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Ch.20 Anesthesia for patients with cardiovascular disease

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Title: 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? ? ? ? ??? ?? ??

17
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

18
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 ? ? ??

19
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?)

22
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

24
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) ??

25
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? ?? ??

26
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 ????

27
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

28
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 ?? ??

32
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)
35
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 ??

36
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

39
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)

41
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 ?? ????
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