1
Q
what are advantages of laparoscopic procedures?
A
- less tissue trauma
- reduced post-op pain
- shorter hospital stays
- more rapid return to normal activities
- significant cost savings
- less potential for post-op complications i.e. ileus
- improved cosmetic results
2
Q
what are indications for laparoscopic procedures?
A
- cholecystectomy
- appendectomy
- fundoplication
- inguinal hernia repair
- gynecologic
- colon resection
- splenectomy
- nephrectomy
- liver biopsy
- diastasis repair and more
3
Q
what are types of gynecologic procedures indicated for laparoscopic?
A
- tubal ligation
- myomectomy
- assisted hysterectomy
- oophorectomy
- lysis of adhesions
- fulgartion of endometriosis
- removal of ectopic pregnancies, tubal repair
- diagnostic procedures
- ovarian cystectomy
4
Q
what are contraindications for laparoscopic procedures?
A
- bowel obstruction
- ileus
- peritonitis
- intraperitoneal hemorrhage
- diaphragmatic hernia
- severe cardiopulmonary disease, CHF
5
Q
what are relative contraindications for laparoscopic procedures?
A
- extreme of weight (large abdomen; may obstruct view)
- inflammatory bowel disease
- presence of large abdominal masses
- advanced intra-uterine pregnancy (size of uterus)
- increased ICPs
- VP shunts (emptying into abdominal cavity)
- coagulopathy
- previous abdominal surgeries with adhesions
6
Q
what are considerations with laparoscopy in pregnant patients?
A
- uterus remains in the pelvis during 1st trimester, allowing safe insertion of Veress needle through umbilicus
- after 23rd week, enlarged uterus obstructs view
7
Q
what are AIs for laparoscopy in pregnant patients?
A
- closely monitor PaCO2 to maintain slightly alkalotic state (increase MV)
- place in 30 degree left-uterine displacement (no compression of IVC or decreased VR)
- limit intraperitoneal pressures to 12 mmHg
- monitor fetal heart rate throughout w/ transvaginal ultrasound
8
Q
what are four potential causes of physiologic changes during laparoscopy?
A
- initial trendelenburg position
- creation of the pneumoperitoneum
- potential for systemic absorption of CO2
- reverse trendelenburg position
9
Q
what is the pneumoperitoneum?
A
insufflation of the peritoneal cavity with CO2 (air, nitrous oxide, helium, and O2)
10
Q
what are characteristics of the pneumoperitoneum?
A
- doesn’t support combustion
- blood solubility enhances tissue diffusion, decreasing risk of gas emboli
- more pain d/t diaphragmatic irritation (shoulder pain)
- can lead to hypercarbia, respiratory acidosis, cardiac dysrhythmias
11
Q
what is an advantage of the pneumoperitoneum?
A
-separates the abdominal wall from the contents of the peritoneal cavity to optimize visualization and access
12
Q
what are disadvantages of the pneumoperitoneum?
A
-limits surgeons freedom of movement, choice of instruments
-involves risk of significant complications r/t use of CO2
(once insufflation begins balance off CO2 by increasing MV)
13
Q
how is the pneumoperitoneum created?
A
- inject local anesthetic into the umbilical area
- insert Veress needle via anesthetized area into peritoneal cavity
- insufflate cavity with CO2 at a pressure less than 19 mmHg (3 L)
- once distended, insufflator placed in automatic mode to maintain pneumoperitoneum at 12 mmHg
- be sure pt. is completely relaxed when surgeon insufflates
- after intubation, be sure to insert suction catheter and suck out any air bubbles in esophagus
14
Q
what are some possible traumatic injuries r/t pneumoperitoneum?
A
- unintentional injuries to abdominal organs
- insertion of the Veress needle and trocars (aorta, intestinal walls)
- subcutaneous emphysema d/t improper placement of the needle b/w fascial planes in the muscle (if severe, like up to neck and face, don’t extubate since airway can collapse under increased pressure)
- massive hemorrhage d/t penetration of vessels or rupture of the spleen w/ stretching of pre-existing splenic adhesions
15
Q
what are physiologic changes associated w/ pneumoperitoneum dependent upon?
A
- pressure attained
- volume of CO2 absorbed
- patient’s intravascular volume (lower CVP can cause “vacuum” sucking more CO2 in)
- ventilator technique
- surgical conditions (length of surgery and position)
- anesthetic agents used
16
Q
what are CV changes associated w/ pneumoperitoneum?
A
- increased SVR
- increased MAP (young, healthy)
- initial decrease in cardiac index (50% baseline-proportional to the pressure achieved)
- increased myocardial filling pressures initially, followed by sustained decrease in preload (decreased VR)
- decreased renal, portal, and splanchnic blood flow (decreased GFR, urinary output, and creatinine clearance)
17
Q
what causes the initial increase in MAP?
A
liver and spleen are huge blood reserves and when squeezed under the pressure of the pneumoperitoneum, vessel contents are pushed out
-long term, VR is decreased
18
Q
what are cerebral changes associated w/ pneumoperitoneum?
A
- increased cerebral blood flow
- increased ICP
- hyperventilation does not help, but hypoventilation makes worse*
19
Q
what are pulmonary changes associated w/ pneumoperitoneum?
A
- decreased pulmonary compliance
- increased peak airway pressure d/t diaphragm shifting upward (make note of PIP when supine, in trendelenburg, then when insufflated so if increased d/t pneumothorax you’ll know difference)
- reduced lung volumes (VC, FRC)
- atelectasis (will happen, need serious alveolar recruitment)
- hypoxemia d/t V/Q mismatch in obese pts. and pre-existing pulmonary disease (not normally in healthy pts.)
- hypercarbia (ETCO2 increases 0-30% from absorption)
- adjust ventilation
- re check breath sounds after insufflation
20
Q
what are physiological changes associated w/ trendelenburg?
A
- 10-20 degrees allows small bowel and colon to move out of the pelvis and minimize needle or trocar perforation
- increases VR and CO
- reduces lung capacity d/t weight of abdominal contents on diaphragm (decreased FRC)
- inadvertent right main stem bronchial intubation when lung and carina is displaced cephalad
- increased intra abdominal pressure and gravity increase risk of aspiration of gastric contents (intubate!)
21
Q
how does trendelenburg and pneumoperitoneum combined affect ICP?
A
increases ICP 150% over baseline
22
Q
what is the position of choice if a gas embolism is suspected?
A
- trendelenburg w/ left lateral tilt
- prevents the bubble from traveling to the right ventricular outflow tract and causing an airlock (if it does can create an obstruction and cause LV infarct)
23
Q
what are physiologic changes associated with reverse trendelenburg position?
A
- allows optimum exposure and minimizes the possibility of bowel injury for some procedures
- decreased VR
- decreased LVEDV
- maintained ejection fraction in healthy pts.; decreased in others, esp. w/ LV dysfunction
- decreases negative pulmonary effects of peritoneal insufflation
24
Q
what are physiologic changes associated w/ CO2 absorption?
A
- PaCO2 rises w/ significant amounts of absorption
- hypercarbia can easily occur, resulting in increased catecholamines (caution w/ CAD)
25
what determines the rate of CO2 absorption w/ pneumoperitoneum?
- tissue solubility of the gas
- diffusion pressure gradient across the containing membrane
- blood flow across the cavity
* increased absorption w/ extra peritoneal vs. intraperitoneal d/t lack of containment of CO2 allowing an increased area for gas exchange
26
how does ETCO2 reflect PaCO2?
- ETCO2 accurately predicts changes in PaCO2 in healthy, mechanically ventilated pts.
* *ETCO2 does not increase comparably w/ increases in PaCO2 in pts. w/ cardiopulmonary disease
27
what is the major concern of anesthesia in laparoscopic procedures?
* prevent the effects of hypercarbia
- controlled PPV w/ increased Vt usu. approx. 8 ml/kg to decrease PaCO2 to normocarbia
- maintain MV by increasing rate
- minimize sympathetic stimulation and hypoxia which would add to increased risk of cardiac arrhythmias
* pre medicate w/ anxiolytic and use 100% O2
* at end of case, when deflate, be aware that Vt can increase w/ decreased pressure causing barotrauma
* at end, do alveolar recruitment for atelectasis: close off pop off, give breath and HOLD to recruit alveoli w/ 100% O2
28
describe GA use for laparoscopic procedures
- most widely accepted technique
- controlled ventilation
- give muscle relaxants to minimize pulmonary compromise, esp. at beginning when inserting trochars
- alters ventilatory response, thus SV under GA results in hypercarbia (intubate and MV!)
29
describe regional anesthesia technique for laparoscopic procedures
- epidural or spinal (level would need to be pretty high w/ lap chole)
- no hypercarbia d/t adequate alveolar ventilation under epidural anesthesia
- combined w/ GA, better pain relief, but no better pulmonary function
30
describe LA anesthesia technique for laparoscopic procedures
- not optimal surgical condition
- inability to control respiration if hypercarbia develops
- delay in treating complications
- risk of injury if pt. moves unexpectedly
- anxiety
- N/V
31
is use of N2O ok w/ laparoscopic procedures?
- controversial
- N2O more soluble than nitrogen and can move into air-filled space faster than nitrogen can move out, causing distention
- increase of intestinal luminal size after 4 hrs.
- expansion of air embolism
- increased vomiting, no difference in nausea
32
what are AIs for laparoscopic procedures?
- adequate muscle relaxation to avoid risks of injury to organs or vessels or umbilical hernia (up until fascia closed)
- evacuate any air from stomach to minimize gastric distention and avoid risk of injury during Veress needle insertion (some surgeons want salem sump left in place)
- stop ventilation during insertion of Veress needle to avoid pushing abdominal contents up toward needle
- explain increased risk of PONV and use prophylaxis (3: scopolamine, decadron, Zofran)
* young, female, non smoker, gynecologic procedure increased risk
33
what are AIs r/t analgesia w/ laparoscopic procedures?
- less painful than open, but still painful
- pre-incisional local infiltration
- intraperitoneal instillation of local?
- NSAIDS
- opioids: induce spasm of sphincter of Oddi (antagonize w/ *glucagon, NTG, or Narcan); increased N/V
* *opioid sparing: NSAIDS, IV Tyl, Gabapentoids (Neurontin)
- deferred pain to shoulders r/t irritation of diaphragm (assist surgeon expel as much CO2 as possible by giving deep breaths to pt. as trocar is open at end of case)
34
what are causes for CV depression and/or collapse during laparoscopic procedures?
- bradycardia and asystole can occur during creation of the pneumoperitoneum secondary to reflex vagal stimulation form stretching and distention of the peritoneum (healthy or not)
* ask surgeon to release pressure is the quickest fix
- ventricular arrhythmias can occur d/t hypercarbia
- PEA can occur d/t compression of the IVC, hemorrhage, and gas embolism (no volume returning to heart)
35
what happens with a carbon dioxide embolism?
- CO2 enters the circulation via open venous access (needle in a vessel, portal circulation)
- b/c of solubility of CO2, small amounts may be reabsorbed w/o consequences (69% TEE)
- w/ large amounts, embolus may form gas lock in the right atrium or ventricle to impair VR and right ventricular outflow
- may reach the pulmonary circulation, causing pulmonary HTN and RH failure
36
what are presenting signs of carbon dioxide embolism?
- hypotension
- jugular venous distention
- tachycardia
- "mill-wheel" murmur
- rapid, but short lived increase in ETCO2 followed by decrease
- hypoxemia
- cyanosis
37
what is the treatment for carbon dioxide embolism?
- stop insufflation and release pneumoperitoneum
- place pt. in trendelenburg w/ left side down to prevent bubble from entering right ventricular outflow tract
- hyperventilate to reduce CO2 levels
- insert central line to aspirate bubble from right atrium
38
what are complications of laparoscopic surgery?
- pneumothorax and pneumomediastinum
- pulmonary dysfunction
- deep vein thrombosis
39
describe pneumothorax and pneumomediastinum and treatment
- tracking of insufflated CO2 around the aortic and esophageal hiatuses of the diaphragm into the mediastinum and rupture of the pleural space (pressure collapses lung when CO2 leaks into thoracic cavity)
- rupture of lung bulla or bleb
- unexplained increased airway pressure (know baseline PiPs), hypoxemia, severe CV compromise w/ hypotension, SQ emphysema
* tx: deflation of abdomen and chest tube decompression if hemodynamically unstable; small pneumothorax may be treated conservatively and allowed to be reabsorbed
40
describe pulmonary dysfunction complications
- less than open procedure, but still compromised
- diaphragmatic dysfunction may last up to 24 hrs (but less dysfunction than an open procedure)
- atelectasis will occur (alveolar recruitment)
* if pt. already has pulmonary dysfunction, this shouldn't be a same day surgery
41
how is deep vein thrombosis prevented?
- compression stockings
| - early ambulation
42
describe concerns w/ robotic assisted laparoscopy
- patient positioning extreme: prostatectomy (steep trendelenburg), pelvis (lithotomy w/ steep trendelenburg)
- d/t length of procedure be cautious of pressure points
- corneal abrasions v. ischemic optic neuropathy
- fluid limit: 1-2 liters of crystalloid; consider colloid use (facial edema, airway edema)
43
describe robotic assisted laparoscopic radical prostatectomy
- mean age 60 y/o
- increase incidence of CAD and renal abnormalities r/t prostatic hypertrophy
- airway assessment
- peripheral neuropathies
- COPD- may be difficult to ventilate
* pressure control over volume control
44
describe thoracoscopy
- indicated for diagnostic procedures as well as operative lung biopsies
- pt. positioned in lateral decubitus position
- local, GA, or regional (intercostal nerve block alone or w/ spinal or epidural)
* one-lung ventilation using double-lumen ET tube placed in left mainstem
45
describe video assisted thoracic surgery (VATS)
- indicated for lung nodules and pleural effusions
- wedge resections
- lung resections: formally requiring open thoracotomy
- three small incisions
* one lung ventilation required
* very painful after
46
describe gasless laparoscopy
- no pneumoperitoneum
- technique using abdominal lift using a mechanical retractor; lifts abdominal wall 10-15 cm w/ only 1-4 mmHg IAP
- avoids effects of CO2 insufflation and high intra abdominal pressures
- minimal changes in cardiopulmonary, renal functions and neuroendocrine responses
- may benefit ASA III and IV pts.
47
describe hysteroscopy
- endoscopic exam of the endocervix and endometrial cavity
- cavity of uterus must be distended w/ either CO2 or liquid distending media
- indications: diagnostic for infertility, abnormal uterine bleeding, localization of IUD, resection of septae, adhesions or lesions
- anesthesia: paracervical block, regional or GA (not preferred)
* limit IV fluid intake
48
describe resectoscope (TURP Syndrome)
venous sinuses opened up and absorption of distending fluid occurs
- if large volumes are absorbed, hypo-osmolar hyponatremia can occur w/ hypervolemia, hyponatremia and decrease osmolarity causing cerebral edema
* HTN (sys. and dias.), bradycardia, CNS changes, N/V, H/A, agitation, and lethargy--lead to cardiac arrest
* close attention must be paid to volume in vs. volume out
* Na+ level pre-op and intra-op if increased volume intake and post-op
49
describe distending medias
- CO2: diagnostic only d/t open vessels w/ resection causing embolism
- Hyskon (32% dextran): anaphylaxis, fld. overload, pulmonary edema, renal failure
- Glycine 1.5%: fld. overload, hyponatremia, hypo-osmolality, hyperammonaemia, hyperglycinaemia
50
what are the effects of glycine?
- glycine is metabolized into ammonia by the liver
| * ammonia toxicity: seizures, mental changes, lethargy
51
what are early signs of TURP Syndrome?
- restlessness leading to confusion
- blurring of vision
- H/A
- N/V
52
how can TURP Syndrome be diagnosed?
CV signs
-unexplained HTN followed by decreased BP
-refractory bradycardia
-nodal/junctional rhythm (loss of P waves), ST changes, U waves, widening QRS
Fluid absorption: avg. rate is 20 ml/min (more than 1 L/hr)
*limit the volume given
53
describe the circulatory overload w/ TURP Syndrome
- absorption
- blood volume increases
- systolic and diastolic pressures increase
- affects contractility and potentiates failure
- dilutes proteins and decreases osmotic pressure
* fluid moves into interstitial causing pulmonary and cerebral edema
54
how can TURP Syndrome be prevented?
* regional anesthesia
- use saline vs. glycine (surgeon's decision)
- minimize surgical resection time ( more than 1 hr. associated w/ increased risk; has occurred within 15 min.)
- use different surgical technique, i.e. laser vaporization (helps close off opening vessels)
- communication- increased risk w/ capsular perforation
55
if TURP Syndrome is suspected, what should be done?
- complete procedure quickly
- draw labs (CBC, electrolytes, Na+, osmolality)
- administer normal saline and furosemide
* glycine deficits of 500 ml lead to decreases in Na+ of 2.5 mEq/L
* if under GA, mental status changes are not assessable
* regional recommended
56
describe endoscopy
- NPO (ensure adequate NPO time)
- bowel prep (colonoscopy; fld. deficit)
- sedation (propofol alone is best option; just need to sedate enough to pass scope; may see w/ versed)
- airway management and pt. safety
- pt. satisfaction
- positioning (most cases flat maybe w/ HOB raised a little; colonoscopy usu. turned)
- PONV and recovery
* no pain post-op, so fentanyl just delays recovery
