EXAM 1: Lecture 8 - principles of hemostasis Flashcards
All hemorrhage ______________
stops eventually!
T/F: Hemostasis is a simple process that only involved clotting factors
false! it is a COMPLEX process that involves platelet activation and circulating clotting factors
what are the benefits of surgical hemostasis
allows appropriate visualization of tissue and prevents life-threatening hemorrhage
how do you use hemostatic forceps
you grab the vessel and clamp it for several minutes until it coagulates
when should you ligate a vessel
when it is a larger vessel
when do you use double ligatures
larger vessels particularly arteries
when should you use transfixation ligatures
may be used for larger arteries to prevent the ligature from slipping off the vessel
what are the benefits and disadvantages of circumferential ligature
benefits - less likely to bleed than transfixation
disadvantages - more likely to slip than a transfixation
what are the benefits and disadvantages of transfixation ligature
benefits - penetrates the lumen of the vessel and less likely to slip than a circumferential
advantages - more likely to bleed than circumferential
what type of throw should NOT be used for vessel ligation
surgeons throw
what are the types of topical hemostatic agents
bone wax, gelatin-based hemostatic products (gel-foam, vetspon), and cellulose-based hemostatic products (surgicel)
when should you not use gelatin-based hemostatic product
in the closure of skin incisions as they may interfere with healing
how does gel foam work
when it has contact activation, it sells and exerts pressure on the wound
should you put gel foam in infected sites
no! it may exert unnecessary pressure on neighboring vital structures
how does surgicel work
it is cut to the size needed and placed on an area of hemorrhage
what is electrocautery
coagulates small vessels/cuts tissue by using heat generated by direct electrical current into a metal wire or probe
T/F: with electrocautery, the electrical current enters the patients body
false! It does not
what is electrosurgery
generating heat inside the tissue using an alternating electric current that passes through the tissue creating a circuit
what is this
electrocautery
what is this
electrosurgery
what size vessels is electrosurgery commonly used for
less than 1.5-2mm in diameter
what happens on the “cut” setting of electrosurgery
there is a constant waveform that produces heat quickly to vaporize or cut tissue
what happens on the “coagulation” setting of electrosurgery
there is intermittent waveform that produces less heat and creates a coagulum rather than vaporizing tissue
what is the most common form of electrosurgery
monopolar electrosurgery
what does monopolar electrosurgery involve
the flow of current from an active electrode (handpiece) through the patient to a ground plate
what can happen with no ground pad in monopolar electrosurgery
the circuit with inadvertently use alternative paths to ground and burn the patient
how do you prevent burns with monopolar electrosurgery
use a large pad placed in good contact with a vascularized area
other than a large ground pad, how can you prevent burns with monopolar electrosurgery
towels dampened with water/conduction gel can improve contact
what does direct contact of the electrode cause in monopolar electrosurgery
produces a lower heat sufficient to coagulate
what does indirect contact of the electrode cause in monopolar electrosurgery
involves touching the electrode to an instruments to allow for more precise application of energy and effective coagulation
what is bipolar electrosurgery
uses forceps-like hand piece. Current passes from one tip of the forceps to the opposite tip through the tissue being held between the tips
T/F: you do not need a ground plate or pad for bipolar electrosurgery
true!
what is radiosurgery
similar to electrosurgery BUT the energy is generated by a low temp high frequency current
what is the most widely used laser in SA surgery
CO2 laser
how does carbon dioxide laser work
tissue vaporization occurs as this light energy is absorbed by water into the soft tissue
what are the advantages of CO2 laser
less bleeding, less pain, less tissue swelling, and decreased risk of infection
when is vessel sealing used
for hemostasis in laparoscopic and thoracoscopic surgery as well as open abdominal procedures and soft palate resection
what is vessel sealing
an electrothermal, feedback controlled, bipolar system that can permanently seal vessels up to 7mm in diameter
