Chapters 13, 15, 16, 17 FROM NOTES ONLY Flashcards
What is recommended size of OR
And if fluoro etc?
37m2 (400 ft2)
56m2 (600 ft2)
What are recommended OR settings for
Ventilation
Humidity
Temp
- Ventilation: 15 air exhanges/hour, horizontal laminar flow
- Humidity: 30 - 60%
- Temp: 20 - 23 Cº
N.B. Laminar airflow –> 61% reduced room bacteria and 92% decreased wound site bacteria
What is antiseptic/disinfectant MoA of:
Alcohols
Povodine-iodine
Chlorhex
- Alcohols: Protein denaturation, lysis, metabolic interruption
- Povodine-iodine: Free iodine oxidation/substitution –> protein denaturation
- Chlorhex: Cell membrane disruption
What is gene that confers chlorhex resistance to Staph aureus
qacA/B
What % solution chlorhex is used for skin prep?
And in wound
4% for skin
0.05% in wound
What 3 factors are associated with increased glove perf
- Non dominant hand
- Non-ST procedure
- Sx > 60 mins
What is rate of perf when single gloved/
Single gloved:
- 13 - 31%
Double gloved:
- 11 - 44% outer glove
- 4 - 13% inner glove
How does waveform (current) of cutting vs coagulating electrocautery differ
Cutting waveform continuous, 100% of time
Coag waveform is intermittent, only 6% of time
For what % of time is cutting coag waveform (i.e. current) ‘active’?
And for coag
100% for cutting
6% for coag
What effect does electrosurgery have on tissues at following temperatures?
40ºC
50ºC
70ºC
90ºC
100ºC
250ºC
40ºC –> inflammation + oedema
50ºC –> enzyme deactivated
70ºC –> protein denaturation
90ºC –> dessication
100ºC –> vapourization + cell rupture
250ºC –> carbonization
Name three contact types for coagulative electrocautery
- Fulguration coagulation: (not in contact –> arcs –> superfiial coagulum)
-
Dessication coagulation: Direct contact of electrode w tissues. Deeper necrosis + thermal spread than fulguration coagulation.
- Coaptive coagulation: Instrument grasping vessel –> collagen weld
On what size vessel can monopolar cautery be used?
And enseal/ligasure?
Harmonic scalpel?
Co2 laser?
Monopolar ≤2mm
Enseal/Ligasure ≤7mm
Harmonic scalpel <3mm
CO2 laser <0.6mm
What is conculsion re using monopolar cautery for skin?
(Scott, VetSurg, 2017)
(Meakin, VetSurg, 2017)
Scott, VetSurg, 2017
- Better haemostasis
- Faster
BUT
- Increased complications
- Delayed healing
Don’t do it.
Meakin, VetSurg, 2017
- Less blood loss
- Same duration
- Same complications/healing
List 2 advantages and 2 disadvantages of bipolar (vs monopolar)
- Less collateral damage
- Can be used when wet
BUT
- Cant cut
- Can adhere to surrounding tissue
List the three machanisms of injury from stray energy
- Insulation failure
- Direct coupling (metal - metal)
- Capacitive coupling (e.gg. current builds up in isolator (e.g. air)
What is thermal spread of ligasure?
And enseal?
harmonic scalpel?
1 - 3 mm Ligasure
2 mm EnSeal (only system to limit thermal spread)
0 - 1 mm Harmonic
At what vibration does harmonic scalpel funtion
55,000 vibrations/s
Cuts + coagulates simultaneously (vibration induced heat –> coaptive coagulation)
List 5 benefits of harmonic scalpel over BSVD
- Reduced smoke/vapour
- Cuts + coags at same time
- Lower temp (50-100 vs 150 - 400)
- Less thermal spread
- No char/dessication/sticking
Which device –> highest bursting pressure
And fastest sealing time
Enseal
Harmonic
What does LASER stand for
Light amplification by stimulated emission of radiation
List 4 characteristics of LASER photons
- Monochromic (same waveform)
- Spacial coherence (move parallel)
- Temporal coherence (in phase)
- Collimated (linear direction)
How does tissue penetration differ between long and short wavelength lasers
Give an example or a long wavelenght laser
And short
Long wavelength have lower tissue penetration
Long wavelenght: CO2, Ho:YAG, Erbium:YAG
Short wavelength: Nd:YAG (deepest tissue penetration!), diode