Preoperative Evaluation Department Of Anaesthesia MCOMS, Nepal

1. Preanesthetic evaluation
and Laboratory tests
Presented By: Dr Abiya Pradhan
Dr Smriti Manandhar
Dr Umang Sharma
Department of Anaesthesiology
Moderator
Dr Gajal Lakhe

2. • Pre-anesthesia evaluation is defined as the process of clinical assessment that
precedes the delivery of anesthesia care for surgery and for nonsurgical
procedures.

3. Goals
1. Reduce risk and morbidity
2. Screen and manage comorbid conditions
3. Establish baseline results
4. Identify who require special anesthetic techniques or post operative care
5. Prepare patient medically and psychologically
6. Complete, accurate, clear evaluation to relay information who take care
perioperatively
7. Obtain an informed consent
8. Establish baseline results
9. Screening tool to anticipate, avoid airway difficulties and problem from
anesthetic drugs
10. Reduce costs

4. Advantages:
• Delays complications, unanticipated post operative admissions
• Review of patients allergies and medication list
• Contraindications for certain drugs to be sought
• Determination of indication for surgical procedure, urgency of the surgery
• True emergency procedures, higher morbidity and mortality
• Anxiety, post operative pain
• Dictates positioning
• Whether blood products will be necessary

5. Should include
(1) evaluation of pertinent medical records,
(2) patient interview(s), and
(3) physical examination (at a minimum)
• an airway examination
• pulmonary examination
• cardiovascular examination
(4) specific preanesthesia tests
timing of an initial assessment of pertinent medical records for high, medium, and
low levels of surgical invasiveness, independent of medical condition

6. Timing
(1) always before the day of surgery,
(2) either on or before the day of surgery,
(3) only on the day of surgery.
Preoperative visit before the day of surgery as good as or better than medication
reducing preoperative anxiety or reducing postoperative pain

7. Response to previous anesthesia
• Detection of difficult airway
• History of MH
• Response to surgical stress and anesthetics
• Previous difficulty with anesthesia
• Family members with difficulties with anesthesia
• Postoperative nausea and vomiting

8. On the day of surgery
• When the patient last ate?
• Sites of pre-existing IV cannulae
• Invasive monitors
• Optimisation of health status prior to surgery
• Clear instructions regarding nothing by mouth
• Which medications to administer prior to surgery

9. American society of anesthesiologist (ASA) physical
status classification system
ASA PS
classificat
ion
definition examples
ASA I A normal healthy patient Healthy, non-smoking, no or minimal alcohol use
ASA II A patient with mild systemic disease Mild diseases only without substantive functional limitations.
Current smoker, social alcohol drinker, pregnancy, obesity, well
controlled DM/HTN, mild lung disease
ASA III A patient with severe systemic disease Substantive functional limitations: one or more moderate to severe
diseases. Poorly controlled DM, HTN, COPD, morbid obesity, active
hepatitis, alcohol dependence or abuse, moderate reduction of
ejection fraction, ESRD undergoing regularly scheduled dialysis,
premature infant PCA<60 weeks, history (> 3months) of MI, CVA,
TIA or CAD/stents

10. ASA IV A patient with severe systemic disease
that is a constant threat to life
Recent (<3 months) MI, CVA, TIA or
CAD/stents, ongoing cardiac ischemia or
severe valve dysfunction, severe
reduction of ejection fraction, sepsis,
DIC, ARDS or ESRD not undergoing
regulary scheduled dialysis
ASA V A moribund patient who is not expected
to survive without operation
Ruptured abdominal/ thoracic aneurysm,
massive trauma, intracranial bleed with
mass effect, ischemic bowel in face of
cardiac pathology or multiple organ/
system dysfunction
ASA VI Declared brain dead person whose
organs are being removed for donor
purpose

11. Airway evaluation
• Previous anesthetic record of difficult airway
• Obstructive sleep apnea
• Evaluation:
1. Dentition
2. Thyromental distance
3. Size of neck
4. Tracheal deviation, masses,
5. Ability to flex base of neck and extend head
6. Trauma or rheumatoid arthritis or down’s syndrome patients:assessment of C-
spine is critical

13. Components of difficult airway

14. Preoperative evaluation of pregnant patients
undergoing non obstetric surgery
Challenges:
• Changes in anatomy
• Maternal-fetal physiology
• History and physical examination:
• Maternal health
• Anesthetic history
• Past obstetric history
• Allergies
• Family history
• Substance abuse
• Risk factors
• Measurement of intrapartum platelet count, blood type antibody screen

16. Preoperative management of geriatric
patients
• Physiologic changes of aging
• Perioperative risks increased due to pathologic conditions
1. Neurocognitive disturbances
2. Atherosclerosis
3. Cancer
4. Degenerative joint diseases
5. Cataract
6. Prostatism

18. Geriatric syndromes and functional assessment
• Comprehensive geriatric assessment
• Focused evaluation of geriatric specific domains
• Risk assessment:
• Risk estimation
• patient’s decision making capacity
• Pre-operative optimization
• Anesthetic and surgical planning
• Perioperative surveillance
• Post operative discharge planning

19. Airway:
• Shorter thyromrntal distance
• Smaller interincisor gap
• Higher modified mallampati score
• Decreased neck range of motion
• Sarcopenia: decreased clearance of mucous and small particles
• Decreased mucociliary clearance
• Premature collapse of distal airways: ventilation and perfusion mismatch
exaggerated in supine postion
• Increased risk of aspiration
• Geriatric patients are likely to develop postoperative delirium

20. Pre-operative laboratory testing
• avoid testing in ASA I and II with low risk, minimally invasive procedures
• Unnecessary to repeat recent testing without significant change in clinical
condition
• When age and medical complexity increases need for thorough pre-operative
evaluation is necessary
• Comprehensive approach:
• Focused physical examinations
• Diagnostic and laboratory analysis on basis of positive findings or anticipated
physiological disturbance during surgery

21. • Pre surgical test “ directly related to comorbidities and risk of procedure”
• False positive result: ecomomic and emotional burden
• If test correctly identifies abnormalities changes in diagnosis to impact
management then test is worth ordering
• Avoid if patient has result within 6 months -1 year or if comorbidity is
management is stable

22. Recommended lab testing
• CBC: Neonates, physiological age>75, malignancy, renal disease,
anticoagulant use, bleeding/hematologic disorder,
• Coagulation studies: chemotherapy, hepatic disease, bleeding
disorder, anticoagulants,
• Electrolytes: renal disease, diabetes, diuretic, digoxin and steroid use,
CNS disease, endocrine disorders
• BUN/creatinine: physiological age>75 years, cardiovascular disease,
renal disease, diabetes, diuretic/digoxin use, CNS disease
• Blood glucose: age>75, diabetes, steroid use, CNS disease
• LFT: hepatic disease, hepatitis, malnutrition

23. • CXR: CDV disease, COPD, malignancy
• ECG: age>75years, CDV disease, pulmonary disease, diabetes, digoxin
use, CNS disease,
• Pregnancy test: possible pregnancy
• Albumin: age>75 years, malnutrition
• Type and screen: age>25 years, hematological disorder, coagulation
abnormality

24. Reasons for automated testing protocols
• Medicolegal concerns
• Institutional rules
• Concern that other physician may find it necessary and delay or camcel case
• Patient satisfaction
• Lack of awareness of published guidelines

26. Pre-Op Evaluation of
Cardiovascular and Pulmonary
Diseases

27. CARDIOVASCULAR DISEASE
• Goals of Pre-Op evaluation:
Identification of perioperative cardiovascular R/F
Determination of patients that will benefit from further
testing
Identification of patients who will benefit from
perioperative coronary intervention/ beta-blocker/statin
therapy
Formation of an appropriate anesthetic plan

28. Identification of R/F for Perioperative
Cardiovascular complications

29. Cardiac risk based on type of surgery

30. Cardiac risk based on exercise tolerance
• Exercise tolerance can be assessed with formal treadmill testing or
with a questionnaire that assesses activities of daily living.
• Self reported exercise tolerance: good predictive value
• Poor exercise tolerance independently predicts perioperative
complications. The likelihood of a serious adverse event is inversely
related to the number of blocks that a patient can walk.
• There is good evidence to suggest that minimal additional testing is
necessary if the patient is able to describe a good exercise
tolerance.

31. • 1 MET = oxygen consumption of 3.5 ml/kg/min
• 4 METs is considered the cut-off value of functional
capacity for any patient to be accepted for surgery.

32. points
History
Age >70 years 5
MI within past 6 months 10
Examination
Signs of CHF (S3/raised JVP) 11
Significant AS 3
ECG
Arrhythmias other than sinus arrhythmia, PAC 7
≥5 VPCs/min 7
General medical conditions
PaO2<60
PaCO2 > 50
Met acidosis
Creatinine>3
Increased AST/CLD
Bedridden
3
Operation
Emergency 4
Intraperitoneal/intrathoracic/Aortic 3
Goldman Cardiac Risk Index in
Non-Cardiac Surgery
Total points: 53
0-5 points: Class I; 1% complications
6-12 points: Class II; 7% complications
13-25 points: Class III; 14%
complications
26-53 points: Class IV; 53%
complications

33. Indications for Further Cardiac Testing
• Non-invasive cardiac tests include resting ECG, echocardiography and
cardiac stress tests (exercise ECG, stress echocardiography, stress
myocardial perfusion imaging)
• Both non-invasive cardiac tests and coronary angiography have very
low positive predictive values for perioperative cardiac events

34. Pre-Op Resting ECG
Recommended: for patients with cardiac risk factor
undergoing intermediate or high-risk surgery
Should be considered: for patients with cardiac risk
factors undergoing low-risk surgery
May be considered: for patients with no cardiac risk
factor undergoing intermediate-risk surgery
Not recommended: for patients with no cardiac risk
factor undergoing low-risk surgery

35. Pre-Op ECHO
Recommended: for patients with severe (NYHA III/IV)
valvular heart disease or recent flare up of signs and
symptoms of CHF
Should be considered: for left ventricular assessment in
patients undergoing high-risk surgery
Not recommended: for left ventricular assessment in
asymptomatic patients

36. Pre-op Cardiac Stress Testing
Recommended: for patients with ≥3 cardiac risk factors
undergoing high-risk surgery
May be considered: for patients with ≤2 cardiac risk
factors undergoing high-risk/intermediate risk surgery
Not recommended: scheduled low-risk surgery

37. Pre-Op Coronary Angiography
• Identifies areas of critical coronary stenosis, at risk
for developing myocardial ischemia,
• functional response of that ischemia cannot be
assessed by angiography.
• A critical stenosis frequently is not the underlying
cause for perioperative MI. Most infarctions are
the result of acute thrombosis of a noncritical
stenosis.

39. Perioperative Coronary
Revascularization
• Indications are same as those for non-surgical
patients with CAD .

40. Patients with Coronary Intervention
PCI: 15-60% restenosis
Bare metallic stents: 10-30% restenosis due to neointimal
hyperplasia
Drug eluting stents (contain paclitaxel/sirolimus)
Dual antiplatelet therapy:
Balloon angioplasty: 2 wks
Bare metallic stents: 6 wks
Drug eluting stents: 1 yr
Indications for CABG:
i. angiography reveals coronary anatomy
that precludes PCI
ii. Failed angioplasty
iii. MI related septal rupture/MR
iv. STEMI with cardiogenic shock/LBBB

41. Recommended time intervals to wait for
elective surgery after coronary intervention
• Balloon angioplasty: 2-4 wks
• Bare metallic stent: 6-12 wks
• Drug eluting stent: 12 months
• CABG: 6-12 wks
• Clopidogrel should be held 5-7 days before surgery whereas, low
dose aspirin should be continued unless absolutely contraindicated.

42. Peri-op B-blocker/ACE inhibitor/statin
therapy
• Indications for beta-blockers:
(i) patients with known coronary artery disease or
myocardial ischaemia on preoperative stress testing
(ii) patients undergoing high-risk surgery
(iii) patients previously treated with b-blockers for coronary
artery disease, arrhythmias, or hypertension (POISE study- the
only ACC/AHA guideline)
To be started at least 1 wk before surgery.
Target HR: 60-70/min; Target SBP>100 mmHg

43. • If ACE inhibitor are being received for LV dysfunction, it should be
continued on day of surgery (risk of LV decompensation weighed over
refractory hypotension)
• Statins continued for their pleiotropic effects (improved endothelial
morphology and coronary plaque stabilisation)

46. RESPIRATORY DISEASES
• Pulmonary complications are more frequent than cardiac
complications; incidence: 5% to 10% in cases having major non-
cardiac procedures.
• Perioperative pulmonary complications include aspiration, atelectasis,
pneumonia, bronchitis, bronchospasm, hypoxemia, exacerbation of
chronic obstructive pulmonary disease, and respiratory failure
requiring mechanical ventilation

47. • Depending on surgical site: thoracic, open aortic, or
upper abdominal surgeries have highest risk for
postoperative pulmonary complications.
• Incidence is higher as incision tends towards
diaphragm
• Decrease in postoperative VC, FRC, V/Q mismatch
and diaphragmatic dysfunction contribute to
hypoxemia and atelectasis.

48. • FRC may take up to 2 weeks to return to baseline.
• Diaphragmatic dysfunction may occur despite adequate analgesia and
is caused by phrenic nerve inhibition.
• Neurosurgery and neck surgery may be associated with perioperative
aspiration pneumonia.

49. Microscopic changes in the respiratory system
produced by GA:
• inhibition of mucociliary clearance,
• increased alveolar–capillary permeability,
• inhibition of surfactant production,
• increased nitric oxide synthetase,
• increased sensitivity of the pulmonary vasculature
to neurohumoral mediators.

50. • Subanesthetic levels of IV or inhalational agents have the ability to
blunt the ventilatory response to hypoxemia and hypercarbia.
• Duration of anesthesia is a well-established risk factor for
postoperative pulmonary complications, with morbidity rates
increasing after 2 to 3 hours.

51. • Preoperative therapies to minimize post op pulmonary
complications:
-Epidural analgesia during the perioperative period,
-lung expansion methods e.g. incentive spirometry
-DVT prophylaxis
-preoperative oral antiseptic decontamination before
ET intubation in high risk cases

52. Pre-Op concerns on smoking
• R/F for post op pulmonary complications
• Even without COPD, smoking increases
carboxyhemoglobin levels, decrease ciliary function,
increases sputum production, and stimulates the
cardiovascular system secondary to nicotine.
• smoking cessation for at least 4 to 8 weeks is
necessary to reduce the rate of postoperative
pulmonary complications.

53. • nicotine transdermal patches used during the perioperative period
have shown increased mortality and are best avoided.
• Patients who smoke often show increased airway reactivity under GA,
and it may be useful to administer a bronchodilator such as albuterol
preoperatively.

54. Pre-Op Concerns on URTI
• M/C etiology(95%): infective (viral>bacterial>fungal)
rhinovirus/influenza/parainfluenza/RSV
• Other causes: allergic/vasomotor
• M/C in pediatric age group

55. • Increased incidence of post-operative respiratory complications in
patients with history:
-copious secretions,
-purulent rhinitis/productive cough/fever/ronchi,
-prematurity,
-ET intubation,
-parental smoking,
-nasal congestion,
-reactive AW disease,
-undergoing airway surgery.

56. • In high risk patients, consultation should be done with
surgeons regarding the urgency of case
• Delaying surgery doesn’t reduce the incidence of adverse
respiratory events if the patient undergoes surgery within 4-
6 wks of URTI because airway hyperreactivity takes at least 6
weeks to abate.

57. Pre-Op concerns with OSA
• Defined as cessation of breathing >10s during sleep, diagnosed by
polysomnography in a sleep lab
• Incidence >70% in bariatric/ neurosurgical cases; majority
undiagnosed
• Mechanism- pharyngeal muscle tone decreased during sleep,
leading to airway collapse
• Turbulent airflow and snoring

58. • Physiological changes: hypoxemia, hypercarbia,
polycythemia, systemic/pulmonary hypertension, RVF,
morning headache, sleep disruption
• Loss of REM sleep for 1-2 nights after surgery and
rebound REM sleep thereafter, which further worsens
OSA
• Use of CPAP before surgery is the mainstay of pre-
operative management of OSA.
• Pre-op CPAP reduces the rate of complications (cardiac>
pulmonary) and shortens hospital stay by 1 day.

59. Bed Side PFTs
1) Sabrasez breath holding test:
• >25s: normal cardiopulmonary reserve
• 15-25s: limited CP reserve
• <15s: poor CP reserve, C/I for elective surgery
2) Single breath and count:
• Healthy person can count upto 30-40 after a single
deep breath

60. 3)Schneider’s match blowing test:
• Measures maximum breathing capacity
• Healthy subjects and those with mild AW obstruction
should be able to blow out a match from at least 15
cm away without purse lipping
• MBC> 60L/min
• FEV1>1.6L
4) Cough test: patient takes a deep breath in f/by
cough. Strong/effective cough suggests VC>= 3*TV

61. 5) Forced expiratory time: after deep breath, exhaled
maximally and forcefully while the physician keeps the
stethoscope over trachea and listens.
• Normal FET= 3-5secs
• Obstructive lung disease >6s
• Restrictive lung disease <3 s

62. 6) Debono’s whistle blowing test:
• Measures PEFR
• Patient blows down a wide bore tube at the end of which is a whistle,
on the side is a hole with adjustable knob. As subject blows, whistle
blows, the leak hole is gradually increased till the whistle becomes
inaudible. At the last position at which the whistle can be blown,
PEFR can be read off the scale

63. 7) Wright respirometer:
• measures TV and MV
• Can be connected to ETT or facemask
• Instrument records for 1 min and reads MV directly
• TV calculated by dividing MV by RR
8) Bedside pulse-oximetry
9)ABG

64. ACP guidelines for pre-operative
Spirometry
• Lung resection surgery
• History smoking with dyspnoea
• Cardiac/thoracic/abdominal surgeries
• Uncharacterised pulmonary disease (h/o pulmonary
disease or symptoms and no PFT in last 60 days)
Pre-op spirometry helps in identification of the type
of respiratory diseases (restrictive vs obstructive) as
well as severity assessment of diseases like asthma
and COPD

65. Concerns on asthma
• One of the most common coexisting diseases that confront the
anesthesiologist.
• During the PAC it is important to elicit information regarding inciting
factors, severity, reversibility, and current status.
• Frequent use of bronchodilators, hospitalizations for asthma, and
requirement for systemic steroids are all indicators of the severity of
the disease.
• After an AE of asthma, airway hyper-reactivity may persist for several
weeks.

66. • In addition to bronchodilators, prophylactic perioperative
steroids may be considered for the severe asthmatic, for
example, hydrocortisone 100 mg intravenously every 8 hours
on the day of surgery.
• The possibility of adrenal insufficiency in patients who have
received steroids in the previous 6 months. This group of
patients should be administered “stress doses” of steroids
perioperatively.
• low complication rate for asthmatics treated with short-term
steroids undergoing surgery with no association with
impaired wound healing or infections.
• For patients using inhaled steroids, they should be
administered regularly, starting at least 48 hours prior to
surgery for optimal effectiveness.

68. Pre-operative evaluation of
Pediatric patient

69. Pre operative evaluation
• A thorough history and physical examination is needed
• Laboratory work is done if indicated
• Speciality referral done when deemed necessary
• Assess neurologic development, airway anomalies, surgical history,
previous intubations, and general medical condition (heart, lung,
endocrine, renal disorders).
• Birth history: premature child

70. Pre operative evaluation
• Look for family history of
1. Malignant hyperthermia (MH)
2. Pseudocholinesterase deficiency
3. Postoperative nausea and vomiting
4. Congenital myopathies
5. Bleeding disorders
• History of Allergies
• Known or possible latex allergy: spinal bifida and bladder exstrophy
• Watch for genetic or dysmorphic syndrome
• Down syndrome (Trisomy 21) : anomalies in the cervical spine

71. Pre operative lab Tests
• No laboratory work is indicated for healthy children undergoing a
procedure with minimal blood loss anticipated
• Hematocrit test may be ordered if a great amount of blood loss is
expected or if the infant < 6 months
• During Tonsillectomy & Adenoidectomy Hct may be send during IV
insertion
• Bleeding time, prothrombin time and partial thromboplastin time,
and platelet count are not routinely recommended

72. Former Premature Infant
Premature infants are born less than 37-weeks gestational age.
Concerns
1. increased risk for postoperative apnea, periodic breathing, and
bradycardia up to 24 hours after surgery when compared with term
infants
• Maintain HCt value of 30% ( low level associated with a higher
incidence of postoperative apnea)
2. Bronchopulmonary dysplasia
Exaggerated risk of bronchospasm and oxygen desaturation in the
perioperative period within the first year of life.

73. Congenital heart disease
• Congenital heart disease :common problem
• Intracardiac murmurs, shunts, and the need for antibiotic prophylaxis
should to be evaluated preoperatively.
• Innocent versus pathologic nature of the heart murmurs should be
distinguished
• Baseline oxygen saturation in room air as well as routine vital signs
has to be determined preoperatively
• Blood pressure should be taken on both arms.

74. Congenital heart disease
• Test
• Electrocardiogram
• Echocardiogram : for significant structural heart defect
• Routine CXR is not recommended
• The need for antibiotic prophylaxis to prevent bacterial endocarditis
should be evaluated in the preoperative period

75. Respiratory Infection
• Very common in the preoperative course
• Average child gets 3 to 9 upper respiratory infections per year, with
each lasting between 7 to 10 days
• An active respiratory infection increases the risk of perioperative
respiratory complications from 2 to 7-folds.
• Complications : laryngospasm, bronchospasm, atelectasis,
postextubation croup, and postoperative pneumonia
• No definitive rules for canceling a procedure based on the presence
of a respiratory tract infection

76. • Signs of active lower respiratory infection, should warrant canceling
an elective procedure.
• Complications are most severe during an active respiratory infection.
Though ,airway reactivity can remain upto 6 weeks postinfection.
• It is advisable to delay an elective procedure 4 to 6 weeks if necessary
• Endotracheal intubation increases the risk of respiratory
complications 11-fold in children with respiratory infectious
symptoms
• Mask airway minimize the risk.

77. Others Coexisting Illnesses
• Seizure disorder
• Anticonvulsant level should be documented in present dosing regimen in past
6 months
• Child receiving Valproic acid should have documented LFT within 6months
• Anticonvulsants should be continued on the day of surgery
• Intellectual impairment
• Child may have several coexisting diseases, most common seizure disorder,
gastroesophageal reflux and chronic lung diseases
• They must be premedicated

78. Others Coexisting Illnesses
Trisomy 21
• Concern
• Macroglossia
• Narrowed cricoid cartilage
• Greater frequency of postoperative obstruction/croup
• Risk of subluxation of OA joint
• History of sleep apnea should be taken properly
• History of symptoms of weakness/paresthesia of upper extremities
should be taken; if present cervical spine radiographs and
examination should be done prior to elective surgery.

79. Fasting guidelines
• Designed to minimize gastric volume
• To reduce the risk of pulmonary aspiration
• preoperative nil per os (nothing by mouth) instructions should be
explicitly explained to the parent because they are frequently
misunderstood

80. Patient or Parental Preoperative Anxiety
• Presenting for surgery can be an overwhelming and frightening idea
for both children and their parents
• It is the job of the anesthesiologist to calm these fears in the
preoperative period to allow for a smooth perioperative course
• Factors associated with higher preoperative anxiety
• younger age
• the child’s first surgery
• Problems with prior health care encounters
• length of procedure
• anxious parents.

81. • Anesthesia course should be explained in terms that are appropriate
for the age, taking into consideration their level of development.

82. Premedication
• Most infants>9 months and children benefit from premedication:
helps to ease the anxiety of separation from the parents.
• The commonly used drugs are midazolam and ketamine
• Attractive alternative : transmucosal fentanyl and oral clonidine (NA)

83. ROUTE OF ADMINISTRATION
• Oral route: most preferred by the child
• Midazolam 0.5-0.75mg/kg (max 15mg) sedation in (10-30min)
• Ketamine 3-10 mg/kg
• For avoiding dreams it is preferable to mix ketamine (5-8 mg/kg) with
midazolam (0.3-0.5 mg/kg).
• To make these drugs palatable these can be mixed with orange
crushes, cola , apple juices or honey.

84. • Rectal route: usually used in the younger age group still in diapers.
• Used to be popular for administrating thiopentone , methohexitone
• Problems : child may expel drug
• Intramuscular route:
• used to administer ketamine (5-10 mg/kg-1) and atropine (0.02 mg/kg)
• Extremely unpleasant for the child
• Nasal route:
• Sedation sets rapidly
• Very irritating to nasal mucosa
• IV route: has gained popularity with the use of EMLA CREAM

85. Preoperative evaluation of
patient with Endocrine Diseases

86. Most commonly encountered endocrine diseases are
• Hypo/ Hyperthyroidism
• Diabetes Mellitus

87. Hypo/Hyperthyroidism

88. Preoperative Assessment
• History
It should be focused on establishing
• If the patient is euthyroid or not??
• Accessing airway compromise
Symptoms of hyper and hypothyroidism :insidious onset
• It is important to establish
• Pathological nature
• Position
• Size of the goitre
To appreciate the complexity and potential complications.

89. Examination
Patient should be assessed for signs of hyperthyroidism or
hypothyroidism.
Hyperthyroidism Hypothyroidism
General Weight loss, Malaise,
Muscle weakness, Heat intolerance,
Cachexia, Palmar erythma,
Proximal muscle wasting,
Pretibial myxoedema (Graves
disease)
Malaise, Cold intolerance,
Myalgia, Arthralgia,
Dry, coarse skin.
‘Peaches & Cream complexion’,
Loss of eyebrows, Hypothermia,
Carpal tunnel syndrome, Myotonia
Central nervous
system
Irritability, Anxiety,
Hyperkinesis, Tremor
Poor memory, Depression, Psychosis,
Mental slowness, Dementia,
Poverty of movement, Ataxia,
Slow relaxing reflexes
Deafness
Cardiovascular Palpitations, Angina, Breathlessness,
Hypertension, Cardiac failure,
Tachycardia, Tachyarrhythmias,
Hypertension, Bradycardia,
Heart failure, Oedema
Pericardial & pleural effusions,

90. Hyperthyroidism Hypothyroidism
Gastrointestinal Increased appetite,
Vomiting, Diarrhoea
Constipation,
Obesity
Genitourinary Oligomenorrhoea,
Loss of libido
Menorrhagia,
Loss of libido
Eye (Graves
disease only)
Blurred / double vision,
Exophthalmos, Lid lag,
Conjunctival oedema

91. Examination
• Examination of the goitre or nodule
Assess size and extent of the lesion
Inability to feel the bottom of the goiter: retrosternal spread
• Retrosternal or large goitres can compress surrounding structures and
may elicit superior vena cava (SVC) obstruction, Horner’s syndrome,
pericardial or pleural effusions
Detailed mandatory airway examination should be done:
assessment of Mallampatti, thyromental distance, mandibular
protrusion ,incisor distance and atlantoaxial flexion and extension

92. Investigation
• Complete hemogram : anaemia, thrombocytopenia and
agranulocytosis.
• Urine : Albumin, Sugar, Microscopy
• RBS, B.Urea, Serum creatinine
• Thyroid function tests.
• ECG
• Echocardiography : heart failure, pericardial effusion

93. Investigation
• Xray Chest
• PA: position of trachea, deviation, retrosternal goiter, calcification
• Lateral thoracic view : retrosternal extension and trachea AP diameter
• CT scan- airway compromise
• Flow volume loop-
• best indications of airway obstruction
• Shouldnot be done routinely
• Nasendoscopy : often performed preoperatively by ENT
• To document vocal cord function
• Invaluable tool to assess the laryngeal inlet and any deviations

94. • Elective surgery should be postponed until the patient is euthyroid.
• On the day of surgery, usual dose of antithyroid medications or
thyroid supplement should be administered
• Benzodiazepines : for anxiolysis, but avoided in patient with airway
compromise
• Anticholinergics : to dry secretions if an inhalational or fibreoptic
technique is planned.

95. • In case of emergency surgery,
• Hyperthyroid patients :immediate control of symptoms with
• beta blockade (e.g. propranolol, esmolol)
• intravenous hydration
• active cooling (if necessary)
• Hypothyroid patients:
• At risk of perioperative myxedema coma
• should be treated with intravenous T3 and T4.

96. Pre-operative Evaluation

97. Pre-operative Evaluation

98. Indicators of difficult airway
 Prayer Sign
Patient is unable to approximate the
palmar surface of phalangeal joints
despite of maximal effort.
 Palm Print Test
Degree of inter-phalyngeal joint
involvement can also be assessed
by scoring the ink impression
made by the palm of dominant hand
In diabetics Palm print is the best single
predictor of a difficult intubation,
followed by Mallampati and the prayer sign.

99. Glycemic control
• Postpone elective surgery if possible if glycemic control is poor
(HBA1c >9%)
• If serum glucose is >350mg/dl, the elective surgery should be
postponed
• Any concentration of BG level associated with DKA and/or a
hyperosmolar state, the surgery should be postponed and metabolic
state is restabilized
• Hypogylcemia must be avoided
• Blood glucose level 140-180 mg/dl

100. PHARMACOLOGIC THERAPY IN DIABETIC
PATIENTS
Non insulin Therapy
• Primary concern: prevention of perioperative hypoglycemia.
• Metformin: first-line oral therapy for type 2 diabetes
• Should be held 24 hours before the procedure because of risk of lactic
acidosis if patients renal function is compromised
• All other OHAs (sulfonylureas: glyburide, glipizide
thiazolidinedione: rosiglitazone ,pioglitazone)
• should be held in the morning of the surgery.

101. PHARMACOLOGIC THERAPY IN DIABETIC
PATIENTS
Insulin therapy
• All patients with type 1 diabetes are on insulin because of its absolute
deficiency.
• These patients need some insulin even while fasting to prevent
ketosis.

102. Insulin therapy
• Long-acting insulin analogues (glargine, detemir, degludec) are less
likely to result in hypoglycemia in the perioperative fasting state, as
they do not peak, thus the usual dose of these medications could be
administered on the day of surgery.
• With the intermediate-acting and premixed insulins, the risk of
hypoglycemia could increase while fasting, thus 25% to 50%
reduction in dose is recommended the night before and the day of
surgery.
• Short-acting insulins are best avoided on the day of surgery and
while patients are fasting.

103. General considerations:
• All diabetic patient should ideally be admitted day before surgery.
• Diabetic patients should be kept first on the surgical schedule so that
they are not NPO for long periods of time.
• Patients blood glucose level should be monitored inorder to prevent
hypoglycemia or severe hyperglycemia in event of delayed or
afternoon surgery.
• Patients should never undergo anesthesia without a blood glucose
determination.

104. Preoperative evaluation of
Patient with Bleeding Disorder

105. History
If a patient presents with bleeding, history should be taken carefully
regarding the following:
1. Site of bleeding
2. Duration
3. Precipitating factors

106. History
4. History of previous operations, dental extraction, etc. is useful to
find out if there is any antecedent bleeding disorder
5. Family history
6. History of hepatic or renal failure, paraproteinaemia or a
collagenosis
7. History of drug intake: NSAIDs

107. Examination
• Look for
a. Bruises, purpura, scars, telangiectasia of lips and tongue
b. Examination of joints
c. Stigmata of liver disease
d. Splenomegaly

108. Investigation
Parameters Normal Range Comment
Platelet count 50,000- 350,000/μL Decreased :congenital and
acquired thrombocytopenia
Bleeding time < 8 minutes Assess platelet endothelial
interaction
Not useful
Prothrombin time (PT) 12-14seconds Prolonged in
factors II, V, VII, X deficiency, liver
disease, warfarin therapy and DIC.
Activated partial thromboplastin time
(aPTT)
30-40 seconds. Prolonged in
deficiency of factors II, V, VIII, IX, X,
XI, hemophilia A and B,
vonWillebrand’s disease and DIC.
Activated clotting time 70-120 seconds Similar to aPTT

109. Investigations
Parameters Normal Range Comment
Fibrinogen level 1.5-3.0 gm/dl. Low in congenital Hypofibrinogenaemia
Plasma thrombin time 15-20 seconds Prolonged in
Afibrinogenaemia
Hypofibrinogenaemia
Therapeutic or circulating
anticoagulants
Inherited dysfibrinogenaemias

110. Investigations
• Routine screening — If the history and physical examination do not
suggest the presence of a bleeding disorder, no additional laboratory
testing is required
• Suspected bleeding disorder based on initial evaluation
• appropriate screening tests should be performed (ie, PT, aPTT, platelet count)

111. Investigations
• A normal bleeding time (BT) does not predict the safety of surgical
procedures, nor does an abnormal BT predict for excessive bleeding;
therefore, the use of the BT in routine preoperative screening does
not appear to be warranted