Preoperative evaluation and preparation by abhijeet anand

Pre-operative Evaluation
&
Preparation
(General Principle)
Moderated by- Dr. Jasveer Singh
Presented by- Dr. Abhijeet Anand

What is Pre-anesthesia evaluation?
➢
The literature does not provide a standard
definition for preanesthesia evaluation.¹
➢
Preanesthesia evaluation consists of the
consideration of information from multiple
sources that may include the patient’s medical
records, interview, physical examination, and
findings from medical tests and evaluations.¹

¹Practice Advisory for Preanesthesia Evaluation -An Updated Report by the American Society of
Anesthesiologists Task Force on Preanesthesia Evaluation

Joint commission mandates documentation of
history & physical examination for any surgical
patient within 30 days before planned
procedure, as well as reassessment within 48 hrs
period immediately preceding the surgical
procedure.

What is the Goal of PAE?
✔
To ensure that patients can safely tolerate
anesthesia for planned surgical procedures.²
✔
To mitigate risks associated with the overall
perioperative period.²

²Miller's Anesthesia 8th
Edition

Pre-anesthesia
clinic visit
Indicated
Investigations
Pre-operative
Visit
Pre-anesthesia Evaluation

What are the benefits of PAE?
✔
Apart from reduced Hospital costs,Surgeon &
Patient satisfaction and establishing rapport
between anesthetist and patient,
✔
PAE guides the anesthetic plan: inadequate
preoperative planning and incomplete patient
preparation are commonly associated with
anesthetic complications.♣

♣Morgan & Mikhail's Clinical Anesthesiology,5th
edition

Additional benefit of PAE includes improved acceptance
by patients of regional anesthesia.
Wijeysundera DN, Austin PC, Beattie WS, et al: A population-based study of anesthesia
consultation before major non-cardiacsurgery, Arch Intern Med 169:595-602, 2009.

Cornerstones of an effective
Pre-anesthesia evalauation ♣
✔
Medical history
♣Morgan & Mikhail's Clinical
Anesthesiology,5th
edition
✔
Physical Examination

Additional elements of PAE
✔
Any INDICATED diagnostic test.
✔
Any INDICATED imaging procedure.

Any INDICATED consultation from other
physicians.
Indicated Investigations are different from routine
investigations,which rarely influence peri-operative and
post-operative outcomes and only add to health care costs
and frustrations of already vulnerable patient.

Source : Miller's Anesthesia, 8th
edition

PAE has pivotal role in estimating and
managing perioperative risk
●
A combination of nine variables provide independent prognostic information:
●
i. Age
●
ii. Sex
●
iii.Socioeconomic status
●
iv. Aerobic fitness
●
v. Diagnosed ischaemic heart disease (myocardial infarction and angina)
●
vi.Diagnosed heart failure
●
vii.Diagnosed ischaemic brain disease (stroke and transient ischaemic attacks)
●
viii.Diagnosed kidney failure
●
ix. Diagnosed peripheral arterial disease
●
Pre-operative and post-operative risks of mortality and morbidity can be
estimated with these variables when adjusted for surgical disease and surgical
procedures respectively.

Survival prediction/Risk assessment
●
Age:
The risk of dying doubles
every 7 years from the age of
10 so that by 90 years the
monthly mortality risk is 5000
times the risk at the age of 10.
●
Sex.
Men are 1.7 times more
likely to die than women the
same age.
●
Aerobic fitness:
The predicted peak power in metabolic equivalents
(METs), where 1 MET requires an oxygen consumption of
3.5 ml.kg -1 .min -1 ;
a) For men 18.4 – (0.16 x age)
b) For women 14.7 – (0.13 x age)
Mortality risk is multiplied by 1.2 for every MET short of
predicted, or by 0.84 for every MET in excess of predicted.
●
Socioeconomic status: The
impoverished are twice as
likely to die as the rich.
Adapted from AAGBI SAFETY GUIDELINE Pre-operative Assessment and Patient Preparation :The Role of the Anaesthetist,january 2010

Survival prediction/Risk assessment
●
Diagnoses of myocardial infarction, heart failure, stroke, peripheral
arterial disease and renal failure ([creatinine] >150 μ mol.l -1 )
independently multiply long-term mortality risk by 1.5 times.
●
Diagnoses of angina and transient ischaemic cerebral events
multiply risk by 1.2 times (in the absence of MI or stroke
respectively).

Note: The class "6E" does not exist and is simply recorded as class "6", as all organ retrieval in
brain-dead patients is done urgently .

Other Pre-operative Risk
assessment scoring systems for
special circumstances
●Goldman index for Cardiac Disease
●Glasgow coma scale for head injury
●Pugh-Childs scoring index for liver disease
●NYHA scoring index for heart disease
●Fleischer Risk Index for cardiac disease
Source: Lee's Synopsis of Anaesthesia, 13th
edition

Few Surgical Procedure Severity Grading Indexes

The modified Johns Hopkins surgical
criteria

Preanesthetic evaluation varies as per required
urgency of the indication of the surgical
procedure
●
Scheduled surgery:
Anaesthetists are central to ensuring the safety
of patients in the peri-operative period.
●
Emergency surgery:
Patients requiring anaesthesia after unplanned
admission are at higher risk of medical errors and
peri-operative complications.
MILLER's Anesthesia 8th
edition: Department of Health. Getting the right start: the national
service framework for children, young people and maternity
services - standard for hospital services. London: HMSO,
2003.

Communication & Informed Consent
PAE gives anesthesiologist a precious opportunity to educate the patient with the
plan of anesthesia procedure,the alternatives available and risk-benefit explanation.
Based on the information shared the patient takes informed decision and
gives consent.
The conversation also allevitate to some extent the fear and anxiety of the patient.
In one way or another PAE is itself one of the best premedication to allay anxiety of
patients.

It is a capital mistake to theorize before you have all the evidence.
It biases the judgment.
- SHERLOCK HOLMES

Significance of Weight &
Height of patient
Weight & Height of the patient is cardinal factor in directing management and
anticipating risks involved.
➢
Body Mask Index BMI =Weight in kilograms/( Height in meters ) × ( Height in meters )
Morbidly obese between 40 and 49.9, and super obese at greater than 50.

●
An increased BMI is predictive of difficulties with
airway management, both bag-mask ventilation and
endotracheal intubation.
●
In addition, obesity is associated with development of
chronic diseases such as heart disease, cancer, or
diabetes.
(Calle EE, Rodriguez C, Walker-Thurmond K, Thun MJ: Over-weight, obesity, and
mortality from cancer in a prospectively studied cohort of U.S. adults, N Engl J Med
348:1625-1638, 2003.)
Significance of Weight &
Height of patient

Weight of patient determines
size of airway devices like LMA.
( adapted from UNDERSTANDING ANESTHESIA EQUPIMENTS,5th
Edition)

Weight determines the Drug dosage, and their
pharmacokinetics and pharmacodynamics
depending on size of various compartments of
three compartment model.
●
Lean Body Mass:
Lean body mass equals body weight minus body fat.
Estimation:
For men: LBM = (0.32810 × W) + (0.33929 × H) − 29.5336
For women: LBM = (0.29569 × W) + (0.41813 × H) − 43.2933
( Hume, R (Jul 1966). "Prediction of lean body mass from height and weight." (PDF). Journal of clinical pathology )
●
Ideal body weight:
Male:
IBW = 50kg + 2.3 kg for each inch over 5ft in height
Female:
IBW = 45.5kg + 2.3kg for each inch over 5ft in height
●
Adjusted body weight:
Obese
ABW = IBW = 0.4 * (TBW - IBW)

Calculation of Drug dosage
based on weight
Based on Total Body Weight (TBW) : Succinylcholine
Propofol (Maintenance)
Based on Lean Body Weight(LBW) Fentanyl
Remifentanil
Propofol (Induction)
Based on Ideal Body Weight
(IBW)
Atracurium
cis-Atracurium
Rocuonioum
Vecuronium

Relationship of Weight with Oxygen
demand and Oxygen reserve
In one study, patients undergoing general anesthesia received 100%
oxygen by facemask before induction of general anesthesia.
After the induction of general anesthesia, the patients were left
without ventilation until their oxygen saturation fell from 100% to
90%.
Patients with normal BMIs took 6 minutes for their oxygen level to fall
to 90%.
Obese patients reached that end point in less than 3 minutes
(Jense HG. Effect of obesity on safe duration of apnea in anesthetized humans. Anesth Analg 1991; 72:89-93).

Height
●
Factor in determining drug dosage and block height in
subarachnoid anesthesia.
●
Helps in estimating size of Double Lumen Tubes and their
depth of placement.
The average depth of insertion for both male and female patients
170 cm tall was 29 cm, and for each 10-cm increase or decrease in
height, average placement depth was increased or decreased 1 cm.
(Anesth Analg. 1991 Nov;73(5):570-2.Depth of placement of left double-lumen endobronchial
tubes. Brodsky JB1, Benumof JL, Ehrenwerth J, Ozaki GT.)

Arterial Pulses
●
Radial Pulse
Place the pads of your three middle fingers over the radial artery.
Assess rate,rhythm and volume.
Count the pulse rate over 15 secs and multiply with 4 to obtain bpm.
●
Other sites:
Brachial pulse (assess character and volume)
Carotid pulse (listen for bruits)
Femoral pulse (check radiofemoral delay and listen for bruits)
Source: McLeod's Clinical Examination 12th
edition

"The best predictor of future behavior is past
behavior."

Goals of Airway Assessment
●
The goal of airway assessment is to identify patients who
may have difficult airways, mandating alternate
approaches to airway management.
●
Airway assessment and prediction of the difficult airway
is an inexact science as there is no method of prediction
of difficult intubation that is both highly sensitive and
highly specific..
●
Despite this, airway assessment is valuable as it helps the
airway practitioner the mindset of anticipating
difficulties and planning appropriately.

Take Home Message
Always be prepared to manage an
unanticipated difficult airway

Previous airway management problems
Look at old anesthetic records, if they are available, to see if problems with airway management
were documented. In practice this means finding comments on ease or difficulty of bag-mask
ventilation, laryngoscopy view, and any special airway techniques or equipment used previously.
You might even consider requesting records from a different hospital if airway management is
expected to be particularly challenging.
Ask the patient!
Although it is unlikely that a patient will be able to provide details about why airway management
was difficult In the past, a statement such as ' they we're struggling to get the tube down' or similar
should obviously ring alarm bells.
Previous interventions potentially affecting airway management
Find out if the patient has had head/ neck surgery before such as laryngeal surgery, neck
dissection, facial reconstruction, tracheotomy or c-spine surgery. Has the patient had radiotherapy
to the neck?
Consider whether a patient had any of these interventions or treatments since the last 'uneventful
intubation'.
Source :Anesthesia Airway Management (AAM),University of California, San Francisco website
History of Airway Management
Difficulty should be enquired

General, physical and regional
examination of Airway♪
i. Patency of nares : look for masses inside nasal cavity(e.g.
polyps) deviated nasal septum, etc.
ii. Mouth opening of at least 2 large finger breadths between
upper and lower incisors in adults is desirable.

iii.Teeth :Prominent upper incisors, or canines with or without
overbite, can impose a limitation on alignment of oral or
pharyngeal axes during laryngoscopy and especially in association
with a large base of tongue,they can compound the difficulty
during the direct laryngoscopy or bag-mask ventilation. An
edentulous state, on the other hand, can render axis alignment
easier but hypopharyngeal obstruction by the tongue can occur.
iv. Palate : A high arched palate or a long, narrow mouth may
present difficulty.

v. Assess patient’s ability to protrude the lower jaw
beyond the upper incisors (Prognathism).
vi. Temporo-mandibular joint movement :It can be
restricted ankylosis/fibrosis, tumors, etc.
vii. Measurement of submental space (hyomental/thyromental
length should ideally be>6 cm).
viii. Observation of patient’s neck : A short, thick neck is often
associated with difficult intubation. Any masses in neck,
extension of neck, neck mobility and ability to assume ‘sniffing’
position should be observed.

ix. Presence of hoarse voice/stridor or previous tracheostomy
may suggest stenosis.
x. Any systemic or congenital disease requiring
special attention during airway management (e.g. respiratory
failure, significant coronary artery disease, acromegaly, etc.).
xi. General assessment of body habitus can yield important
information.
xii. Infections of airway (e.g. epiglottitis, abscess,
croup,bronchitis, pneumonia).
xiii. Physiologic conditions : Pregnancy and obesity.
♪:GUPTA,SHARMA,JAIN ,Indian Journal of Anaesth49 : (4)AIRWAY ASSESSMENT :
PREDICTORS OF DIFFICULT AIRWAY

“One should never take away anything (Airway
and Ventillation) from a patient that one is not
confident one can replace.”
-Airway Management (Rashid Khan)
The Soul of Airway Management

Factors posing difficulty in Bag & Mask ventillation
(i) Presence of beard : Difficulty in creating proper seal with a mask.
(ii) Body mass index : Patients with BMI > 26 kgm 2-2 may be difficult to mask
ventilate,
(iii) Lack of teeth: Difficult to establish effective seal,
(iv) Age and snoring : Patients older than 55 years with
history of snoring are probably associated with varying
degrees of obstructive sleep apnea and are difficult to mask
Ventilate,
(v) Jewellery worn by piercing of lips, tongue,
cheek, chin, eye brows and ear may also create difficulty
in mask ventilation.

Specific physical tests for assessment of
airway
●
Mallampatti test
●
Atlanto occipital joint (AO) extension
●
Thyromental (T-M) distance (Patil’s test)
●
Sterno-mental distance
●
Mandibulo-hyoid distance
●
Inter-incisor distance

●
Mallampatti test
●
The Mallampati classification correlates
tongue size to pharyngeal size.
●
How to perform:
●
This test is performed with the patient in the sitting
position, head in a neutral position, the mouth wide open
and the tongue protruding to its maximum.
●
Patient should not be actively encouraged to phonate as
it can result in contraction and elevation of the soft
palate leading to a spurious picture.
Mallampaati SR, Gatt SP, Gugino LD, Waraksa B, Freiburger D, Liu PL. A Clinical
sign to predict difficult intubation; A prospective study. Can Anaesth Soc J 1985; 32:
429-434.

Class I : Visualization of the soft palate, fauces; uvula, anterior and the
posterior pillars.
Class II : Visualization of the soft palate, fauces and uvula.
Class III : Visualization of soft palate and base of uvula.
In Samsoon and Young’s modification (1987) of the Mallampati classification,
a IV class was added.
Class IV: Only hard palate is visible. Soft palate is not visible at all.

●
It assesses feasibility to make Sniffing or
Magill position for intubation i.e. alignment of
oral, pharyngeal and laryngeal axes into an
arbitrary straight line.
●
How to perform:
●
The patient is asked to hold head erect, facing directly to the front,
then he is asked to extend the head maximally and the examiner
estimates the angle traversed by the occlusal surface of upper
teeth. Measurement can be by simple visual estimate or more
accurately with a goniometer.

●
Grade I : >35°
●
Grade II : 22°-34°
●
Grade III : 12°-21°
●
Grade IV : < 12°
●
Normal angle of extension is 35° or more.
Banister FB, Mc Beth RG. Direct laryngoscopy and tracheal intubation.Lancet 1964; 2: 651.
Bellhouse CP, Dove C. Criteria for estimating likelihood of difficulty of endotracheal intubation with
the Macintosh laryngoscope. Anaesth intensive care 1988; 16: 329.

●
Thyromental (T-M) distance (Patil’s test)
●
This measurement helps in determining how
readily the laryngeal axis will fall in line with
the pharyngeal axis when the atlanto-occipital
joint is extended.
●
Alignment of these two axes is difficult if the
T-M distance is < 3 finger breadths or < 6 cm in
adults;
6-6.5 cm is less difficult,
while > 6.5 cm is normal.
Patil VU, Stehling LC, Zauder HL. Predicting the difficulty of intubation utilizing an intubation
guide. Anaesthesiology, 1983; 10: 32.

Sterno-mental distance
●
Savva (1948) estimated the distance from the
suprasternal notch to the mentum and
investigated its possible correlation with
Mallampati class, jaw protrusion, interincisor
gap and thyromental distance.
●
It was measured with the head fully extended
on the neck with the mouth closed.
●
A value of less than 12 cm is found to predict a
difficult intubation.
Savva D. Prediction of difficult tracheal intubation. Br J Anaesth 1994;73: 149-153.

Mandibulo-hyoid distance
●
Measurement of mandibular length from chin
(mental) to hyoid should be at least 4 cm or
three finger breadths.
●
It was found that laryngoscopy became more
difficult as the vertical distance between the
mandible and hyoid bone increased.
Chou HC, Wu TL. Mandibulohyoid distance in difficult laryngoscopy.Br J Anaesth
1993; 71: 335-9

Spine
➢
Evaluation of spine for planned subarchnoid or epidural block should be done
with keeping contraindications of the procedure in mind.
➢
Patient refusal for Neuraxial blocks should be assessed by alleviating the fear of
patient of lying awake while surgery,or permanent paralysis,back ache or even
needle puncture,through empathic didactic discussion with risk-benefit appraisal.
➢
Local deformity such as scoliosis and it's severity should be assessed.
➢
Local infections should be looked for as they 'may' cause neuraxial infection if
traversed.
➢
Coagulopathy should always be assessed before planning and performing neuraxial
blockade.
➢
ICP may be assessed if clinical history and condition warrants.
➢
Patient's limitation to maintain proper position for procedure should also be given
importance.

Venous Access
●
Sites of Peripheral venous access should be assessed
specially in obese and pediatric age group.
●
In emergency or major routine surgery preoperative
evaluation where patient's are already dehydrated or
at risk of blood loss on table,Central venous sites
should also be examined.

GENERAL HISTORY
&
SYSTEM WISE COMORBIDITIES
DIRECTED HISTORY,
PHYSICAL EXAMINATION
&
INVESTIGATIONS

Past Surgical/Anesthesia History
●
Past surgical/anesthesia history holds a very important place in
general history as it provides the anesthetist valuable
information for anticipating diificulties and complications in the
planned procedure or even may guide to change the plan of
anesthesia.
●
Peri-operative records provide information about any serious
intraoperative complication,if occured.That's why diligent peri-
operative record maintenance is of utmost importance.A copy of
record must ideally be provided to patient.
●
Post-anesthesia status history and if any,post-anesthesia
intervention history also provide valuable information to the
anesthetist.

Medication history
●
The anesthetist should enquire in detail about on going
medications of the patient with regards to dose,timing and
duration of treatment.
●
History of Pharmacologic Hypermetabolic state like
MALIGNANT HYPERTHERMIA in the patient or near-relatives
should always be asked.
●
Steroid administration history with dose and duration within
last one year should be asked as patient with depressed
Hypothalmic-Pituitary-Adrenal axis may need Steroid
supplementation intra-operatively as well as post-operatively to
tolerate surgical stress depending upon the surgical procedure.

Drugs to be Continued on day the of surgery
●
CVS:
Anti-Hypertensives (Possible Contraindication ACEi & ARBs)
Statins
Cardiac Medications (like beta-blockers,digoxin).
●
CNS:
Antidepressants, anxiolytics, and other psychiatric medications.
Anticonvulsant medications
MAO-inhibitors

Drugs to be Continued on day the of surgery
●
Respiratory:
Asthma medications
●
Endocrinologic drugs:
Thyroid medications
Steroids (oral and inhaled)
Birth control pills
●
Eye drops
●
Pain/Anti-inflammatory
Narcotic medications
COX-2 inibitors (unless the surgeon is concerned about bone healing)
●
GIT
Heart burn or reflux medications

Drugs to be Discontinued on day of Surgery
●
Topical Medications
●
Diuretics (exception: thiazide diuretics taken for
hypertension, which should be continued on the day of
surgery).

Other drugs to be discontinued
●
Sildenafil & congeners – 24 hrs before surgery
●
NSAIDs -48 hrs before surgery
●
Warfarin -4 days before surgery

Aspirin
●
Consider selectively continuing aspirin in patients where the
risks of cardiac events is felt to exceed the risk of major
bleeding. Examples would be patients high-grade CAD or CVD.
●
If reversal of platelet inhibition is necessary, aspirin must be
stopped at least 3 days before surgery.
●
Do not discontinue aspirin in patients who have drug-eluting
coronary stents until they have completed 12 months of dual
antiplatelet therapy
●
In general, aspirin should be continued in any patient with a
coronary stent, regardless of the time since stent implantation.

Thienopyridines (e.g., clopidogrel, ticlopidine)
●
Stop only if reversal of platelet inhibition is necessary, then
Clopidogrel must be stopped 7 days before surgery &
Ticlopidine 14 days before surgery.
●
Do not discontinue thienopyridines in patients who have drug-
eluting stents until they have completed 12 months of dual
antiplatelet therapy.
●
The same applies to patients with bare metal stents until they
have completed 1 month of dual antiplatelet therapy.

Insulin
●
Regular insulin : Discontinue on day of surgery
except if taken by continuous pump
at basal rate.
●
Patients with type 2 diabetes should take none, or up to
one half of their dose of long-acting or combination (e.g.,
70/30 preparations) insulin,on the day of surgery.
●
Patients with type 1 diabetes should take a small amount
(usually one third) of their usual morning long-acting
insulin dose on the day of surgery.
Source:BOX 38-3 Preoperative Management of Medications,Page 1098,Miller's
Anesthesia,8th
edition

Oral Hypoglycemic Agents
Peri-operative management of thesurgical patient with diabetes 2015,Published by The Association of Anaesthetists of Great Britain & Ireland,Sept 2015

Allergy History
●
Patients do not tend to differentiate between side-effects
and true allergies.
●
Explain in vernacular the sypmtoms of allergy to the patient.
●
Always ask for Egg allergy.
●
The most common precipitating drugs are neuromuscular
blocking agents (50% to 70% of cases),followed by latex and
antibiotics.

Addiction history
● Establish daily nicotine and alcohol intake and for how
long.
● Patients with a history of alcohol abuse may have liver
dysfunction and be relatively resistant to effects of
sedative drugs.
● Enquire about recreational drug abuse.
● Drug addicts may be HIV and Hep B & C positive.
Source : Lee Synopsis of Anesthesia,13 th edition

GERD history
●
Find out about the severity of any gastric reflux or hiatus
hernia symptoms,especially when lying flat,and
medications to control them.
●
Patient with history of GERD are at increased risk for
Mendelson syndrome.
●
Patients with a high risk should have a rapid sequence
induction.
●
The risk may be reduced by administering a non-
particulate antacid (e.g. Sodium Citrate) or an H2-
antagonist like Ranitidine.

Always check fasting status while Properative visit
American Society of Anesthesiologists (ASA) guidelines
permit-
● Soild food up to 6h prior to surgery.
● Breast milk up to 4 h prior to surgery.
● Clear liquids up to 2 h preoperatively.
Additionally AAGBI guidelines permit-
● Chewing gum up to 2 h before induction of anaesthesia.*

CARDIOVASCULAR SYSTEM
●
Two Cardinal Symptoms of Cardiac Disease Patients:
Exercise Intolerance & Chest discomfort (pain,
pressure,tightness)
(Numerous grading system like NYHA and METS can
classify exercise tolerance)
●
Other Symptoms
Ankle Swelling,Nocturia,Palpitations and occasionally
Syncope.
Source:Lee's Synopsis of Anesthesia,13th
edition

CARDIOVASCULAR SYSTEM
● Diseases/Conditions of Concern are:
Ischemic Heart Disease
Coronary Stents
Heart Failure
Murmurs and Valvular Abnormalities
Rhythm Disturbances
Cardiovascular Implantable Electronic Devices
Peripheral Arterial Disease

Ischemic Heart Disease
The goals in the preanesthetic evaluation of
patients with ischemic heart disease are as
follows:
● Identify the risk of heart disease based on risk factors
● Identify the presence and severity of heart disease
based on symptoms, physical findings, or diagnostic
tests.
● Determine the need for preoperative interventions.
● Modify the risk of perioperative adverse events.

Revised Cardiac Risk Index (RCRI) has been extensively validated for predicting
perioperative cardiac risk in noncardiac surgery.

Preoperative laboratory tests for patients with
known or suspected CAD
●
Blood creatinine
●
Hemoglobin concentrations
●
ECG,especially for intermediate- to high-risk surgical procedures.
●
Review of medical records and previous diagnostic studies,
especially stress tests and coronary angiography results.
Special tests based on clinical status,diagnostic studies &
severity of surgery may include:
●
Echocardiography, combined with exercise or a pharmacologic
agent, is used to look for wall motion abnormalities

Should I Order ECG in all
Patients?
NO...!!
Order ECG depending upon
Clinical Risk Factors and Risk
Stratification of Surgery

The above 2009 guidelines propose an algorithm for preoperative
cardiac risk evaluation that is followed in stepwise fashion and stops
at the first point that applies to the patient
●
Step 1 in this guideline algorithm considers the urgency of
surgery.
●
Step 2 focuses on active cardiac conditions such as acute MI,
unstable or severe angina, decompensated heart failure,
severe valvular disease or significant arrhythmias.
●
Step 3 considers the surgical risk or severity.
●
Step 4 assesses the patient’s functional capacity based on
METs.
●
Step 5 considers patients who have poor or indeterminate
functional capacity and need intermediate-risk or vascular
surgery

Coronary Stents
●
If urgent surgery is needed, strong consideration is given
to continuing dual antiplatelet therapy (i.e., thienopyridine
and aspirin) throughout the perioperative period.
●
Bridging Therapy
Unfractionated heparin and low-molecular-weight heparin
(LMWH) are not appropriate for “bridging”patients with
coronary stents who have been withdrawn from all
antiplatelet therapy. Specifically, heparin administration
can paradoxically increase platelet aggregation and
thereby may actually increase risk.
Miller's Anesthesia,8th
edition

Proposed bridging protocols for patients on dual-
antiplatelet therapy referred to cardiac or
noncardiac surgery.
Source : Circulation December 24, 2013, Volume 128, Issue 25

Heart Failure
●
Decompensated heart failure is a high-risk characteristic
that warrants post-ponement of surgery for all except
lifesaving emergency procedures.
●
Heart failure may result from systolic dysfunction or
diastolic dysfunction.
●
Hypertension is a cause of diastolic dysfunction, and LVH
on an ECG raises suspicion.
●
Ischemic heart disease is the most common cause of
systolic dysfunction in developed countries.
●
Cardiomyopathies can be classified in both.
edition

Heart Failure
● Symptoms
Patients with decompensated heart failure feel like they are
“suffocating” or have “air hunger.”
● Physical examination focuses on finding:
third or fourth heart sounds,
tachycardia,
a laterally displaced apical pulse,
rales,
jugular venous distention,
ascites,
hepatomegaly, and
peripheral edema.

Investigations in Patients suspected or
diagnosed with Heart Failure
●
Brain natriuretic peptide (BNP)
●
ECG
●
Serum Electrolytes
●
BUN
●
Creatinine
●
Echocardiography (if indicated)
●
MRI (if indicated)
●
Endomyocardial biopsy (if indicated)

Murmurs and Valvular
Abnormalities
●
Diastolic murmurs are always pathologic and
require further evaluation.
●
Significant abnormalities found by history,
physical examination, or ECG may require a
preoperative echocardiogram or cardiology
consultation.
●
Prophylaxis to prevent endocarditis is also no
longer recommended for patients with valvular
abnormalities (other than transplant recipients).
edition

Murmurs and Valvular
Abnormalities

Rhythm Disturbances on the Preoperative
Electrocardiogram
●
Supraventricular and ventricular arrhythmias are
associated with a higher risk of perioperative
adverse events.
●
Conditions warranting postponement of elective
procedures and referral to cardiology for further
evaluation:
Uncontrolled atrial fibrillation
New onset atrial fibrillation
Ventricular tachycardia
Symptomatic bradycardia
High-grade heart block

Rhythm Disturbances on the Preoperative
Electrocardiogram
●
An LBBB on an ECG necessitates a detailed
history and examination to ascertain the
presence of cardiac disease and associated risk
factors.
●
If the history and physical examination do not
suggest significant pulmonary, congenital, or
ischemic heart disease or Brugada syndrome,
no further evaluation of an isolated RBBB is
warranted.

Cardiovascular Implantable Electronic
Devices
●
Patients with CIEDs should be interrogated
preoperatively.
●
Special features to be disabled pre-operatively:
rate-adaptive mechanisms
antitachyarrhythmia functions
●
CIEDs should be reprogrammed to an asynchronous
pacing mode before surgical procedures where
interference may occur.
●
Reliance on a magnet without specific information
about the CIED is not recommended, except in
emergency situations.

●
Patients with PAD have a high cardiac risk even
when undergoing nonvascular surgery.
●
Claudication related to PAD generally limits
functional capacity and thereby masks the
symptoms of underlying ischemic heart
disease.

●
Arterial BPs should be measured in both upper extremities &
pulse should be checked in both arms.
●
Auscultation for bruits over the abdomen and femoral
arteries.
●
Palpation for abdominal masses.
●
A creatinine concentration should be determined before
procedures involving injection of radiocontrast dye.
●
If needed Dipyridamole,should be stopped 48hrs prior to
surgery.
●
If significant vascular disease is diagnosed by examination
even for non-vascular surgery,refer to vascular expert.

Respiratory System
●
Diseases/Conditions of Concern are:
Asthma
Chronic Obstructive Pulmonary Disease
Restrictive Pulmonary Disorders
Dyspnea
Patients Scheduled for Lung Resection
Obstructive Sleep Apnea
Pulmonary Hypertension
Smokers and Patients Exposed to Second-Hand Smoke
Upper Respiratory Tract Infections
Cystic Fibrosis

●
Asthma
●
Patients with mild, well-controlled asthma have no greater
perioperative risk than do individuals without asthma.
●
Previous exacerbations with anesthesia must be explored.
●
Medical therapy must be determined.
●
The patient’s best exercise level is important information for risk
assessment.

Asthma
●
Wheezing is common in asthmatic patients, but it is not
specific for this disease.
●
The degree of wheezing does not always correlate with the
severity of bronchoconstriction.
●
Observing the degree of accessory muscle use helps gauge
severity of the bronchoconstriction.
●
Analysis of arterial blood gases is not necessary unless the
patient is having a severe acute exacerbation.
●
Determining oxygen saturation by pulse oximetry is needed.
●
Chest radiography is necessary only to evaluate infections or
pneumothorax.

Asthma
●
PFTs have no perioperative predictive value for asthmatic
patients.
●
Typical findings on PFTs include reduced forced expiratory
volume in 1 second (FEV 1 ) and normal to slightly reduced
forced vital capacity (FRC).
●
Bronchodilators, inhaled and oral steroids, and antibiotics (if
taken) must be continued on the day of surgery.
●
A short course of steroids (20 to 60 mg of prednisone daily for
3 to 5 days) preoperatively may be considered in any patient
who is not “as good as they can be.”

Chronic Obstructive
Pulmonary Disease
●
Emphasize on changes in sputum amount, color, or other signs
of infection
●
The severity of COPD is classified based on spirometry
findings, specifically forced vital capacity (FVC) and FEV 1 .
●
Typically, the FEV 1 is reduced secondary to obstruction of
airflow, whereas the FRC is increased because of reduced
airflow, loss of elasticity, and overexpansion.
●
PFT results are generally not predictive of perioperative
outcomes in patients with COPD.
●
Diffusing capacity of the lung for carbon monoxide (D lco ) is
often decreased, with the severity of decrease often
correlating with the degree of hypoxia and hypercarbia.

Chronic Obstructive
Pulmonary Disease
●
A preoperative determination of oxygen saturation by pulse
oximetry is important to establish a baseline.
●
Arterial blood gas determinations for hypoxic patients.
●
Chest radiograph is useful only when infection or bullous disease
is suspected.
●
Look for Cor-pulmonale features on ECG.
Right axis deviation,
RBBB, or
peaked P waves.
●
Inhalers and other long-term medications for COPD should be
continued on the day of surgery.

Restrictive Pulmonary Disorders
●
Reduction in total lung capacity.
●
Preoperative PFTs are not routinely necessary.
●
PFTs along with CXR are indicated to establish a evaluate
acute or progressive worsening.
●
Typically, the FEV 1 and the FVC are reduced proportionally
such that the FEV 1 /FVC ratio is normal (i.e., >0.7).
●
Risk of pulmonary hypertension must be evaluated.

Obstructive Sleep Apnea
●
The severity of OSA is measured based on the apnea-
hypopnea index (AHI).
●
Mask ventilation,direct laryngoscopy, endotracheal intubation,
and fiber-optic visualization of the airway are more difficult in
patients with OSA.
●
Patients with OSA are more sensitive to the respiratory
depressant effects of opioids.
●
Echocardiography may be indicated if heart failure or
pulmonary hypertension is suspected.
●
Patients should be instructed to bring their CPAP devices to
the hospital on the day of operation.

Smokers and Patients Exposed to
Second-Hand Smoke
●
The perioperative clinical benefits of preoperative smoking
cessation demonstrated in systematic reviews are evident only
when cessation occurred at least 3 to 4 weeks before the
surgical procedure.
Wong J, Lam DP, Abrishami A, et al: Short-term preoperative smoking cessation and postoperative
complications: a systematic review and meta-analysis, Can J Anaesth 59:268-279, 2012.

Upper Respiratory Infection
●
Cancellation of surgery should not be routine.
●
Elective surgical procedures are postponed for at least 4 weeks
only in case of severe symptoms or with underlying conditions.
●
If Infection is mild or uncomplicated in healthy patients,risk is
low.
●
Yet, decisions regarding suitability to proceed are made on an
individual basis.

Diabetes Mellitus
●
Assess organ damage and blood glucose control.
●
Focus on the cardiovascular, renal, and neurologic systems.
●
Patients with autonomic dysfunction (or hypovolemia) have
more than a 20-mm Hg decrease in systolic BP,or more than a
10-mm Hg decrease in diastolic BP when changing from a
supine to standing position.
●
Investigations:
ECG
Electrolytes
BUN
Creatinine
Blood glucose.
●
Optimization of glucose control is a goal even before these
patients proceed with surgery.

Thyroid disorders
●
Significant hyperthyroidism or hypothyroidism appears to
increase perioperative risk.
●
Symptoms and findings of both hypothyroidism and
hyperthyroidism can be subtle and nonspecific, particularly in
older adults.
●
If symptoms and therapy have not changed, tests within the 6
months before the surgical procedure are generally adequate.
●
Elective surgical procedures should be postponed until
patients are euthyroid.
●
Consult an endocrinologist if surgery is urgent in patients with
thyroid dysfunction.
●
Determination of medical therapy is important.Medications
are to be continued on day of surgery.

Renal Disorders
●
The creatinine level is often not an accurate indicator of renal
function, especially in older individuals.
●
The GFR can be reduced by 50% without a rise in creatinine.
●
CKD is a significant risk factor for perioperative cardiovascular
morbidity and mortality.
●
Focus of preoperative evaluation of patients with renal
insufficiency are on the cardiovascular system,cerebrovascular
system, fluid volume, and electrolyte status.
●
Monitoring of patients’ weight is important for assessing
volume status.

Renal Disorders
●
Investigations needed:
ECG ,electrolytes, calcium, glucose, albumin, BUN, and
creatinine function.
●
CXR,ECHO & Cardiac evalation as needed.
●
Venous access sites or blood draws from the nondominant
upper extremity are avoided in patients who may eventually
need fistulas in those locations for dialysis.
●
In elective surgical cases, dialysis should be performed within
24 hours of surgery but not immediately before.

Hepatic Disorders
●
The perioperative risk of patients with chronic hepatitis or
cirrhosis is predicted by
Histologic severity
Portal hypertension
Impairment of liver function
●
Enquire history of “Hepatitis” following any anesthetic
procedure to anticipate halothane toxicity.
●
History should explore causes and degree of hepatic dyfunction.
●
Elective surgery is contraindicated in patients with acute or
fulminant liver disease, including alcoholic,viral, or undefined
hepatitis.

Hepatic Disorders
●
Investigations:
ECG,CBC (with platelet count), electrolytes, BUN, creatinine,
LFTs, albumin, and PT.
Serology for viral hepatitis.
CXR (to rule out effusion).
Ammonia (if enephalopathy is suspected).
●
Optimization for coagulopathy should be directed to the cause
aiming for an international normalized ratio (INR) of less than
1.5 .
●
Lactulose with the last dose within 12 hours of surgery, or oral
bile salts with intravenous hydration beginning the night
before the operation, may reduce perioperative progression
of renal disease in patients at risk.
●
Reduction of ascites preoperatively may decrease the risk of
wound dehiscence and improve pulmonary function.

Having a Surgeon
estimate the blood loss is like
Having a used Car Salesman
estimate his honesty.

Anemia
●
Preoperative anemia is a recognized risk factor.
●
Determine its etiology, duration, stability,related symptoms,
and therapy (especially transfusions).
●
Consider the type of surgical procedure, anticipated blood
loss, and comorbid conditions that may either affect
oxygenation or be affected by hypoxia.
●
Accurate determination of the patient’s medications is
required, especially because anemia has implications for the
risk-to-benefitprofile of some medications in the perioperative
period,such as β-adrenergic blockers.
●
Look for palpitations, fatigue, chest pain, melena, bloody
stools,weight loss, pallor, murmurs, hepatosplenomegaly, or
lymphadenopathy.

Anemia
●
The ASA Task Force on Blood Component Therapy concluded
that red blood cells should not be transfused based solely on a
hemoglobin level, but rather they should be used to address
risks for complications from inadequate oxygenation.
●
Transfusion is rarely indicated when the hemoglobin level is
higher than 10 g/dL and is almost always needed when
hemoglobin is less than 6 g/dL.
●
Elective procedures must be postponed in patients found to
have significant anemia, regardless of the anticipated blood
loss of the planned procedure.
●
Blood type and screening, and in selected cases, preoperative
transfusion may be necessary depending on the level of
anemia and the degree of anticipated surgical blood loss.

Adapted from the movie BATMAN Vs SUPERMAN : Dawn Of Justice (2016)

Coagulopathies
●
Ask about known diagnoses,tests, treatments, previous
bleeding episodes, and family history.
●
Diagnostic testing may include a platelet count, CBC, PT, and
aPTT.
●
Routine screening for coagulopathies is not indicated.
●
Elective surgical procedures should be postponed until the
etiology of abnormal tests is determined and corrections are
made.

Neurologic Disorders
●
Information about prior investigations or therapy is important.
●
Evaluate deficits in mental status, speech, cranial nerves,
gait,motor function, and sensory function
●
This baseline determination also allows for comparison of
possible new deficits postoperatively.

Seizure Disorder
●
Document the type of seizure.
●
Determining the etiology of the seizure disorder is also
important because of possible associated morbidities.
●
Careful documentation of anticonvulsants and adequacy of
seizure control is necessary.
●
Poorly controlled or new-onset seizures entail a consultation
with a neurologist before the patient undergoes anything
other than emergency surgery.
●
Continuation of anticonvulsant therapy in the perioperative
period is necessary.
●
Order CBC and Electrolytes.

Musculoskeletal and Connective
Tissue Disease
Rheumatoid Arthritis
●
Document symptoms related to the many organ systems affected
by rheumatoid arthritis:
Neurologic, Airway, Pulmonary, and Cardiovascular systems.
●
Documentation of deformities and neurologic deficits is
important to establish a baseline level of function.
●
Significant hoarseness
Consider evaluation by an otolaryngologist to assess the mobility
of the vocal cords and the presence of cricoarytenoid arthritis.
●
Indications for preoperative cervical spine radiographs include
neurologic findings, long-standing severely deforming disease, or
procedures requiring prone positioning or manipulation of the
cervical spine.

●
Radiographical view required are Anteroposterior and Lateral
cervical spine with flexion, extension, and open-mouth
odontoid views.
●
Significant abnormalities (i.e., anterior atlas-dens interval >9
mm or posterior interval <14 mm)require consultation with a
neurologist or neurosurgeon.

●
New or worsening pulmonary symptoms:
pulse oximetry, chest radiographs,PFTs, or possibly a pulmonary
consultation.
●
Muffled heart sounds, pericardial rubs, enlarged heart (examina-
tion or radiograph), and low voltage on an ECG suggest the
presence of a pericardial effusion, which necessitates an
echocardiogram.
●
Any suspicious murmur merits further investigation in these
patients. Because rheumatoid arthritis is associated with a very high
prevalence of CAD,patients require ECGs, as well as possible cardiac
stresstesting, with cardiology referral as indicated.
●
Other tests-CBC , BUN & Creatinine levels.
●
Advanced planning for management of potential difficult airways is
important

Roizen and Cohn have suggested a protocol for screening tests based on the preoperative
evaluation using a benefit–risk analysis.
Recommended Laboratory Testing
Blood Count
Neonates
Physiologic age ≥75 yr
Class C procedure
Malignancy
Renal disease
Tobacco use
Anticoagulant use
Coagulation Studies
Chemotherapy
Hepatic disease
Bleeding disorder
Anticoagulants
Electrolytes
Renal disease
Diabetes
Diuretic, digoxin, or
steroid use
CNS disease
BUN/Creatinine
Class C procedure
Cardiovascular disease
Renal disease
DiabetesDiuretic or
digoxin use
CNS disease
Blood Glucose
Class C procedure
Diabetes
Steroid use
CNS disease
Chest X-Ray
Pulmonary disease
Malignancy
Radiation Therapy
Tobacco ≥20 p-y
Pregnancy Test
Possible pregnancy
Albumin
Class C procedure
Malnutrition
ECG
Class C procedure
Pulmonary disease
Radiation therapy
Diabetes
Digoxin use
CNS disease
From-Clinical Anesthesia 5th
ed.,Barash

Take Home Message
ALL PREOPERATIVE TESTING SHOULD BE
DICTATED BY YOUR HISTORY AND EXAM

Rational Preoperative Medication
●
A classic study showed that a preoperative visit from an
anesthesiologist resulted in a greater reduction in patient
anxiety than preoperative sedative drugs.
●
Preoperative sedative-hypnotics or opioids are almost never
administered before patients arrive in the preoperative
holding area.
●
The fundamental message here is that premedication should
be given purposefully, not as a mindless routine.
Page no.300-301,Chapter 18,Morgan & Mikhail,5th
edition,Clinical Anesthesiology

So,apart from giving unintended
supra-tentorial noci-ceptive stimuli to surgeons,
Pre-Operative Evaluation serves very vital role in
patient management.

Preoperative evaluation and preparation by abhijeet anand

Preoperative evaluation and preparation by abhijeet anand

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