Ch.20 Anesthesia for patients with cardiovascular disease

1
Ch.20 Anesthesia for patients with cardiovascular
disease

• R1 ???

2
Introduction

• Cardiovascular disease most frequently
  encountered in anesthetic practice
• Already compromised cardiovascular system? ??
• Surgical stimulation? ?? adrenergic response
• Anesthetic agents, endotracheal intubation,
  positive-pressure ventilation, blood loss, fluid
  shifts, body temperature ??? ?? circulatory
  effects
• Chronically enhanced sympathetic activity? ????
  acute circulatory decompensation ??
• Choice of anesthetic agent is not as important as
  how the agent is used and an understanding of the
  underlying pathophysiology

3
Cardiac risk factors
4

• ?? ???? ???
• Perioperative myocardial infarction
• Pulmonary edema
• Congestive heart failure
• Arrhythmias
• Thromboembolism
• Cardiovascular complication
• 25-50 of deaths following noncardiac surgery

5
Clinical predictors of increased perioperative
cardiovascular risk

• Mj predictor ?? ?
• Noninvasive cardiac evaluation
• ?? ??? ??
• Unstable coronary syndrome
• Congestive heart failure
• C/I of elective op
• 1? ??? MI
• Uncompensated heart failure
• Severe aortic or mitral stenosis

6
Mx of intermediate or minor predictors
7
Cardiac risk stratificationfor non cardiac
surgical procedures

• ????? 2-5?? ???
• Poorly controlled HTN? wide intraOP BP swing? ??
  ??
• intraOP HTN? cardiac morbidity? hypotension?? ??
• Well-managed general anesthesia?? spinal ??
  epidural anesthesia? hemodynamic effect? ?? ???
  ?? ??

8
HYPERTENSION
9
Preoperative considerations

• HTN leading cause of death and disability
  most frequent preOP abNL in surgical Pt
• Overall prevalence 20-25
• Mj risk factor for
• Cardiac, cerebral, renal and vascular disease
• Cx
• MI, CHF, stroke, renal failure
• Peripheral occlusive disease, aortic dissection
• LVH, carotid bruits cardiac mortality ??

10
Definitions

• BP measurements
• Affected by posture, time, emotional state,
  recent activity, drug intake, equipment,
  technique
• Preoperative anxiety or pain BP ?? ??
• Stage 3 (accelerated or severe HTN) renal
  dysfunction ??
• Malignant HTN gt210/120 ?Hg with papilledema,
  encephalopathy

11
Pathophysiology

• Idiopathic(essential) or less commonly secondary
• renal dis., primary hyperaldosteronism,
  Cushings syndrome, acromegalym,pheochromocytoma,
  pregnancy, estrogen therapy ?
• Essential hypertension? course of the disease
• Cardiac output ??, but, SVR appears in NL
• Cardiac output ??, but, SVR becomes high
• Chronic increase in cardiac afterload? concentric
  LVH, altered diastolic function ??
• Cb autoregulation ??? NL Cb blood flow? ??

12
Pathophysiology(2)

• Mechanisms remain elusive but
• Vascular hypertrophy
• Hyperinsulinemia
• intracellular Ca ??
• vascular smooth muscle and renal tubular cell ??
  Na ?? ??
• Sympathetic nervous system overactivity
• Overactivity of renin-angiotensin-aldosterone
  system important tole in accelerated HTN

13
Long-term treatment

• Drug therapy
• progression of HTN ??
• Stroke, CHF, CAD, renal damage ??
• LVH, altered Cb autoregulation?? ?? ??
• ??? single-drug therapy? ?? ??
• Low doses of a thiazide diuretic for most
  patients
• ACE inhibitor Lt ventricular dysfunction or
  heart failuretl 1st-line choice
• ACEI or ARB (angiotensin-receptor blocker)
  hyperlipidemia, chr. Renal dis., DM? optimal
  initial single agent
• ß-adrenergic blocker, calcium channel blocker
• 1st-line agent for CAD
• Elderly Pt. diuretic with or without
  ß-adrenergic blocker, or calcium channel blocker
  alone

14
HYPERTENSION

• PREOPERATIVE MANAGEMENT

15

• ??? HTN Pt.? ???? HTN? ??? op room? ???
• Untreated or poorly controlled hypertensive Pt.
• Intraoperative episodes of MI, arrhythmias, both
  hypertension and hypotension
• ??? ???? ?? ? vasoactive drug ??? post-op Cx? ??
  ? ??
• Altered Cb. Autoregulation??? ??? BP ??? Cb.
  Perfusion ??? ??? ? ??

16

• Antihypertensive drug? ?? ???? ??
• ????? intraop hypotension ?? ??? ?? ?? ACE
  inhibitor ??? ????? ?
• ??? ?? perioperative HTN ??? ???? parenteral
  antihypertensive agent ??? ???
• 110 ?Hg ??? sustained preoperative diastolic BP
  ??? (?? end-organ damage ?? ??) ??? ?? BP
  control? ? ? ? ??? ?? ??

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History

• Severity and duration of the HTN, drug therapy,
  hypertensive complication ??
• Sx of MI, ventricular failure, impaired Cb
  perfusion, peripheral vascular dis.
• Pts record of compliance with the drug regimen
• Questions should concern
• Chest pains, exercise tolerance
• Shortness of breath(?? ??)
• Dependent edema, postural lightheadedness,
• Syncope, amaurosis, claudication
• Adverse effects of current antihypertensive drug

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Physical examination laboratory evaluation

• Ophthalmoscopy
• Visible changes in the retinal vasculature
• Arteriosclerosis? ?? ??? hypertensive damage ???
  ??? ??
• Physical findings
• S4 gallop LVH
• Pulm rale S3 gallop CHF
• ASx carotid bruits
• atherosclerotic vascular dis.? ??
• Doppler?? ???? hymodynamically significant
  blockage? r/o ? ? ??

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Physical examination laboratory evaluation(2)

• BP ??? supine and standing position ???? ?? ?
• Orthostatic changes
• Volume depletion
• Excessive vasodilation
• Sympatholytic drug therapy
• ?? ?? preoperative fluid ??? induction ?? severe
  hypotension ?? ? ??

20
Physical examination laboratory evaluation(3)

• ECG ?? ??
• Evidence of ischemia, conduction abNL, old
  infarction, LVH, strain
• NL ECG? CAD or LVH ???? ??? ? ??
• Echocardiography more sensitive of LVH
• CXR
• Boot-shaped heart LVH ??
• Frank cardiomegaly
• Pulmonary vascular congestion

21
Physical examination laboratory evaluation(4)

• Renal function
• Serum Cr, BUN level? ?? ??
• s-electrolyte diuretics, digoxin ?????? renal
  impairment?? ???? ??
• Mild to moderate hypokalemia(3-3.5mEq) taking
  diuretics Pt., ?? ??? ??
• K replacement? ?? ??? digoxin ?? ???
• Hypomagnesemia ??? ???? ?? ??
• Hyperkalemia taking K-sparing diuretics or ACE
  inhibitors(?? impaired renal function?)

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Premedication

• Reduce preoperative anxiety
• Mild to moderate preop. HTN
• Anxiolytic agent (midazolam)
• Antihypertensive agents should be continued
• With a small sip of water
• Central a2-adrenergic agonist (clonidine 0.2mg)
• Sedation ??
• Intraop. Anesthetic ??? ??
• Periop. HTN ??
• Profound intraop. Hypotension and bradycardia ??

23
HYPERTENSION

• INTRAOPERATIVE MANAGEMENT

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Objectives

• Maintain an appropriate stable BP range
• Long-standing or poorly controlled HTN
• Cb blood flow? autoregulation ??
• ?? ???? ?? ?? ?? BP ??
• HTN, with tachycardia
• MI, ventricular dysfunction ?? ??
• Arterial BP? preop level? 10-20? ??
• Marked HTN(gt180/120 ?Hg) in preop.
• High-NL range(150-140/90-80 ?Hg) ??

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Monitoring

• Direct intraarterial pr. Monitoring
• With wide swings in BP
• Cardiac preload or afterload? ? ??? ????Mj
  surgical procedures
• ECG monitoring
• Detecting signs of ischemia
• Urinary output
• Renal impairment?? 2?? ??? procedure
• Invasive hemodynamic monitoring
• LVEDV,CO?? ?? PCWP12-18mmHg? ?? ??

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Induction

• Induction, intubation period of hemodynamic
  instability
• ??? induction? hypotension, intubation? ??
  hypertensive response ??
• Induction? hypotensive response? anesthetic
  agents? antihypertensive agents? additive
  circulatory depressant effets? ??(vasodilator
  cardiac depressants ??)
• ??? HTN ??? ?? volume depleted state
• Sympatholytic agents ?? NL protective circulatory
  reflex ????

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Induction(2)

• 25???? endotracheal intubation? severe
  hypertension ??
• ??? ? duration of laryngoscopy ?? ?
• Intubation? deep anesthesia ???? ??
• Intubation ? Hypertensive response ??? ??
• ?? ?????? 5-10?? ?? ???? ??
• Bolus opiod(fentanyl 2.5-5?/? alfentanil 15-25
  ?/? sufentanil 0.25-0.5 ?/? remifentanil 0.5-1
  ?/?)
• Lidocaine 1.5?/? iv or intratracheally
• ß-adrenergic blockade c esmolol 0.3-1.5?/?
  propranolol 1-3? labetalol 5-20?
• Topical airway anesthesia

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Choice of anesthetic agentsa. Induction agents

• Regional anesthesia??? HTN Pts.? ????? ? ?? ????
  ??
• ??? propofol, barbiturates, benzodiazepines,
  etomidate? equally safe
• Ketamine
• Sympathetic stimulation??? elective op.?? C/I
• Benzodiazepine or propofol ?? ???? ????

29
Choice of anesthetic agentsb. Maintenance agents

• Volatile agents(N2O), balanced technique (opioid
  N2O muscle relaxant), or totally IV
  techniques
• Addition of volatile agent or IV vasodilator
• Volatile agent
• Vasodilation and relatively rapid reversible
  myocardial depression gt BP? ?? titration ??
• ????? sufentanil? ?? autonomic suppression?? BP
  control ????? ??

30
Choice of anesthetic agentsc. Muscle relaxants

• Can be used routinely
• Pancuronium
• vagal blockade, neural release of catecholamines
• Can exacerbate HTN in poorly controlled Pts
• Large doses of tubocurarine, metocurine,
  atracurium, mivacurium? hypotension ??

31
Choice of anesthetic agentsd. Vasopressors

• HTN Pts? endogenous catecholamine?? exogenous
  sympathetic agonist? ?? ??
• Small dose of a direct-acting agent
  (phenylephrine 25-50?)
• High vagal tone small dose ephedrine (5-10?)
• Sympatholytics ????? ?? ??? epinephrine 2-5 ? ???
  ?? ??
• Improper dosing of epinephrine? significant
  cardiovascular morbidity ?? ??

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Intraoperative hypertension

• Anesthetic depth ??? ?? ?? ?? ?? parenteral
  agent? ?? ??
• Antihypertensive therapy ?? ? inadequate
  anesthetic depth, hypoxemia, hypercapnia ? ?? ???
  ???? ???? ?
• ß-adrenergic blockade
• Good ventricular function and elevated heart rate
• C/I in bronchospastic disease
• Nicardipine
• Preferable for bronchospastic disease
• Sublingual nifedipine? reflex tachycardia? MI
  ???? delayed onset ??

33
Intraoperative hypertension(2)

• Nitroprusside
• Most rapid and effective agent for the
  intraoperative treatment of moderate to severe
  HTN
• Nitroglycerin
• Less effective but useful in treating or
  preventing MI
• Fenoldopam
• Improve or maintain renal function
• Hydralazine
• Sustained BP control
• Delayed onset, can cause reflex tachycardia
• Reflex tachycardia? labetalol ??? combined a-
  ß-adrenergic blockade ???? ?? ? ??

34
Intraoperative hypertension(3)
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Postoperative management

• ??? poorly controlled HTN Pts?? ?? ??
• Close BP monitoring in recovery room early
  postop period
• Marked sustained elevations in BP
• MI and CHF
• Formation of wound hematomas
• Disruption of vascular suture lines
• HTN in recovery period? ??
• Respiratory abNL, pain, volume overload, bladder
  distention
• Labetalol useful in HTN and tachycardia
• Nicardipine useful in HTN with slow heart rate
• ?? MI? ????? bronchospasm ?? ??
• Oral intake ????? ??? medication ??

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ISCHEMIC HEART DISEASE
37
Preoperative considerations

• O2 supply? ???? metabolic oxygen demand
• Ischemia result from
• Marked increase in myocardial metabolic demand
• Reduction in myocardial O2 delivery
• Common causes
• Severe HT or tachycardia
• Coronary arterial vasospasm or anatomic obx.
• Severe hypotension, hypoxemia, anemia
• Severe aortic stenosis or regurgitation

38
Preoperative considerations(2)Artherosclerosis
of the coronary arteries

• Major risk factors
• Hyperlipidemia, HTN, diabetes, cigarette smoking
• Increasing age, male sex, positive family history
• Obesity, menopause, high estrogen oral pills
• History of cerebrovascular or pph vascular
  disease
• High estrogen oral contraceptives (with smoking)
• Sedentary lifestyle,coronary-prone behavior
  pattern
• Clinical manifestation
• Sx of myocardial necrosis (infarction)
• ischemia (usually angina)
• Arrhythmias (including sudden death)
• Ventricular dysfunction (CHF) gt ischemic
  cardiomyopathy

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Unstable angina

• Defined as
• ??? ???? severity, frequency (1? 3? ??), or
  duration of anginal attacks (crescendo angina)
• Angina at rest
• New onset of angina(2? ??) with severe or
  frequent episodes(1? 3? ??)
• ?? severe underlying coronary dis, MI? ??
• ?? ? ?? ?? coronary care unit ?? ??
• Anticoagulation with heparin
• Together with aspirin, iv nitroglycerin,
  ß-blockers, calcium channel blockers
• 24-48h?? ?? ??? coronary angiography??
  angioplastry or emergency surgical
  revascularization ??

40
Chronic stable angina

• Chest pain
• Substernal, exertional, radiating to the neck or
  arm, relieved by rest or nitroglycerin
• Nonexertional ischemia, silent ischemia? ??
• DM ???? silent ischemia ?? ??
• ?? artherosclerotic lesion? 50-75 occlusion ???
  ??? ?? ??
• Stenotic segment? 70? ???? maximum compensatory
  dilatation?? ??? blood flow? ????? increased
  metabolic demand?? ??
• Emotional upset, hyperventilation?? ?? coronary
  vasospasm ?? transient transmural ischemia? ??
  (Prinzmetals angina)

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Treatment of ischemic heart dis

• The general approach
• Progression? ??? ?? coronary risk factor ??
• Exercise tolerance ??? ?? lifestyle ??
• Complicating medical condition ??
• HTN, anemia, hypoxemia, thyrotoxicosis, fever,
  infection, adverse drug effects ?
• Pharmacological manipulation
• Coronary lesion ??
• Percutaneous coronary intervention
• PCI (angioplasty with or without stenting, or
  atherectomy)
• Coronary artery bypass surgery
• Pharmacological agents
• Calcium channel blockers vasospastic angina
• ß-blockers exertional angina adequate
  ventricular function
• Nitrates both types of angina

42
Treatment of ischemic heart disa. nitrates

• Relax all vascular smooth muscle (?? vein)
• ??? venous tone return (cardiac preload) ? wall
  tension? afterload? ???? myocardial O2 demand?
  ????
• CHF ??? ??
• Dilate coronary arteries
• Flow? radius? 4??? ????? stenotic site? ??? ?????
  blood flow? ???? ??
• ?? ????? subendocardial blood flow? ??
• ??? ??? collateral? ??? ??
• Acute ischemia ?? ? frequent anginal episode? ???
  ??
• Negative inotropic effect? ??

43
Treatment of ischemic heart disb. calcium
channel blockers

• Cardiac afterload? ?? myocardial O2 demand? ?????
• coronary vasodilation?? blood flow? ?? O2 ???
  ????
• Verapamil? diltiazem? HR? ?? O2 demand ???? ?
• Nifedipine hypotension, reflex tachycardia
• Sublingual ? fast-onset preparation? ???? MI?
  ????? ?
• Afterload? ????? ?? negative inotropic effect?
  ??? ? ??
• Slow-release form suitable for ventricular
  dysfunction
• Amlodipine similar to nifedipine but no effect
  on heart rate

44
Treatment of ischemic heart disb. calcium
channel blockers(2)

• Verapamil diltiazem greater effects on
  cardiac contractility AV conduction
• Ventricular dysfunction, conduction abNL,
  bradyarrhythmia ?? ? ?? ????? ?
• Diltiazem? ventricular dysfunction?? ? ?? ??
• Nicardipine nimodipine same effects as
  nifedipine
• Nimodipine SAH ?? Cb vasospasm ??
• Nicardipine iv arterial vasodilator
• Significant interactions with anesthetic agents
• Potentiate neuromuscular blocking agents
  circulatory effects of volatile agents
• Verapamil decrease anesthetic requirements
• Verapamil diltiazem ????? ?? depression of
  cardiac contractility conduction in the AV
  node? ????
• Nifedipine volatile iv agents? ?? systemic
  vasodilation? ??

45
Treatment of ischemic heart disc. ß-adrenergic
blocking agents

• HR? contractility? ?? myocardial oxygen demand?
  ????
• Optimal blockade ??? HR 5060bpm, ??? ??? ??
  ??(lt20bpm)
• Membrane stabilization Intrinsic
  sympathomimetic properties
• Low dose beneficial for compensated CHF
• Nonselective ß-receptor blockade
• C/I in significant ventricular dysfunction,
  conduction abNL, bronchospastic dis.
• ß2-adrenergic receptors blockade
• Can mask hypoglycemic Sx in awake DM Pt.
• Delay metabolic recovery from hypoglycemia
• Impair the handling of large potassium loads
• Vasospastic angina??? C/I
• Cardioselective agents(ß1-specific)
  selectivityrk dose dependent??? reactive airway
  Pt?? ?? ??
• Acebutolol ß1-selectivity? intrinsic
  sympathomimetic activiry? ?? ???? bronchospastic
  airway dis. ? ??

46
Treatment of ischemic heart disd. other agents

• ACE inhibitors
• Prolong survival in CHF or LV dysfunction
• Digoxin
• Rapid ventricular response ??? artrial
  fibrillation
• Cardiomegaly Pt (?? Sx ?? ??)
• Chronic aspirin therapy reduce coronary events
• Inducible sustained ventricular tachycardia or
  ventricular fibrillation
• Automatic internal cardioverter-defibrillator
  (ICD) ?? ??

47
Treatment of ischemic heart dise. combination
therapy

• Ventricular dysfunction Pt
• Combined negative inotropic effect of ß-blocker
  calcium channel blocker? ??? ??
• ACE inhibitor? survival ??? ? ?? ??
• Amlodipine long-acting nitrate
• ?? significant ventricular dysfunction ???? well
  tolerated
• ????? ??? vasodilation ??? ?? ??

48
ISCHEMIC HEART DISEASE

• PREOPERATIVE MANAGEMENT

49

• Perioperative outcome? disease severity?
  ventricular function? ??
• Extensive(3-vessel or Lt main) CAD, recent Hx of
  MI, or ventricular dysfunction
• gt greatest risk for cardiac complications
• ??? MI? transmural or subendocardial ??? risk? ??
• Perioperative MI ? non-Q wave infarction????
  mortality rates? 50? ??
• Preop. PCI cardiovascular Cx in high-risk Pt?
  ???? ??? ??
• ?? postsurgical bleeding? ?? ?? PCI ?? ?? 2??
  ????? ?
• Chronic stable angina not increase perioperative
  risk
• Coronary a. bypass surgery or coronary
  angioplasty Hx? ?? ???? perioperative risk ????
  ??
• Preop. ß-blocker
• Periop. Mortality ? postop. Cardiovascular Cx ??
  ??

50
ltPreop. Mx of Mj clinical predictorsof
increased cardiovascular riskgt
51
History

• Questions Sx, Tx, Cx, ??? evaluation ? ??
• Sx
• Include chest pains, dysnea, poor exercise
  tolerance, syncope or near syncope
• Ability to do light work at home or climb one
  flight of stairs slowly -gt 4 metabolic
  equivalents(METs)
• Very sedentary lifestyle? ?? severe dis.?? ???
  asymptomatic ? ? ??
• DM silent ischemia ??
• Easy fatigability or shortness of breath?
  compromised ventricular function ??
• Ischemia ??? localization? ??? ECG ??? ?? lead?
  ??? ?? ??
• ??? MI? poor ventricular function ???
  ????Arrhythmia and conduction abNL ??

52
Physical examination Routine laboratory
evaluation

• Serum cardiac enzymes
• Cardiac-specific troponins (T or I), creatine
  kinase (MB isoenzyme), lactate dehydrogenase
  (LDH, type 1 isoenzyme)
• Serum digoxin levels excluding drug toxicity
• ECG
• Baseline ECG CAD ?? ??? 2550?? NL
• Very straight ST underlying CAD? ??
• m/c baseline abNL nonspecific ST- T-save
  changes
• Prior infarction infarct ??? lead?? Q waves or
  loss of R waves
• First-degree AV block, bundle-branch block,
  hemiblock
• Persistent ST-segment elevation Ix of LV
  aneurysm
• Long QT interval ventricular arrhythmia ?? ??
• gt drug toxicity? electrolyte imbalance? r/o?
  ?? Op.
• Chest film
• Screening test in excluding cardiomegaly or pulm.
  Congestion

53
Specialized studiesa. Holter monitoring

• Continuous ambulatory electrocardiographic
  monitoring
• Arrhythmias, antiarrhythmic drug therapy,
  severity frequency of ischemic episode ??? ??
• ??? frequent ischemic episodes on Holter
  monitoring correlates well with intraop. And
  postop. Ischemia
• Excellent negative predictive value for postop.
  Cardiac complications

54
Specialized studiesb. exercise
electrocardiography

• Baseline ST-segment abNL unable to increase HR
  because of fatigue, dyspnea, or drug therapy
• Sensitivity is 65, specificity is 90
• NL test NOT exclude CAD
• Low level??? myocardial ischemic response? peri
  op. Cx? long-term cardiac events? ?? ??? ??

55
Specialized studiesc. myocardial perfusion scans

• Exercise ?????? underlying ECG ??? ?? ??
  Thallium-201 or technetium-99m ???? myocardial
  perfusion imaging ??
• Dipyridamole ???? exercise? ??? hyperemic
  response ??
• Best for detecting 2- or 3-vessel disease
• NL perfusion scan? negative predictivive value? ?
  99

56
Specialized studiesd. echocardiography

• Regional and global ventricular function, at
  rest, following exercise or with dobutamine
• Dobutamine ?? ? new or worsening wall motion
  abNL? ?? ischemia ???
• Ejection fraction 50??? ?? periop. Morbidity ???
• Dobutamine stress echo LBBB? ??? ??

57
Specialized studiese. coronary angiography

• Noncardiac surgery ?? PTCA or CABG? ?? ??? ?? ?
  ?? ??? ?? ??
• Location and severity of occusion ? coronary
  vasospasm? ?? ??
• Lt main coronary a.? ?? LV ??? ???? significant
  stenosis? ?? ??
• Indicators of significant ventricular dysfunction
• Ejection fraction lt 0.5
• LVEDP gt 18mmHg after injection of contrast
• Cardiac index lt 2.2 L/min/m2
• Marked or multiple wall motion abnormalities

58
Premedication

• ?? fear, anxiety, pain? ??
• Sympathetic activation? ?? ?
• Overmedication? hypoxemia, resp. acidosis,
  hypotension ??? ? ???? ???
• Benzodiazepine, alone or with opioid are m/c used
• Or morphine, 0.10.15 ?/?, and scopolamine
  0.20.4 ?, IM
• O2 via nasal cannula
• ???? antianginal medication? ??? sudden increase
  in ischemic episode(rebound) ??
• Prophylactic ß-blocker reduce intraop and
  postop ischemic episodes
• Iv nitrate? cardiac preload? ?????? iv fluid ?? ??

59
ISCHEMIC HEART DISEASE

• INTRAOPERATIVE MANAGEMENT

60

• Adversely affect the myocardial oxygen
  demand-supply relationship
• Activation of sympathetic system plays a Mj role
• HTN enhanced contractility increase myocardial
  O2 demand
• Tachycardia increase demand and reduce supply

61
Objectives

• Maintaining a favorable myocardial supply-demand
  relationship
• Autonomic-mediated increase in HT and BP? deep
  anesthesia or adrenergic blockade? ??
• ??? coronary perfusion pressure or a. O2 content
  ?? ???
• a. diastolic pressure? 50?Hg ???? ??
• LVEDP? ??? ??? ventricular wall tension?
  ?????(afterload) subendocardial perfusion? ????
• ??? Hb (gt 9-10 ?/?)? a. O2 tension(gt 60?Hg) ??

62
Monitoring

• Severe CAD? Mj or multiple cardiac risk factor?
  ?? ?? ???? intraarterial pr. Monitoring
• Large fluid shift or blood loss ???? ?? ??? CVP
  or pulm. a. pr.? ??
• Pulm. a. pr.? ?? ventricular dysfunction??? ??
  (ejection fraction lt 40-50)
• TEE
• Contractility and ventricular chamber
  size(preload)
• Intraop. detection of ischemia
• Recognition of ECG change
• Hemodynamic manifestation
• Regional wall motion abNL on TEE
• Doppler TEE? ischemic papillary m. dysfunction?
  ?? mitral regurgitation ?? ??

63
Monitoringa. electrocardiography

• T wave change
• Inversion, tenting, or both
• Pregressive ST-segment depression
• down-sloping horizontal ST depression? ??
  specific
• New ST elevation severe ischemia, vasospasm,
  infarction
• Lead II for inferior wall ischemia and arrhythmia
• Lead V3 for anterior wall ischemia

64
Monitoringb. hemodynamic monitoring

• HTN, tachycardia m/c hemodynamic abNL
• Hypotension late, ?? progressive ventricular
  dysfunction? ??
• Ischemia? ?? PCWP? ??? ??

65
Monitoringc. transesophageal echocardiography

• Detecting global and regional cardiac dysfunction
  valvular function
• Decreased systolic wall thickening? ??? index for
  ischemia

66
Internal cardioverter-defibrillator management

• Surgical electrocautery ??? ?? ??
• Ventricular fibrillation?? ???? ICD firing
• Cautery artifact? ?? pacemaker function ??
• Rate-responsive sensor ???? pacing rate ??
• Resetting to a back-up or reset mode
• ????? defibrillator ?? ? ?

67
Choice of anesthesiaa. regional anesthesia

• Extremities, perineum, lower abd. ??? regional
  anesthesia? ?? ??? ? ? ??
• Spinal or epidural anesthesia? BP ??? ??
  phenylephrine(25-50?)? ??? iv fluid? ??
• Bradycardia ??? ephdrine (5-10?) ??
• Prior volume loading?? marked hypotension ??
• Epinephrine (2-10?) ?? ??
• Compensated CHF? preop volume loading ???
  sympathectomy? ?? ? ??

68
b. general anesthesia1. induction

• Moderate to severe CAD
• 3-vessel dis, Lt main dis, or ejection fraction lt
  40)
• ??? ????(a. BP reaches its lowest acceptable
  limit)? intubation? vasopressor response? ??
• ??? ??? ??, ??? titration
• Eyelid reflex ??? ? ?? muscle relaxant ??,
  controlled ventilation ??

69
b. general anesthesia2. Choice of agents

• Induction agents
• Ketamine indirect sympathomimetic effect? C/I
• Benzodiazepine ketamine EFlt30?? ??
• Opioid ??? cardiac depression ??
• High dose opioid? withdrawal of elevated baseline
  sympathetic tone?? ??? cardiac depression ?? ? ??

70
b. general anesthesia2. Choice of agents

• Maintenance agents
• ?? opioid-volatile anesthetic technique ??
• N2O? opioid ??? cardiac depression ??
• All volatile agent? demand? supply?? ? ???
• ??? ischemia ??? oxygenation Hct check ?
  hemodynamic abNL (hypotension, HTN, tachycardia)
  ??
• ?? ?? ??? iv NTG start

71
b. general anesthesia2. Choice of agents

• Muscle relaxants
• Lack of significant circulatory side effects
• Vecuronium or atracurium? opioid? ??? severe
  bradycardia ??
• Succinylcholine autonomic ganglia, cardiac
  muscarinic receptor ??
• Reversal CAD ???? ? ?? ??
• Atropine ?? glycopyrrolate ???? ??? tachycardia ??

72
ISCHEMIC HEART DISEASE

• POSTOPERATIVE MANAGEMENT

73

• ??? oxygenation? ? ??? ?? ??
• Shivering meperidine 20-30? iv ??
• Hypothermia forced-air surface warmer ??
• Postop pain? ??
• Fluid overlead ??? ??? poor ventricular functon
  ?? ? CXR ??
• Pulm. Congestion furosemide 20-40 ? iv
• Non-Q-wave infarction ? 50????? chest pain ????
  routine postop 12-lead ECG ??

74
VALVULAR HEART DISEASE

• 1. General evaluation of patients

75
1. General evaluation of patients

• severity of lesion, hemodynamic significance,
  residual ventricular function, presence of
  secondary effects on pulmanary, renal, hepatic
  function ?? ??
• CAD, MI ?? ??

76
History

• Ventricular fuction? ??? Sx? ?? ??? lab data?
  focus??? ?
• Exercise tolerance, fatigability, pedal edema,
  shortness of breath in general(dyspnea), when
  lying flat(orthopnea), or at night(paroxysmal
  nocturnal dyspnea) ?
• Review of medication efficacy, side effects ?
• Digoxin AF ?? ???? ventricular rate ??
• Digoxin toxicity arrhythmia, N/V, confusion,
  altered color perception or scotomas
• Preop. Vasodilator preload, afterload ??? ??
• Excessive vasodilation? exercise tolerance? ?????
  postural hypotension ??

77
Physical examination

• Signs of CHF ?? ?
• Lt sided S3 gallop or pulmonary rales
• Rt sided jugular venous distention,
  hepatojugular reflux, hepatosplenomegaly, pedal
  edema
• Auscultation?? valvular dysfunction? ? ? ???
  echocardiographic study? ?? reliable
• Embolic phenomena? ?? neurological deficit ??? ?

78
Laboratory evaluation

• LFT assessing hepatic dysfunction
• ABGA
• PT, aPTT reversal of anticoagulants
• ECG ?? nonspecific
• Special studies
• Echocardiography, radionuclide angiography,
  cardiac catheterization
• ??? ??
• ?????? ?? valve? ??? ?? ?????
• Lesion? severity? ?????
• ?? ??? ventricular impairment? ??????
• ?? ??? ???? ???? ??? ????
• CAD? ??? ?????

79
VALVULAR HEART DISEASE

• 2. Premedication

80
2. Premedication

• NL ventricular function ?? ????? standard dose?
  premedication ??
• Poor ventricular function reduced doses
• ?? ?? ?? ??? ???? ???? ??
• Supplemental O2 pulm. HTN or ??? pulm. dis.

81
Antibiotic prophylaxis anticoagulation Mx

• abNL? ?? endocarditis ???? ??
• Bacteremic events dental, oropharyngeal or
  nasopharyngeal, gastrointestinal, genitourinary
  surgery or I D
• General guideline? ?? ??? prophylaxis ??
• Anticoagulant? ???? ? 1-3?? ??
• Thromboembolic Cx ??? ??? embolism or thrombus
  Hx, AF, prosthetic mechanical valve? ?? ??
• Mitral or tricuspid position? caged-ball
  mechanical (Starr-Edwards) prosthesis valve? ??
  ??? ?? ??
• Tilting disc (St. Jude) valve? intermediate
• Bioprostheses (porcine or bovine tissue valve)?
  ?? ??
• ?? 3?? warfarin? ????, ?? 2-3?? restart
• Thromboembolic risk ?? ??? ?? 1?? anticoagulation
  ?? ? Vit.K or FFP ??? reverse ??
• Surgical hemostasis? ??? ?? ??? 12-24??? iv
  heparin therapy ??

82
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83
VALVULAR HEART DISEASE

• 3. Specific valvular disorders

84
MITRAL STENOSISPreoperative considerations

• ?? acute rheumatic fever? delayed Cx? ??
• Female? 2/3
• Acute disease??? ??? 2? ??? stenotic process ???
• Progressive fusion calcification of valve
  leaflets
• Sx? ??? 20-30? ?
• Mitral valve orifice? ?? (4-6 ?)?? 2 ????
• 50???? mitral regurgitation ??, 25?? rheumatic
  involvement of aortic valve ?? (stenosis or
  regurgitation)

85
MITRAL STENOSISPathophysiology

• Rheumatic process
• Valve leaflets to thicken, calcify, funnel shaped
• Annular calcification
• Mitral commissures fuse, chordae tendinae fuse
  and shorten, valve cusps become rigid
• ?? valve leaflet? ???? bowing or doming
• Blood flow? ???? transvalvular pr. Gradient
• CO, HR ??? higher transvalvular pr. Gradient
• LA dilated, supraventricular tachycardia(AF)
• Formation of thrombi ?? LA appendage??
• LA pr.? acute elevation? pulm. Capillary? ??
• Mean pulm. Capillary pr? 25?Hg??? ?? pulm. Edema
• Chr. Elevation? pulm. Lymph flow ??? ?? ?????
  irreversible increases in PVR pulm. HTN ??
• Lung compliance ??? chronic dyspnea ??
• RV afterload ??? RVF ???? RV dilatation, TV or
  PV regurgitation ??

86
MITRAL STENOSISPathophysiology (2)

• MS AF?? embolic event ??
• To the cb. Circulation, or pulm. Emboli, pulm.
  Infarction, hemoptysis, recurrent bronchitis ??
• 10-15?? chest pain ??
• Emboli in coronary circulation or acute RV pr
  overload ??
• Enlarged LA? Lt recurrent laryngeal n. ??
  hoarseness ?? ??

87
MITRAL STENOSIScalculating mitral valve area
transvalvular gradient

• Gorlin equation
• MV flow as mL/s, pr as mmHg, valve area as cm2
• ? 38
• Mitral valve flow(MVF) as
• Mitral valve area(MVA) as
• SV(stroke volume), VTI(velocity time integral)
• MVA? 1cm2 ??? ?? tranvalvular gradient? 20mmHg?
  ?? rest? minimal exertion?? dyspnea ??(critical
  MS)
• LV preload ??? ??? CO ? ??? ???? ??

88
MITRAL STENOSISTreatment

• Sx ????? 5-10?? ???, ???? 2-5? ?? ??
• Significant Sx ?? ?? surgical correction (open
  valvuloplasty) ??
• Recurrent MS ??? valve replacement ??
• Percutaneous transseptal balloon valvuloplasty
• Selected young or pregnant Pt, older Pt.(poor
  surgical candidates)
• Medical Mx supportive
• Limitation of physical activity, sodium
  restriction, diuretics
• Digoxin AF rapid ventricular response ???
• ß-adrenergic blocker mild to moderate Sx
• Emboli or high risk(40???, large atrium with chr.
  AF)
• -gt anticoagulation

89
MITRAL STENOSISAnesthetic management

• Objectives
• Maintain a sinus rhythm
• Avoid tachycardia, CO ??, hypovolemia, fluid
  overload
• Monitoring
• Full hemodynamic monitoring
• Direct intraarterial pressure, pulmonary artery
  pressure
• ??? ????? pulm. Edema ??
• PCWP? transvalvular gradient? ??
• ECG ??? ????? notched P wave ???
• CVP ?? prominent cv wave? secondary tricuspid
  regurgitation? indication

90
MITRAL STENOSISAnesthetic management(2)

• Choice of agents
• Spinal epidural anesthesia? vasodilating
  effect? ?? ??
• Ketamine? sympathetic stimulation?? ???,
  pancuronium? tachycardia ????? ??? ?
• Opioid? volatile agent?? ?? ??? ? ? ??
• Volatile agent
• Halothane HT ??? vasodilating ??? ??
• ?? volatile agent ?? ?? ??
• N2O? PVR? ??? ???? ? ???? ??
• Intraop. Tachycardia??? Deepening anesthesia with
  opioid, ß-blocker ??
• AF ????? diltiazem or digoxin?? ventricular rate
  ??
• Sudden SVT ??? cardioversion ??? ?? ??
• Phenylephrine?? ß-adrenergic agonist activity?
  ???? ephedrine?? ??

91
MITRAL REGURGITATIONPreoperative considerations

• Chronic MR? ??
• Rheumatic fever
• Congenital or developmental abNL of valve
  apparatus
• Dilation, destruction, or calcification of mitral
  annulus
• Acute MR? ??
• Myocardial ischemia or infarction
• Infective endocarditis
• Chest trauma

92
MITRAL REGURGITATIONPathophysiology

• Systole ??? ??? LA? ???? forward stroke volume?
  ??
• LV? dilating increasing end-diastolic volume
• LV afterload? ????
• End-diastolic volume? ???? volume-overloaded? LV?
  efection fraction? ????? CO? ????? ??? ? ??
• Eccentric Lt ventricular hypertrophy ??
• Regurgitant volume? valve orifice? ??, HR,
  systole ??? LV-LA pr. Gradient? ?? ???
• Atrial compliance ?? ????? ?? ??
• Acute MR??? atrial compliance? ?? ????? pulm.
  Congestion edema ??
• Long-standing MR??? low CO? ??? ??
• Echocardiopraphy (?? TEE)
• MV leaflet motion?? ??
• Color-flow Doppler echo??? eccentric regurgitant
  jet? ????? ???

93
MITRAL REGURGITATIONcalculating regurgitant
fraction

• Regurgitant fraction (RF)? ??? ???? forward
  stroke volume (SV)? regurgitant stroke volume
  (RSV) ??? ????? ?
• RSV? 65? ??? ?? severe MR? ??

94
MITRAL REGURGITATIONTreatment

• Medical treatment
• Digoxin, diuretics, vasodilators (ACE inhibitors)
  ?
• Afterlod ??? ??
• SVR ??? forward SV ??? regurgitant volume ??? ???
• Surgical treatment
• Surgical valvuloplasty
• Valve replacement? ???? ??? ?? ??

95
MITRAL REGURGITATIONAnesthetic management

• Objectives
• MR? ??? LV function? ?? ??
• Slow HR, acute increase in afterload ?? ?
• HR 80100 bpm ??
• ????? ? ????? ?? acute increase in LV afterload?
  ?? ????? ?
• Monitoring
• Pulm. a. pr. Monitoring ??? (large v wave, rapid
  y descent)
• Color-flow Doppler TEE? ?? MR???? ????
• Choice of agent
• ??? ? ??? ventricular function? ?? ??? ???? ?????
  ? ??
• Spinal, epidural anesthesia are well tolerated
• ?? MR ??? volatile agent? depressant effect? ??
  ????? opioid-based anesthetic? ?? ??? ? ???
  bradycardia ??? ??? ?
• Opioid-based anesthetic? pancuronium ??? ???

96
MITRAL VALVE PROLAPSEPreoperative considerations

• ??
• Midsystolic click with or without late apical
  systolic murmur
• ??? ??? ?? ??? ? 5?? ??
• Post. Mitral leaflet?? ?? ?? ??
• Marfan synd ?? connective tissue disorder?? ??
  incidence ??
• ??
• Auscultation ? ???? click ? ??
• Echocardiography ??? systolic prolapse of MV
  leaflets into the LA (confirm)

97
MITRAL VALVE PROLAPSEPreoperative considerations
(2)

• ????
• ??? asymptomatic, ????? myxomatous degeneration
• Chest pain, arrhythmias, embolic events, florid
  mitral regurgitation, infective endocarditis,
  rarely sudden death
• Ventricular volume (preload)? ???? ? prolapse ???
• ECG ?? ??, ???? inverted or biphasic T wave or
  ST-segment change
• PSVT ?? ??? arrhythmia
• ??? NL life span ??

98
MITRAL VALVE PROLAPSEAnesthetic management

• ??? asymptomatic?? special care? ???
• ?? ?? Ventricular arrhythmia ??? ?? lidocaine or
  ß-blocker? ?? ? ??
• Volatile agent? ??? ?? ???? ??? ?
• MR??? ventricular size ??? ????? hypovolemia?
  ventricular emptying? ???? factor(sympathetic
  tone ??, afterload ??)? ??? ?
• Vasopressor? phenylephrine ?? pure a-adrenergic
  agonistrk ???

99
AORTIC STENOSISPreoperative considerations

• Valvular aortic stenosis? LV outflow? Obx ???? ??
  ?? ??
• ? ?? hypertrophic cardiomyopathy, discrete
  congenital subvalvular stenosis, or, rarely,
  supravalvular stenosis
• ?? congenital, rheumatic, degenerative? ??
• Rheumatic AS? aortic regurgiration or mitral
  valve disease ?? ??

100
AORTIC STENOSISPathophysiology

• AS? ?? LV outlet obx? gradual onset?? ???
  ventricle? compensation ?? SV? ???
• Critical AS
• Aortic valve orifice? 0.50.7?? ??? ??
• ??? transvalvular gradient? ? 50mmHg ??? ??? ??
  CO ??? ???
• Advanced aortic stenosis
• Dyspnea on exertion, angina, orthostatic or
  exertional syncope
• LVH? ?? Lt ventricular compliance ??
• CO? ????? ?? ???? ?????, ????? exertion ?? ???
  ???? ??
• CAD ?? angina Sx ?? ? ??

101
AORTIC STENOSISTreatment

• Aortic valve flow (ml/s)
• Peak velocity? 4.5m/s???? severe stenosis? ???
• Treatment
• ?? Sx ??? ? 2-5? ?? ??? ??
• CHF? digoxin, ????, ??? ??? ??
• Percutaneous balloon valvuloplasty
• Aortic valve replacement

102
AORTIC STENOSISAnesthetic management

• ??
• NL sinus rhythm, HR, intravascular volume ??
• ??? fixed SV ??? ?? CO? very rate dependent ?
• HR 6090 bpm ??? ?
• Monitoirng
• Close monitoring of ECG BP
• Severe AS ? intraarterial pr. Monitoring ??
• ??? LVEDV ??? ?? PCWP? ???? ?? ??
• TEE useful for monitoring ischemia, ventricular
  preload, contractility, valvular function,
  effects of therapeutic interventions

103
AORTIC STENOSISAnesthetic management(2)

• Choice of agents
• Mild to moderate AS spinal, epidural ??
• Preload, afterload ??? ?? hypotension ??
• Severe AS ??? spinal, epidural C/I
• Opioid-based anesthetic technique
• Minimal cardiac depression
• Etomidate, combination ketaminebenzodiazepine
• Volatile agent ??? ??? myocardial depression,.
  Vasodilation, loss of normal atrial systole ??
• Tachycardia, HTN? ?? ??? ??
• ?-blocker? esmolol? short half life? ???
• Hypotension 25-50? of phenylephrine?? ??
• Intraop. SVT with hemodynamic compromise
• Immediate synchronized cardioversion
• Frequent ventricular ectopy iv lidocaine?? ??
• Amidarone? supraventricular ventricular
  arrhythmia ?? ????