Lecture 16 11/12/24

Question 1

How does electrocautery work?

Answer 1

-vaporization of the cells
-thermal necrosis of the edges of the incision
-no bleeding

Question 2

What are the characteristics of CUT electrocautery?

Answer 2

-constant impulse
-vaporization of the tissue
-minimal collateral damage

Question 3

What are the characteristics of COAG electrocautery?

Answer 3

-intermittent impulse
-activates coagulation of the proteins to form blood clot

Question 4

What are the components of the electric circuit on a monopolar handle electrocautery unit?

Answer 4

-active electrode
-patient
-plate

Question 5

What are the characteristics of plate installation for monopolar handle electrocautery?

Answer 5

-close to surgical site
-adequate contact
-well vascularized area
-prevent burns

Question 6

What should be done to ensure best outcome with electrocautery?

Answer 6

-surgical site must be somewhat dry
-electrode should be maintained clean

Question 7

What are the characteristics of bipolar handle electrocautery?

Answer 7

-maximal distance between tips of 1 mm
-precise coagulation
-can be used in a wet wound
-limits thermal collateral damages

Question 8

What are the principles of a bipolar radio-frequency energy device?

Answer 8

-high current with a low voltage in a bipolar circuit
-denaturation of collagen and elastin within vessel wall
-device detects changes of impedance of the tissue and automatically stops
-can seal veins up to 7mm in diameter

Question 9

What are the characteristics of a harmonic scalpel?

Answer 9

-ultrasound device
-waves are transmitted to tip of blade
-energy is transferred to adjacent tissue
-denaturation of proteins

Question 10

What is LASER?

Answer 10

Light Amplification by Stimulated Emission of Radiation

Question 11

What is Class 1 LASER?

Answer 11

incapable of production of damaging radiation during operation

Question 12

What is Class 2 LASER?

Answer 12

potential to cause optical damage if viewed directly during prolonged exposition

Question 13

What is Class 3 LASER?

Answer 13

-potentially hazardous under some direct viewing conditions if the eye is appropriately focused and stable
-probability of actual injury is small

Question 14

What is Class 4 LASER?

Answer 14

-hazardous to the skin by direct beam
-direct or indirect exposure of the eye to the beam causes injury to the eye
-produces air contaminant by vaporization of cellular debris

Question 15

What are the characteristics of the LASER light?

Answer 15

-different sources of emission of light
-energy in joules
-power in watts
-density of power in watts/cm^2

Question 16

How does the LASER work?

Answer 16

-absorption of light produces heat
-denaturation of proteins occurs at 65-90 deg. C
-dehydration occurs at 90-100 deg. C
-vaporization/carbonization occurs at greater than 100 deg. C

Question 17

What are the safety steps taken when working with LASER?

Answer 17

-no attenuation of the signal
-wear protective glasses that match the LASER
-protect the endotracheal tubes and the high conc. of O2
-close doors and windows
-have indicators to the outside that say LASER is in use
-have a way to evacuate/filter the smoke

Question 18

How does the focus of the laser beam impact its use?

Answer 18

-more focused laser beam is used for incision
-less focused laser beam is used for coagulation

Question 19

What are the characteristics of photodynamic cells?

Answer 19

-dye is given that is only taken up by cancer cells
-a LASER is used in which the light produced can only be taken up by cells that also took up the dye
-very targeted treatment of cancer cells

Question 20

What are the benefits of cryosurgery?

Answer 20

-limit inflammation
-lower pain

Question 21

What are the characteristics of cold cytotoxicity?

Answer 21

-intracellular formation of ice crystals alters cellular membrane
-extracellular formation of ice crystals dehydrates and causes hyperosmolarity

Question 22

What temperature must be reached to cause cold cytotoxicity?

Answer 22

-20 deg. C/-4 deg. F

Question 23

What is used to freeze tissue in cryosurgery?

Answer 23

liquid nitrogen, which reaches temps of -196 deg. C/-320 deg. F

Question 24

What are the indications for cryosurgery?

Answer 24

-cutaneous tumors
-ophthalmic surgeries
-dentistry

Question 25

What is the primary damage that occurs in cryosurgery?

Answer 25

formation of ice crystals

Question 26

What are the secondary damages that occur in cryosurgery?

Answer 26

-increase in vascular permeability
-local hemoconcentration
-damage to the endothelium of small vessels
-thrombus formation
-ischemia/infarction of tissue

Question 27

Which materials are needed for cryosurgery?

Answer 27

-hollow probes
-solid probes
-freeze guns

Question 28

What does cryosurgery consist of?

Answer 28

-two cycles each of fast freezing and slow thawing
-fast freezing increases the intracellular conc. of ice crystals
-slow thawing increases the size of ice crystals and increases cellular damage

Question 29

What is electrochemotherapy?

Answer 29

application of an electrical current to a tumor to increase the conc. of chemotherapy in the tumor cells

Question 30

Which tumors are electrochemotherapy used on in dogs and cats?

Answer 30

-mast cell tumors
-hemangioma
-perianal tumor
-squamous cell carcinoma
-Schwannoma

Question 31

Which tumors are electrochemotherapy used on in horses?

Answer 31

-sarcoids
-fibrosarcomas

Question 32

What are the indications for the use of a surgical stapler?

Answer 32

-skin closure
-intestinal resections and anastomosis

Question 33

What are the benefits of surgical stapler use?

Answer 33

-reduction in surgery time
-less intra-operative contamination

Question 34

What are the characteristics of a skin stapler?

Answer 34

-wounds not placed under tension
-excellent wound edge eversion
-no strangulation of tissue
-minimal tissue reaction
-associated with increased SSI in some procedures

Question 35

Which staplers are used for resection-anastomosis?

Answer 35

-thoraco-abdominal stapler: 2 rows of staples
-gastrointestinal anastomosis stapler: 4 rows of staples and a blade

Question 36

What are resection-anastomosis staplers used for?

Answer 36

-resection and biopsy
-functional end-to-end anastomosis