GRADED A+
✔✔troubleshooting steps: loss of working space: complete loss of operative image -
✔✔1. check for disconnected power cords, video cables
2. check for blown light source bulb
3. check for disconnected light cable
✔✔Monopolar electrosurgery curcuit - ✔✔electrical surgical unit-->active electrode--
>patient tissue-->dispersive electrode (grounding pad)
low frequency from wall source to high frequency at active electrode
✔✔monopolar: tissue coagulation - ✔✔occurs as a result of tissue heating and protein
denaturation.
✔✔monopolar: desiccation - ✔✔tissue temp rises--->water is evaporated from the
tissue--> increased impedance---> electricity stops flowing because of increased
resistance-->tissue turns brown, bubbles and steams.
Hemostasis due to fibrous binding between dehydrated, denatured cells of vessel
endothelium
✔✔monopolar: current density - ✔✔amount of current flowing through cross sectional
area.
directly proportional to power, inversely related to tissue resistance
ie larger the area, less current density
✔✔monopolar: cut mode - ✔✔heat tissue quickly. cell water is converted to steam,
causing the cell to explode. minimal later thermal tissue damage, but poor thermal
coagulation. unmodulated waveform with low voltage. electrode should not contact
tissue directly.
✔✔monopolar: coag mode - ✔✔rapid surface heating, shallow depth of necrosis-
fulguration. intermittent wave with high voltage
significant cutting does not occur because heat is more widely dispersed
✔✔potential hazards of laparoscopic monopolar: current diversion - ✔✔risk of current
diversion. current follows path of least resistance and can pass through unintentional
tissue
, ✔✔potential hazards of laparoscopic monopolar: capacitive coupling - ✔✔transfer of
current from an active electrode through its insulation to a passive electrode.
active electrode (such as monopolar hook) can give a charge if it touches a grasper or
camera briefly, they store energy, then they contact tissue and injure it
✔✔bipolar definition - ✔✔tissue is placed between two electrodes. current flows only
through the tissue contiguous with both electrodes. lower energy requirement, less
lateral tissue damage.
Can seal vessels up to 7mm
✔✔bipolar energy delivery - ✔✔computer measures tissue impedance of grasped
tissue--.controlled energy delivery--> denaturation of collagen-->creation of permanent
seal
✔✔bipolar hazards: inadvertent thermal injury - ✔✔avoid activating the device in close
proximity to adjacent organs
✔✔bipolar hazards: inadvertent cutting of vessels before adequate sealing - ✔✔make
sure to complete entire activation cycle prior to cutting
✔✔bipolar hazards: improper functioning if metal is within the jaws - ✔✔including clips
or staples
✔✔ultrasonic dissection - ✔✔mechanical energy converted to high frequency ultrasonic
vibration
✔✔ultrasonic shears - ✔✔consist of vibrating jaw or blade and a passive jaw. the
passive jaw acts as a backstop to trap tissue against the active blade.
active blade is unprotected and can damage tissue during or after use
✔✔warfarin discontinue time - ✔✔3 days
✔✔important history to consider preOP (5) - ✔✔1. history of DVT/PE
2. hx radiation
3. hx hip prosthetics
4. sig cardiopulmonary conditions (important to continue throughout preoperative
period)
5. need for stress dose steroids
✔✔NSAIDs including ASA - ✔✔do not need to be discontinued