Principles of Hemostasis (8) Flashcards
Dr. Thompson
How should you stop low-pressure hemorrhage from small vessels in surgery?
applying pressure to the bleeding points with gauze sponges
once clots form, sponge should be gently removed
Which instrument can be used to control bleeding from small vessels?
small hemostatic forceps (mosquito)
How should you ligate larger vessels, particularly arteries?
double ligatures - transfixation (to prevent ligature from slipping off the vessel end)
Using the [smallest/largest] suture possible for vessel ligation improves knot security
smallest
Explain the location of the circumferential ligature to the transfixation ligature and why it is so
circumferential: closer to the heart - more likely to slip!
transfixation: less likely to slip, more secure
Ligature types?
transfixation
What is the difference between a transfixion on a vessel versus an ovarian pedicle?
arteries: SQUARE throw
pedicle: surgeon’s throw because under tension
T/F: A surgeon’s throw can be used situationally on arteries
FALSE
What is bone wax, and when do you use it?
plug in bone, create pressure, bleeding stops
pressed into bleeding channels of bone to control hemorrhage through a tapenade effect
When are gelatin-based hemostatic products not appropriate to use?
in closure of skin incisions, as they may interfere with healing
What is gel foam?
provides a physical matrix that initiates clotting through contact activation
What is a punch biopsy?
hemostatic foam
6 mm minimum
What is this?
punch biopsy
What is surgicel?
absorbable cellulose sponge that is more like a 4x4 gauze in appearance
What are the pros and cons of surgicel?
- substrate for clot formation
- can be cut to the desired size and placed on an area of hemorrhage
not activated by tissue fluids other than blood
What is the difference between electrocautery and electrosurgery?
electrocautery: coagulates small vessels or cuts tissue by using heat generated by direct electric current into a metal wire or probe — electric current does not enter the body
electrosurgery: refers to generating heat inside the tissue using an alternating electric current that passes through the tissue creating a circuit
T/F: Electrosurgery has current pass through the patient’s body
TRUE
Electrocautery or electrosurgery?
electrosurgery
Electrocautery or electrosurgery?
electrocautery
When is electrosurgery used?
for hemostasis for vessels less than 1.5 to 2 mm in diameter
Which waveforms are on the cut and coagulation settings regarding electrosurgery?
cut: constant waveform
coagulation: intermittent waveform (can cut on this setting depending on tissue type)
Electrocautery or electrosurgery?
electrosurgery
What is monopolar electrosurgery?
involves the flow of current from an active electrode (handpick) through the patient to a groundplate
- most common electrosurgery technique
How can monopolar electrosurgery be harmful?
if an adequate low-impedance ground pad is not present, the circuit will inadvertently use alternate paths to ground, and as a result will burn the patient
How do you reduce risks of burn with monopolar electrosurgery?
use a large pad placed in good contact on a well-vascularized area of tissue that is close to the operative site
How do you prevent burns with monopolar electrosurgery?
What are the conditions for using monopolar electrosurgery?
- field must be relatively dry, and the electrode kept clean and free of debris
- direct contact of the electrode with the tissue produces lower heat sufficient to coagulate
What is indirect contact with monopolar electrosurgery?
involves touching the electrode to an instrument, allowing more precise application of energy and effective coagulation
How do bipolar electrosurgery work?
uses a forceps-like hand piece
current passes from one tip of the forceps to the opposite tip through the tissue being held between the tips
What does bipolar electrosurgery not require? When is it used?
ground plate or pad
used when precise coagulation is necessary and to prevent damage to adjacent structures
What is radiosurgery?
How does CO2 laser work?
tissue vaporization occurs as this light energy is absorbed by water into soft tissues
T/F: With CO2 laser, little heat is dissipated to the surrounding tissues
TRUE - has less bleeding, less pain, less tissue swelling, decreased risk of infection
What is vessel sealing? When is it used?
hemostasis in laparoscopic and thoracoscopic, open abdominal procedures
Uses pressure and pulsed low-voltage energy to fuse collagen and elastin of the vessel wall and achieve homeostasis
