Update in Cardiac Anesthesia

1
Update in Cardiac Anesthesia

• Charles Smith, MD
• Professor of Anesthesia
• Director, Cardiothoracic Anesthesia
• MetroHealth Medical Center
• Case Western Reserve University School of
  Medicine
• Cleveland, Ohio

2
Objectives

• Review practice trends
• Discuss lessons learned from SCA annual meeting,
  Vancouver, June 2008
• Evaluate controversial issues

3
Aprotinin

• Cardiac surgery pts receive 10 RBCs
• Antifibrinolytics standard of care to ? trx
• Multiple RCTs aprotonin ? blood loss trx
• 2006 observational study Mangano
• Aprotinin AEs renal, cardiac neuro outcome.
• Labeling changed by manufacturer ongoing
  studies stopped abruptly

C. David Mazer. The Aprotinin Controversy
4
Aprotinin, contd

• Manufacturer released database
• 70,000 pts - ? AEs mortality
• BART study Blood conservation using
  Antifibrinolytics. Canadian multicenter RCT
• Amicar vs tranexamic acid vs aprotinin
• Terminated early after 2163 pts b/c ? mortality
  in aprotinin gp despite ? bleeding reop
• Subsequent studies aprotinin assoc w renal
  dysfunction, ? Cr ? mortality

C. David Mazer. The Aprotinin Controversy
5
Recombinant Factor VIIa

• Approved for hemophilia if bleeding inhibitors
  against replacement coag factors.
• First report of its use was in an Israeli soldier
  with uncontrollable bleeding in 1999
• Rationale will only induce coagulation in those
  sites where tissue factor (TF) is also present.
• Multiple case reports of success in uncontrolled
  hemorrhage after failure of standard therapy

Ian Black. Anesthesia on the frontlines. Lessons
from Iraq
6
Recombinant Factor VIIa

• Military in Iraq using FVIIa off label
• Massive trx protocol
• 1-2 doses FVIIa, 35-70 mcg/kg
• 11 FFP pRBC
• Level of evidence 2C (weak) b/c lack of studies
• AEs arterial thrombosis, MI, DVT, PE, CVA

Ian Black. Anesthesia on the frontlines. Lessons
from Iraq
7
Ascending Aorta Transverse Arch Surgery

• Neuroprotection strategy is key element for
  repair of ascending aorta transverse arch
• Techniques vary widely
• DHCA
• Selective brain perfusion
• Retrograde brain perfusion
• All geared towards preventing stroke
  neurocognitive dysfunction

David L. Reich. Brain protection during ascending
aortic and transverse aortic arch surgery.
8
Ascending Aorta Transverse Arch Surgery

• Many non-randomized reports of clinical cohorts-
  problems w institutional preferences, publication
  bias, and changes over time
• surgical technique, perfusion technology,
  anesthesia, monitors, prosthetic graft materials,
  ICU.
• Best method short periods of DHCA antegrade
  axillary artery perfusion

David L. Reich. Brain protection during ascending
aortic and transverse aortic arch surgery.
9
DHCA

• 30-40 min at 18 C generally safe in infants
  children
• Longer periods preferential damage to basal
  ganglia which controls tone movement
• Formation of free radicals dopamine release may
  be major cause of endothelial damage brain
  edema
• pH stat mgt delays onset of extracellular
  dopamine release by 15 min. May have improved
  brain metabolism outcome

William J. Greeley. Strategies to improve outcome
after DHCA
10
Monitoring the Brain

• Available monitors
• multichannel EEG
• evoked potentials
• TCD
• jugular bulb sat
• BIS
• cerebral oximetry

Hilary P. Grocott. Evidence based monitoring
during cardiac surgery.
11
BIS Cardiac

• Has changed practice of cardiac anesthesia
• Allows separation of hemodynamic from anesthetic
  goals
• Hemodynamic changes now treated w vasodilators,
  pressors, ß-blockers if adequate depth of
  anesthesia
• B-AWARE trial ? awareness w BIS
• B-UNAWARE trial 2 cases of awareness in BIS
  End Tidal preset alarm gp
• Conclusion BIS is noninvasive, inexpensive,
  unilateral EEG. Uses cardiac, elderly, TIVA,
  DHCA, detecting intraop catastrophic events

Hilary P. Grocott. Evidence based monitoring
during cardiac surgery.
12
Cerebral Oximetry

• Measures sat of cerebral tissue- pulse ox of the
  brain
• Based on relation between jugular bulb sat
  outcomes
• Severe desat assoc w worsened cognitive outcome
• Multiple anecdotal reports of early detection
  prompt correction of cerebral perfusion defects
  during CPB
• Stepwise mgt for low or asymmetric rSO2 on CPB
• normalize pCO2
• ? MAP
• ? FiO2
• ? Hct
• Additional mgt propofol infusion, hypothermia

Hilary P. Grocott. Evidence based monitoring
during cardiac surgery.
13
Is Propofol Based Anesthesia Good for You?

• Free radical scavenging
• Stabilizes lipid membranes
• Converts O2 N2 derived free radicals to lt toxic
  species
• Enhances antioxidant capacity during reperfusion
• Prevents arachidonic acid peroxidation
• Inhibits plasma membrane Ca channels
• Inhibits cytokine generation
• ? mitochondrial permeability transition lt
  oxidative stress.
• Several studies w clinical evidence of propofol
  cardioprotection (superior to volatiles)
• Dose/conc therapeutic window being evaluated

David M. Ansley. Propofol for myocardial
protection.
14
Dexmedetomidine?

• Prospective blinded RCT lorazepam vs dex in
  mechanically ventilated ICU pts
• N 106. Up to 120 hrs sedation
• Dex more days alive without delirium or coma
• Dex more time at targeted sedation level
• Conclusion Dex 1 intervention for preventing
  delirium in hospitalized patients

Pandharipande et al JAMA 20072982644. Siddiqi
et al The Cochrane Collaboration, 2008
15
Endovascular Repair of TAA AAA

• 4 FDA approved devices since original cases in
  1991
• ? cardiac, respiratory, renal complications
• ? surgery time, blood trx, LOS, mortality
• Patient selection anatomy of aneurysm proximal
  distal landing zones
• Complications related to stent deployment
  (perforation, rupture, dissection), structural
  failure of device endoleaks.

Michael Andritsos. Anesthesia and the
endovascular stenting patient
16
Endovascular Repair of TAA AAA

• Anesthesia- have evolved w improvements in
  surgical/radiological technique. Low incidence
  conversion to open repair
• Types local anesthesia sedation / regional /
  combined regional/GA or GA alone
• AAA- std ASA monitors, art line, 2 PIVs
  TAA- add CSF drain, IOTEE
• May need to ? BP during stent deployment
• SNP, NTG, adenosine, rapid pacing

Michael Andritsos. Anesthesia and the
endovascular stenting patient
17
Ultrasound Line Placement to LV Assessment
Beyond

• CVCs routinely inserted w std landmark techniques
  by experienced operators w low morbidity
• 1996 study anatomical variation of CA w respect
  to IJ
• 2001 study asymmetry between RIJ LIJ including
  several pts with v small RIJ (CSA lt0.4 cm2) or
  thrombus 2003 study US? failed placement rate
  complications
• Other studies US- ? first time success, ? time
  to insertion infections, ? number of CVC kits
  opened
• Conclusion US guidance beneficial to ? CVC
  complications
• Similar benefit as skin antisepsis, sterile
  gloves, gown drape to ? infection

Gregg Hartman. The use of ultrasound during
cardiac anesthesia
18
(No Transcript)
19
(No Transcript)
20
(No Transcript)
21
Ultrasound Line Placement

• Ultrasound guided internal jugular access now a
  recommended practice by Agency for Healthcare
  Research and Quality

Feller-Kopman Chest 2007132302
22
Ultrasound Line Placement to LV Assessment
Beyond

• TEE has changed cardiac anesthesia
• Baseline real time wall motion, end-diastolic
  volume, RV LV function, intracardiac air,
  diastolic function, valve anatomy function,
  intracardiac shunting, PE in transit, great
  vessel anatomy.
• Better than Swan for response to therapy
• Guides line placement cannula wires in SVC/RA.
  IABP in descending thoracic aorta

Gregg Hartman. The use of ultrasound during
cardiac anesthesia
23
Echocardiography in the ICU From Evolution to
Revolution

• Recommend echo (TTE) as first line diagnostic
  tool for evaluation of unstable ICU patients
• Specific programs required to educate train
  intensivists anesthesiologists prior to
  implementation (France)

Viellard-Baron et al Intensive Care Med
200834243
24
The Anemia Paradox

• Anemia assoc w multiple AE in cardiac
• ? kidney injury
• ? tissue O2 delivery
• impaired coag
• oxidative stress
• ? NO
• ? mortality morbidity

Keyvan Karkouti. Worse outcome after cardiac
surgery from both anemia transfusion
25
The Anemia Paradox

• RBC Trx assoc w multiple AE in cardiac
• Storage injury RBCs lt deformable, ? ATP 2,3
  DPG, inability to generate NO, etc.
• ? tissue O2 delivery
• Promote pro-inflammatory state
• Exacerbate tissue oxidative stress
• Activate leukocytes coagulation cascade
• ? mortality, morbidity cost

Keyvan Karkouti. Worse outcome after cardiac
surgery from both anemia transfusion. Murphy et
al Circulation 20071162544
26
Does Shelf Life Matter?

• 6000 cardiac surgery patients _at_ CCF
• Compared young (lt 14 d) vs old (gt 14 d) RBC Trx
• Propensity scoring to balance differences in
  population
• Regression analysis
• Worse outcomes in old gp
• ? renal failure (2.7 vs 1.6)
• ? sepsis (4 vs 2.8)
• Prolonged intubation (9.7 vs 5.6)
• ? in-hospital 1-year mortality

Koch CG et al N Engl J Med 20083581229-39.
Mazer CD Age of red cells does shelf life
matter?
27
Implications of The Anemia Paradox

• Treat anemia before surgery
• Antifibrinolytics routinely
• Minimize blood letting hemodilution retrograde
  autologous priming (RAP)
• Cell saver spin hemoconcentrate
• Use RBC stored for short duration

Keyvan Karkouti. Worse outcome after cardiac
surgery from both anemia transfusion
28
Erythropoetin/ Darbepoetin Preop?

• 3 trials of erythropoesis stimulating agents
  (ESAs) vs placebo in cancer
• ? venous thromboembolism mortality in ESA gp
• FDA black box warning for off-label use of ESAs

Bennett et al Crit Care Med 2007299914. Mitka
JAMA 20072971868
29
Post-Op Intensive Insulin Therapy

• Van den Berghe 42 risk reduction in mortality
  with tight glucose control (80-110 mg/dl) vs
  conventional tx. N Engl J Med 20013451359
• ? bacteremia, dialysis, CVVH, polyneuropathy,
  prolonged ventilation, ICU antibiotics
• Concerns single center, not blinded, stopped
  early, high mortality, risk of hypoglycemia
• Data extrapolated to other settings including OR

30
Observational Study of Intraop Hyperglycemia
Outcome in Cardiac

• Independent contribution of intra-op
  hyperglycemia on outcome not known
• Reviewed 409 pts undergoing cardiac surgery
• Glucose levels were higher in pts who had event
  141 vs 127 mg/dl
• ? renal failure, death, pulmonary events

Gandhi et al Mayo Clin Proc 200580862
31
Randomized Trial of Intensive Insulin Therapy
Intraop, N 371 pts

• Intensive gp IV insulin, gluc 80-110
• Controls Insulin for gluc gt 200
• Both gps intensive insulin postop, gluc 80-110
• Endpoints 30 day incidence of
• Death
• Deep sternal infection
• Stroke
• Acute renal failure
• Cardiac new AF, heart block, cardiac arrest
• Prolonged ventilation

Gandhi et al Ann Intern Med 2007146233-43
32
Randomized Trial of Intensive Insulin Therapy
Intraop, N371 pts

• Insulin infusion protocol maintained intraop gluc
  levels in desired range, but did not reduce
  morbidity or mortality
• More strokes in intensive gp patients vs
  controls, (8 vs 1, P 0.02)
• Conclusion- tight gluc control does not add
  benefit, may cause harm, ? resource use

Gandhi et al Ann Intern Med 2007146233-43
33
POISE Results Prophylactic Periop
ß-Blockade

• PeriOperative ISchemic Evaluation Trial
• 190 hospitals, 8351 patients
• ? MI in metoprolol gp vs placebo (4.2 vs 5.7)
  but
• ? stroke in metoprolol gp (1.0 vs 0.5)
• ? mortality in metoprolol gp (3.1 vs 2.3)
• Conclusion- ß-blockers ? risk, especially in
  context of anemia hypotension

POISE Study Group Devereaux PJ, Yang H, et al
Lancet 20083711839-47. Yang H Can J Anesth
20085511 (Editorial)
34
CT Anesthesia Credentialing?

• Multiple complaints questions from SCA members
• E.g., surgeons want TEE certified
  anesthesiologists
• but in our gp everyone does everything
• there isnt enough business for multiple
  fellowship trained cardiac anesthesiologists
• By the way, how many cases per yr should a
  cardiac anesthesiologist do?

Glenn P. Gravlee. Should the SCA recommend
credentialing guidelines to hospitals for CT
anesthesia?
35
CT Anesthesia Credentialing, contd

• SCA should recommend CT anesthesia credentialing
  board certification, similar to pain, critical
  care, cardiology, CT surgery
• 1 yr ACGME cardiac fellowship NBE
  testamur/boards gt 25 cardiac cases/yr
• Equivalent clinical experience for
  grandfathering period of 3-5 yrs
• There will be problems supporting cardiac
  anesthesiologists in low volume programs

Glenn P. Gravlee. Should the SCA recommend
credentialing guidelines to hospitals for CT
anesthesia?
36
Summary

• Reviewed practice trends discussed lessons
  learned from SCA 2008
• Insulin hyperglycemia
• Neuromonitoring protecting the brain
• Ultrasound
• Propofol, Dexmedetomidine
• Anemia transfusion
• Prophylactic ß-blockade stroke