Surgery

Question 1

Sepsis

Answer 1

Presence of pathogens

Question 2

Asepsis

Answer 2

Free from infection

Question 3

Antisepsis

Answer 3

Prevention of sepsis

Question 4

Sterilisation

Answer 4

Elimination of all microorganisms including spores

Question 5

Disinfection

Answer 5

Removal of all microorganisms, sometimes not including spores.

Question 6

Bacterial infection

Answer 6

defined as having more than 10^5 bacteria per gram of tissue i.e. bigger than colonisation.

Question 7

Classification of surgical wounds

Answer 7

1. Clean
2. Clean-contaminated
3. Contaminated
4. Dirty

Question 8

Clean wound

Answer 8

Non-traumatic, non-inflamed operative wounds that do not enter respiratory, gastrointestinal, urogenital, oropharyngeal tracts.
E.g. elective neuter, THR

Infection rates = 0-4.4%

Question 9

Clean-contaminated wound

Answer 9

Operative wounds in which respiratory, gastrointestinal, urogenital, oropharyngeal tracts are entered but under controlled conditions without unusual contamination.
E.g. bronchoscopy, enterotomy

Infection rates =4.5-9.3%

Question 10

Contaminated wound

Answer 10

Open, fresh, accidental wounds or procedures in which GI contents or infected urine is spilled or a major break in aseptic technique occurs.
E.g. cystotomy with spillage of infected urine, open cardiac massage for CPR

Infection rates =5.8-28.6%

Question 11

Dirty wound

Answer 11

Old traumatic wounds with purulent discharge, devitalised tissues or foreign bodies; procedures in which a viscus is perforated or faecal contamination occurs.
E.g. excision/drainage of an abscess, bullae osteotomy for otitis media, perforated intestinal tract

Gross infection is present

Question 12

Circumstances in which antibiotics should be used prophylactically

Answer 12

• Surgery time longer than 90 mins
• Prosthesis implantation E.g. mesh, pacemaker, bone cement
• Patients with pre-existing prosthesis E.g. hip replacement undergoing certain surgical procedures
• Severely infected or traumatised wounds

Question 13

Factors affecting the establishment of infection

Answer 13

• Host factors e.g. age, physical condition, nutritional status etc.
  
  • Diagnostic procedures e.g. placing a catheter increases likelihood of an ascending infection
  • Concurrent metabolic disorders e.g. HAC
  • Medication e.g. corticosteroids, chemotherapy
• Operating room practice
  
  • Aseptic technique
  • Sterilisation, disinfection
  • Anaesthesia
  • Atraumatic technique
• Characteristics of bacterial contaminants

Question 14

Discuss the rational use of antibiotics in the surgical patient

Answer 14

• Generally, antibiotics are used for contaminated/dirty wounds
• Sometimes they are used for clean-contaminated wounds
• Prophylactic use is rarely recommended, but may be indicated in specific circumstances
• Rational selection of antibiotics should be used
• Ideally this would depend on culture and sensitivity, but in practice time and financial constraints mean this isn’t possible

Question 15

Give an example of an antibiotic that could be used for a patient undergoing large intestine surgery

Answer 15

• In this case we might be particularly concerned about anaerobes
• Metronidazole has good anaerobe coverage

Question 16

Which should you use for cutting skin: scissors or a scalpel?

Answer 16

A scalpel

Scissors = poor practice, would crush the skin as they cut.

Question 17

What is the most commonly used scalpel blade?

Answer 17

Number 10

Question 18

Which scalpel blade should you use for the most delicate tissues? e.g. a urethrostomy

Answer 18

Number 15

Question 19

Which forceps are considered the go-to for soft tissue surgery?

Answer 19

Debakey forceps

They were originally designed for vascular use and are the least traumatic of forceps

Question 20

Here are some forceps. What are they used for?

Answer 20

Haemostat forceps

• Designed to occlude blood vessels and prevent haemorrhage

Question 21

Here are some forceps. What are they used for?

Answer 21

Tissue holding forceps

• Designed to handle and manipulate tissues.
• Specific design varies according to relevant tissue.

Question 22

Tensile strength

Answer 22

breaking strength per unit area.

i.e. how strong it is under tension

Question 23

Memory

Answer 23

tendency to retain original configuration when it comes out of the packet.

Question 24

Which has higher memory: monofilaments or multifilament? What does this mean?

Answer 24

Monofilaments have higher memory, making it potentially harder to tie secure knots.

Question 25

**Chatter/tissue drag**

Answer 25

lack of smoothness/friction while passing through the tissue. Multifilaments have more drag than monofilaments.

Question 26

**Tissue reaction**

Answer 26

inflammatory response to the placement of sutures

Question 27

What are the advantages of absorbable suture material?

Answer 27

✅ They disappear ✅ Low risk of long-term foreign body reaction

Question 28

What are the disadvantages of absorbable suture materials?

Answer 28

❌ Lose strength ❌ Limited period of wound support

Question 29

What are the advantages of non-absorbable suture materials?

Answer 29

✅ Permanent ✅ Provide indefinite wound support

Question 30

What are the disadvantages of non-absorbable suture materials?

Answer 30

❌ They do not disappear ❌ Possibility of delayed reactions e.g. foreign body reaction

Question 31

What are the advantages of braided (multifilament) suture materials?

Answer 31

✅ Easy to handle ✅ Excellent knotting; very secure

Question 32

What are the disadvantages of braided (multifilament) suture materials?

Answer 32

❌ Greater friction and tissue drag ❌ More tissue trauma

Question 33

What are the advantages of monofilament suture materials?

Answer 33

✅ Minimal tissue trauma ✅ Passes through tissues easily: minimal drag ✅ No capillary action

Question 34

What are the disadvantages of monofilament suture materials?

Answer 34

❌ Harder to handle ❌ Harder to knot ❌ Require different knotting technique for greater security

Question 35

What are the advantages of natural suture materials?

Answer 35

✅ Easy to handle ✅ Easy to knot compared to synthetic monofilament sutures ✅ High histocompatibility

Question 36

What are the disadvantages of natural suture materials?

Answer 36

❌ Moderate/high tissue reaction ❌ Low tensile strength

Question 37

What are the advantages of synthetic suture materials?

Answer 37

✅ High tensile strength ✅ Predictable biological behaviour

Question 38

What are the disadvantages of synthetic suture materials?

Answer 38

❌ Poorer knotting than natural materials (if synthetic monofilament)

Question 39

What are the consequences of suture material implantation?

Answer 39

* Suture material is a foreign body which causes a tissue reaction * Methods of absorption: * Phagocytosis - more aggressive * Hydrolysis - generally smaller tissue reaction

Question 39

What are the consequences of suture material implantation?

Answer 39

* Suture material is a foreign body which causes a tissue reaction * Methods of absorption: * Phagocytosis - more aggressive * Hydrolysis - generally smaller tissue reaction

Question 40

How are natural sutures absorbed?

Answer 40

via phagocytosis e.g. catgut

Question 41

How are synthetic sutures absorbed?

Answer 41

Hydrolysis

Question 42

If there is infection in a wound, are you better off closing it with monofilament or multifilament?

Answer 42

Monofilament Multifilament has a large surface area and provides nooks and crannies for bacteria to colonise

Question 43

What size suture material would we use for ophthalmic surgery?

Answer 43

11-0

Question 44

What are some issues with eyed needles?

Answer 44

❌ Have to use a double strand of suture material → increased tissue trauma ❌ Multiple uses will blunt the needle

Question 45

Why are swaged needles the needles of choice?

Answer 45

✅ Cause minimal trauma ✅ Single use ✅ Optimal penetration properties However, they are more expensive

Question 46

When would we use a **taperpoint needle**?

Answer 46

When suturing the intestines (where we don't want to make a big hole)

Question 47

What is ductility?

Answer 47

**Ductility**: the bending property of the needle. It warns the surgeon that the force being placed upon it is too great.

Question 48

Name some prophylactic antibiotics you could give to an equine patient undergoing surgery (if antibiotics were required).

Answer 48

* Procaine penicillin (IV) * Gentamicin (IV) * Oxytetracycline (non IV)

Question 49

How should theatre be cleaned at the start of the day?

Answer 49

Damp dust with disinfectant