Medical Consultation and Preoperative Evaluation

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Medical Consultation and Preoperative Evaluation

• Diane Doerner MD PhD
• University of Washington Medical Center

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Ten Commandments for Effective Consultations

• Determine the question being asked

1. Determine the question being asked.
2. Establish the urgency of the consult.
3. Gather primary data.
4. Communicate as briefly as possible.
5. Make specific recommendations.
Goldman, L et al. Arch Int. Med (1983), 143 1753
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Ten Commandments for Effective Consultations

• Determine the question being asked

6. Provide contingency plans.
7. Understand your role in the process.
8. Offer educational information.
9. Communicate recommendations directly.
10. Provide appropriate follow-up.
Goldman, L. et al. Arch Int. Med (1983), 143 1753
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• One study looking at patterns of consultation
  among internists showed that 67 of consultations
  were for preoperative evaluation. In 12 of
  cases, the findings of the consultation resulted
  in a significant change in perioperative
  management in 7, surgery was delayed a
  decision was made to cancel surgery altogether in
  2 of cases.
• Mollema, et al (2000) Neth J Med 567

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Why Preoperative Evaluation?

• 10 percent of the United States population
  undergoes non-cardiac surgery annually.
• Over 8 million have known CAD or cardiac risk
  factors.
• Over 50,000 will suffer a perioperative
  myocardial infarction.
• The economic burden of these complications has
  been estimated at more than 20 billion
  annually.

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• The purpose of preoperative evaluation is not to
  give medical clearance, but rather to perform an
  evaluation of the patients current medical
  status make recommendations concerning the
  evaluation, management, and risk of cardiac
  problems over the entire perioperative period
  and provide a clinical risk profile that the
  patient, primary physician, anesthesiologist, and
  surgeon can use in making treatment decisions
• Kim A. Eagle, FACC, Chair, ACC/AHA Task Force on
  Practice Guidelines for Perioperative
  Cardiovascular Evaluation for Noncardiac
  Surgery

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Steps to Preoperative Evaluation

• Surgical Risk Factors
• Patient Risk Factors
• Preoperative Testing
• Perioperative Management

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Case 1

• A 74-year old man is referred to you for
  preoperative evaluation prior to undergoing a
  right total hip replacement. He is severely
  limited due to his osteoarthritis and can
  ambulate only limited distances in the home. His
  medical history is notable for CAD, for which he
  underwent an uncomplicated 3-vessel CABG 2 years
  ago. He has been symptom-free since. He has
  mild HTN and chronic renal insufficiency with a
  creatinine of 2.0 at baseline. Other than his
  CABG, he has no surgical history. His current
  medications include aspirin and lisinopril, 10 mg
  daily. His vital signs are notable for a BP of
  140/87, HR 88. Examination is essentially
  normal.
• What are his surgical and medical risk factors?

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Risk Type of ProcedureACC/AHA Guidelines

• High risk (reported risk of adverse cardiac event
  gt5)
• Emergency surgery
• Aortic procedures
• Peripheral vascular surgery
• Prolonged surgical procedures associated with
  large volume shifts or high EBL

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Risk Duration of Anesthesia
Reilly, et al. (1999) Arch Int Med 1592185
Percent Complications
Duration (hours)
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Risk Type of ProcedureACC/AHA Guidelines

• Intermediate Risk (reported cardiac risk lt 5)
• Carotid endarterectomy
• Head and neck surgery
• Intraperitoneal and Intrathoracic
• Orthopedic surgery
• Prostate surgery

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Risk Type of ProcedureACC/AHA Guidelines

• Low risk (reported cardiac risk lt 1)
• Endoscopic procedures
• Superficial procedures
• Cataract surgery
• Breast surgery

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Case 1

• A 74-year old man is referred to you for
  preoperative evaluation prior to undergoing a
  right total hip replacement. He is severely
  limited due to his osteoarthritis, and can
  ambulate only limited distances in the home. His
  medical history is notable for CAD, for which he
  underwent an uncomplicated 3-vessel CABG 2 years
  ago. He has been symptom-free since. He has
  mild HTN and chronic renal insufficiency with a
  creatinine of 2.0 at baseline. Other than his
  CABG, he has no other surgical history. His
  current medications include aspirin and
  lisinopril, 10 mg daily. His vital signs are
  notable for a BP of 140/87, HR 88. Examination
  is essentially normal.
• What are his surgical and medical risk factors?

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Steps to Preoperative Evaluation

• Surgical Risk Factors
• Patient Risk Factors
• Preoperative Testing
• Perioperative Management

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Patient Factors Exercise Tolerance
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• McPhail, et al (1988) J Vasc Surgery 760
• 100 patients requiring vascular reconstructive
  surgery were evaluated preoperatively with
  treadmill testing or arm ergometry.
• Patients able to achieve 85 of their maximal
  predicted heart rate had a 6 cardiac
  complication rate, whereas patients unable to
  achieve 85 MPHR had a 24 rate of complications
  (p 0.04)
• Patients who had a positive stress test but
  achieved gt 85 MPHR had fewer cardiac
  complications.

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1 MET the oxygen consumption (VO2) of a 70 kg,
40 y.o. man at rest3.5 cc/kg/minDuke Activity
Status Index

• lt 4 METS gt 4 METS
• Baking Ice skating
• Slow dancing Moderate cycling
• Golfing with a cart Walking 4 mph
• Playing a musical instrument Heavy housework
• Walking 2 3 mph Skiing

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Risk Patient FactorsMajor Clinical Predictors
ACC/AHA Guidelines

• Unstable coronary syndromes
• Decompensated CHF
• Significant arrhythmias
• Severe valvular disease

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Risk Patient FactorsIntermediate Clinical
PredictorsACC/AHA Guidelines

• Mild angina pectoris
• Prior MI
• Compensated or prior CHF
• Diabetes mellitus
• Renal insufficiency

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Risk Patient FactorsMinor Clinical
PredictorsACC/AHA Guidelines

• Advanced age
• Abnormal ECG
• Rhythm other than NSR
• Low functional capacity
• History of CVA
• Uncontrolled HTN

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Case 1

• A 74-year old man is referred to you for
  preoperative evaluation prior to undergoing a
  right total hip replacement. He is severely
  limited due to his osteoarthritis, and can
  ambulate only limited distances in the home. His
  medical history is notable for CAD, for which he
  underwent an uncomplicated 3-vessel CABG 2 years
  ago. He has been symptom-free since. He has
  mild HTN and chronic renal insufficiency with a
  creatinine of 2.0 at baseline. Other than his
  CABG, he has no other surgical history. His
  current medications include aspirin and
  lisinopril, 10 mg daily. His vital signs are
  notable for a BP of 140/87, HR 88. Examination
  is essentially normal.
• What are his surgical and medical risk factors?
• What preoperative testing is indicated?

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Steps to Preoperative Evaluation

• Surgical Risk Factors
• Patient Risk Factors
• Preoperative Testing
• Who
• How
• Perioperative Management

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Cardiac Testing Resting ECG

• Class I (definite indication)
• Recent ischemic symptoms
• Major / intermediate clinical predictors and high
  or intermediate risk procedure
• Class II (probably warranted)
• Asymptomatic diabetics
• History of cardiac revascularization
• Asymptomatic man gt 45 yo or woman gt 55 yo
• Prior hospitalization for cardiac causes
• Class III (not indicated)
• Asymptomatic patient low risk procedure

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Echocardiography

• Class I (definite indication)
• Current or poorly-controlled CHF unless prior
  studies have documented severe ventricular
  dysfunction
• Class II (probably warranted)
• Prior CHF and no recent evaluation
• Dyspnea of unknown etiology
• Evidence of significant valvular disease
• Class III (not indicated)
• Routine testing of ventricular function in
  asymptomatic patients without a prior history of
  CHF

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emergency
Need for non-cardiac surgery
O. R.
elective
N
Y
Recurrent S/sx?
Recent cardiac revascularization ?
N
Y
Recent cardiac evaluation?
Favorable result?
N
Unfavorable result or change in sx?
Clinical Predictors
ACC/AHA Guidelines
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Clinical Predictors
Major Clinical Predictors?
Intermediate or Minor Clinical Predictors?
Further evaluation
Exercise Tolerance?
Poor Exercise Tolerance lt 4 METS
Good Exercise tolerance gt 4 METS
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Minor or No Clinical Predictors
Poor Exercise Tolerance lt 4 METS
Good Exercise tolerance gt 4 METS
High risk procedure
Intermediate or low risk procedure
Non-invasive cardiac testing
Low risk
High risk
O. R.
Further evaluation
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Intermediate clinical predictors
Poor Exercise Tolerance lt 4 METS
Good Exercise tolerance gt 4 METS
High risk procedure
Intermediate risk procedure
Low risk procedure
Non-invasive cardiac testing
High risk
Low risk
O. R.
Further evaluation
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Preoperative Stress Testing
Y
Major clinical predictors?
Further evaluation
N
N
2 or more of the following Intermediate
clinical predictors Poor exercise
tolerance lt 4 METS High risk surgery
O.R.
Y
Patient ambulatory and can exercise?
Test ONLY if outcome will impact management
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Patient ambulatory and can exercise?
Y
N
Male, normal ECG at rest?
Bronchospasm? Second degree AV block? Theophylline
dependent? Valvular dysfunction?
N
Y
ECG ETT
ETT Echo or Perfusion scan
Y
N
Pharmacological Echo or Perfusion Scan
Prior symptomatic arrhythmia? Poor Echo
window? Extreme blood pressure?
Hx Arrhythmias? Severe HTN?
N
Y
Y
N
Persantine or Adenosine Perfusion Scan
Dobutamine Echo or Perfusion Scan
Further evaluation
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Perioperative ManagementPercutaneous
Intervention (PCI)

• No randomized trials have demonstrated benefit of
  balloon angioplasty or stenting in decreasing
  cardiac risk before non-cardiac surgery.
• Posner KL, et al (1999) Anesth Analg 89553
• Retrospective cohort study comparing patients
  undergoing preoperative PTCA, patients with known
  CAD that did not undergo PTCA preoperatively, and
  normal controls (no known CAD).
• No reduction in early postoperative MI or death
  in patients who underwent PTCA.
• Study was not controlled for severity of CAD,
  differences in medical management between the
  groups, or comorbidity.

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Case 1

• A 74-year old man is referred to you for
  preoperative evaluation prior to undergoing a
  right total hip replacement. He is severely
  limited due to his osteoarthritis, and can
  ambulate only limited distances in the home. His
  medical history is notable for CAD, for which he
  underwent an uncomplicated 3-vessel CABG 2 years
  ago. He has been symptom-free since. He has
  mild HTN and chronic renal insufficiency with a
  creatinine of 2.0 at baseline. Other than his
  CABG, he has no other surgical history. His
  current medications include aspirin and
  lisinopril, 10 mg daily. His vital signs are
  notable for a BP of 140/87, HR 88. Examination
  is essentially normal.
• What are his surgical and medical risk factors?
• What preoperative testing is indicated?
• What measures would you initiate preoperatively
  to optimize his risk?

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Steps to Preoperative Evaluation

• Surgical Risk Factors
• Patient Risk Factors
• Preoperative Testing
• Who
• How
• Perioperative Management

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Perioperative Management Beta-Blockers

• Poldemans D, et al (1999) NEJM 3411789
• 112 patients identified to be at increased
  cardiac risk (positive dobutamine Echo)
  preoperatively were randomized to treatment with
  bisoprolol or placebo.
• Cardiac complications and cardiac death was
  significantly less in the treatment group
  (p0.02)
• Bisoprolol 3.4
• Placebo 17.0
• Wallace A, et al (1998) Anesthesiology 887
• 200 patients undergoing general surgery were
  randomized to 7 day treatment with Atenolol or
  placebo.
• Patients treated with Atenolol had significantly
  fewer episodes of ischemia by continuous
  monitoring (p0.03)

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Perioperative Management Cardiac Devices

• Pacemakers
• Current generated through use of electrocautery
  can interfere with function of implantable
  devices
• Temporary reset to a VVI mode
• Increase in pacing rate due to activation of
  rate-responsive sensor
• Failure to sense or capture

Recommendations Obtain information
preoperatively regarding the pacer manufacturer,
model and serial number, battery status,
and most recent interrogation. If the
pacer is programmed in a rate-responsive mode,
this feature should be inactivated
preoperatively. If a patient is
pacer-dependent, temporary reset to a non-sensing
mode preoperatively may be indicated.
Operative techniques to minimize stray current
(short electrocautery strokes, placement
of electrocautery grounding pad away from pacer
pocket).
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Perioperative Management Cardiac Devices

• Implantable Defibrillators
• Can fire due to activation by stray electrical
  current from electrocautery use
• Must be programmed OFF preoperatively and then
  reactivated postoperatively
• Place defibrillator patches intraoperatively
• Telemetry monitoring is indicated postoperatively
  until the AICD has been reactivated.

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Perioperative ManagementBlood Thinners

• Aspirin (general indication) 14 days
• Aspirin (TIA / CVA / MI) 7 days
• NSAIDS 3-7 days
• Cox II inhibitors --------
• Clopidogrel (Plavix) 4-7 days
• Persantine 7 days
• Coumadin variable
• Herbal remedies 14 days
• (Gingko, Ginseng, Garlic, Feverfew)

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Perioperative Management of Selected Drugs
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Case 2

• A 60-year old woman is referred to you for
  preoperative evaluation prior to undergoing a
  right femoral-popliteal bypass procedure. She
  develops symptoms of claudication at about 1
  block but states she can walk 2 blocks if need
  arises. Her medical history is otherwise notable
  for obesity, hyperlipidemia and type II diabetes,
  diagnosed 6 years ago and well controlled on oral
  medications. ROS is significant for infrequent
  atypical CP. Her current medications include
  glucophage and atorvastatin and cilostazol. Her
  vital signs are normal. Examination is only
  remarkable for a cool right lower extremity with
  a non-palpable dorsalis pedis pulse.
  Cardiopulmonary examination is normal and there
  are no bruits.
• What are her surgical and medical risk factors?
• What preoperative testing is indicated?
• What measures are needed perioperatively?

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Preoperative management of diabetics

• General anesthetic produces relative insulin
  hyposecretion and resistance due to changes in
  neuroendocrine balance (increased production of
  ACTH, catecholamines, GH, and glucagon).
• Postoperative factors such as inability to eat or
  absorb oral medications, use of steroids,
  hyperalimentation or tube feeds can affect
  glycemic control.
• Perioperatively
• Assess glycemic control preoperatively.
• Oral hypoglycemics can generally be continued up
  until the time of surgery but should not be taken
  on the morning of the procedure. Metformin
  should be held for 48 hours postoperatively, and
  then restarted only if renal and hepatic function
  are stable.
• The dose of intermediate and long-acting insulins
  should be reduced on the night prior to surgery.
• For long or complicated procedures in patients
  requiring insulin, intravenous insulin should be
  used in the immediate perioperative period. For
  short procedures, it may be possible to either
  delay the use of morning insulin, or use a
  fraction of the normal dose of intermediate-acting
  insulin.

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THANKS