Contour Systems

•Anesth Analg. 2003 May;96(5):1254-7.

•Eur J Anaesthesiol. 2004 Feb;21(2):132-8.

•Chest. 2005 Aug;128(2):848-54

•Anesth Analg. 2001 Apr;92(4):984-9


ROC curve for CVP, PAOP, spontaneous venous pulse, and pulse pressure variation

Δ PP, change in pulse pressure; Δ SP, change is systolic pressure; PAOP, pulmonary artery

occlusion pressure; RAP, right arterial pressure. Michard F, Boussat S, Chemla D, et al.: Relation between respiratory changes in arterial pulse pressure and fluid

responsiveness in septic patients with acute circulatory failure.

Am J Respir Crit Care Med 2000, 162:134–138.


ROC curves comparing the ability of the pulmonary artery occlusion pressure (PAOP), the left ventricular end-diastolic area index (EDAI), and the delta down component (dDown) of the positive pressure ventilation-induced arterial systolic pressure variation

Tavernier B et al. Anesthesiology. 1998 Dec;89(6):1313-21.


Summary

Measures of Cardiac Output and Volume

Responsiveness

•Cardiac Output

– PAC thermodilution

– Pulse Contour

•Volume Responsiveness

– Transpulmonary

thermodilution (GEDVi)

– Stroke Volume Variation

•Pulse Contour – Offers CO and SVV monitoring

•PAC – CO monitoring, CVP, and PCWP

•GEDVi – Offers GEDVi, CO, and SVV


Summary: How to monitor volume status

• Physical Exam

• Filling pressures

– CVP and PCWP

• Chest Radiograph

• Echocardiography

• Quantitative Measures of Cardiac Output


In order to follow stroke volume,

an accurate measure of cardiac

output is required


How to monitor cardiac output

• Thermodilution

– Pulmonary Artery Catheterization

– Transpulmonary – GEDV thermodilution

• Lithium Dilution

• Impedance Plethysmography

• Pulse Contour

• Esophageal Doppler

• TEE



Impedance Cardiography (ICG)

• Alternating Current is Transmitted

Through the Chest

• Current Seeks Path of Least Resistance: The Blood Filled Aorta

• The ICG Measures the Baseline Impedance to this Current

• With Each Heartbeat, Blood Volume and Velocity in the Aorta Change

• ICG Measures the Corresponding Change in Impedance

• ICG Uses the Baseline and Changes in Impedance to Measure and Calculate Hemodynamic Parameters


Aortic Blood Flow

Changes Impedance

Aorta ICG Waveform


Global End Diastolic Volume

Index

• Requires CVP and thermodilution

arterial line

• Cold solution infused via CVP and

thermodilution curve generated

• This parameter is closely linked to intra-

thoracic blood volume

• Predicts volume responsiveness

Michard et al, CHEST 2003; 124:1900 –1908



Li Dilution Cardiac Output • Technique

– Involves injecting small amount of Li into CVP and detecting dissappearance with special monitor on arterial line

• Reliabiltiy – As less invasive

– As good as PAC

• Drawbacks – Cumbersome

– Requires Li injectate

Crit Care Med 1997 25(11):1796-800

British Journal of Anaesthesia, 1993, Vol. 71, No. 2 262-266



Pulse Contour Cardiac Output

• Utilizes Standard Arterial Line

• Calculates Stroke Volume


Effect of vascular tone • The algorithm looks for characteristic

changes in the arterial pressure waveform that reflect changes in tone (i.e., MAP, Skewness, Kurtosis)


Trending Stroke Volume

• Blood pressure is sampled at 100 Hz

• Changes in stroke volume will result in corresponding changes in the pulse pressure

• Whole waveform measure of the pulse pressure is achieved by taking the standard deviation of the sampled points of each beat

• Std(BP) Pulse Pressure Stroke Volume

• SV estimates are averaged over 20 seconds

PP SV

SBP

DBP


Summary

• Most Reliable CO Monitor

– PA Catheter

– Pulse Contour

• Minimally Invasive

– LiCO

– Pulse Contour

• Non-Invasive

– Bioimpedance


Conclusion

• Optimal assessment of intra-vascular volume status requires quantitative measures of cardiac output

• PA catheters reliably provide this function

• Echocardiography is also reliable

• Less invasive technologies are evolving and appear promising

Documents

Hemodynamic Monitoring and Volume Management€¦ · Hemodynamic Monitoring and Volume Management ... 121:2000–2008 ... •Tousignant CP, Anesth Analg 2000;