Lt Col AK SinghDept of Anaesthesia

Preoperative/PreanaestheticEvaluation(PAC)

Contents

• Definition

• Goals

• Steps of Preoperative Evaluation

• Airway Assessment

• Role of primary care physician & nursing officers

• Conclusion

• This is a procedure to ensure that patient is asymptomatic from the anaesthetic risk point of view before surgery by physiological and psychological preparation.

Part 1

General consideration

Part 2

Anaesthetic implication of concurrent disease

Definition

What is Anesthesia ?

•Amnesia (reversible loss of

consciousness)

•Analgesia

•Areflexia (muscle relaxation)

Triad of

Types of Surgical Procedure

• Type A- Minimally invasive Little physiological changes e.g. cataract

• Type B- Moderately invasive Modest physiological changes e.g. TURP

• Type C- Highly invasive Significant physiological disruption e.g. THR

Goals

Quality of preoperative care

Morbidity and mortality of surgery

Cost of preoperative care

Anxiety

Problem Identification

Risk Assessment

Plan of Anesthetic Management

Preanaesthetic Instructions

Steps of preoperative evaluation

Problem Identification

History

Physical examination

laboratory investigations

History and physical examination are the

most important assessors of disease

and risk.

History

History

• First areas of concern:

– Previous anaesthetic exposure

– Unusual Bleeding

– Medication

– Personal history

– Family history

– Any other illness

– Exercise tolerance

Exercise Tolerance

• 1 MET walk 200-300 m on ground level at

3.2 to 4.8 km/hr

• 4 MET climb a flight of stairs

• 10 MET participate in strenuous

activities (swimming,cycling

tennis,football)

Exercise Tolerance in METs

• 10 METs : Excellent

• 7 – 10 METs : Good

• 4 - 6 METs : Moderate

• < 4 METs : Increased anaesthetic risk

Physical Examination:

General examination

Airway assessment

Respiratory system

Cardiovascular system

System related problems identified from

the history

Airway Assessment

Predictors of difficult intubation

• Mallampati

• ULBT

• Measurements (IID, TMD, SMD)

• Movement of the Neck

• Deformities

MALLAMPATI

PATIENT DOCTOR

Upright, maximal jaw opening, tongue protrusion without phonation

Class I = visualize the soft palate, uvula, anterior and posterior pillars.

Class II = visualize the soft palate and uvula.

Class III = visualize the soft palate and the base of the uvula.

Class IV = soft palate is not visible at all.

Mallampati Classification

ULBT

• Class 1:Lower incisors can bite upper lip

above vermillion line.

• Class 2:Lower incisors can bite upper lip

below vermillion line.

• Class 3:Lower incisors cannot bite the upper lip.

Less than or equal to 4.5 cm is

considered a potentially

difficult intubation.

Generally greater than 2.5 to 3

fingerbreadths (depending on

observers fingers)

Interincisor distance (IID)

Thyromental distance(TMD)

Upright, neck extension, mouth closed, Distance < 6.5cm difficult intubation

Sternomental Distance(SMD)

Extended head and neck, mouth closed, distance <12.5cm is a difficult intubation

Movement of the Neck

CRANIOFACIAL DEFORMITIES

Pierre Robin Goldenhar'sTreacher Collins

Why would this man’s airwaybe difficult to manage?

Laboratory Tests

•Routine or standing lab tests discouraged

•Based on history or physical examination

Disadvantage1. Increased cost2. Delay in surgery3. Medico legal problem

Advantage 1. Surgeon comfortable 2. Anaesthesiologist comfortable

Recommended test Guidelines For Asymptomatic Patient

• Age up to 49 yrs CBC

• Age 50-64yrs CBC,ECG

• Age > 65 yrs CBC, ECG, CXRUrine analysisBUN/ Cr, ElectrolyteBlood Sugar

• Type C Surg Blood Gr , ALB, Plt

Disease based identification Tests

Alcohol abuse CBC, PT/PTT, AST/Alkp, ECG, Plt

Adrenal cortical Disease CBC, Elec, Glu, Plt

Anemia CBC, Plt

Cancer, except skin, without known metastases

CBC, CXR, Plt

Diabetes Elec, BUN/Cr, Glu, ECG

Hematologic abnormalities CBC, T/S &AB, PT/PTT, Plt

Exposure to hepatitis AST/Alkp, BUN/Cr

Hepatic disease PT/PTT, BUN/Cr, AST/Alkp

Malignancy with chemotherapy CBC, PT/PTT, BUN/Cr, AST/Alkp, CXR, Plt

Malnutrition CBC, T/S &AB, PT/PTT, Plt

Morbid obesity BUN/Cr, Glu, ECG

Peripheral vascular disease or stroke CBC, Glu, BUN/Cr, ELEC, Plt

Disease based identification tests

Personal or family history of bleeding

CBC, PT/PTT, Plt

Poor exercise tolerance or “real age” over 60

CBC, BUN/Cr, Glu, Plt

Possibly pregnant HCG, CXR+

Pulmonary disease CBC, Elec, BUN/Cr , Glu, Plt

Renal disease CBC, Elec , BUN/Cr, Plt

Rheumatoid arthiritis CBC, ECG, CXR+, Plt

Sleep apena CBC, ECG, Plt

Smoking>40 pk/yr CBC, ECG, CXR+, Plt

Suspected UTI r prosthesis insertion U A

Systematic lupus BUN/Cr, ECG, CXR+

Therapy based indications TESTS

Radiation therapy CBC, ECG, CXR, Plt

Use of anticoagulants CBC, PT/PTT, Plt

Use of digoxin and diurectics Elec, Bun/Cr, ECG

Use of statins AST/Alkp, ECG

Use of steroid Eelc, Bun/ Cr, Glu

Procedure based indications

Procedure with significant blood loss CBC, T/S & ALB, Plt

Procedure with radiographic dye Bun/Cr

Class C Procedure CBC, T/S & ALB, Elec, Bun/Cr, Plt

• Respond specifically to the question posed

• Optimize the condition

• Indicate any new observation

• Do not suggest any anaesthetic/surgical

methods

• Statement like “cleared for surgery” or

“prevent hypoxia and hypotension

preoperatively” is not advisable .

Role of The Primary Care Physician

or Consultant

– The consulting internists’ role in

perioperative care is focused on the

elucidation of medical factors that may

increase the risk of anaesthesia and

surgery . Selecting the anaesthetic

technique for a given patient ,

procedure , surgeon , and anaesthetist

is highly individualized and remains the

responsibility of the anaesthesiologist

rather than the internist.

• As to disagreement with the primary care

American College of physician

highlights the role of primary

care physician as-:

Role of Nursing officers

• Relieve anxiety

• Find new complaint

• Follow PAC instructions

• Proper intravenous access

• Monitoring of vitals

• Patient shifted to OT at right time

• Send Patient trolley to OT as soon as informed

medical status mortality

ASA I Normal healthy patient without organic, biochemical, or psychiatric disease

0.06-0.08%

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

Unlikely to have an impact0.27-0.4%

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 Physical Status Classification System

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

INGESTED MATERIAL

MINIMUM FASTING PERIOD,

APPLIED TO ALL AGES (hr)

Clear liquids 2

Breast milk 4

Infant formula 6

Nonhuman milk 6

Light meal (toast and clear liquids) 6

Fasting Recommendations

Anaesthetic Plan

Conclusion

• Anaesthesia/surgical risk can be significantly reduced by combined skill of

– Surgeon

– Anaesthesiologist

– Primary care physician

– Nursing officers and Paramedics

– Patient (follow instructions )