Non-Invasive Hemodynamic Monitoring: Does it Have a Role in ...
Transcript of Non-Invasive Hemodynamic Monitoring: Does it Have a Role in ...
Non-Invasive Hemodynamic Monitoring:
Does it Have a Role in Shock Management?
Phillip D. Levy, MD, MPH
Asst. Professor of Emergency MedicineWayne State University/Detroit Receiving Hospital
Disclosures
• Consultant– ElectroSonics Medical, Inc
• Honorarium– SonoSite, Inc
• Research support (equipment only)– Cardiodynamics, Inc.
All material in this lecture has been prepared withoutexternal input or review and is free from bias
Learning Objectives
• To appreciate the importance of hemodynamics in shock
• To understand the shift away from invasive monitoring
• To recognize existing and emerging non-invasive modalities
Case Example
• 38 yo white female with history of IVDA presents to the ED with dyspnea– No chest pain or fever reported
• Initial vitals:HR 100; BP 90/50; RR 18; Temp 40.4 º C
• Lung exam: coarse breath sounds without wheezing, rales or rhonchi
• Cardiac auscultation: non-radiating II/VI DM
Case Example
• Initial differential– Endocarditis
– Sepsis
– Pneumonia (possible pneumocystis carini)
• Work-up initiated– CXR (-)
– Labs essentially nl
– Blood cultures obtained
Do I Really Need to Know Hemodynamics ?
Tissue Oxygen Delivery
• Oxygen content– CaO2 = (1.34 x Hgb x SaO2) + (0.0031 x PaO2)
• Perfusion– CO = HR x SV
– MAP = (CO x SVR) + CVP
– MAP = DBP + [SBP - DBP]/3
From: Schwaitzberg et al. J Pediatr Surg 1988;23;:05-9.
r=0.27, r2=0.07 r=-0.1, r2=0.0001
Can You Predict Perfusion Based on HR and MAP ?
From: Wo et al. Crit Care Med 1993;21:218-23.
But Perfusion is What Matters !
Hemodynamics of Perfusion
Afterload
Cardiac Output(CO)
HeartRate(HR)
StrokeVolume(SV)
Preload Contractility
(-) Diuretics(+) Volume Expanders
(-) Vasodilators(+) Vasoconstrictors
(-) Negative Inotropes(+) Positive Inotropes
(-) Neg.Chronotropes(+) Pos.Chronotropes
Invasive Hemodynamic Monitoring
• Pulmonary artery catheterization (PAC) 1,2
– Time honored mechanism
– Provides accurate information
– Questionable safety and benefits
• May not be ideal (or possible) in ED setting!
1 Swan et al. NEJM 1970;283:447-51.2 Silver et al. CHF 2004;10:17-21.
ESCAPE Trial 1,2
• Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness– Comparison of clinical assessment vs. PAC for severe ADHF
– At 6-month follow-up • No difference is primary endpoint (days alive)
• Slight improvement in secondary endpoints
– Stopped early by safety board !!
1 Shah et al. Am Heart J 2001;141:528-35.2 The ESCAPE Investigators and ESCAPE Study Coordinators* JAMA. 2005;294:1625-33.
ESCAPE – Adverse Events
The ESCAPE Investigators and ESCAPE Study Coordinators* JAMA. 2005;294:1625-33.
Is PAC Use Justified ?
Shah et al. JAMA 2005;294:1664-70.
Is PAC Use Justified ?
Shah et al. JAMA 2005;294:1664-70.
Non-Invasive Hemodynamic Monitoring Modalities
• Ultrasound – Cardiac output monitor (UsCoM)
– “Quick-look” echocardiography
– Central venous pressure estimation• Inferior vena cava
• Internal jugular vein
• Basilic vein
• Impedance cardiography (ICG)
• Esophageal doppler monitoring (EDM)
• Micro-impulse radar
Non-Invasive Measures of Oxygen Balance
• Pulse oximetry
• Near infrared spectroscopy (NIRS)
• Point of care lactate
• Gastric tonometry
• Sublingual capnography
• Orthogonal polymerized spectroscopy
Sublingual Testing
Healthy Volunteer Septic Shock
Orthogonal PolarizedSpectral Imaging
Ultrasound Cardiac Output Monitoring
• 10 parameters of cardiac function– Heart rate
– Cardiac output/index
– Stroke volume
– Systemic vascular resistance
Ultrasound Cardiac Output Monitoring
• Operator dependent– Requires considerable pressure
• Non-continuous monitoring
• Unreliable with pneumothorax
• No large correlation trials
• CE Mark but not yet FDA approved
USCOM
“Quick-Look”Echocardiography
Correlation with Cardiologist
Moore et al. Acad Emerg Med 2002;9:186-93.
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Correlation with Cardiologist
Moore et al. Acad Emerg Med 2002;9:186-93.
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
CVP Estimate: IVC
• Respiratory variance in IVC can be used to estimate CVP 1
IVC size Resp change RA pressure< 1.5 cm Total collapse 0-5 cm/H201.5-2.5 > 50 % collapse 5-101.5-2.5 < 50 % collapse 11-15>2.5 < 50 % collapse 16-20>2.5 No change > 20
1 Ma, OJ and Mateer JR. Emergency Ultrasound, p 111. 2003
Correlation with Cardiologist
Randazzo et al. Acad Emerg Med 2003;10:973-
7.
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
CVP Estimate: IJ
• Based on visualization of blood column within IJ
• Find point of collapse and measure to angle of Louis
• Add 5 cm H20 toyield CVP
Lipton B. Am J Emerg Med 2000;18:432-
4.
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
CVP Estimate: Basilic Vein
• Compression detectorattached to probe
• Measures external compression required to occlude vein
• Preliminary work
• Poor precision
Baumann et al. Resuscitation 2005;64:193-9.
Impedance Cardiography
• Emerging technology
• Utilizes variance in thoracic electrical impedance to estimate changes in blood volume– Impedance ↓ as fluid volume ↑
• Change in impedance over time used to calculate cardiovascular parameters
Aortic Blood Volume Changes Thoracic Impedance
Aorta Impedance Waveform Impedance Waveform (inverse)(inverse)
Determinants of Baseline and Dynamic Impedance
Base Impedance (ZBase Impedance (Z00))Thoracic blood and plasma volume
Muscle mass (cardiac and skeletal)
Lung tissue/air
Thoracic adipose tissue
Dynamic Impedance (Dynamic Impedance (∆∆∆∆∆∆∆∆Z)Z)Aortic blood volume and velocity
Aortic compliance
Pulmonary artery blood volume and compliance
Specific resistivity of blood
Strobeck et al. Congest Heart Fail. 2000;6:3-6.
ICG: Set-Up
• Low-amplitude signal transmitted across thorax– Filtered to remove respiratory variation
• ∆ impedance monitored – Variance represents ventricular ejection
ICG: Monitor Display
Comparison of ECG and ICG Waveforms
Osypka and Bernstein. AACN Clinical Issues. 1999;10:385-399.
ECGECG
dZdZ
dZdZ//dtdt
TimeTime
QQ = Ventricular = Ventricular depolarizationdepolarization
B = Opening aortic B = Opening aortic & pulmonic valves& pulmonic valves
C = Maximal slope C = Maximal slope dZ dZ
X = Closure aortic valveX = Closure aortic valve
Y = Closure of pulmonic Y = Closure of pulmonic valvevalve
O = Opening mitral O = Opening mitral
valve / rapid filling valve / rapid filling
of ventriclesof ventricles
ICG Measurements
• Cardiac function 1
– Stroke volume and cardiac index/output
• Afterload– Systemic vascular resistance
• Contractility 2,3
– Velocity index and systolic time ratio
• Fluid status 4
– Thoracic fluid content• Reciprocal of impedance 1 Albert et al. J Am Coll Cardiol 2003;41:211A.
2 Ranaei et al. J Card Fail 2002;8:S97.3 Parrott et al. CHF 2004;10:11-3.4 Peacock et al. CHF 2000;6:86-9.
Sample Status Report
Validation Studies
0.870.761.01
-0.240.19-0.43
0.840.890.80
ICG - FickTD - FickICG - TD
COYung et alPulm. HTN (39)
1.09-0.170.81ICG - TDCOVan de Water et al
Post CABG (53)
0.400.070.92ICG - TDCISageman et alPost CABG (20)
1.2-0.450.89ICG - TDCOZiegler et alMech vent.(52)
1.10.951.1
0.740.750.03
0.730.810.76
ICG - FickTD - FickICG - TD
CODrazner et al HF in cath lab(59)
1.380.080.89ICG - TDCOAlbert et alHF in ICU (33)
PrecisionBiasR valueComparisonParameterAuthorsPopulation (n)
Adapted from Yancy and Abraham . Congest Heart Fail. 2003;9:241-250.
Comparison of Cardiac Output Measurement Reproducibility
0.430.97ICG 3 vs. ICG 1
0.390.98ICG 3 vs. ICG 2
0.440.97ICG 2 vs. ICG 1
1.070.83TD 3 vs. TD 1
1.010.84TD 3 vs. TD 2
1.020.83TD 2 vs. TD 1
Stand. Dev.
(l/min)
Correlation
(R value)
Comparison
Van De Water JM, et al. Chest. 2003;123: 2028-33.
ICG Instead of PAC ?
• Reduction of PAC usage by 71% – 95% CI: 41.9 –91.6%
Silver et al. Congest Heart Fail. 2004;10(suppl 2):14-16.
Estimated Cost Savings Resulting from ICG Replacement
of PAC
Silver et al. Congest Heart Fail. 2004;10(suppl 2):14-16.
Esophageal Doppler 1,2
• First described in 1971
• Measures flow in descending aorta
1 DiCorte et al. Ann Thorac Surg. 2000;69(6):1782-6.2 Seoudi et al. J Trauma. 2003;55(4):720-5.
PreloadContractility (SV)AfterloadCardiac Output
Flow time 330-360 msecPeak Velocity 60-100 cm/secSVRI 800-1200 dynes/m2
CI 2.2-2.5 L/min/m2
Esophageal Doppler Monitoring
• Not tolerated by awake patients– Good for intubated patients in shock with elevated CVP
• Not continuous– Requires readjustment for each read
• Contraindicated with varices, caustic ingestion or perforated esophagus
MicroImpulse Radar
• Ultra-wide bandwidth (1-4 GHz)
• Short radar pulses (< 1 ns)– 2 MHz repetition rates
• Rapid digitization– Spatial accuracy ~ 5mm
• Non-ionizing– 50 mW RMS
• Enables non-contact monitoring– Developmental stages
Case Example
• After 2 hrs, pt deteriorates
• New vitals: HR 110; BP 70/40; RR 20; Temp 101 º F
• Lung exam remains unchanged
• Cardiac exam: increased rate
• Fluid resuscitation initiated– 1 L NS bolus
– Pt given vancomycin, tobramycin and cefepime
Simple Sepsis ?
Case Example
• ICG performed– CI = 1.8 L/min/m2
– SVR = 1600 dyne(s)(cm-5)
– TFC = 45 ohms
– LCWI = 2.4 kg(min)/m2
Case Example
• Dobutamine drip started at 10 mcg/kg/min
• Repeat BP at 15 min: 95/60
• ICG at 15 min– CI = 2.4 L/min/m2
– SVR = 1200 dyne(s)(cm-5)– TFC = 40 ohms– LCWI = 2.8 kg(min)/m2
Case Example
• Emergent echocardiogram obtained showing large vegetation on tricuspid valve
• Pt stabilized and transferred to ICU
Diagnosis = cardiogenic shock due to presumed
valvular insufficiency from endocarditits
Take Home Points
• Hemodynamic monitoring can impact patient care
• Non-invasive techniques are emerging and are likely to increase in importance
• The ED physician should be familiar with these tools to maximize outcomes