seminar on PAC

1. Preoperative Assesment
Moderator –Prof RS THAKUR
Speaker-Dr Dipankar Singh
8/10/2020

2. ANAESTHESIA
 Anaesthesia ( from Greek an “ WITHOUT “ asthesis “ SENSATION “ )
 Anaesthesia state includes:
>Reversible Loss Of Consciousness
>Loss of Memory ( AMNESIA )
>Lack of pain ( Analgesia )
>Immobility ( Skeletal Muscle relaxation ) and loss of sensation to any noxious
stimuli .
 Three Periods of Anaesthesia :-
1. Preoperative Period
2. Perioperative Period
3. Postoperative Period

3. Discussion On Following :-
 Evolution of Preoperative evaluation
 Goals And Benefits Of Preoperative Evaluation
 Scope Of Preoperative Evaluation
 Components Of Airway Examination
 Preoperative Evaluation In Specific Conditions And Diseases
 Preoperative Risk Assessment
 Planning For Anaesthesia
 Benefits Of Preoperative Evaluation

4. Preoperative Evaluation :
 Definition :- The process of clinical assessment that precedes the delivery of
anaesthesia for surgery and for non-surgical procedures
 It consists of the consideration of information of multiple sources , which
includes:-
> Patient’s interview
> Medical Records
> Physical Examination
> Airway Assessment
> Finding from Medical tests and evaluations

5. Goals Of Preoperative Evaluation
 Allay Anxiety
 Information regarding pertinent medical history
 Doctor Patient Relationship
 Formulate assessment of patient’s perioperative risk and develop a plan for
any clinical optimisation
 Focussed clinical examination
 Documentation of comorbid illness
 Selective referral to specialist
 Ordering Preoperative investigations as needed
 Discussing Perioperative and Postoperative care with surgical team
 Delay and cancelling the surgical procedure if deemed appropriately
 Patient consent

7. Components Of Preoperative Evaluation
 Medical History
 Physical Examination
 Assessment of functional status
 It is observed that 56% Diagnosis is made on the basis of Medical History and
when done with Physical Examination then 73% of the diagnosis is made.
 Inadequate preoperative evaluation leads to 3% perioperative adverse
outcome .

8. Medical History
 Demographic Details
 Presenting Complaints
 H/O Presenting Illness
 Past Medical History
 Allergy History
 Any Surgical History
 Previous Anaesthetic History – any h/o Difficult intubation , any h/o allergy at
that time .
 Drug History
 Family History
 Social History

9. Physical Examination
 General Examination:-
 Vitals-
> Blood pressure measurement
> Pulse rate
>Respiration rate
> Temperature
=> Jaundice , Pallor , Cyanosis , Clubbing and Edema
=> Hydration Status
=> Weight ( Kg )
=> Height (cm)

10. .
 Systemic Examination :-
> Cardiovascular examination
> Pulmonary Examination
> Central Nervous Examination
> Hepatic System Examination
> Renal System examination
 Special Examination :-
>Airway Assessment
>Peripheral Venous Access
> Spinal Examination

11. Cardiovascular Examination
 Pulse :- Rate, rhythm, character and volume.
 BP
 JVP:- Height and character
 Ankle edema:- Present or absent
 Inspection :- any scar , abnormal vessels, lumps, chest shape, apex beat position
 Palpation :- confirm apex beat, character, presence of thrills and peripheral
pulses on both sides
 Percussion :- Precordium- size of heart
 Auscultation :- heart sounds, murmur

12. Pulmonary Examination

13. Assessment Of Functional Status
 The assessment of the patient’s cardiopulmonary fitness or functional
capacity is an integral component of the preoperative clinical examination.
 This information is typically used to estimate a patient’s risk for major
postoperative morbidity or mortality
 There is a reasonable body of evidence demonstrating an association between
poor preoperative functional capacity and increased perioperative risk .
 Functional Capacity is typically quantified in using the Metabolic Equivalent of
Task (METS)
 One MET is approximately the rate of energy consumption at rest ( 3.5
ml/kg/min )

15. METS
 Significance
If METS > 4 , the perioperative risks are minimal
If METS < 4 , the perioperative risks are maximum and needs further
evaluation

16. .
 DASI scores have been shown to improve prediction of postoperative cardiac
complications following non-cardiac surgery
 Formula for conversion of DASI to METS:-
Estimated METS =[( 0.43 X DASI score ) + 9.6 ] / 3.5
 Other alternatives for estimating functional capacity include simple exercise
tests ( eg – 6 minute walk test, incremental shuttle walk test ) , ECG exercise
test , or CPET .

17. AIRWAY
 Definition – Airway is the passage through which the air/ gas passes during
respiration.
 Incidence of Difficult Intubation reported to range between 0.13-5.9%.
 Difficult Intubation can be predicted and expert Anaesthesiologist is called for
the case.
 Evaluation is the first step in management of difficult intubation .

18. AIRWAY CLASSIFICATION SYSTEM
MALLAMPATI SCORE Laryngoscopic view
CORMACK LEHANE
GRADE GRADE
1 Full view of soft palate,fauces,
uvula, tonsillar pillars.
2 Soft palate , fauces , upper
portion of uvula
3 Soft palate , uvula base
4 Hard Palate Only
1 Entire Glottic
2 Posterior Commissure
3 Tip Of Epiglottis
4 No Glottic Structure

21. AIRWAY EVALUATION
 Mentothyroid distance -> Normal >6.5 cm
 Mentosternal distance -> Normal >12.5 cm
 Mentohyoid distance -> Normal >6 cm
 Neck Movement -> Flexion And Extension of Neck, History Of Radiation
 Nasal Cavity

22. Difficult Intubation
 Mouth opening -> Less than 3 cm
 Head Extension -> Less than 80 degrees
 Neck Flexion -> Less than 25 degrees
 Head / Neck Rotation -> Less than 70 degrees
 Micrognathia
 Macroglossia
 Protrusion of teeth
 Short Neck / Thick Neck
 Morbid Obesity

23. Airway Examination
 Normal :-
Examination has to done in sitting position.
-> Opens Mouth Normally ( Adults : greater than 2 fingers widths OR 3 cm )
-> Able to visualize at least part of the Uvula and tonsillar pillars with mouth
wide open and tongue out ( patient sitting )
-> Normal Neck Flexion and Extension without pain / paresthesias

24. .
 Abnormal
-> Small or recessed chin
-> Inability to open mouth normally ( < 3cm )
-> Inability to visualize at least part of Uvula or Tonsils with mouth open and
tongue out.
-> High Arched Palate/ Narrow Palate
-> Tonsillar Hypertrophy
-> Limited range of Neck movement
-> Low set ears
-> Significant obesity of the face/neck

25. Airway assessment : Predictive tests
sensitivity = 50-60%
 Mallampati modified test :
Visibility of pharyngeal structure
 Patil test:
Thyromental distance < 6cm
 Mandibular protrusion:
Class C – Inability to protrude lower incisors beyond the upper
incisors
 Wilson Test
 Radiological assessment of the mandible and cervical spine

27. ASA ( American Society of Anaesthesiologist )
physical classification system
GRADE 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 eg- controlled DM/HTN,
obesity( 30<BMI<40)
Unlikely to
have impact
0.27-0.4
ASA III Severe Systemic disease that limits activity eg-
poorly controlled DM/HTN, BMI>=40, H/O (>3
months ) of MI,CVA,TIA,or CAD/stents
Probable
impact
1.8-4.3
ASA IV An incapacitating disease that is a constant
threat to life eg-(<3months) MI,CVA,TIA,or
CAD/stents,Sev LV dyfn, ARDS, ESRD
Major impact
7.8-23
ASA V Moribund patient not expected to survive 24 hrs
eg:-ruptured aneurysm, massive trauma ,ICH
9.4-51
ASA VI Brain dead patient whose organs are being
removed for donor purposes
E EMERGENCY OPERATION

28. Preoperative Evaluation of Patient with
Co-existing diseases
Cardiovascular disorders:-
-> Ischaemic Heart Disease
-> Hypertension
-> Heart Failure
-> Conduction Defect and Arrhythmia
-> Peripheral Vascular Disease
 Patient with history of MI are at greater risk of perioperative reinfarction.
 The presence of unstable angina has been associated with high perioperative risk
of MI.
 The presence of active congestive heart failure has been associated with an
increased incidence of perioperative cardiac morbidity.

29. RISK CALCULATOR
 Quantifies the cardiac risks during perioperative period.
 REVISED CARDIAC RISK INDEX (undergoing elective major non cardiac
procedures)
1) High Risk Type Of Surgery
2) H/O Ischaemic heart Diseases
3) H/O Congestive Heart Failure
4) H/O Cerebrovascular Disease
5) Preoperative Treatment with INSULIN
6) Preoperative Serum Creatinine > 2mg/dl

30. PULMONARY DISORDERS
 Pulmonary diseases which are concerned to the anaesthesiologists are as follows:-
1. OSTRUCTIVE LUNG DISEASES
I. ASTHMA
II. COPD
III. BRONCHIECTASIS
IV. CHRONIC BRONCHITIS
V. EMHYSEMA
2. RESTRICTIVE LUNG DISEASES
I. INTERSTITIAL LUNG DISEASES
II. IDIOPATHIC PULMONARY FIBROSIS
III. SCOLIOSIS
IV. NEUROMUSCULAR DISEASE ( AMYOTROPIC LATERAL SCLEROSIS or MUSCULAR
DYSTROPHY

31. Preoperative Investigation
 General
1. Complete Blood Count
2. Electrolytes
3. Blood Urea Nitrogen ( BUN ) , Serum Creatinine
4. Blood Sugar Level
5. Liver Function Test
6. ECG
7. ECHO

33. Preparation For Anaesthesia
 Continuing Current medications
 It is the responsibility of the anaesthesiologist to instruct patients regarding
which medications to take and which to hold preoperatively.

34. Benefits Of Preoperative Evaluation
 Decreased Cost of treatment
 Decreased Hospital stay
 Decrease Morbidity and Mortality
 Unnecessary cancellation and postponement of Surgical procedures

35. Take Home Message
 A Mnemonic has been suggested for pre-anaesthetic assessment , to ensure that
all aspects are covered.
A-Affirmative history, Airway
B-Blood Hemoglobin,blood loss estimation,and blood availability, Breathing
C-Clinical Examination , Co-morbidities
D-Drugs being used by the patient, Details of previous Anaesthesia and Surgeries
E-Evaluate investigations, End point to take up the case for surgery
F-Fluid status , Fasting
G-Give physical status , Get consent

36. THANK YOU

37. REFERENCES
 1. CLINICAL ANESTEHESIOLOGY, Morgan & Mikhail’s, 5TH Edition, Page № 295-
307
 2. Clinical Anaesthesia, Paul G. Barash, Seventh Edition, Page № 583- 609
 3. Rashid Khan Airway Management 4th edition Page no. 21-23
 4. Miller’s Anaesthesia 8th edition