1. Preoperative Assessment
M K Alam MS; FRCS

2. ILO’s At the end of this presentation students will be able to:
Understand the principles of preparing patients for surgery.
Describe the systemic approach in preoperative assessment.
Name common problems affecting patient’s fitness for surgery.
Describe the management of chronic medical problems.
Outline DVT prophylaxis measures.
Describe how to take informed consent.

3. Introduction
Careful preoperative assessment essential for good surgical outcome.
Assessment modified for emergency surgery.
Benefit of operation vs no surgery vs no treatment.
Decision to operate- patient fitness for surgery usually decided few weeks before surgery.
Identify comorbid conditions and optimize it.
Preoperative clinics before admission for surgery.

4. Priorities Establish extent & severity of condition requiring surgery.
General medical history.
Assessment for comorbid and undiagnosed diseases.
Medications.
Details of previous surgery and anaesthesia.
Anaesthetic review before admission.
Morning of surgery: Reassess with all investigation results.

5. Oxygen Postop. Morbidity/ mortality related to O2 delivery to tissues.
Patients with poor cardiorespiratory reserve and anaemia at higher perioperative risk.
Optimizing this- minimizes the risk

6. Systemic preoperative assessment CVS
Angina, myocardial ischemia, exertional dyspnoea, orthopnoea, paroxysmal nocturnal dyspnoea, dependent oedema, arrhythmia, murmur, hypertension, antiplatelet drugs and anticoagulant are indication of cvs disease.
Cardiology consultation.
Optimization before surgery.

7. Respiratory system
New cough, sputum or wheeze- new or exacerbation of pre-existing respiratory disease.
Asthmatics or COPD with purulent sputum- infective exacerbation.
Respiratory viral illness- postpone surgery if possible.
Smoking- advise to quit.
Functional reserve: How many stairs can climb before needing rest?
ABG, respiratory function test.
Pulmonologist consultation

8. Nutritional status Weight (<90% predicted), BMI
History of weight loss-
Malnutrition:
Low BMI- less than predicted
> 20% weight loss
Hypoproteinaemia
Hypoalbuminaemia
Delay surgery to treat malnutrition if possible
Obesity: Increased risk from surgery & anaesthesia Advise: Loose weight (dietician referral, supervised exercise)

9. Medications
Long term steroids: needs higher dose during perioperative period. 100mg Hydrocortisone every 6 hours. Gradually reduced in postoperative period.
Antiplatelet drugs: Aspirin, clopidogrel should be withdrawn only after cardiology consultation.
Warfarin: Stopped 4-5 days before surgery, started on IV unfractionated heparin or subcutaneous low molecular weight heparin. Warfarin restarted after risk of bleeding is over. Heparin stopped once INR is in therapeutic range (2.5-3)

10. Psychiatric medications can complicate anaesthesia
Psychiatric medications can complicate anaesthesia. Anaesthetist informed. MAOI stopped 2-3 weeks before surgery.
Allergies
Pregnancy- if surgery is necessary, safe period- 2nd trimester.
Previous surgery & anaesthesia details.

11. Preoperative investigations
Identify new problems to correct before surgery.
Fitness for anaesthesia
Avoid unnecessary tests

12. Investigations FBC, Coagulation profile, Cross match group & save.
Urea, electrolytes, LFTs
Microbiology- urine culture, sputum, virology
Imaging: CXR, US, CT, MRI, Isotope studies
RFT: ABG, FVC, FEV1 (Pulmonology consultation)
CVS: ECG, Echocardiography, Thallium scan, exercise testing. (Cardiology consultation)

13. High risk patients HBV, HCV patients HIV patients
Patients with unknown HBV,HCV,HIV status.
IV drug users
Recipients of multiple transfusion.
Patients from endemic area.
Universal precaution to protect surgical team.

14. Emergency surgery Assessment curtailed due to lack of time.
Frequently need resuscitation before surgery.
ABC approach.
Restore hypovolemia before surgery (except for life threatening bleeders).
Avoid – delaying surgery to correct moderate biochemical abnormalities.

15. Risk factors for VTE Malignancy Age > 60 years Dehydration
Past or family history of VTE
Obese
Significant comorbidity (CVS, RS, metabolic)
HRT, oestrogen containing contraceptives.
Pelvic or lower limb surgery
Surgery time > 90 min.

16. Preoperative round
Consent: Full explanation to patient and all question answered.
Patient fully understands ( simple language)
All treatment options
All potential serious outcome, even if rare
Risk & benefit quantified
Surgeon or his deputy (knowledgeable, experienced)
Respect patients decision
No pressure to accept recommendation

17. Check all chronic/ acute conditions optimized.
DVT prophylaxis- anti embolic stockings, intermittent pneumatic compression device, heparin (LMWH, unfractionated)
Antibiotic prophylaxis.
Anxiolytics
Preoperative fasting- average 6 hours

19. Perioperative management of chronic disease
CVS disease: Cardiology assessment. Antibiotic for valvular disease (BE prophylaxis) Pacemaker- avoid monopolar diathermy. Bipolar or ultrasonic devices preferred.
RS: Chest physician consultation.
May need HDU/ ICU- arrange bed in consultation with anaesthetist.
Pre/postop. chest physio.- incentive spirometry + good analgesia

20. Perioperative management of chronic disease
Diabetes: Poor glycaemic control is associated with increased complication. Surgery → hyperglycaemia. Needs close monitoring.
Glucose level mmol /L reasonable target.
Management:
Omit oral hypoglycemic on morning of surgery, monitor sugar level postop until eating freely (mild cases). If glucose > 10mmol/L- start glucose/insulin/K⁺ infusion
Insulin dependent: Start glucose/ insulin/ K⁺ prior to surgery. Convert to- sc short acting insulin then regular insulin as the diet is introduced.

21. Chronic renal failure
Dialysis dependent: Careful IV fluid administration.
Care of dialysis access- PDC, venous fistula
Venous fistula- never use for venous access/ phlebotomy.
Preoperative dialysis to optimize patient.
Non-dialysis dependent: Reasonable renal function.
Avoid: Nephrotoxic drugs, hypotension, treat sepsis aggressively and maintain careful fluid balance.

22. Jaundice Mostly obstructive, may be hepatocellular
Coagulopathy due to Vit K dependent factor deficiency (II,VII,IX,X).
Coagulopathy corrected by FFP.

23. Anticoagulant therapy
Warfarin stopped 4-5 days before surgery.
Started on IV unfractionated heparin or subcutaneous low molecular weight heparin.
INR before surgery <1.5
Warfarin restarted after risk of bleeding is over, concurrent with heparin.
Heparin stopped once INR

24. Anaemia Mostly iron deficiency due to GI bleeding or menorrhagia.
Preoperative haemoglobin around 10 G/ dl
If major blood loss expected- cell salvage technique

25. Thank you!