anesthesia and basics of preoperative evaluation PAC

1. PREANAESTHESIA EVALUATION
MODERATOR- Dr. A.B. Roy
Presented by- Dr. Richa Kumar

2. Definition*
• Preanesthesia evaluation: process of clinical
assessment & optimization of patient
preceeding delivery of anesthesia care for
surgery and for nonsurgical procedures.

3. FUNDAMENTAL PURPOSE:
• obtain relevant information
• Formulate assessment for perioperative risks
• Ordering preoperative investigations
consistent with medical history and
examination.

4. • Verify an already known disease, disorder, medical or
alternative therapy that may affect perioperative
anesthetic care
• Formulation of specific plans and alternatives for
perioperative anesthetic care and post operative pain
management.
• Develop plan for any clinical optimization.
• To describe the proposed anesthetic plan and related risks
to the patient.
• give psychological support to patient.

5. • Fig 38-1 pg 1087

6. 1.DETECTING DISEASES IN
PREOPEARTIVE EVALUATION
HISTORY PHYSICAL EXAM. DIAGNOSTIC
TESTS

7. HISTORY TAKING
• Not simply asking questions.*
• Use of lay language*

8. COMPONENTS of MEDICAL HISTORY
• Start with name , age*, sex of patient followed by
indication of surgery and planned procedure.
• Current and past medical problems
• Previous surgical procedures with type of anesthesia
and related complications(if any).
• Simple notation of names disease/s NOT ENOUGH*.

9. • Prescriptions & over the counter medications with
dosage and schedule.
• Allergies
• Use of tobacco/alcohol/ellicit drugs*(quantitative
record of smoking)

10. • Day time somnolence/obesity/snoring (airway)*
• Any significant heart burn/ reflux
• LMP in case of females of childbearing age.
• Past History*
• Family history

11. • Status of cardiorespiratory fitness:
quantified in metabolic equivalents of task (METS)-
measure of volume of oxygen consumed during an
activity.

12. *

13. CVS
• identify risk factors of CAD ( smoking, hypertension, age,
male sex, hypercholestrolemia, family history)
• chest discomfort (pain , pressure, tightness) –duration,
precipitating factors , associated symptoms and relieving
factors.
• SOB
• Past cardiac procedures
• Goal is identify patients with high perioperative cardiac
risk and who have modifiable risk.

14. PULMONARY
• Asthma (SOB/recent
exaccerbations/therapy/hospitalization/critical care
unit admission ,endotracheal intubation)
• COPD (smoking,alpha1 antitrypsin def. ,chronic
infection,long standing asthma)

15. PHYSICAL EXAMINATION
1.Vital signs
2.BMI
3.Inspection of airway

18. 4. Systemic examination:
5.Inspection of peripheral veins

19. PREOPERATIVE EVALUATION OF
PATIENT WITH SYSTEMIC DISEASE &
LAB. INVESTIGATIONS REQUIRED

20. CARDIOVASCULAR DISEASE
• CVS complications are very common serious
perioperative adverse events.
• Role of perioperative evaluation?*

21. HTN*
In young individuals:
COA, hyperthyroidism, phaeochromocytoma or ellicit drug use
• Long standing severe/uncontrolled HTN:
ECG, BUN, S. creat,
Electrolytes for patients on diuretcs
if LVH on ECG :CAD
Elective surgery delayed if DBP>115 & SBP>200 until BP <
180/110
All long term antihypertensives to continue except ACEI /ARB

22. • AHA suggests that potential benefits of delaying
surgery to optimize antihypertensive treatment
should be weighed against the risks of delaying the
surgical procedure.*
• The preoperative period :excellent opportunity for
appropriate referrals for future management of
inadequately treated HTN.

23. • IHD: 4 goals:
1.identify cardiac risks
2. presence and severity
3. need of preoperative interventions
4. modify risk of perioperative adverse effects
AHA suggests postponement of surgery if patient had
acute MI
For recent MI nonemergency surgery should be
postponed.

24. • The revised Cardiac Risk Index (RCRI) has been
extensively validated for predicting perioperative
cardiac risk in non-cardiac surgery.

25. SUSPECTED CAD:
INVESTIGATIONS
1. Blood creatinine & Hb concentration
2.KFT (RCRI)
3.ECG
4. cardiac stress test*
5. Echocardiography
6. angiography

26. CORONARY STENTS:
Recent <30days
(bare metal stents)
<1 year
(drug eluting stents)
Should not
undergo
elective
surgery

27. HEART FAILURE* (systolic/diastolic/combination)
• NYHA categories for degree of HF*.
• Class III and IV should be evaluated in conjuction with
cardiologist
• INVESTIGATIONS:ECG, electrolytes, BUN, creatinine,
BNP, chest radiography, echocardiography
• Selective continuation & discontinuation of drugs
depending on IV volume ,hemodynamic status, degree
of cardiac dysfunction and anticipated surgical
procedure and IV volume challenges.

28. • RHYTHM DISTURBANCES:
• SVT and ventricular arrythmias – higher risk of post-op
adverse effects.
• New onset / uncontrolled AF
• Symptomatic bradycardia
• High grade heart blocks
• LBBB more ominous than RBBB
(CAD & HF) (congenital/pulmonary/degeneration/Burguda syndrome*)
Prolonged QT interval: electrolyte disturbances, drugs*,
cardiology reference in patients with H/O syncope and family
H/O sudden death
Warrant
postponement of
elective procedures
and referral to
cardiology

31. PULMONARY DISORDERS
ASTHMA:
• Can be precipitated by airway intrumentation.
• Risk assessement by further questioning
• Degree of wheeze has no correlation with severity of
bronchoconstriction
• CXR-necessary investigation.
• ABG necessary only in acute exacerbation
• Blood glucose in patients on steroids
• PFTs =no perioperative predictive value
• Beta agonist is most useful prophylactic measure to lower risk of
bronchospasm.

32. COPD
• COPD severity classified based on spirometery findings.
• Barrel shaped chest and pursed lip breathing suggests advanced
disease
• Degree of disease correlates with degree of hypoxia and
hypercarbia
• Diffusing capacity of lung for CO(DLCO) is decreased
• Preoperative SpO2 is important to establish a baseline.
• ABG is beneficial if patient is hypoxic or requires supplemental
oxygen

33. • CXR is useful in infection and when bullous disease is
suspected
• ECG: RBBB, peaked P waves suggest RV changes and
pulmonary HTN
• Inhalers and long term medications should be
continued on the day of surgery.

34. Restrictive Lung Disease
• Characterised by decreased TLC
• Causes can be pulmonary or extrapulmonary- obtain
medical history of associated diseases or symptoms.
• FEV 1 /FVC > 0.7 (both decreased)

35. DYSPNEA
• Associated with cardiac, pulmonary, hematologic and
neuromuscular diseases
• Onset, progression, precipitating factor, associated
conditions and drug exposure
• Chronic dyspnea: asthma, COPD, ILD, or cardiac
dysfunction.
• Should be classified using NYHA class categories.
• ECG, Hematocrit ABG, thyroid function, CXR, spirometery
and oximetery

36. • PATIENTS SCHEDULED FOR LUNG RESECTION
• PFT and V/Q scans :helps to predict risk or exclude patients
who lack adequate pulmonary reserve after resection.
• Predicted postoperative FEV1 =
FEV1 X
𝑅𝑎𝑑𝑖𝑜𝑎𝑐𝑡𝑖𝑣𝑒 𝑐𝑜𝑢𝑛𝑡𝑠 𝑖𝑛 𝑛𝑜𝑛𝑜𝑝𝑒𝑟𝑎𝑡𝑖𝑣𝑒 𝑙𝑢𝑛𝑔
𝑟𝑎𝑑𝑖𝑜𝑎𝑐𝑡𝑖𝑣𝑒 𝑐𝑜𝑢𝑛𝑡𝑠 𝑓𝑟𝑜𝑚 𝑏𝑜𝑡ℎ 𝑙𝑢𝑛𝑔𝑠
should be >0.8 or >40%
VO2peak >20mL/Kg/minute =low risk of complications
<15ml/kg/minute =increased risk
<10ml/kg/minute=very high risk

37. • OBSTRUCTIVE SLEEP APNEA
• Severity based on AHI (apnea-hypopnea index)
• >30 episodes of apnea-hypopnea/hour of
sleep=severe OSA
• Mask ventilation , DL ,endotracheal intubation
and fibro-optic visualization of airway is more
difficult in patients with OSA

38. • SMOKERS
Increases risk of:
• perioperative complications
• Wound infections
• Respiratory complications
• Severe coughing
• Episodes of ST segment depression (compared to non
smokers)
• Decreases macrophage function
• Negatively affects coronary flow reserve
• Vascular endothelial dysfunction
• HTN
• Ischemia
• Require longer hospital stay

39. • Peroperative benefits of smoking cessation are evident
only when cessation is atleast for 3-4 weeks before
surgical procedure.
• Soon after patient quits , there is decrease in CO levels,
increase oxygen delivery, decreased nicotine levels lead
to improved vasodilatation, decrease in toxic substances
that impair wound healing.

40. URTI
• Surgical procedures of patients with severe symptoms
with underlying conditions (significant asthma, heart
disease, immunosuppression) are postponed for at least
4 weeks as the underlying conditions may further
compromise a safe anesthetic regimen.

41. CYSTIC FIBROSIS
• Optimization of pulmonary status is necessary
• Electrolytes, LFTs, Chest radiographs are useful
• Continuation of most medications is recommended

42. POST OPERATIVE PULMONARY COMPLICATIONS
Risk factors:
1. History of cigarette smoking
2. ASA-PS score of >2
3. Age >70 years
4. COPD
5. Neck, thoracic , upper abdominal, aortic and neurologic
surgical procedures
6. Anticipated prolonged procedures (>2 hours)
7. Planned GA (especially with ET intubation)
8. Albumin <35 g/dl
9. Inability to walk two blocks on the level or climb one flight
of stairs
10. BMI>30

43. ENDOCRINE DISEASES
• DIABETES MELLITUS
GOAL IS:
• Optimization of glucose control before surgery
• Avoidance of hypoglycemia
• Avoidance of marked hyperglycemia
• INVESTIGATIONS: Blood glucose, ECG, electrolytes , BUN,
creatinine , HbA1C
• Risk of multiorgan failure , renal insufficiency, stroke, PVD,
autonomic dysfunction, cardiovascular disease (DM is CAD
equivalent)
• Poor control of disease is associated with increased risk of heart
failure, infection and poor outcome.

44. THYROID DISEASES
• Thyroid function test 6 months before the surgery are
adequate if patient is asymptomatic.
• TSH is best to evaluate hypothyroidism
• FT3, FT4, TSH are best to evaluate hyperthyroidism
• Elective surgical procedures should be postponed until
patient is euthyroid.
• Surgery,stress and illness can precipitate myxedema or
thyroid storm.

45. • Endocrinologist consultation is necessary if surgery is
urgent in patient with thyroid dysfunction
• CXR and CT is useful to evaluate mediastinal or
tracheal involvement by goitre.
• Medications of thyroid disorder should be continued
on day of surgery.

46. PARATHYROID DISEASE:
• Hyperparathyroidism :Primary, secondary, tertiary
• Rarely may become large enough to compromise
airway.
• Hypoparathyroidism : can result from total
thyroidectomy

47. HYPOTHALAMIC-PITUITARY-ADRENAL DISORDER
Serum cortisol and ACTH Levels establish the
diagnosis and cause of adrenal insufficiency.

48. • MEN SYNDROMES
• Undiagnosed phaeochromocytoma can cause substantial
morbidity and even death. Therefore it is important to
remove this tumor before other endocrine tumors.

49. Triad of symptoms of
PHAEOCHROMOCYTOMA
• Paroxysmal HTN is classical sign

50. RENAL DISEASE
It is important to know the type and severity of renal
disease
Associated diseases: HTN, CVS disease, electrolyte
disturbances
CKD : GFR< 60ml/min/1.73m2
CRF:GFR <15ml/min/1.73m2
ESRD: loss of renal function for 3 or more months
AKI: sudden decrease in renal function (RIFLE criteria &
AKIN)

52. HEPATIC DISORDERS
• Liver diseases affect hepatocytes, biliary system,
protein synthesis, bile regulation and metabolism of
drugs/toxins.
• Obstructive disorders cause bile stasis
• Drug induced liver diseases affect both hepatocytes
and biliary system.

54. It is appropriate to delay elective surgery in:
• Acute or fulminant liver
disease(alcoholic/viral/undefined)
• Until acute episode of hepatitis has resolved
The perioperative risk in patients with chronic hepatitis or
cirrhosis is predicted by:
1. Histologic severity
2. Portal HTN
3. LFT

55. HEMATOLOGICAL DISORDERS
ANEMIA (Hb<13g/dL males, <12g/dL females)
• Determine etiology, duration, stability , related symptoms and
therapy(esp. transfusion)
• Risk factor: colon cancer, GI bleeding, GU bleeding,
menorrhagia, chronic infections, Inflammatory ds, nutritional
deficiencies and prior weight reduction procedures
• Assess for fatigue, palpitations, chest pain , malena, pallor,
murmurs , HS, LNpathy
• Consider type of surgical procedure , anticipated blood loss &
comorbid conditions.

56. • Transfusion is always indicated if Hb< 6 and rarely indicated if Hb
>10 (report by ASA in 2015)
• ASA Task force on Blood Component Therapy concluded that RBC
should not be transfused solely on the basis of Hb but rather they
should be used to assess risk of complications from inadequate
preoxygenation.
• formula
• Elective procedures should be postponed in patients with
significant anemia regardless of anticipated blood loss during
surgery and meanwhile patient can be treated for anemia

57. • COAGULOPATHIES
• Hypocoaguable states can be inherited or acquired
• Inquire about: 1. known diagnosis
2. treatments
3.previous bleeding episodes
4.family history
• INVESTIGATIONS: platelet count/CBC/PT/aPTT
(routine screening for coagulopathies is not indicated)

58. • Prolonged PT without history of above : repeat test >Liver
enzymes>hepatitis panel Trial of Vit.K (1-5mg x ODX 3days)
• Prolonged aPTT: hypo/hypercoaguable state>repeat
test>ascertain heparin exposure,vWF disease.

59. • THROMBOEMBOLIC DISORDERS
• If prophylaxis is not administered the risk is:
 0.1-0.8 % in elective general surgery
 2-3% after elective hip replacement
 4-7% after repair of fractured hip
• Patients should be stratified preoperatively for the
risks of perioperative venous thromboembolism

60. ANTICOAGULANT THERAPY
WARFARIN
• May increase perioperative bleeding
• Witheld 4-5 days before surgery( if INR 2-3) to decrease INR <1.5
•
• If INR >3.0 withheld > 4-5 days
• If day before surgery INR >1.8 , a small dose of oral or s/c dose
of Vit. K (1-5 mg) can reverse anticoagulation
• Vit K has effect for 6-10 hours, peak action 24-48 hours.
• High doses of viatmin K can lead to warfarin resistance when
therapy is initiated again.

61. DECISION OF BRIDGING THERAPY:
• Individualized decision for every patient
• If planned : INR checked 2 days after last dose of warfarin
• if INR <1.5, intravenous Heparin or LMWH can be started
• IV unfractionated heparin is stopped 6 hours before surgery for normal
intaoperative caoagulation
• Therapeutic LMWH witheld 24hours before
• Prophylactic LMWH withld 12 hours before
• Adjustment of LMWH doses are necessary for patients with impaired
renal function ( eGFR < 30ml/minute)
• Epidural catheters are removed 12 hours after last prophylactic dose
and 2 hours before next dose

62. NEUROLOGICAL DISORDERS
SEIZURE DISORDER
• Document: TYPE OF SEIZURE (e.g., grand mal, absence) and
specific SYMPTOMS (e.g., staring, focal findings).
• 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.

63. CEREBROVASCULAR DISEASE:
• 1-3 months interval is considered safe between acute
stroke and surgery
• Risk of perioperative cardiac complications should be
evaluated

64. CANCER AND TUMORS
• Ask about side effects during chemotherapy or
radiotherapy
• Assess hypercoagulable state: thromboembolic events
• Head and neck irradiation: carotid artery disease,
hypothyroidism or difficult airway management
• Irradiation of lung,breast or mediastinum:radiation
pneumonitis

65. • Mediastinal , chest wall or left breast irradiation:
pericardial abnormalities and premature CAD
• Chemotherapy associated S/E :
cardiomyopathy, pulmonary toxicity, hemorrhagic cystitis,
peripheral neuropathy, myelosupression
• Paraneoplastic syndromes ,difficult airway,mediatinal
masses: lung cancer
• INVESTIGATIONS
CBC, electrolytes, BUN, creatinine , LFTs, ECG, CXR

66. 2.PREOPERATIVE MANAGEMENT OF
MEDICATIONS

67. 3.PREOPERATIVE RISK ASSESSMENT

68. 4. PLANNING FOR ANAESTHESIA
1. PREOPERATIVE FASTING STATUS
• clear fluids:2 hours.
• light meal: 6 hours
• fried or fatty foods: 8 hours or more
For neonates/ infants:
• Breast milk: 4 hours
• Formula/solids: 6 hours

69. 2. PLANNING FOR POST-OPERATIVE PAIN
MANAGEMENT
• In Pre-op evaluation we should note baseline opioid use.
• Facilitate early involvement of acute pain service or chronic
pain specialist
• Encourage regional anesthetic techniques
• Plan adjunct analgesics and continue use of regular analgesic
on day of surgery.
• Patients with chronic pain should be informed that care
provider will do everything possible to maintain postop
comfort but patient should not expect to have no pain at all

70. THANKYOU !

71. • MURMURS AND VALVULAR ABNORMALITIES
Goals:
1. Location and intensity of murmur
2. cause of murmur
3. Distinguish significant and clinically unimportant
murmurs
4. Grading of murmurs (6 grades)
5. Functional and benign murmurs.
 Effects Valsalva maneuver, standing, squatting.
 INVESTIGATIONS: ECG, ECHO
 Cardiac consultation