Hypotensive Epidural Anesthesia in Patients with Aortic Stenosis Undergoing Total Hip Replacement

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Hypotensive Epidural Anesthesia in Patients with
Aortic Stenosis Undergoing Total Hip Replacement

• Regional anesthesia and pain medicine, vol 33, No
  2, 2008 pp 129-133

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Content

• Introduction
• Nitroprusside ??
• Miller
• NEJM
• Nitroprusside in critically ill patients with
  left ventricular dysfunction and aortic stenosis
• NEJM 2003 may 1
• 2004 Regional anesthesia and pain medicine
• 2008 Regional anesthesia and pain medicine

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Miller ??Nitroprusside??

• The overall incidence of sudden death in
  asymptomatic AS patients ? 2
• Severely reduced EF with AS? 21
• Pseudo-aortic stenosis
• Dobutamine
• Nitroprusside

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NEJM 2003
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Nitroprusside in critically ill patients with
left ventricular dysfunction and aortic
stenosisNEJM 34818 may 2003

• Vasodilator are considered to be contraindicated
  in patients with severe AS? may cause life
  threatening hypotension
• If peripheral vasoconstriction ?afterload?
  vasodilator may improve myocardial performance

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Method

• 25 patients with severe AS and left ventricular
  systolic dysfunction
• LVEFlt0.35
• AVAlt1cm2
• CIlt2.2

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Conclusion I

• Vasodilatation is traditionally contraindicated
  in severe AS?
• CO is fixed
• The vasodilatation would reduce SVR without any
  compensatory increasing in CO? severe
  hypotension
• Oversimplification scenario to severe AS

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Conclusion II

• In severe AS and severe left ventricular systolic
  dysfunction? nitroprusside leads rapid, marked
  and consistent improvements in CO
• Pseudo-AS?
• Nitroprusside ? improve CO
• Echo, TEE, even surgical proved

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Conclusion III

• Aortic valve ? not the only factor
• Afterload
• The sum of the resistance across the aortic valve
  and the SVR
• The failing heart is sensitive to afterload?
  SVR?? leads to proportional increases in CO ?
  even prevent development of hypotension

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AS vs Nitroprusside

• Suitable to nitroprusside
• Severe AS, candidates for surgery? to optimize
  cardiac function before valve replacement
• Bridge to oral vasodilators
• No restriction to LV function, coexisting
  valvular heart disease, any aspect coronary
  artery disease
• Contraindicate to nitroprusside
• Severe AS with hypotension

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2004 Regional anesthesia and pain medicine
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Is neuraxial blockade contraindicated in the
patient with aortic stenosis? Regional
anesthesia and pain medicine vol 29 no 5, 2004
pp 496-502
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Goal of anesthesia

• Decreased SVR
• May have a profoundly negative effect on coronary
  perfusion? ?contractility? CO?? further
  hypotension
• Diastolic dysfunction? hypertrophy needs
  maintenance adequate preload and NSR
• Af in AS will reduce 40 CO

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2008 Regional anesthesia and pain medicine
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Hypotensive Epidural Anesthesia in Patients with
Aortic Stenosis Undergoing Total Hip
ReplacementRegional anesthesia and pain vol 33,
No 2 2008

• Method
• 1994-1005
• 1947 THR patients, 22 patients had AS confirmed
  by TTE
• Epidural tipT11-12 0.75 bupivacaine2
  lidocaine
• Bosmin infusion immediately at 2ug/min
  (0.04ug/Kg/min) to keep systolic pressure of
  60-100mmHg
• IVG with propofol, fentanyl and keep spontaneous
  breathing
• Post-OP EPCA usage

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Results
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Discussion

• Epidural ? gradual onset
• If the level of epidural was too high? abolishes
  reflex tachycardia ? reduction CO
• ? choose Bosmin to attain appropriate heart rate
• aadrenergic agonists? may be also benefit in the
  patient with AS
• High level epidural? may has the effect of
  normalize myocardial blood flow
• 2005 circulation

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• 2003 NEJM
• Stroke volume increased 68 and wedge pressure
  fell 30
• The population in this study was not the same as
  2003 NEJM
• No symptom and sign
• Not in heart failure?
• were less sensitive to reduce after load

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Thanks for your attention!!