1
Q
Outline the layers of the skin
A
- Epidermis
- Dermis
- Hypodermis/Subcutaneous
2
Q
Epithelium of the epidermis
A
Keratinised squamous epithelium
3
Q
Where do the skin’s natural tension lines lie
A
Right angles to the angle of contraction of the underlying muscle
4
Q
What constitutes a superficial wound
A
Involve only epidermis and dermis
5
Q
What constitutes a deep wound
A
Involve layers deep to the dermis
6
Q
Describe primary intention wound healing
A
- Occurs in uncontaminated wounds with minimal tissue loss
- Wound edges easily approximated
- Wound heals by rapid epithelialisation and formation of minimal granulation tissue
7
Q
Describe secondary intention wound healing
A
- Occurs in wounds with substantial tissue loss
- Wound is left open and allowed to heal from deep aspects by granulation, epithelialisation and contraction
8
Q
Describe tertiary intention wound healing
A
- Wound is closed several days after its formation
- e.g. Delayed primary closure
9
Q
List the 3 phases of wound healing
A
- Acute inflammatory phase
- Proliferative phase
- Maturation phase
10
Q
Outline the inflammatory phase of wound healing
A
- Initial trauma
- Vasodilatation and increased vascular permeability
- Influx of inflammatory cells (neutrophils) and fibroblasts
- Platelet activation and initiation of the coagulation and complement cascades
11
Q
When do neutrophils arrive at the wound
A
0-1 days
12
Q
When do macrophages arrive at the wound
A
1-2 days
13
Q
When do fibroblasts arrive at the wound
A
2-4 days
14
Q
When do myofibroblasts arrive at the wound
A
2-4 days
15
Q
When do endothelial cells arrive at the wound
A
3-5 days
16
Q
Outline the proliferative phase of wound healing
A
Characterised by migration and proliferation of:
- Epithelial cells
- Fibroblasts
- Endothelial cells
17
Q
When is epithelial closure usually achieved
A
48 hours
18
Q
What is the role of fibroblasts in the proliferative phase of wound healing
A
Synthesise extracellular matrix components including collagen and ground substance
19
Q
What is granulation tissue
A
Temporary structure that forms during the proliferative stage. Contain capillaries, fibroblasts, macrophages and endothelial cells. Has a characteristic pink, granular appearance.
20
Q
How long does skin take to regain full strength
A
6 months
21
Q
How long does bowel and muscle take to regain full strength
A
1 month
22
Q
How long does full maturation of the scar take
A
12-18 months
23
Q
What vitamin aids the cross-linking of the fibrils in matrix remodelling
A
Vitamin C
24
Q
Describe Neuropraxia
A
- Temporary and reversible loss of function lasting 6-8 weeks (motor function first to be lost)
- No axonal disruption
- Crush, stretch, or contusion of the nerve
25
Describe Axontmesis
- Axonal disruption
- Supportive tissue framework is preserved
- Wallerian degeneration occurs
- Regeneration takes weeks to months
26
What is Wallerian degeneration
- Occurs when a nerve is cut or crushed
- Part of the axon that is separated from the neuron's cell nucleus degenerates
- Begins 24 hours following injury during which time the distal axon remains excitable
27
What supportive tissues are preserved in Axontmesis
- Epineurium
| - Perineurium
28
Describe Neurotmesis
- Both the supportive tissue and the axon are disrupted
| - Neuroma forms at the proximal stump
29
How long does mucosal integrity take to return after uncomplicated GI tract surgery
24 hours
30
How is liver regeneration achieved
- Stimulated by reduction in liver mass:body ratio and release of TNF and IL-6
- Achieved by proliferation of all cell types (hepatocytes, biliary epithelial cells, Kupffer cells)
31
What clinical sign precludes wound dehiscence
Pink serosanguinous fluid from the wound
32
At what rate does nerve regrowth occur when it happens
1mm/day
33
List the drugs that impair wound healing
- NSAIDs
- Steroids
- Immunosuppressive agents
- Anti-neoplastic drugs
34
Outline the two types of abdominal wound dehiscence
1. Superficial = skin alone fails
| 2. Complete = all layers fail
35
List the common factors that increase the risk of wound dehiscence
- Malnutrition
- Vitamin deficiencies
- Jaundice
- Steroid use
- Major wound contamination
- Poor surgical technique that does not follow Jenkins rule
36
How should sudden dehiscence be managed
1. Analgesia
2. IV fluids
3. IV broad-spectrum antibiotics
4. Cover wound with saline impregnated gauze
5. Arrange return to theatre
37
How can scar contractures be treated
Z-plasty
38
Define a Hypertrophic scar
Excessive remaining scar tissue confined to the site of the original wound due to fibroblast overactivity
39
Define a Keloid scar
Excessive scar tissue that extends beyond the original wound
40
List the risk factors for Keloid scar formation
- Young age
- Male sex
- Dark pigmented skin
- Genetic
- Site (shoulders, sternum, head, neck)
- Tension on wound
- Delayed healing
41
Does hair removal prior to surgery reduce surgical site infection
No evidence to suggest this
42
What is the ideal theatre temperature
20-22 degrees
43
What are the stages of the WHO surgical checklist
1. Before induction of anaesthesia
2. Before skin incision
3. Before patient leaves operating room
44
What suture should be used for abdominal mass closure
1 PDS
45
What gas is used to induce pneumoperitoneum
CO2
46
Describe Jenkin's rule
Each bite of abdominal wall should be a minimum of 1cm and adjacent bites must be a maximum of 1cm apart
47
What layers are included in mass closure of the abdomen
All layers of the abdominal wall and peritoneum, except subcutaneous fat and skin
48
Describe monopolar diathermy
- Current flows through the diathermy unit into a handheld device
- Electricity flows from the tip of the device into the patient
- The earth electrode is some distance away and a large part of the patient is included in the circuit
49
Describe bipolar diathermy
- Electrical current flows from one electrode to another
| - Both electrodes are contained within the same handheld device
50
Which of monopolar and bipolar diathermy has a higher voltage
Monopolar
51
Monopolar power output
400W
52
Bipolar power output
50W
53
Which parts of the body is bipolar diathermy useful for
Extremities - penis, scrotum, digits
54
What purpose is bipolar diathermy limited to
Coagulation (some cutting devices have been developed)
55
What type of current and frequency do diathermy circuits use
AC at 200kHz to 3.3MHz
56
When is continuous current used
- Monopolar cutting
| - Bipolar circuits
57
When is attenuated current used
- Monopolar blended cutting
- Desiccation (coagulation)
- Fulguration
- Spray
58
What is the minimum electrode pad size
70cm^2
59
What output is used for pure cutting
Continuous output - high local temperature causes tissue disruption
60
When is blended cutting favoured over pure cut
When small vessel haemostasis is required
61
What is the difference between blended and pure cutting
Blended cutting uses an attenuated output
62
What is dessication
Contact coagulation used to obtain haemostasis in small blood vessels
63
What is Fulguration
Non-contact coagulation used to dry an area of capillary bleeding using an attenuated output
64
Uses of argon beam laser
- Eye surgery
| - Endoscopic ablation
65
Use of CO2 laser
- ENT ablation surgery
| - Cervical ablation surgery
66
Use of Nd:YAG laser
- Endoscopic debulking surgery
- GI bleeding coagulation
- Laparoscopic surgery
67
How do Harmonics work
- Provide electrical energy to piezoelectric ceramic plate
- Expands and contracts at 55500Hz
- Creates ultrasonic waves that break down H-H bonds resulting in protein denaturation
68
List the types of braided non-absorbable suture
- Silk
- Linen
- Cotton
- Polyester
- Nurolon
69
List the types of monofilament non-absorbable suture
- Polypropylene (Prolene)
- PVDF (Novafil)
- Steel
70
List the types of braided absorbable suture
- Polyglycolic acid (Dexon)
| - Polyglactin 910 (Vicryl)
71
List the types of monofilament absorbable suture
- Polydiaxone (PDS)
| - Polyglyconate (Maxon)
72
Which needle should be used for abdominal closure
Round-bodied blunt needle
73
Which needle should be used for skin closure
Cutting needle
74
When should facial sutures be removed
4-5 days
75
When should scalp sutures be removed
6-7 days
76
When should hand/limb sutures be removed
10 days
77
When should abdominal wound sutures be removed
10-20 days
78
Most commonly used abdominal self-retainer
Balfour
79
Most commonly used retainer for inguinal hernia repair
West
80
What size blade should be used for opening the abdomen
10
81
What size blade should be used for stab incisions e.g. laparoscopic ports
11
82
What is the difference between open and closed drains
- Open = into dressings
| - Closed = into container
83
What is the purpose of latex tube drains e.g. T-tube
- Act as sump drains
| - Desired effects is to generate fibrosis along the drain tract
84
List the purposes of drains
- Minimise deadspace
- Where there is risk of leakage
- Drain fluid collections
- Divert fluid
- Decompression
85
How do hydrocolloid dressings work
Form a gel that absorbs secretions
86
What type of dressing is useful for desloughing wounds
Hydrogels
87
What class of laser is Nd:YAG
Class 4
88
What is Argon laser used for
Coagulation
89
How is the penetrance of the laser determined
Determined by wavelength of the laser
90
What suture is typically used for anchoring drains
2/0 Silk
91
What suture is suitable for mass closure of the abdomen
1 PDS
92
What suture is suitable for skin closure
Vicryl
93
What suture is suitable for vascular anastomosis
6/0 Polypropylene (Prolene) - non-absorbable continuous suture
94
What is the thinnest available suture size
11-0
95
What is the thickest available suture size
1
96
What suture is most commonly used in laparoscopic surgery
Polyester (Ethibond)
97
How long should a patient be monitored following core biopsy
6 hours
98
What type of biopsy is typically taken for skin tumours
Excisional biopsy
99
List the medical contraindications to day-case surgery
- ASA >2
- BMI >35
- Specific problems e.g. bowel resection
- Extensive pathology
- Operation >1 hour
100
What are the early complications of vascular anastomosis
- Haemorrhage or leak
| - Thrombosis
101
Late complications of vascular anastomosis
- Infection
- Stenosis
- Pseudoaneurysm at the suture line
- Rupture
102
What suture should be used for duct anastomosis
Monofilament absorbable sutures e.g. PDS
103
List the early complications of duct anastomosis
Leak
104
List the late complications of duct anastomosis
- Stenosis
| - Intraductal stone formation
105
Which anastomoses are at biggest risk of leak
- Oesophageal
| - Rectal
106
Pneumoperitoneum pressure
15mmHg
107
List the physiological consequences of pneumoperitoneum
- Raised or reduced CO
- Increases SVR
- Increases MAP
- Increases CVP
- Reduces venous return
- Increases partial pressure of CO2
- Increases peak inspiratory pressure
- Reduces urine output
108
How should 10mm laparoscopic ports be closed
In layers
109
How should 5mm laparoscopic ports be closed
Skin only required
110
When should the tourniquet be deflated to allow for reperfusion
- 90 minutes in upper limb
| - 120 minutes in lower limb
111
How high should the tourniquet be inflated
- 50mmHg over SBP in upper limb
| - 100mmHg over SBP in lower limb
Perioperative Care
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Decks in class (6)
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