Preoperative Evaluation 1

Mansoor Masjedi MD , FCCM

Grand round of anesthesia dept.,

SUMS , 21st. Nov. 2013

Unique, remarkable, and revolutionary event has occurred in the field of

anesthesia

Many anesthesiologists have essentially replacedmultiple medical specialties

in patients being prepared for surgery

besides

Anesthesia care is no longer limited to the operating room

Many departments of anesthesiology changed to

“anesthesia and perioperative care”

Anesthesiologists preoperatively perform:

1.Focused clinical examinations 2.Plan for medical intervention and optimization 3.↓patient's & family's anxiety and fears4.Discuss periop. care & postop pain control5.Laboratory tests and diagnostic studies 6.Discuss anesthesia risks 7.Obtain informed consent

Anesthesia preop. evaluation can :

↓surgical morbidity ↓delays & cancellations on the day of op. ↑perioperative efficiency

Pre-Anesthesia Assessment

PATIENT PERSPECTIVE

Preoperative Risk Assessment

The concept of risk associated with anesthesia is unique in that rarely does the

anesthetic itself offer benefit but merely allows others to do things that potentially

offer benefit

Preoperative Risk Assessment

11.6% of reports identified inadequate or incorrect preoperative assessment

communication failure was cited as the most significant factor (preoperative evaluations moments before op.)

medical status mortalityASA I normal healthy patient without organic,

biochemical, or psychiatric disease0.06-0.08%

ASA II

mild systemic disease with no significant impact on daily activity e.g. mild diabetes, controlled hypertension, obesity .

Unlikely to have an impact

0.27-0.4%ASA III

severe systemic disease that limits activity e.g. angina, COPD, prior myocardial infarction

Probable impact

1.8-4.3% ASA IV

an incapacitating disease that is a constant threat to life e.g. CHF, unstable angina, renal failure ,acute MI, respiratory failure requiring mechanical ventilation

Major impact 7.8-23%

ASA V

moribund patient not expected to survive 24 hours e.g. ruptured aneurysm

9.4-51%

ASA VI

brain-dead patient whose organs are being harvested

Preoperative Risk Assessment

ASA Physical Status Classification System

For emergent operations, you have to add the letter ‘E’ after the classification.

ASA risk classification system;limitations

Neither the type of anesthesia Nor the location of Op. Most importantly, no attempt to quantify

the risk

Detecting Disease in Preoperative Evaluation

56% of correct diagnoses were made with the Hx. alone, which increased to 73% with the addition of P/E

cardiovascular disease : C-xray & ECGs helped with only 3% of diagnoses, and special tests (e.g., exercise ECG) assisted with 6%

1 Eating, working at a computer, dressing 2 Walking down stairs or in your house, cooking 3 Walking 1-2 blocks 4 Raking leaves, gardening 5 Climbing 1 flight of stairs, dancing, bicycling 6 Playing golf, carrying clubs 7 Playing singles tennis 8 Rapidly climbing stairs, jogging slowly 9 Jumping rope slowly, moderate cycling 10 Swimming quickly, running or jogging briskly 11 Skiing cross country, playing full-court basketball 12 Running rapidly for moderate to long distances

At a minimum, the preanesthetic examination should include vital signs (BP, HR, RR,T, Spo2), height, and weight

BMI is more accurate than weight in establishing obesity

↑BMI is predictive of airway difficulties & development of chronic diseases such as heart disease, cancer, and diabetes

Length of the upper incisors Condition of the teeth Ability to protrude or advance the lower incisors in front of

the upper incisors ( ULBT ) Interincisor or intergum (if edentulous) distance Tongue size Visibility of the uvula Presence of heavy facial hair Compliance of the mandibular space Thyromental distance with the head in maximum

extension Length of the neck Thickness or circumference of the neck Range of motion of the head and neck

Cardiovascular complications are the most common serious perioperative adverse event

Cardiac morbidity will occur in 1% to 5% of

unselected patients undergoing noncardiac surgery

≥ 2 BP greater than 140/90 mm Hg, affects 1 billion individuals worldwide

End-organ damage and morbidity and mortality correlate with the duration and severity of HTN

IHD is the most common type of organ damage associated with hypertension

Each 20 mm Hg ↑SBP or 10–mm Hg ↑DBP above 115/75 , doubles the lifetime risk for cardiovascular dis. (in 40 to 70 y/o)

Hx. & P/E : determine cardiac, neurologic, or renal dis. (important)

If severe end-organ damage normalize BP as much as possible before surgery

Postpone elective op if severe hypertension (DBP >115 mm Hg, SBP >200 mm Hg) until BP ≤180/110

lowering of risk requires 6 to 8 wks of Rx (regression of vascular and endothelial changes)

Too rapid or extreme lowering → ↑cerebral and coronary ischemia

Benefits of delaying op for Rx must be weighed against the risks

Cardioselective β-blocker therapy is the best treatment preoperatively because of a favorable profile in lowering cardiovascular risk

Perioperative Ischemia Evaluation (POISE) trial has recently questioned the safety of starting these agents acutely

The optimal time to start β-blocker therapy to achieve its benefit while minimizing risk is unknown

Periop stroke, role of β blockers in general and metoprolol in particular

Routine use of preop metoprolol, but not atenolol, is associated with stroke after noncardiac sx., even after adjusting for comorbidities

Intraoperative metoprolol but not esmolol or labetalol, is ass. with increased risk of periop stroke

Drugs other than metoprolol should be considered during the perioperative period

if β blockade is required

The goals of preop evaluation are to:

1) Identify the risk for heart disease based on risk factors

2) Identify the presence and severity of heart disease from symptoms, physical findings, or diagnostic tests

3) Determine the need for preoperative interventions

4) Modify the risk for perioperative adverse events

1. High-risk surgery (intraperitoneal, intrathoracic, or suprainguinal vascular procedures) *

2. IHD (by any diagnostic criteria) 3. Hx of CHF4. Hx of cerebrovascular dis.5. IDDM [†] 6. Cr. >2.0 mg/dL * This risk factor is not considered a clinical predictor in the ACC/AHA 2007

guidelines for perioperative cardiac evaluation for noncardiac surgery † This risk factor has been changed to simply diabetes mellitus in the ACC/AHA

2007 guidelines for perioperative cardiac evaluation for noncardiac surgery

Copyright ©2007 American College of Cardiology Foundation. Restrictions may apply.

Fleisher, L. A. et al. J Am Coll Cardiol 2007;50:e159-e242

Cardiac evaluation and care algorithm for noncardiac surgery based on active clinical conditions, known cardiovascular disease, or cardiac risk factors for patients 50 years of

age or greater

Patients with risk factors for CAD or symptoms suggestive of ischemia, including atypical ones such as dyspnea, need an ECG

An ECG should not be ordered simply because of advanced age

Establishing a baseline for comparison is the most important reason to obtain an ECG preoperatively

Class IClass I At least one clinical risk factor * undergoing vascular surgical

procedures Known CHF, peripheral arterial disease, or cerebrovascular dis.

undergoing intermediate-risk surgical procedures

Class IIaClass IIa No clinical risk factor undergoing vascular surgical procedures Class IIbClass IIb At least one clinical risk factor undergoing intermediate-risk

operative procedures Class IIIClass III Not indicated for asymptomatic persons undergoing low-risk

surgical procedures

Class I recommendations: the procedure should be performed; class IIa: it is reasonable to perform the preocedure; class IIb: the procedure may be considered; class III: the procedure should not be performed because it is not helpful

Noncardiac surgery soon after revascularization (CABG or PCI with or without stents) is associated with high rates of perioperative cardiac morbidity and mortality

Patients who need noncardiac surgery within the next year are not good candidates for implantation of drug-eluting stents, and if revascularization is absolutely necessary, these patients need to be considered for either CABG or PCI without stenting or with a bare metal stent

Cardiac catheterization, which some consider the gold standard for evaluation of coronary lesions, does not absolutely risk-stratify patients

Perioperative cardiac risk increases with increasing amounts of at-risk myocardium

If a patient has undergone a specific test in the past, it is most useful to obtain the same test for comparison

2% of the population in USA

Significant risk factor for postop adverse events

One in 100 individuals between 50 and 59 y/o has a 5% to 7% risk of perioperative cardiac complications, but those with decompensated failure have a 20% to 30% incidence

IHD is the most common cause of systolic dysfunction in the United States (50% to 75% of cases

In patients undergoing noncardiac surgery, preoperative BNP levels predict cardiac complications and death

Class I: no limitation of physical activity; ordinary activity does not cause fatigue, palpitations, or syncope

Class II: slight limitation of physical activity; ordinary

activity results in fatigue, palpitations, or syncope

Class III: marked limitation of physical activity; less than ordinary activity results in fatigue, palpitations, or syncope; comfortable at rest

Class IV: inability to perform any physical activity

without discomfort; symptoms at rest

Continuing or discontinuing anti failure drugs depends on:

Volume and hemodynamic status of the pt Degree of cardiac dysfunction Anticipated surgery and volume challenges

Class IClass I—echocardiography is useful useful in asymptomatic patients with the following cardiac murmurs:

Diastolic murmurs Continuous murmurs Late systolic murmurs Murmurs associated with ejection clicks Murmurs that radiate to the neck or back Grade 3 or louder systolic murmurs Class I1a Class I1a —in favor of the usefulness in favor of the usefulness of echocardiography in

asymptomatic patients with the following cardiac murmurs: Murmurs +abnl heart P/E Murmurs +abnl EKG or C-xray Class III Class III — echocardiography is not useful not useful in asymptomatic pts + Grade 2 or softer midsystolic murmurs

considered innocent or functional by an experienced observer

The most important preop. issues are:Underlying condition requiring

replacementType of prosthesis Need for anticoagulationPeriop. management

Risk of thrombosis:Multipe prosthetic valaves >mitral v. > aortic v. Caged-ball valves >single tilting-disk

valves>bileaflet tilting-disk prostheses

Bioprosthetic valves generally do not require long-term anticoagulation

Decision To stop anticoagulants Duration off anticoagulantsTo “bridge” with a shorter-acting drugType of bridging agent (heparin or LMWH)

need to be made in conjunction with the treating cardiologist and surgeon

http://homepage.mac.com/claudio/Avantgo/UCLA.html

Classification Intermittent (paroxysmal), Persistent (able to be cardioverted)Permanent (unable to be converted)

Rate control is more important than rhythm control

Patients with rapid ventricular rates (>100 beats/min) require control before elective surgery

Ventricular vs atrial ectopicswide QRS (>0.12 msec) lack of a P wave

The traditional grading system of Lown, organized by morphology (unifocal or multifocal), frequency (less than or greater than 30 beats/min), and other characteristics (couplets, R on T phenomenon), is limited in its ability to stratify risk

BenignBenign: isolated VPBs without heart disease No need for further evaluation No risk of sudden cardiac arrest

Potentially lethalPotentially lethal: >30 VPBs/hr or nonsustained VT with underlying heart dis Cardio consult with possible echocardiography, stress testing,

catheterization, or electrophysiologic testing Moderately high risk of sudden cardiac arrest; may benefit from an

ICD LethalLethal: sustained VT, VF,syncope, or hemodynamic

compromise ass. with VPBs with underlying heart dis. & often depressed cardiac function Requires cardiology evaluation with possible stress testing,

echocardiography, catheterization, or electrophysiologic testing High risk of sudden cardiac arrest; likely to benefit from an ICD

Thank you