Preoperative Evaluation and Management with Cardiac Evaluation

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Preoperative Evaluationand Management with
Cardiac Evaluation

• Lauren Hojdila, MSA, AA-C
• Nova Southeastern University

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The Preoperative EvaluationA Standard of Care

• The Joint Commission for the Accreditation of
  Healthcare Organizations (TJC) requires that all
  patients receive a preoperative anesthetic
  evaluation
• The American Society of Anesthesiologists (ASA)
  has approved Basic Standards for Pre-Anesthetic
  Care, which outlines the minimum requirements for
  a preoperative evaluation

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Goals of the Preoperative Evaluation

• Primary Goals
• Reduce patient risk
• Reduction of perioperative morbidity and
  mortality
• Secondary Goals
• Promote efficiency
• Reduce costs
• Conducting a preoperative evaluation is based
  on the premise that it will modify patient care
  and improve outcome.

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Does the Preoperative Evaluation alter Patient
Care ?

• Gibby et al found that anesthetic plans were
  altered in 20 of all patients due to conditions
  identified at the preoperative evaluation
• The most common conditions resulting in
  modification of the anesthetic plan were gastric
  reflux, IDDM, asthma, and suspected difficult
  airway
• These findings indicate the need to do the
  initial preoperative evaluation before the day of
  surgery

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Components of the Preoperative Evaluation

• Personal Interview
• Review of systems
• Prior anesthetic experience (Difficult
  intubation, delayed emergence, MH, delayed NMB,
  PONV)
• Drug allergies
• Physical Examination
• Airway exam
• Body habitus
• Review of Medical Records
• Medications
• Substance use (alcohol, tobacco, illicit)
• Surgical history
• Surgical Diagnosis (Organ systems involved,
  Planned procedure)

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ASA Classification

• Class 1
• Healthy patient, No medical problems
• Class 2
• Mild systemic disease
• Class 3
• Severe systemic disease, but not
  incapacitating
• Class 4
• Severe systemic disease that is a
  constant threat to life
• Class 5
• Moribund, not expected to live 24
  hours irrespective of operation
• Class 6
• Organ donor
• E may be added to the status number to designate
  an emergency operation

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Thyromental DistanceAirway Examination

• Distance from the thyroid cartilage to the inside
  of the mentum
• Measured with the neck in the sniff position
• What is normal thyromental distance?

A higher Mallampati class combined with a mental
distance lt2 finger-breadths may better predict
increased difficulty with intubation.
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Mallampati ClassificationAirway Examination

• Class I
• Soft palate, fauces, uvula, tonsillar pillars
• Class II
• Soft palate, fauces, uvula
• Class III
• Soft palate, base of uvula
• Class IV
• Hard palate only

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What other feature increase the likelihood of
difficult intubation?

• Short, thick neck (Neck circumference)
• Diminished neck extension
• Decreased tissue compliance
• Large tongue
• Teeth (Overbite, Large teeth)
• Decreased TMJ mobility

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NPO Guidelines

• Healthy Adults (No risk factors)
• No solid foods for a minimum of 6 hours
• Clear liquids up to 2 hours prior to elective
  case
• Oral medications up to 1-2 hours with sip of
  water
• Pediatric patients
• Clear liquids up to 2 hours preOp
• Breast milk up to 4 hours preOp
• Solid foods, nonhuman milk, formula up to 6 hours
  preOp

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AspirationWho has a higher risk ?

• Gastrointestinal Obstruction
• GERD
• Diabetes mellitus
• Recent solid-food intake
• Abdominal distention
• Pregnancy
• Depressed consciousness
• Recent opioid administration
• Upper GI or naso-oropharyngeal bleeding, with or
  without trauma
• Emergency surgery

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The Healthy PatientSystems Approach

• Airway
• Examination as previously described
• Pulmonary
• History Tobacco use, asthma, SOB/DOE, sleep
  apnea, wheezing, cough, etc.
• Physical exam Lung sounds, chest excursion, use
  of accessory muscles, cyanosis, clubbing, etc.
• Cardiovascular
• HTN, CAD, MI, angina, CHF, dysrhythmias, valvular
  dx, heart sounds, carotid bruits, peripheral
  pulses
• Neurologic
• Mental status, h/o seizures, neuromuscular
  disease, nerve injury
• Endocrine
• Diabetes mellitus, thyroid disease, adrenal
  cortical suppression, etc.

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The Patient with Known Cardiac Disease

• Define risk
• Goldman risk index (Independent predictors)
• High-risk surgery, h/o ischemic heart dx, h/o
  CHF, h/o cerebrovascular dx, preOp insulin
  therapy, and preOp serum creatinine gt 2 mg/dL
• Need for further testing
• Recent MI or ECG changes
• Poor exercise tolerance
• Need for cardiac surgery
• Prior to current elective surgery

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The Patient withPulmonary Disease

• Site and Type of Surgery
• Thoracic and upper abdominal procedures are
  associated with increased pulmonary complications
• Type and Severity of Disease
• Does the disease have a reversible component ?
• When were they last hospitalized ?
• Interview
• Exercise tolerance, chronic cough, smoking
  history
• What are their current treatment modalities?
• Physical Exam
• Lungs sounds wheezing, rhonchi, decreased
  breath sounds

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Other Diseases of Concern

• Diabetic Mellitus
• Increased risk of CAD, perioperative MI,
  hypertension, and CHF
• Consider beta-blockade in diabetics with CAD to
  help limit myocardial ischemia
• Renal Disease
• Altered drug metabolism
• Fluid management
• Liver Disease
• Coagulation abnormalities
• Altered protein binding and volume of
  distribution

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PerioperativeLab Testing

• No evidence supports the use of routine
  laboratory testing
• There is support for the use of selected lab
  analysis based on the patients preOp history,
  physical exam, and proposed surgical procedure
• A positive result is frequently a false-positive
• High incidence of false-positives when performing
  tests in normal patients (a population with a
  very low prevalence of disease)
• Risk/Cost vs. Benefit
• Medical testing is associated with significant
  cost
• The risk of intervention may outweigh the benefit
• Is it going to change what you do ???

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Recommended Lab Tests

• CBC / Hemoglobin
• Hgb of 7 g/dL is acceptable in patients without
  systemic disease (depending upon proposed
  surgical procedure)
• In patients with systemic disease, signs of
  inadequate systemic oxygen delivery are an
  indication for transfusion
• Electrolytes
• Creatinine and glucose in older asymptomatic
  adults
• BUN and creatinine in patients with systemic
  disease or on medications that affect the kidneys
  
• Coagulation Studies
• Recommended in patients with bleeding disorders,
  liver dysfunction, or on anticoagulant therapy

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Recommended Lab TestsContinued

• Pregnancy Testing
• Current practice
• testing all females of child-bearing age
• Chest X-rays
• Routine testing in the population without risk
  factors can lead to more harm than good
• Is indicated in patients with a history or
  clinical evidence of active pulmonary disease,
  and may be indicated routinely in patients of
  advanced age

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Preoperative Medications

• What is the goal of premedication ?
• Anxiolysis, Sedation, Amnesia, Analgesia, etc.
• What drug, when, and how much ?
• Several classes of drugs may be available to
  facilitate the desired goal
• Timing of drug delivery is as important as drug
  selection
• There is no BEST drug or combination of drugs for
  preoperative medication
• The specific drugs selected are based on the
  goals of premedication balanced with the
  potential side effects these drugs may produce

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Preoperative Medications

• Benzodiazepines
• Act on GABA receptors to produce selective
  anxiolysis at doses that do not produce excessive
  sedation, depression of ventilation, or adverse
  cardiac effects
• Note May lead to any of the above when given
  with opioids
• Opioids
• Should be used when there is a need to provide
  analgesia

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Preoperative MedicationsContinued

• Antiemetics
• Administered in the preOp or intraOp period as
  prophylaxis against PONV
• Droperidol (Black-Boxed), Reglan (? Antiemetic),
  5HT3 inhibitors, Decadron, Scopolamine patch
  (apply several hours before induction of
  anesthesia)
• Drugs used to alter gastric volume/pH
• Clinically significant pulmonary aspiration of
  gastric fluid is rare in healthy patients
  undergoing elective surgery, maintenance of a
  patent airway is more important than routine
  pharmacologic prophylaxis
• Use in patients with specific indications

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What has changed about your plan?

• Airway
• Medications
• Trends of Vital Signs

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Pre-Operative Cardiac Evaluation
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Cardiovascular Disease

• During a lifetime, a heart contracts more than 4
  billion times
• To support the active cardiac state, the heart
  supplies more than 4 million liters of blood to
  the myocardium and more than 200 million liters
  to the systemic circulation
• Cardiac output can vary from 3 L/min to 30 L/min
  depending on activity level
• Regional blood flow can vary up to 200

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Cardiovascular DiseaseMajor Disease Categories

• Coronary heart disease (CHD/CAD)
• Hypertension (HTN)
• Rheumatic heart disease (RHD)
• Bacterial endocarditis
• Congenital heart disease

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Coronary Heart Disease

• Leading cause of death in the United States
• Around 1 million deaths per year from
  cardiovascular pathology
• About ½ of these related to ischemic disease
• No. 1 cause of death among women in the U.S.
• Lifetime risk of death from CHD 31
• Lifetime risk of death from breast CA 2.8

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Coronary Heart DiseaseRisk Factors

• Past medical history
• Chronic disorder
• Hypertension
• Hyperlipidemia
• Diabetes mellitus
• Thyroid dysfunction
• Cardiac surgery
• Rhythm disorder
• Acute rheumatic fever

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Coronary Heart DiseaseRisk Factors Family
History

• Diabetes mellitus
• Heart disease
• Hypertension
• Congenital heart defects
• Particularly VSD
• Sudden death
• Early age cardiovascular disease

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Coronary Heart DiseaseRisk Factors Social
History

• Stressful or physical work
• Tobacco use
• Poor nutritional status
• High strung personality
• Lack of relaxing activities
• Use of alcohol
• Use of illegal drugs

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Preoperative Clinical Evaluation

• Identification of serious cardiac disorder
• CAD, CHF, Arrhythmias
• Initial history, Physical examination, ECG
• Define disease severity, stability, and prior
  treatment
• Functional capacity
• Age
• Comorbidities
• DM, peripheral vascular disease, renal
  dysfunction, chronic pulmonary disease
• Type of surgery
• Consider higher risk
• Vascular procedures
• Prolonged complicated thoracic, abdominal and
  head and neck procedures

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HypertensionManagement of Preoperative
Cardiovascular Conditions

• Severe Htn(DBP gt110mmHg) should be controlled
  before surgery when possible
• Continuation of preoperative antihypertensive
  treatment is critical to avoid severe
  postoperative hypertension.
• Consider the urgency of surgery and the potential
  benefit of more intensive medical therapy.

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Valvular Heart DiseaseManagement of Preoperative
Cardiovascular Conditions

• Symptomatic stenotic lesions (MS or AS)
  associated with risk of perioperative severe CHF
  or shock and often require percutaneous valvotomy
  or replacement to lower cardiac risk.
• Symptomatic regurgitant lesions (AR or MR)
  usually better tolerated perioperatively and may
  be stabilized before surgery with intensive
  medical therapy and monitoring

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Myocardial Heart DiseaseManagement of
Preoperative Cardiovascular Conditions

• Dilated and hypertrophic cardiomyopathy are
  associated with an increased incidence of
  perioperative CHF.
• Maximizing preoperative hemodynamic status and
  providing intensive postoperative medical therapy
  and surveillance.

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Arrhythmias and Conduction AbnormalitiesManagemen
t of Preoperative Cardiovascular Conditions

• Careful evaluation for underlying cardiopulmonary
  disease, drug toxicity, or metabolic abnormality.
• Therapy reverse any underlying cause and treat
  the arrhythmia

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Medical Therapy for Coronary Artery Disease

• If patients require ß-blockers, calcium channel
  blockers, or nitrates before surgery, continue
  them into the operative and post-op period.
• The same is true for therapies used to control
  CHF
• ß-blockers reduce postoperative ischemia
• Protection against ischemia may also reduce risk
  of MI

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Cardiac Evaluation

• Clinical predictors
• Functional capacity
• Surgical risk
• Non-invasive testing
• Invasive testing

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Method of Assessing Cardiac Risk

• Resting Left Ventricular Function
• Exercise Stress Testing
• Pharmacological Stress Testing
• Ambulatory EKG monitoring
• Coronary Angiography

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Clinical Predictors of Increased Perioperative
Cardiovascular Risk(Myocardial Infarction,
Congestive Heart Failure, Death)

• Minor
• Advanced age
• Abnormal EKG(LVH, LBBB, ST-T abnormalities)
• Rhythm other than sinus (eg, atrial fibrillation)
• Low functional capacity (eg, unstable to climb
  one flight of stairs with a bag of groceries)
• History of stroke
• Uncontrolled systemic hypertension
• Intermediate
• Mild angina pectoris(Canadian Cardiovascular
  Society Class I or II)
• Prior myocardial infarction by history or
  pathological waves
• Compensated or prior CHF
• Diabetes mellitus

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Clinical Predictors of Increased Perioperative
Cardiovascular Risk(Myocardial Infarction,
Congestive Heart Failure, Death)

• Major
• Unstable coronary syndromes
• Recent myocardial infarction with evidence of
  important ischemic risk by clinical symptoms or
  noninvasive study
• Unstable or severe angina
• Decompensated CHF
• Significant arrhythmias
• High grade atrioventricular block
• Symptomatic ventricular arrhythmias in the
  presence of underlying heart disease
• Supraventricular arrhythmias with uncontrolled
  ventricular rate
• Severe valvular disease

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Functional Capacity
1 MET Can you take care of yourself?
Can you eat, dress, or use the toilet?
Can you walk indoors around the house?
Can you walk a block or two on level ground at 2-3 mph?
Can you do light housework, such as dusting or washing dishes?
4 METs Can you climb a flight of stairs or walk up a hill?
Can you walk on level ground at 4 mph?
Can you run a short distance?
Can you do heavy housework, such as scrubbing floors or lifting or moving heavy furniture?
Do you participate in moderate recreational activities, such as golf, bowling, dancing, doubles tennis, or throwing a baseball or football?
gt10 METs Do you participate in strenuous sports, such as swimming, singles tennis, football, basketball, or skiing?
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Surgical RiskLow Risk Procedures

• Low surgical risk
• Endoscopy
• Bronchoscopy
• Cystoscopy
• Dermatologic procedures
• Breast biopsy
• Opthalmologic procedures

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Surgical Risk

• Intermediate surgical risk
• Orthopedic surgery
• Urologic surgery
• Uncomplicated abdominal surgery
• Uncomplicated head and neck

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Surgical Risk

• High surgical risk
• Emergency surgery
• Cardiac procedures
• Aortic or vascular surgery
• Anticipated prolonged surgery
• Large fluid shifts or blood loss
• Ex Whipple, spinal surgery

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ElectrocardiogramSignificant ECG Findings

• Past myocardial infarction
• Left bundle branch block
• Bifasicular block
• Atrioventricular block
• Mobitz-Type II or 3AVB
• Prolonged QT interval
• Right ventricular hypertrophy

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Echocardiography

• Displays 2-dimensional ultrasound images of the
  heart
• Can be used to produce accurate assessment of the
  velocity of blood and cardiac tissue
• Utilizes pulse wave Doppler ultrasound
• Diagnostic uses
• Wall motion abnormalities
• Valvular dysfunction (valve area and function)
• Septal defects
• Calculation of cardiac output and ejection
  fraction

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EchocardiographyTypes of Echocardiography

• Transthoracic (TTE)
• Exercise stress echo
• Dobutamine stress echo
• Transesophageal (TEE)

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Stress Testing

• Used to evaluate myocardial perfusion during
  stress as compared to at rest
• Diagnostic usefulness debatable!
• Types of evaluation
• Exercise (a.k.a. treadmill)
• Dobutamine or adenosine
• Radiotracer
• Tc99m Sestamibi (Cardiolite)
• Thallium

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Cardiac Catheterization

• Invasive angiography of myocardial perfusion
• Diagnostic usefulness
• Arterial occlusion
• Thrombotic lesions
• Aneurysmal enlargement
• Concurrent procedures
• Percutaneous transluminal coronary angioplasty
  (PTCA)
• Coronary artery stent placement
• Dissection and stroke

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Stepwise Approach to Preoperative Cardiac
Assessment
Postoperative risk stratification and risk
factor management
Need for noncardiac surgery
emergency
O.R.
no
Urgent or elective
Recurrent symptoms or signs
Coronary revascularization within 5 yrs
yes
yes
no
Recent coronary angiogram or stress test?
Favorable result and no change in symptoms
yes
Recent coronary evaluation
O.R.
Unfavorable result and change in symptoms
no
Clinical predictors
Intermediate
Major
Minor or No
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Stepwise Approach to Preoperative Cardiac
Assessment
Minor or no clinical predictors
Poor(lt4METs)
Moderate or excellent(gt4METs)
High surgical risk procedure
Intermediate surgical risk procedure
low risk
Noninvasive testing
O.R.
Postoperative management
High risk
Consider coronary angiography

• Minor clinical predictors
• Advanced age
• Abnormal ECG
• Rhythm other than sinus
• Low functional capacity
• History of stroke
• Uncontrolled systemic hypertension

Subsequent care by findings and treatment results
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Stepwise Approach to Preoperative Cardiac
Assessment

• Intermediate clinical predictors
• Mild angina pectoris
• Prior MI
• Compensated or prior CHF
• DM

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Stepwise Approach to Preoperative Cardiac
Assessment

• Major clinical predictors
• Unstable coronary syndromes
• Decompensated CHF
• Significant arrhythmias
• Severe valvular disease

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Summary

• How has the information gained in the pre-op
  evaluation changed your plan?
• Is there anything further that you need to
  deliver a safe anesthetic?
• Should you proceed with the case?
• Dont forget to monitor closely.
• Have a back-up plan ready to implement.