Haemostasis and asepsis

Question 1

Give examples of some haemostatic techniques

Answer 1

Pressure
Ligatures
Haemostat forceps
Electrosurgery 
Vessel sealing devices
Vascular clips
Topical haemostatic agents

Question 2

Pressure can be used for what types of bleeding?

Answer 2

Capillary ooze (low pressure for 5 minutes) 
Severe haemorrhage - only temporarily whilst preparing to cauterise/ligate vessel

Question 3

Why should you dab when applying pressure during haemostasis, not wipe?

Answer 3

Disturb the clot

Question 4

Haemostat forceps are used to crush or occlude a blood vessel. What angle should they be used at?

Answer 4

90 degrees to vessel

Question 5

Electrosurgery can be used to coagulate tissue and cause vessel thrombosis. When should you avoid electrosurgery?

Answer 5

With spirit based preparation

Dachshund on fire story

Question 6

What are the 2 types of cauterisers used in electrosurgery?

Answer 6

Monopolar - can cut and cauterise

Bipolar - more precise, requires less current

Question 7

How do electrothermal bipolar vessel sealers work?

Answer 7

Use radio frequency to weld vessels together

Question 8

How do harmonic scalpels work as vessel sealers?

Answer 8

Use ultrasonic vibrations to cause heating and coagulation

Can cut at certain frequencies

Question 9

Ligatures include simple, circumeferential and transfixing types. When may a ligature not be useful?

Answer 9

If vessel too large

Use other technique

Question 10

Vascular clips are metal or absorbable clips with applicators. What is the advantage/disadvantages of these clips?

Answer 10

Faster than traditional ligature
More expensive
Vessel has to be greater than 1/3 and less than 2/3 length of clip

Question 11

Topical haemostatic agents can be in the form of granules, powders or sheets. What are they usually derived from?

Answer 11

Collagen

Fibrin

Question 12

How do topical haemostatic agents work?

Answer 12

Act as a scaffold for fibrin clot formation

Question 13

When may topical haemostatic agents be used?

Answer 13

Persistent capillary haemorrhage

Beaks, nails

Question 14

Define a surgical infection

Answer 14

Infection at site of surgery within 30 days

Question 15

Define a nosocomial infection

Answer 15

Infection acquired in hospital, often by resistant bacteria

Question 16

Define sterilisation

Answer 16

The process of destroying all micro-organisms

Question 17

Define disinfection

Answer 17

Use of germicidal substances on inanimate objects

Question 18

Define antisepsis

Answer 18

Use of germicidal substances on living tissue

Question 19

What is the difference between prophylactic and therapeutic antibacterials?

Answer 19

Prophylactic = before infection occurred
Therapeutic = to treat existing infection

Question 20

All surgical wounds are contaminated with bacteria. What factors influence whether contamination leads to infection?

Answer 20

Type and number of bacteria
Clipping of surgical site
Anaesthetics and surgical time 
Endocrinopathies
Number of people in operating room
Sex of patient
Local wound environment and host defence

Question 21

Wounds can be classified into 4 groups. What are these?

Answer 21

Clean
Clean-contaminated
Contaminated
Dirty

Question 22

How can clipping influence contamination of the surgical site? How can this be reduced?

Answer 22

Clippers cause microtrauma to skin - increases bacterial growth
(Only clip immediately prior to op)

Question 23

During anaesthesia and surgery time, the risk of wound infection doubles every hour. Why?

Answer 23

Immunosuppression from anaesthesia
Tissue handling
Longer exposure to bacteria

Question 24

How does propofol contribute to wound contamination?

Answer 24

Propofol supports bacterial growth

If contaminated/injected at wound site can cause infection

Question 25

Patients with endocrinopathies are more at risk of wound infection. Give examples of these endocrionopathies

Answer 25

Diabetes mellitus Hyperadrenocorticisim Hypothyroidism

Question 26

Why does wound infection rate increase with the number of people in the operating room?

Answer 26

More people = more airborne contamination

Question 27

How does the sex of the patient impact risk of wound infection?

Answer 27

Males more at risk | Due to immunomodulatory effects of androgens

Question 28

Give examples of local wound environments that may put an animal at higher risk for a wound infection

Answer 28

Trauma near wound Foreign materials Ischaemia

Question 29

Give examples of host factors that may put an animal at higher risk of wound infection

Answer 29

Sex - males Systemic disease and health conditions Poor nutrition Medications e.g. chemo

Question 30

Give examples of endogenous and exogenous sources of bacterial contamination

Answer 30

Endogenous - skin, GIT, respiratory tract | Exogenous - room air, surgical team, instruments, drapes

Question 31

How can patients with pre-existing disease have risk of surgical infections reduced?

Answer 31

Ideally postpone until problem resolved

Question 32

What preparation of patients before surgery can prevent infections?

Answer 32

Clip just before surgery Thoroughly clean with chlorhexidine/povidone-iodine Use surgical drapes

Question 33

How can you prevent wound infections?

Answer 33

Prep patient Sterilise equipment and room Wound lavage - irrigation, rinse with saline

Question 34

What post-op care should be given to prevent wound infections?

Answer 34

Monitor for signs of infection | If suspected, culture before giving antibacterials

Question 35

If prophylactic antibacterials are given before surgery, when should they be given?

Answer 35

Immediately before induction via IV | Repeat as required then stop at end of procedure unless already infected

Question 36

When should prophylactic antibacterials be used?

Answer 36

Only if surgery lasting more than 90 mins or animal at risk For clean-contaminated and contaminated wounds Dirty surgeries