A for laparoscopic surgery (linda's PPT)

Question 1

advantages of minimally invasive surgery

Answer 1

• smaller incision: less surgical stress
• less postop pain: fewer opioids, earlier ambulation, shorter hospital stay, rapid return of ADLs
• same surgical outcomes: good for obese population and older/sicker populations

Question 2

complications

Answer 2

• vascular injury
• sub-Q emphysema
• gas embolism
• capnothorax

Question 3

implications

Answer 3

pneumoperitoneum
- hemodynamics
- pulmonary
- neurohormonal

patient positioning
- upper abd → reverse trend
- lower abd → trend

Question 4

surgical procedure

Answer 4

• use insufflation of CO2 to create pneumoperitoneum that allows surgical exposure and manipulation
• insufflator that stops gas flow at a determined inra-abd pressure: < 15 mm Hg

Question 5

why CO2?

Answer 5

noncombustible
soluble
increased safety margin

Question 6

closed technique

Answer 6

blunt needle
check for placement
trocar

Question 7

open technique (Hassan)

Answer 7

mini-laparotomy
trocar
direct visualization

Question 8

cardiovascular effects d/t pneumoperitoneum: hemodynamics

Answer 8

• increase in MAP, SVR, and HR-increase
• Cardiac filling volumes- increase or no ▲ (compression of the liver & spleen)
• cardiac index- decrease or no ▲ (increase afterload, decrease filling pressures)

Question 9

cardiovascular effects d/t pneumoperitoneum: cardiac arrhythmias

Answer 9

brady or tachyarrhythmias
vasovagal response
can increase QT interval

Question 10

respiratory effects

Answer 10

reduction in lung volumes and pulmonary compliance

diaphragm has cephalad displacement and is even worse in trendelenburg position

Question 11

cardiovascular effects d/t pneumoperitoneum: sick patients

Answer 11

exaggerated response - sick patients
elderly - decreased MAP
Obese? no difference

Question 12

absorption of CO₂

Answer 12

• hypercarbia: acidosis & increased SNS activity
• most in the first parts of insufflation, will stabilize eventually
• if acidosis is more severe you have more hydrogen ions which will switch for K in cells and cause hyperkalemia and the potential for serious arrhythmias
• myocardial depressant effect but the increase in SNS activity overrides this
• increase cerebral blood flow, ICP, IOP→ dilated pupils with sluggish response

Question 13

mechanical effects pneumoperitoneum

Answer 13

cephalad diaphragm
position effects severity
endobronchial intubation
impair AA gradient
shunt can be a big deal in sicker patients

increase peak airway pressures & increase in CO₂, as you increase patietns MV to compensate for increase CO₂ will increase there peak pressures

Question 14

Sub-Q CO₂

Answer 14

RAPID rise in CO₂
risk factors: BMI < 25, long surgical time, operative approach

Question 15

renal effects

Answer 15

transient increase in creatinine clearance
decrease RBF, GFR, and UO

Question 16

hepatic effects

Answer 16

inconclusive results
decreased hepatic blood flow

Question 17

cerebral

Answer 17

increased CBF & ICP
increased CO₂→ increased CBF

Question 18

A management: if done without general, need to have pneumo with low pressures

Answer 18

local: usually for minor GYN surgeries & sterilization procedures

regional: need high sensory level, shoulder pain

general: most common, new IA- quick on/off, LMA?

induction: intubation with mechanical ventilation

Question 19

ventilation

Answer 19

• increase RR or TV (usually RR)
• PCV > VCV
• increase MV by 15-35%
• ARMS, PEEP (improve compliance) PEEP @ 10 increase PIP to 20 slowly, improve arterial saturations
• NO₂: shouldn’t necessarily avoid it

Question 20

anesthesia managment

Answer 20

opioids: beware of treating HTN with opioids, maybe Remi good choice
fluid management: controversial, watch fluids - facial, pharyngeal, and orbital edema. if they are exchanging air around the tube you should be good
PONV - greater risk, may be as high as 72%
Post-op pain: origin - visceral not parietal, shoulder pain, non-opioids if possible

Question 21

primary complicaitons

Answer 21

dysrhythmias
CAUSE: brady = peritoneal stretching → increased vagal
tachy: from hypercapnia
Tx: supportive

hypoxemia
CAUSE: low FiO₂, hypoventilation, endobronchial intubation, atelectasis
Tx: fix the problem, ARMS, listen for breath sounds

hypercarbia
increase CO2 absorption, capnomediastinum, CO2 embolism

Question 22

how does carbon dioxide absorption happen?

Answer 22

inadvertent placement of veres needle or passage of CO₂ into open vessels

signs: arrhythmias (widening of QRS), hypoxemia, hypotension

diagnosis: TEE is gold standard

treatment: deflate abdomen, hyperventilate, left lateral decub/trend → this allows the embolus to get to the top of the RV and not into the pulmonary vasculature

Question 23

other complications

Answer 23

hypothermia: no difference from open; heat loss due to convection

positioning problems: usually d/t steep trend and pneumo → POVL, facial edema, dont give too many fluids. brachial plexus injury

hemorrhage: trocar into major vessle, damage to cystic or hepatic artery, promt treatment is key!! can take patient off vent when trocar is going in. bleeding can be hard to see b/c of positioning

Question 24

subcutaneous emphysema

Answer 24

cause: inadvertent extraperitoneal insufflation

predictors: operative time > 200 mins, 6 or more surgical ports

signs: crepitus, increased ETCO₂ hypersomnolence, increased SNS, resp acidosis