1. Critical Care in the Cardiac Patient
Mark Joseph, MD
Carilion Cardiothoracic Surgery

2. Objectives
Identify indications for invasive hemodynamic monitoring in the critically ill cardiac patient
Describe key heart failure risk factors
Illustrate the rationale for mechanical circulatory support for the hemodynamically compromised critical care patient

3. What is Critical Care in the Cardiac Patient?

4. The Heart Center of the being
Directly and Indirectly Controls the input and output of every organ in the body
Ancient books/scriptures describe the “heart” as the part of the body that “controls” the being
Reports of patient post cardiac transplant having the same urges as their donors
Let me start by saying that the heart is not just a big muscle pumping blood
There appears to be some form of memory within cardiac cells that “controls” even the brain

6. A happy heart = happy organs (patient)
Taking care of a cardiac patient by default means taking care of every system that is associated to the heart
The entire patient
A happy heart = happy organs (patient)
So what does critical care in the cardiac patient mean?
Isn’t that the same for every ICU patient—not necessarily –other damaged organs can cause other organs to fail but not necessarily cause complete shutdown of the body.

7. Challenges in Cardiac Patients
Heart Failure
MI/Injury
Pulmonary Hypertension
Immune Disorders
Diastolic Dysfunction
Coronary Disease
Valvular Disease
HOCM
Renal Failure
Nutrition
Immune disorder—chronic steroids/RA

8. Heart failure patient

9. Invasive Monitoring What types of invasive monitoring Who needs it
Non invasive monitoring
Does it really exist?
What do we need to take care of patient with cardiac issues

10. Types of hemodynamic monitoring

11. Swan Ganz catheter
Pulse Contour Analysis
Bioimpendance
Applied Fick
Echocardiography

12. Obituary: pulmonary artery catheter 1970 to 2013
“The birth of the conventional pulmonary artery catheter (fondly nicknamed PAC) was proudly announced in the New England Journal of Medicine in 1970 by his parents HJ Swan and William Ganz. PAC grew rapidly, reaching manhood in 1986 where, in the US, he was shown to influence the management of over 40% of all ICU patients. His reputation, however, was tarnished in 1996 when reports suggested that he harmed patients. This was followed by randomized controlled trials demonstrating he was of little use. Furthermore, reports surfaced suggesting that he was unreliable and inaccurate. It also became clear that he was poorly understood and misinterpreted. Pretty soon after that, a posse of rivals (bedside echocardiography, pulse contour technology) moved into the neighborhood and claimed they could assess cardiac output more easily, less invasively and no less reliably. To make matter worse, dynamic assessment of fluid responsiveness (pulse pressure variation, stroke volume variation and leg raising) made a mockery of his ‘wedge’ pressure. While a handful of die-hard followers continued to promote his mission, the last few years of his existence were spent as a castaway until his death in His cousin (the continuous cardiac output PAC) continues to eke a living mostly in cardiac surgery patients who need central access anyway.”

13. Reasons for declining use of PAC
Increased risk of mortality (24%) with use of right heart catheterization using PAC
Connors et al. JAMA. 1996 Sep 18;276(11).
Thermodilution data provided may not be accurate
Phillips et al. Crit Care Res Pract. 2012
Clinicians didn’t know how to interpret data and large interobserver variability
Ilberti et al. JAMA. 1990 Dec 12;264(22).
ESCAPE trial
JAMA, October 5, 2005—Vol 294, No. 13
propensity matching, this study demonstrated a 24% increased risk of death in ICU patients who received a PAC within 24 hours of admission to an ICU.
Thermodilution CO with surgically implanted ultrasonic flow probes in an ovine model showing . The percentage bias and precision was −17% and 47% respectively; the PAC under-measured dobutamine induced CO changes by 20% (relative 66%) compared with the flow probe
496 physicians practicing in 13 medical facilities in the United States and Canada to assess their knowledge and understanding of the use of the pulmonary artery catheter and interpretation of data derived from it. The mean test score was 20.7 (67% correct), with an SD of 5.4 and a range of 6 to 31 (19% to 100%). Mean scores varied independently by training, frequency of use of pulmonary artery catheter data in patient treatment, frequency of inserting a pulmonary artery catheter, and whether the respondent's hospital was a primary medical school affiliate and large interobserver variability in terms of how to interpret data

15. Movement across all ICUs away from invasive monitoring
“Not helpful so we shouldn’t use it”
Alternatives
Unfortunately most ICUs/clinicians have taken a “minimalist” approach
Cite studies here.
Study of Cochran showing that increased mortality in patients with swans
Clinicians didn’t know how to interpret data
ESCAPE trial
Typical “ICU” patient now usually means----No aline/central line. On pressors through peripheral iv, intubated no foley

17. Swan Ganz Catheter PAC “Gold standard” operator dependent
Tricuspid/mitral valve insufficiency, shunt or misplacement may influence reliable cardiac output assessment
Some overcome by CCO PAC

18. Minimally invasive Pulse contour analysis, pulsed Doppler technology,
Calibrated
uncalibrated
pulsed Doppler technology,
applied Fick principle,
bioimpedance/bioreactance.

19. Minimally Invasive Pulse contour
based on the principle that SV can be continuously estimated by analyzing the arterial pressure waveform.
severe arrhythmias may reduce the accuracy of cardiac output measurement, and that the use of an intra-aortic balloon pump precludes adequate performance of the device.
Pulse pressure analysis is based on the principle that SV can be continuously estimated by analyzing the arterial pressure waveform obtained from an arterial line. The characteristics of the arterial pressure waveform are affected by the interaction between SV and individual vascular compliance, aortic impedance and peripheral arterial resistance. For reliable cardiac output measure- ment using all devices that employ pulse pressure analysis technology, optimal arterial waveform signal (i.e., eliminating damping or increased tubing resonance) is a prerequisite. Moreover, it cannot be overemphasized that severe arrhythmias may reduce the accuracy of cardiac output measurement, and that the use of an intra-aortic balloon pump precludes adequate performance of the device.

20. “Non-invasive” monitoring
Pulse contour
Pro/cons
All “noninvasive” hemodynamic monitoring devices are compared to “Gold Standard”
How good is something when compared to something not so good?

21. Applied Fick Principle
Partial CO2 rebreathing
Intubation/vented pts.
Assume CO unchanged between normal/rebreathing states
Stable pt. with no pulmonary shunt
Partial CO2 rebreathing: The e NICOTM system (Novametrix
Medical Systems, Wallingford, USA) applies Fick
principle to carbon dioxide (CO2) in order to obtain
cardiac output measurement in intubated, sedated, and
mechanically ventilated patients using a proprietary
disposable re-breathing loop that is attached to the ventilator
circuit. THz e NICOTM system consists of a mainstream
infrared sensor to measure CO2, a disposable
airflow sensor, and a pulse oximeter. CO2 production is
calculated as the product of CO2 concentration and
airflow during a breathing cycle, whereas arterial CO2
content is derived from end-tidal CO2 and its corresponding
dissociation curve. Every three minutes, a partial
re-breathing state is generated using the attached rebreathing
loop, which results in an increased end-tidal
CO2 and reduced CO2 elimination. Assuming that cardiac
output does not change signifi cantly between normal and
re-breathing states, the diff erence between normal and
re-breathing ratios are used to calculate cardiac output
Variations in ventilator settings, mechanically assisted
spontaneous breathing, the presence of increased
pulmonary shunt fraction, and hemodynamic instability
have been associated with decreased accuracy

22. Minimally/Non-invasive Monitoring
Echocardiography
Non invasive
Readily available
Contractility
TAPSE
Volume Status
E/e’
Can be helpful for both systolic and diastolic HF. RV function can be reliably shown via TAPSE and LV filling pressures can be estimated using ratio of mitral flow velocity over mitral annular tissue velocity.

23. Echocardiography Cons Not real time
Studies show unreliability of E/e’ in patients on inotropic support/exercise/decompensated HF/ischemia
Tachycardia
MR or MVR
Annular calcification
MS/AI
Downside is that these measurements don’t always correlate in decompensated heart failure.
Tachycardia with fusion of E and A velocities Unreliable measurement of E velocity - Significant mitral regurgitation (>2+) Unreliable measurement of e’ velocity - Mitral valve repair or replacement - Severe mitral annular calcification - Significant mitral stenosis - Presence of left bundle branch block Significant aortic regurgitation (>2+)

24. Bioimpendence
Electrical bioimpedance uses electric current stimulation for identification of thoracic or body impedance variations induced by cyclic changes in blood flow caused by the heart beating.
Cardiac output is continuously estimated using skin electrodes or electrodes mounted on an endotracheal tube
Mathematical algorithms/modeling to measure CO.
Conflicting results—may be promising based on modifications.
Electrical bioimpedance uses electric current stimulation
for identifi cation of thoracic or body impedance variations
induced by cyclic changes in blood fl ow caused by
the heart beating. Cardiac output is continuously estimated
using skin electrodes (BioZ®, CardioDynamics,
San Diego, USA) or electrodes mounted on an endotracheal
tube (ECOMTM, Conmed Corp, Utica, USA) by
analyzing the occurring signal variation with diff erent
mathematical models. Despite many adjustments of the
mathematical algorithms, clinical validation studies
continue to show confl icting results [30,31].
Recently, however, Bioreactance® (NICOM®, Cheetah
Medical Ltd, Maidenhead, Berkshire, UK) a modifi cation
of thoracic bioimpedance, has been introduced [32]. In
contrast to bioimpedance, which is based on the analysis
of transthoracic voltage amplitude changes in response to
high frequency current, the Bioreactance® technique
analyzes the frequency spectra variations of the delivered
oscillating current. Th is approach is supposed to result in
a higher signal-to-noise ratio and thus in an improved
performance of the device. In fact, initial validation
studies reveal promising results
which is based on the analysis
high frequency current

25. Integrative Model

26. What can we use? Look at all the variables
Sv02, urine output, acidosis (lactate)
If 2 out of 3 are abnormal likely to be issue with cardiac output
CO/CI, Filling pressures (PAD, CVP), SVR/SVRI
PA pressures, oxygenation
Echocardiography
How do we use what we have?
Depends on availability, patient status and
Echocardiography should be used as an adjunctive tool to support/isolate diagnosis

27. Integrative Model Physical Exam Hypoperfused state Cool extremities
Low urine output
Increasing CR
Confusion
Nausea/Vomiting
Peripheral edema
Ascites
SOB

28. Integrative Model Labs Increasing BUN/CR ratio LFT
Coagulation abnormalities
BNP
Hyponatremia
Acidosis

29. Which patients need this type of monitoring?
Current guidelines suggest selective use
Cardiogenic shock
Acute on chronic heart failure
Transplant/VAD patients
Escalating Inotropic support
Post procedure/MI with heart failure
At risk for RV/LV failure

30. Key Factors Heart Failure
Pulmonary Hypertension
COPD
OSA
Morbid Obesity
Congenital Cardiac
Valvular abnormalities
History of RF
Endocarditis
History of heart failure

31. Advances in Cardiac ICUs
Improved understanding of blood utilization
Use of hypothermia in decreasing metabolic demand
Treatment strategies for heart failure
Rematch Trial

32. Mechanical Circulatory Support
Rationale
Indications
Contraindications
Timing
Devices

33. Rationale Based on concept of reversibility Minimize collateral damage
Body/organ can recover minimal to moderate damage as long as it is allowed to recover and has reserve

34. Indications Cardiac- post heart TX, cardiac stun, Cardiac Failure
Massive PE, reperfusion lung injury
Severe Sepsis with Shock
Cardiac arrest

35. Mechanical Circulatory Support
Respiratory Failure
Heart Failure
Critically ill patient
Failed Maximal Medical or Ventilatory Strategies
MCS

36. Types of Mechanical Circulatory Support
IABP
VAD
ECMO
Artificial Heart
MCS

37. E E C C L M S O xtra orporeal embrane xygenation xtra orporeal ife
upport

38. What is ECMO? First from 1971 Oxygenation outside the body
Support heart and/or lung function
Similar to bypass used in the operating room but can be used for longer periods of time

39. How does ECMO Work?
Artificial pump used to pump blood out of the body; oxygen is added to the blood and carbon dioxide is removed before it is returned to the patient.
As the patient improves, we may decrease the work of artificial pump and let their heart and lungs do more of the work.

40. Physiologic goal Improve tissue oxygen delivery Remove CO2
Allow normal aerobic metabolism
Allow heart and/or lung rest

43. Traditional VA Cutdown Access

44. Percutaneous

47. First Successful Adult ECMO patient, 1971
First successful extracorporeal life support patient, treated by J. Donald Hill using the Bramson oxygenator, Santa Barbara, 1971.

48. Contraindications No likelihood of organ recovery
Irreversible organ damage
Disseminated malignancy
Severe brain injury
Unwitnessed cardiac arrest
Aortic dissection/aortic regurgitation

49. VAD (Ventricular Assist Devices)

50. REMATCH Trial
Figure 2. Kaplan–Meier Analysis of Survival in the Group That Received Left Ventricular (LV) Assist Devices and the Group That Received Optimal Medical Therapy.
Crosses depict censored patients. Enrollment in the trial was terminated after 92 patients had died; 95 deaths had occurred by the time of the final analysis.
N Engl J Med Nov15;345(20):

51. Outcomes in Advanced Heart Failure Patients With Left Ventricular Assist Devices for Destination Therapy
Inference of the survival benefit of current destination therapy with current continuous-flow left ventricular assist device (LVAD) compared with medical management from the REMATCH trial. HMII indicates HeartMate II.
Soon J. Park et al. Circ Heart Fail. 2012;5:

52. Future Devices

54. Conclusion Cardiac patients most challenging ICU patients
Selective use of invasive hemodynamic monitoring should be employed for patients with identifiable risk factors for heart failure in a integrative model
As this patient population grows, treatment options improving