This document summarizes the importance of preoperative investigations and assessments. It outlines key tests that should be performed for major surgeries, such as complete blood count, serum creatinine, ECG, coagulation screening, and chest x-rays. Additional tests like blood glucose, liver function tests, and arterial blood gases are recommended for patients with certain medical conditions. The results of preoperative investigations help optimize patient health prior to surgery and identify risks. A thorough preoperative evaluation is essential to reduce preventable complications.

1. Preoperative
investigations
and significance
Dr. Moyukh Chowdhury
Indoor Medical Officer, Department of Surgery
Sylhet Women’s Medical College Hospital
Sylhet Bangladesh.

2. 19th century
The Victorian era
• Evolution of revolution when barbers stopped
doing surgeries &
• concept of antisepsis started to take place.

3. Strabismus correcting operation in 19th century .

4. Compressing the arteries of arms and legs
to reduce blood loss

6. Renowned Scottish surgeon Robert Liston
with anesthetic support

7. Experience without anesthesia or Poor anesthesia
Poorly controlled blood loss .
Gazillions of microbe .
Lack of preoperative assessments and post
operative management .

8. Surgery
or
DEATH
sentence ?

9. Welcome to the

10. According toWHO …
• The reported crude mortality rate after major
surgery is 0.5-5% .
• complications after inpatient operations occur in
up to 25% of patients;
• In industrialized countries, nearly half of all
adverse events in hospitalized patients are
related to surgical care.
• At least half of the cases in which surgery led to
harm are considered preventable .

12. Per
operative
Post
operative
Pre
operative

13. History
Examination
Investigation

14. Key points

15. • Major surgery can lead to organ
system dysfunction so needs most
investigations .
Type of surgery:
• For example, sickle cell test for
patient with Afro- Caribbean
origin .
Patient:
• Peak flow rates for severe
asthmatics .Comorbidities:

17. Complete blood count (CBC)

18. Serum creatinine, Urea and
electrolytes.
• Needed before all major operations, in most
patients over 60 years of age especially with
cardiovascular, renal and endocrine disease
or if significant blood loss is anticipated.
• It is also needed in those on medications
which affect electrolyte levels, e.g. steroids,
diuretics, digoxin, NSAIDs , intravenous fluid
or nutrition therapy.

19. Electrocardiography (ECG) &
Echocardiogram
• Required for those patients aged over 60
years or cardiovascular, renal and
cerebrovascular involvement, diabetes and in
those with severe respiratory problems.

20. Clotting screening
If a patient has a history suggestive of
• bleeding diathesis,
• liver disease,
• eclampsia,
• cholestasis ,
• family history of bleeding disorder, or
• on antithrombotic or anticoagulant agents,
then coagulation screening will be needed. However,
the effects of antiplatelet agents, low molecular
weight heparins and newer agents affecting factor
“Xa” cannot be measured by routine laboratory tests.

21. Chest radiography
• A chest x-ray is not required unless the patient
has a significant cardiac history, cardiac
failure, severe chronic obstructive pulmonary
disease (COPD), acute respiratory symptoms,
pulmonary cancer, metastasis or effusions, or
is at risk of tuberculosis.

22. Urinalysis
• Dipstick testing of urine should be performed on
all patients to detect urinary infection, biliuria,
glycosuria and inappropriate osmolality.
Human chorionic gonadotrophin:
• Pregnancy needs to be ruled out in all women of
childbearing age.

23. Blood glucose and HbA1c :
• These should be performed in patients with
diabetes mellitus and endocrine problems. HbAlc
indicates how well diabetes has been controlled
over a longer duration.
Arterial blood gases :
• This test allows detailed assessment of severe
respiratory conditions and acid-base disturbances.

24. Liver function tests :
• These are indicated in patients with jaundice, known
or suspected hepatitis, cirrhosis, malignancy or
patients with poor nutritional reserves.
Other investigations:
• Further relevant investigations should be undertaken
to assess capacity of specific organ system and
risks associated. Specialist radiological views and
recent imaging are sometimes required. If imaging is
going to be needed during surgery then this needs to
be planned in advance. Blood grouping and Viral
markers.

25.  Specific medical problems encountered
during preoperative assessment should be
corrected to the best possible level.
 Many patients with severe disease will be
needed to be referred to specialists; the
referral letter should include all the details
including history, examination and
investigation results .

26. • Neuromuscular Diseases (Muscular
Dystrophies, Myotonias, Amyotrophic
Lateral Sclerosis, Myasthenia Gravis)
Patients with muscular dystrophy, myotonia, or
amyotrophic lateral sclerosis (ALS) undergoing
surgery have an increased risk for respiratory and
cardiac complications. The risk of life-threatening
cardiac dysrhythmia and depression of cardiac
contractility should be carefully considered, and
cardiac function should be evaluated by specialist.

27. • It’s a system for assessing the fitness of cases
before surgery .
• In 1963 the American Society of
Anesthesiologists (ASA) adopted the
five-category physical status classification
system; a sixth category was later added.

28. Grade 6
A declared brain dead person whose organs are being
removed for donor purposes
Grade 5
A moribund person who is not expected to survive without
the operation.
Grade 4
Severe systemic disease that is a constant threat to life.
Grade 3
Severe systemic disease.
Grade 2
Mild systemic disease.
Grade 1
Healthy person.

30. Reference :
• Bailey and Loves Short practise of Surgery
( 26th Edition )
• www.who.int/patientsafety/safesurgery
• www.elitereaders.com/crucial-interventions-
reveal-surgery-victorian-era