Cardio pulmonary interactions during Mechanical Ventilation lecture presented by Dr Lluis blanch at the Egyptian Critical care Summit, the leading medical event in Egypt

1. Dr. Lluís Blanch
Senior Critical Care
Director of Research and Innovation
Corporació Sanitària Parc Taulí
Cairo, 12th of January 2015
Cardio Pulmonary
Interactions in the
Mechanically
Ventilated patients
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2. Consequences & Complications of
Mechanical Ventilation
• endotracheal intubation
• heart-lung interaction
• dynamic hyperinflation
• barotrauma
• ventilator induced lung injury
• difficult patient-ventilator interaction
• infections
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3. Primary Determinants of Oxygen Delivery
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4. Intrathoracic pressure is transmitted directly to
the heart.
All bedside intracardiac pressures measurement
represent the sum of:
intracardiac plus intrathoracic pressures
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5. Heart is surrounded by pericardium and the thorax:
Intracardiac pressure measurements therefore are
subject to influence of blood volume in the cardiac
chambers, the pericardial pressure, and the
intrathoracic pressure.
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6. Physiologic Principles
Intracardiac pressure (mmHg): Hemodynamic Monitoring
Intrapericardial pressure and intrathoracic are equal and
subatmospheric in healty patients (cmH2O)
P intracardiac – P intrathoracic = P transmural
or distending pressure: Preload
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7. P intracardiac – P intrathoracic = P transmural
RAP - ∆∆∆∆PPL (Pes) = RAP transmural
+5 - (-2) = + 7 mmHg
+5 - (+4) = + 1 mmHg
1 cmH2O = 0.74 mmHg
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8. Spontaneous breathing: activation of inspiratory muscles
decrease intrathoracic pressure!!
VR
RA LA
Cardiac filling
Paradoxic PRA, wedge and PAP
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9. End-expiration
Sharkey SW. Lippincott- Raven 1997
Influence of Laboured Respiration on
Wedge Pressure Waveform
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10. Effects of Mean Intrathoracic Pressure on
Systemic Vascular Return
Systemic venous return to the right atrium is passive
Cheifetz IM. Respir Care 2014;59:1937–1945
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11. Effects of preload augmentation on
systemic vascular return
Intravascular fluid administration shifts the systemic
venous return line upward and rightward.
Cheifetz IM. Respir Care 2014;59:1937–1945
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12. MECHANICAL VENTILATION (MV)
AFTERLOAD
INSPIRATION
right V
afterload
left V
afterload
Compression of
yuxta-alveolar
vessels
Thoracic-
extrathoracic
aorta pressure
gradient
HYPERINFLATION:
asthma, emphysema
high PEEP
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13. Effects of Intrathoracic Pressure on Left Ventricular
Afterload
An augmentation of mean intrathoracic pressure will
reduce left ventricular afterload
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14. Alveolar vessel: surrounded by alveolar pressure
Extraalveolar vessel: surrounded by interstitial
pressure (= intrathoracic pressure)
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15. AcidosisAcidosis
Intracellular Corrected in Hours
Renal Compensation 1 – 2 days
PulmonaryPulmonary
Vasoconstriction & Increase in PVR
- Aggravates PHT & Potentiates HPV
Increase Intrapulmonary Shunt
Laffey JG & Kavanagh BP. Permissive Hypercapnia. In Tobin MJ.
Principles & Practice of Mechanical Ventilation. 2006 & 2013.
CardiovascularCardiovascular
Systemic Vasodilation
- Endogenous Catecholamine Production
Increase in Cardiac Output
CellularCellular &&
MolecularMolecular
Attenuation of Inflammatory Response
- Inhibit Release of TNF-ά, IL-1 & IL-8 in Macrophages
- Neutrophil Activation
- Free Radical Generation & Activity
- Regulates Gene Expression: inhibits endotoxin-
induced NF-kB activation
PhysiologicPhysiologic EffectsEffects ofof HypercapniaHypercapnia
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16. Crit Care Med 2001;29:1551-5
Individual Predictors of Acute Cor Pulmonale in ARDS
n = 75
Mortality 32 % 32 % NS
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17. N Engl J Med 2013;368:806-13.
N Engl J Med 2013;368:795-805.
Why?: deleterious effects of heavy sedation and NBA,
hemodynamic compromise due to adverse effects of
high mean airway pressure on the right ventricle, or
increased VALI among HFOV non-responders.
Durbin CG, Blanch L, Fan E, Hess D. Respir Care 2014
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18. Ppeak & Pplat
Overdistension
Air Trapping
Adverse Physiologic Effects of IRV
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19. Chest 1993;104:871-5
*
**
*
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20. Pulse Pressure Variation and Frank-Starling Curve
Teboul JL, Monnet X. Minerva Anesthesiol 2013;79:398-407
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21. Arterial Pressure in a MV Patient
PPV(%)=PPmax-PPmin/[(PPmax+PPmin/2)]x100
Teboul JL, Monnet X. Minerva Anesthesiol 2013;79:398-407
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22. Analysis of ∆Pp is a simple method for predicting and assessing the
hemodynamic effects of volume expansion and is a more reliable
indicator of fluid responsiveness
Am J Respir Crit Care Med. 2000 Jul;162(1):134-8.
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23. PPV in ARDS & Low VT
PPV marker of preload responsiveness.
PPV > 10-12% still good predictive value.
PPV < 10% false negatives may occurs and
passive leg raising (PPV↓) or end-expiratory
occlusions (PP↑) are needed.
Limits: SB, arrhythmias, low lung
compliance, right ventricle dysfunction.
Teboul JL, Monnet X. Minerva Anesthesiol 2013;79:398-407
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24. Heart Lung Interactions duringHeart Lung Interactions during
Mechanical VentilationMechanical Ventilation
•• Positive pressure ventilation causes:Positive pressure ventilation causes:
–– increase in ITP pressureincrease in ITP pressure
–– increase in lung volumeincrease in lung volume
•• Increase in ITP & lung volume affect:Increase in ITP & lung volume affect:
–– heart rateheart rate
–– venous returnvenous return
–– RV & LV filling andRV & LV filling and afterloadafterload
•• Reduced cardiac output by:Reduced cardiac output by:
–– increase PVRincrease PVR
–– reduced preloadreduced preload
–– ventricular interdependenceventricular interdependence
–– changes in contractilitychanges in contractility
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25. D
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26. Pepe PE, Marini JJ. Am Rev Respir Dis 1982;126:168.
Effect of Discontinuation of MV in a PatientEffect of Discontinuation of MV in a Patient
with Severe Airflow Obstructionwith Severe Airflow Obstruction
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27. Apnea during Severe Asthma
Relative Lung Volume by Inductive Plethysmography
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28. PEEP & AutoPEEP in COPD Patients
Blanch L, Fernandez R. In: Mancebo J, Brochard L, eds. Arnette 1996; 329-345.
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29. PEEP-Induced Changes
in Lung Volume &
Cardiac Index in COPD
Patients
Changes occur only
when external PEEP is
higher than the critical
pressure value:
85% of autoPEEP
Ranieri et al
ARRD 1993;147:5-13
Baigorri F et al.
Crit Care Med 1994;22:1782-91
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30. Tobin M & Jubran A. PPMV 2013
Weaning Failure Patient
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31. Jubran A et al. Am J Respir Crit Care Med 1998; 158:1763.
Pathophysiologic Factors for Respiratory
Distress during a Weaning Trial
Tissue oxygenation: TO2 EO2
Elevations in right & left
ventricular afterload
n=11
n=8
↑SAP
↑PCWP
↓CI
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32. Lemaire F, Teboul JL, et al. Anesthesiology 1988; 69:171.
Pathophysiologic Factors for Respiratory
Distress during a Weaning Trial
Heart & lung interaction: acute LV dysfunction
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33. CPAP vs O2
IOT < 60%
NIV in ACPE
Masip J JAMA 2005;294:3124-30
Need to Intubate
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34. CPAP vs O2
Mortality < 47%
NIV in ACPE
Masip J JAMA 2005;294:3124-30
Mortality
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35. Cardio Pulmonary Interactions in
Mechanically Ventilated Patients
1. Heart and lungs are connected anatomically and
physiologically in a complex relationship
2. Oxygen delivery to all organs and tissues of the body
must be optimized
3. Clinicians should titrate the Paw to optimize the
balance between mean lung volume (arterial oxygenation)
and ventricular function (cardiac output)
4. Clinicians should minimize PVR and routinely monitor
cardiorespiratory parameters closely.
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