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Anesthesia and the Cardiac Patient

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Anesthesia and the Cardiac Patient Wayne E. Ellis, Ph.D., CRNA * * * * * * * * * * * * * * * Wayne E. Ellis Anesthesia for Noncardiac Surgery * * Wayne E. Ellis ... – PowerPoint PPT presentation

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Title: Anesthesia and the Cardiac Patient


1
Anesthesia and the Cardiac Patient
  • Wayne E. Ellis, Ph.D., CRNA

2
(No Transcript)
3
Preoperative Preparation
  • Angina
  • Medications to control it
  • Blood pressure controlled
  • Diastolic lt 95 torr
  • Congestive heart failure treated
  • Diuretics
  • Afterload reduction
  • Bedrest if indicated
  • Control diabetes

4
Preoperative Medications
  • Sedation
  • Prevent tachycardia
  • Hypertension
  • Prepared for hypoxia
  • Supplemental oxygen
  • Calcium channel blockers not protective of
    perioperative ischemia
  • Antihypertensives continue on day of surgery
  • Stop Diuretics

5
Antianginal medications
  • Beta-blockers
  • Calcium Channel Blockers
  • Nitrates
  • Nitropaste morning of surgery

6
Beta Blockers
  • Negative inotropic effects
  • Withdrawal following stoppage of beta blocker
  • Unstable angina
  • Myocardial infarction

7
Monitoring
  • EKG
  • Blood Pressure
  • Temperature
  • Pulse oximetry
  • End tidal CO2

8
Arterial Catheter
  • Beat to beat blood pressure monitoring
  • ABGs
  • Early detection of hypotension

9
Laboratory studies
  • HGB HCT
  • Electrolytes
  • Liver function studies
  • Creatine clearance
  • Osmolality

10
PA catheter
  • Assessment of LV Function
  • Early detection of ischemia
  • v waves
  • Increased PCWP
  • More accuracy than CVP
  • Intravascular volume problems
  • Especially in patients with severe lung disease

11
Transesophageal Echocardiography
  • Demonstrates regional wall motion abnormalities
  • Suggestive of ischemia
  • Most accurate measure of left ventricular volume

12
Non-invasive Continuous Cardiac Output Monitors
  • Transesophageal Doppler
  • Thoracic impedance
  • Limited
  • Accuracy is controversial
  • No information about systemic vascular resistance
  • Measure CVP

13
Improved outcomes
  • Aggressive monitoring treatment
  • Vasoactive drugs
  • Reduced intraoperative ischemia
  • MI lt 6 months has better survival rate
  • Occurrence reduced from 30-5
  • Multi-institution study over last 10 years
  • 5000 patients
  • Continued for 3 days post-operatively

14
Decision to use Invasive Monitoring
  • Patients with severe inoperable CAD
  • Chronic stable angina undergoing significant
    abdominal or thoracic surgery
  • Large blood loss
  • History of remote MI with stable angina
  • Not necessary to use invasive monitors

15
Anesthetic Management
  • Regional vs general
  • Anesthetic management skills more important than
    technique
  • Safest technique is the one the practitioner does
    best

16
General anesthesia
  • Avoids sympathectomy
  • Risks with intubation
  • Sympathetic stimulation
  • Hypoxia
  • Increased catecholamines
  • Loss of subjective monitor
  • Chest pain
  • Ischemia

17
General Anesthesia required
  • Narcotics
  • Effective control of catecholamines
  • Respiratory depression
  • Prolonged ventilation

18
Inductions Agents
  • Avoid Ketamine
  • Hypertension
  • Tachycardia
  • Use in trauma
  • Etomidate
  • Painful to inject
  • More CV stability
  • Barbiturate
  • Direct depressant
  • Extended duration of activity
  • Smaller doses
  • 1-2 mg/kg
  • Add benzodiazepines and narcotic

19
Benzodiazepines
  • Quell anxiety
  • Hemodynamic stability
  • Extended duration of action
  • Potential for hypoxia
  • Lidocaine
  • Esmolol

20
Muscle Relaxants
  • Avoid pancuronium
  • Tachycardia
  • ST segment changes consistent with ischemia
  • Doxacurium
  • Duration similar to pancuronium
  • No cardiovascular effects

21
Avoid Histamine releasing drugs
  • Curare
  • Atracurium
  • Mivacurium lt15 mcg/kg
  • Hypotension
  • Tachycardia

22
Inhalation Agents
  • Potential for coronary steal
  • Alters coronary autoregulation
  • Alters regional blood flow
  • Little influence on outcome

23
Nitrous Oxide
  • Constricts coronary arteries
  • Aggravates myocardial ischemia
  • High FiO2 recommended
  • Maintain saturation at 95-100

24
Regional Anesthesia
  • Monitor patient more accurately
  • Control sympathetic responses
  • Fluids
  • Esmolol

25
Intraoperative predictors
  • Choice of anesthetic
  • Site of surgery
  • Duration of Anesthesia
  • Emergency Surgery

26
Intraoperative predictors
  • Choice of Anesthetic
  • No difference in infarction rate GETA vs.
    Regional
  • No significant hypotension
  • No significant tachycardia
  • TURP
  • Regional decreased risk post MI
  • Reinfarction rate
  • SAB lt 1
  • GETA 2-8

27
Intraoperative predictors
  • Choice of Anesthetic
  • Patient with CHF will benefit from regional
    technique
  • Sympathectomy
  • Decreased preload
  • Coronary Steal
  • Potent inhalation agents vs. narcotics

28
Intraoperative predictors
  • Site of Surgery
  • Thoracic and upper abdominal
  • 2-3 Xs risk of extremity procedures
  • Duration of Anesthetic
  • gt 3 hours gt risk of morbidity mortality
  • Emergency Surgery
  • 2 - 5 Xs greater risk than nonemergent surgery

29
Cardioactive drugs
  • Nitroglycerin
  • Lower LVEDP
  • Vasodilator
  • Poor ventricular function

30
Esmolol
  • Control heart rate and blood pressure
  • Induction
  • Emergence

31
Labetalol
  • Mixed alpha and beta
  • Control hypertension
  • Heart rate management

32
Lidocaine
  • Blunt effects of intubation
  • 1.5 mg/kg 4-6 minutes prior to intubation

33
Clonidine
  • Less hypertension
  • Decreased anesthesia requirements

34
Nifedipine
  • Controlling hypertension
  • Manage coronary artery spasm

35
Postoperative Management
  • Maintain analgesia
  • Balance supply and demand
  • Supplemental oxygen
  • Continue monitoring into postoperative period
  • Early transfusion

36
Coronary Artery Disease
  • Major Goal
  • Balance Supply and Demand
  • Primary Determinants of Myocardial Oxygen Demand
  • Wall tension and Contractility

37
Coronary Artery Disease
  • Factors modifying coronary blood flow
  • diastolic time
  • perfusion pressure
  • coronary vascular tone
  • intraluminal obstruction

38
Coronary Artery Disease
  • Myocardial O2 Extraction
  • infrequently the cause of ischemia
    intraoperatively
  • Arterial O2 Content
  • Correction of anemia
  • High FiO2

39
Hemodynamic Goals for the Patient with CAD
  • P - keep the heart small, decrease wall
    tension, increase perfusion pressure
  • A - maintain, hypertension better than
    hypotension
  • C - depression is beneficial when LV function is
    adequate
  • R - slow, slow, slow

40
Hemodynamic Goals for the patient with CAD
  • Rhythm - usually sinus
  • MVO2 - control of demand frequently not enough,
    monitor for and treat supply ischemia
  • CPB - elevated ventricular filling pressure
    usually not needed after CABG

41
Valvular Heart Disease
  • Aortic Stenosis
  • IHSS
  • Aortic Insufficiency
  • Mitral Stenosis
  • Mitral regurgitation

42
Aortic Stenosis
  • Characterized by
  • Obstruction to LV outflow
  • Intraventricular systolic pressure and wall
    tension increase
  • Concentric hypertrophy
  • Decreased LV compliance
  • Reliance on atrial contribution

43
Hemodynamic Goals for the Patient with AS
  • P - full, adequate intravascular volume to fill
    noncompliant ventricle
  • A - already elevated but relatively fixed,
    coronary perfusion pressure must be maintained
  • C - usually not a problem, inotropes may be
    helpful preinduction in end-stage AS with
    hypotension

44
Hemodynamic Goals for the Patient with AS
  • R - not too slow (decrease CO), not too fast
    (ischemia)
  • Rhythm - Sinus!! Cardioversion if hemodynamic
    instability from SV dysrhythmias
  • MVO2 - Ischemia is an ever present risk, Avoid
    tachycardia and hypotension

45
Idiopathic Hypertrophic Subaortic Stenosis
  • Characterized by
  • Myocardial hypertrophy
  • 20 -30 have subvalvular obstruction
  • Outflow tract of LV is narrowed
  • Increases in contractility, heart rate or
    decreases in preload or afterload increase the
    risk of ischemia

46
Hemodynamic Goals for the Patient with IHSS
  • P - Full, full, full volume is treatment for
    hypotension
  • A - Up, up, up vasoconstrictor follows fluid for
    hypotension
  • C - Depression is ok
  • R - not too slow, not too fast

47
Hemodynamic Goals for the Patient with IHSS
  • Rhy - Sinus, sinus, sinus consider pacing PA
    cath to control atrial mechanism
  • MVO2 - Usual precautions apply
  • CPB - Avoid inotropes post-CPB, the myocardial
    disease is still present, try vasoconstrictors
    first

48
Aortic Insufficiency
  • Characterized by
  • Chronic volume overload
  • Ventricular dilatation
  • Eccentric hypertrophy
  • Forward stroke volume higher than normal causing
    increased systolic pressure
  • Regurgitation across the valve causes diastolic
    pressure to be lower than normal

49
Hemodynamic Goals for the Patient with AI
  • P - normal to slightly increased
  • A - Reduction beneficial with anesthetics or
    vasodilators,increases augment regurgitant flow
  • C - usually adequate
  • R - Modest tachycardia reduces ventricular
    volume, raises aortic diastolic pressure

50
Hemodynamic Goals for the Patient with AI
  • Rhythm - usually sinus, not a problem
  • MVO2 - Not usually a problem
  • CPB - observe for ventricular distention
    (decreased HR, increased ventricular filling
    pressure) when going onto bypass

51
Mitral Stenosis
  • Characterized by
  • Normal ventricular function
  • Obstruction to left atrial emptying decreases
    cardiac output
  • Pulmonary congestion from elevations in LA and
    pulmonary venous pressure
  • Pulmonary hypertension and RVH over time

52
Hemodynamic Goals for the Patient with MS
  • P - Enough to maintain flow across stenotic valve
  • A - Avoid increased RV afterload
  • C - LV usually ok until after CPB, with
    longstanding PHTN RV may be impaired
  • R - slow to allow time for ventricular filling

53
Hemodynamic Goals for the Patient with MS
  • Rhythm - Often atrial fibrillation, control
    ventricular response
  • MVO2 - Not a problem
  • CPB - Vasodilators may help post-CPB RV failure,
    control of ventricular response may be difficult

54
Mitral Regurgitation
  • Characterized by
  • Chronic volume overload similar to AI
  • Increased ventricular compliance without change
    in LVEDP
  • May mask signs of impaired ventricular function

55
Hemodynamic Goals for the Patient with MI
  • P - Usually pretty full, may need to keep that
    way, although preload reduction may reduce
    regurgitant flow
  • A - Decreases are beneficial, increases augment
    regurgitant flow
  • C - Unrecognized myocardial depression possible,
    titrate myocardial depressants carefully

56
Hemodynamic Goals for the Patient with MI
  • R - A faster rate decreases ventricular volume
  • Rhythm - Atrial fibrillation is occasionally a
    problem
  • MVO2 - only if associated with CAD, then caution!
  • CPB - New valve will increase afterload,
    unmasking impaired ventricle

57
Anesthetic Technique
  • Goals of Anesthesia
  • loss of conciousness
  • amnesia
  • analgesia
  • suppression of reflexes (endocrine and autonomic)
  • muscle relaxation

58
Inhalation Agents
  • Advantages
  • Myocardial oxygen balance altered favorably by
    reductions in contractility and afterload
  • Easily titratable
  • Can be administered via CPB machine
  • Rapidly eliminated

59
Inhalation Agents
  • Disadvantages
  • Significant hemodynamic variability
  • May cause tachycardia or alter sinus node
    function
  • Possibility of coronary steal syndrome

60
Coronary Steal
  • Arteriolar dilation of normal vessels diverts
    blood away from stenotic areas
  • Commonly associated with adenosine, dipyridamole,
    and SNP
  • Forane causes steal and new ST-T segment
    depression
  • May not be important since Forane reduces SVR,
    depresses the myocardium yet maintains CO

61
Opioids
  • Advantages
  • Excellent analgesia
  • Hemodynamic stability
  • Blunt reflexes
  • Can use 100 oxygen

62
Opioids
  • Disadvantages
  • May not block hemodynamic and hormonal responses
    in patients with good LV function
  • Do not ensure amnesia
  • Chest wall rigidity
  • Respiratory depression

63
Induction Drugs
  • Barbiturates
  • Benzodiazepines
  • Ketamine
  • Etomidate

64
Nitrous Oxide
  • Rarely used due to
  • increased PVR
  • depression of myocardial contractility
  • mild increase in SVR
  • air expansion

65
Muscle Relaxants
  • Used to
  • facilitate intubation
  • prevent shivering
  • attenuate skeletal muscle contraction during
    defibrillation

66
Postoperative predictors
  • Ischemia does occur most commonly in the
    postoperative period
  • Persists for 48 hours or longer following
    non-cardiac surgery
  • Predictor value is unknown
  • Goldman, L., (1983) Cardiac Risk and
    Complications of noncardiac surgery, Annals of
    Internal Medicine. 98504-513

67
Medications
  • Beta Blockers
  • CEB
  • Nitrates
  • Lidocaine
  • Procainamide
  • ACE Inhibitors
  • MAO Inhibitors
  • Psychotropic Medications
  • Alternative and supplemental additives

68
Affects Oxygen Supply
  • Coronary blood flow
  • Perfusion
  • Atria and normal RV during entire cycle
  • Left ventricle during diastole
  • With increased heart rate diastole is shortened
  • Coronary perfusion pressure (LV)
  • Diastolic pressure minus left ventricular end
    diastolic pressure
  • CPP DP - LVEDP

69
Heart Rate
  • The faster the rate the more oxygen required
  • The faster the rate there is less time for tissue
    oxygenation
  • Many studies have focused on the best anesthesia
    technique for the cardiac patient
  • Gonzales, University of Iowa
  • The best technique in the hands of the
    practitioner with an adequate knowledge of
    physiology, pathophysiology, pharmacology and
    patient dynamics

70
Beta-blockers
  • Reduce perioperative ischemia in those undergoing
    noncardiac surgery
  • Known coronary artery disease
  • High risk of coronary artery disease (2 or more
    risk factors)
  • Atenolol
  • Started preoperatively and continued until
    discharge from the hospital
  • May decrease overall mortality at 2 years
  • Most of the lower mortality is attributable to
    lower cardiac mortality in the 6 to 8 months
    after surgery
  • Bisoprolol with similar results
  • References
  • New England Journal of Medicine 3351713-1720,
    1996
  • Anesthesiology 17-17, 1998
  • New England Journal of Medicine 3411789-94,
    1999.

71
Oxygen Supply
  • With coronary stenosis
  • Improve CPP
  • Increase systemic pressure
  • Lower elevated LVEDP
  • Nitroglycerin
  • Hemoglobin Level
  • Oxygen saturation

72
Temperature
  • Keep warm
  • Decreasing temperature
  • Shift Oxygen dissociation curve to left
  • Hemoglobin retains oxygen at tissue level
  • Prevent alkalosis

73
Preoperative considerations
  • Medications
  • Pacemaker
  • Does Patient have one?
  • Does Patient need one?
  • Defibrillator

74
Monitoring
  • Enough ECGs already
  • Invasive monitors
  • Radial arterial catheter
  • CVP
  • PA
  • TEE
  • Transesophageal echocardiography

75
Anesthesia
  • Goal
  • Does technique make a difference?
  • Laryngoscopy
  • Maintenance
  • Regional anesthesia

76
Treatment of ischemia
  • Is it real?
  • Optimize oxygenation and hemodynamics
  • IV NTG
  • SL Nifedipine
  • Diltiazem
  • Intra-aortic Ballon Pump
  • Improves systolic run off
  • Provides diastolic augmentation

77
IABP
Systole
Coronary arteries
Diastole
Aortic valve
78
IABP
Systole
Systole Balloon deflates
79
IABP
Diastole
Systole
Diastole Balloon inflates
80
IABP
Systole
Systole Balloon deflates
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