UPMC Critical Care

Transcription

1 UPMC Critical Care

2 Cardiovascular insufficiency with Initiation and Withdrawal of Mechanical Ventilation Michael R. Pinsky, MD, Dr hc Department of Critical Care Medicine University of Pittsburgh

3 Ventilation and Cardiovascular Stress Spontaneous Ventilation is Exercise Spontaneous Ventilation Increases Preload and LV Afterload Positive-Pressure Ventilation Decreases Preload and LV Afterload

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5 Breathing as Exercise Nasal CPAP treatment improved gut blood flow in CHF patients Baratz et al. Chest 102: , 1992 Gastric mucosal ph predicts weaning success Mohsenifar et al. Ann Intern Med 119:794-8, 1993 Both upper airway and endotracheal tubes contribute to breathing workload Straus et a. Am J Respir Crit Care Med 157:23-30, 1998 Increase a-v O 2 gradients in COPD weaning failures Jubran et al. Am J Respir Crit Care Med. 158:1763-9, 1998 Increased gastric PCO 2 during exercise indicates gastric ischemia Kolkman et al. Gut 44:163-7, 1999 Gastric mucosal ph and pco 2 change during exercise Hurtado et al. Crit Care Med 29:70-6, 2001 Exercise induces gastric ischemia in health volunteers Otte et al. J Appl Physiol 91:866-71, 2001

6 Gastric mucosal ph predicts success in weaning 7.5 * ** Success Failure 6.9 Initial Final * P < 0.01 success to failure ** p < 0.01 initial to final Mohsenifar et al. Ann Intern Med 119:794-8, 1993

7 Evidence of cardiovascular failure in patients with COPD who fail weaning Weaning Successes Weaning Failures Jubran et al. Am J Respir Crit Care Med. 158:1763-9, 1998

8 Breathing is Exercise Potentially, the reason why all mechanical weaning parameters are so poor at predicting weaning success is that they do not include cardiovascular reserve in their determination. Pinsky. Intensive Care Med 26:

9 Exercise Limitation is a Big Fish

10 Weaning is a Cardiac Stress Test Acute LV dysfunction during unsuccessful weaning from MV in COPD patients Lemaire et al. Anesthesiology 69: , 1988 Thallium-201 myocardial perfusion impaired during weaning from MV in ventilator-dependent patients Hurford et al. Anesthesiology 74: , 1991 LV dysfunction during weaning in COPD patients Richard et al. Intensive Care Med 20:171-2, 1994 Association of myocardial ischemia with failure to wean Hurford et al. Crit Care Med 23: , 1995 Cardiac ischemia during weaning from MV Chatila et al. Chest 109:1421-2, 1995 Increase a-v O 2 gradients in COPD weaning failures Jubran et al. Am J Respir Crit Care Med. 158:1763-9, 1998 Cardiac ischemia during weaning from MV Srivastava et al. Crit Care Med 27: , 1999

11 Lemaire et al. Anesthesiology 69: , 1988 Effects of Spontaneous Ventilation on LV Filling Baseline Ppao 5 min SV 9 min SV Ppao Ppao Peso Peso Peso Peso Ppao

12 Liberation from Mechanical Ventilation

13 Hemodynamic Effects of Ventilation Changes in Lung Volume Changes in Intrathoracic Pressure

14 Lung Volume and Pulmonary Vascular Resistance Pulmonary Vascular Resistance can be altered by ventilation through changes in: P A O 2 and Blood ph (Hypoxic pulmonary vasoconstriction) Marshall & Marshall J Appl Physiol 49:189-96, 1980 Lung volume (Mechanical vascular compression) Whittenberger et al. J Appl Physiol 15:878-82, 1960 Autonomic Tone Glick et at. J Clin Invest 48:467-72, 1969

15 Effects of Lung Volume on Pulmonary Vascular Resistance Differential Effects on Alveolar and Extra-Alveolar Vessels Extra-Alveolar Vessels sense interstitial or pleural pressure (P pl ) as outside pressure Alveolar Vessels sense alveolar pressure (P alv ) as outside pressure P alv - P pl = transpulmonary pressure Howell et al. J Appl Physiol 16:71-76, 1961

16 Lung Volume and PVR Pulmonary Vascular Resistance Total Alveolar Extra- Alveolar RV FRC TLC Lung Volume Howell et al. J Appl Physiol 16:71-76, 1961

17 Effect of PEEP on Pulmonary Pulmonary Vascular Resistance (dyn cm sec -5 ) Vascular Resistance ZEEP ALI Control Canada et al. Crit Care Med 10:719-23, 1982 Control ALI

18 PEEP and Cardiac Output PEEP decreases cardiac output by decreasing LV preload Jardin et al. N Engl J Med 304:387-92, 1981 Minimal effects at < 5 cm H 2 0 PEEP Pinsky, Vincent, DeSmet. Am Rev Respir Dis 143:25-31, 1991 Mitigated by Volume Loading or Heart Failure Calvin et al. Am Rev Respir Dis 124:121-8, 1981 Grace & Greenbaum Crit Care Med 10:358-60, 1982

19 Hyperinflation is Common Induced by increased respiratory rate, larger tidal volume or inadequate expiratory time Bergman Anesthesiology 37:626-33, 1969 Hyperinflation can induce acute RV failure (acute cor pulmonale) Conway. Br J Anaesth 47:761-6, 1975 Marked over-ventilation induces an auto PEEP effect compromising blood flow Pepe & Marini. Am Rev Respir Dis 126:166-70, 1982

20 Occult PEEP and Cardiovascular Compromise Pepe & Marini. Am Rev Respir Dis 126:165-70, 1982

21 PEEP Decreases Bi-ventricular Volumes Expiration Inspiration ZEEP 10 PEEP

22 Hemodynamic Effects of Ventilation Changes in Lung Volume Changes in Intrathoracic Pressure

23 Hemodynamic Effects of Changes in Intrathoracic Pressure Venous Return Thorax LV Ejection

24 Simultaneous Determinants of Cardiac Output and Venous Return 6 Blood Flow (l/min) Equilibrium Point LV Function Curve Venous Return Curve Right Atrial Pressure (mm Hg)

25 Spontaneous Ventilation Positive-Pressure Ventilation SVrv (ml/kg) Time (sec) Pra tm (mm Hg) Ppl (mm Hg) CVP (mm Hg) Pinsky. J Appl Physiol 56: , 1984

26 Effect of Decreases in Intrathoracic Pressure on LV Performance and Venous Return 6 Blood Flow (l/min) B A Decreased ITP Thoracic Pump No change in LV Function Right Atrial Pressure (mm Hg)

27 Effect of spontaneous efforts on venous return SVrv P pl Normal spontaneous inspiration P Ao P LAtm Occluded inspiration P PAtm P RAtm Paw Pinsky J Appl Physiol 56:765-71, 1984 P RA

28 Loaded Spontaneous Inspiration Increases Venous Return Heart failure increases depth of ventilation Fisher et al. Circulation 62:59, 1980 Loaded inspiration causes pulmonary edema Fletcher et al. Am J Respir Crit Care Med 160: , 1999 Inspiratory impedance during CPR increases CBF Lurie et al. Circulation 105:124-9, 2002 Some researchers are now recommending resistive loaded breathing for trauma patients who can not be initially resuscitated to augment cardiac output! Langhelle et al. Resuscitation 52: 39-48, 2002 Negative expiratory pressure ventilation improves cardiac output and short term survival during porcine hemorrhagic shock Krismer et al. Crit Care Med 34: , 2006

29 Blood Flow (l/min) Effect of Increases in Intrathoracic Pressure on LV Performance A Increased ITP B C No change in LV Function Volume Infusion Right Atrial Pressure (mm Hg) Guyton et al. Am J Physiol 189:609-15, 1957 Pinsky. J Appl Physiol 56: , 1984

30 Effect of Positive-Pressure Ventilation on LV Volumes and Pressure ECG (mv) Intact Anesthetized Human Pa (mm Hg) Ppa (mm Hg) Pra (mm Hg) LV Area (cm? 4 2 Paw (cm H 2 O) Time (seconds) Denault et al. Chest 1999; 116:176-86

31 Effect of Tidal Volume on the Dynamic Intrathoraic Blood Volume Shifts Inspiration Expiration SV RV SV LV (ml) Vt 25mL/kg Vt 15mL/kg Vt 10mL/kg Vt 5mL/kg Heart beat Mesquida et al. Intensive Care Med 37: ,

32 Transmural Pressure is the Amount Above the Surface Do you care how tall the kids are? Or how far above the water s surface their heads end up? Height: 1.4m 1.7m 1.2m Height: 0.21m 0.24m 0.21m above water

33 Effects of changes in ITP on LV ejection Decreases in ITP increase LV ejection pressure increasing LV AFTERLOAD Buda, Pinsky et al. N Engl J Med 301:453-9, 1979 Increases in ITP decrease LV ejection pressure decreasing LV AFTERLOAD Pinsky et al. J Appl Physiol 54:950-5, 1983

34 Decreases in ITP increase LV Afterload Buda, Pinsky et al. N Engl J Med 301:453-9, 1979

35 Decreases in ITP Increase LV Afterload Buda, Pinsky et al. N Engl J Med 301:453-9, 1979

36 Negative Swings in ITP Produce Pulmonary Edema Status Asthmaticus Stalcup and Mellins. N Engl J Med 297: , 1977 Upper Airway Obstruction Kanter and Watchko. Am J Dis Child 138: , 1984 Pulmonary Edema Luke et al. Pediatrics 37: , 1966 Oswalt et al. JAMA 238: Miro et al Chest 96: , 1989

37 Increases in Intrathoracic Pressure Decrease LV Afterload and Increases Cardiac Output Acute heart failure induced by β-blockage in dogs Pinsky et al. J Appl Physiol 54:950-5, 1983 Pinsky et al. J Appl Physiol 58: , 1985 In human CHF cardiomypaths Pinsky & Summer. Chest 84:370-5, 1983 Cardiac cycle-specific increases in ITP in acute heart failure dogs Pinsky et al. J Appl Physiol 60:604-12, 1986 Prevents the fall in CO in hypovolemia Matuschak et al. J Appl Physiol 61:44-53, 1986 In acute mitral regurgitation in dogs Stein et al. J Appl Physiol 69:2120-5, 1990

38 Effect of Increased Intrathoracic Pressure on LV Performance Blood Flow (l/min) Acute Ventricular Failure Increased ITP B A Improved LV Performance Right Atrial Pressure (mm Hg)

39 Asynchronous High Frequency Jet Ventilation in Acute Ventricular Failure SVrv SVlv PAo Pla tm Ppa tm Pra tm Paw Ppl Pinsky et al. J Appl Physiol 58: , 1985

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41 Application: Any relative increase in intrathoracic pressure decreases LV afterload Abolishing negative swings in ITP will decrease LV afterload

42 Noninvasive CPAP and BiPAP Decrease Cardiac Stress CPAP decreases ischemia in acute cardiogenic pulm edema (ACPE) Rasanen et al. Am J Cardiol 55: , 1985 CPAP benefits seen only if negative ITP swings abolished in ACPE Rasanen et al. Chest 87:158-62, 1985 Mask CPAP prevents need for intubation in ACPE Bersten et al. N Engl J Med 325: , 1991 Both mask BiPAP and PSV improve gas exchange and prevents the need for intubation in ACPE Massip et al. Lancet 356: , 2000 Giacomini et al. Chest 123: , 2003 Nava et al. Am J Respir Crit Care Med 168:1432-7, 2003 Ferrer et al. Am J Respir Crit Care Med 168: , 2003 CPAP and BiPAP have similar survival benefit in ACPE Park et al. Crit Care Med 32: , 2005 Mask BiPAP improves LV function in OSA patients Kaneko et al. N Engl J Med 348: , 2003

43 Summary As the work of breathing increases or cardiovascular reserve decreases spontaneous ventilation may impose an excessive metabolic demand on the heart inducing shock Failure to wean from mechanical ventilation often reflects cardiovascular insufficiency Spontaneous inspiration cyclically increases intrathoracic blood volume (ITBV) Positive airway pressure by reversing negative swings in ITP decreases LV afterload

44 Thank You