Laparoscopic Anesthesia Flashcards
(186 cards)
1
Q
advantages of laparoscopic procedures (7)
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 (ex. development of an ileus)
- improved cosmetic results
2
Q
what two things have improved the safety of laparoscopic procedures dramatically?
*Nagelhout
A
- open entry trocar
- videoscopic imaging
3
Q
what are the three main challenges associated with laparoscopic procedures?
*Nagelhout
A
- pneumoperitoneum
- positioning
- increasingly critical patients
4
Q
indications for laparoscopic procedures
*huge list Iām never gonna memorize
A
- cholecystectomy
- appendectomy
- fundoplication
- inguinal hernia repair
- gynecologic procedures (tubal ligation, myomectomy, assisted hysterectomy, oophorectomy, lysis of adhesions, removal of ectopic pregnancies, tubal repair, diagnositc procedures, ovarian cystectomy)
- colon resection
- splenectomy
- nephrectomy
- liver biopsy
- diastasis repair
- bariatric surgeries
- undescended testicles
- prostatectomy
- cystectomy
- robotic procedures
5
Q
absolute contraindications for laparoscopic procedures (6)
A
- bowel obstruction
- ileus
- peritonitis
- intraperitoneal hemorrhage
- diaphragmatic hernia
- severe cardiopulmonary disease/CHF
6
Q
relative contraindications for laparoscopic procedure (8)
A
- extremes of weight
- inflammatory bowel disease
- presence of large abdominal masses
- advanced intra-uterine pregnancy
- increased intracranial pressures
- VP shunts
- coagulopathy
- previous abdominal surgeries with adhesions
7
Q
laparoscopic splenectomies are often at high risk for what intra-op complication?
A
bleeding
8
Q
what allows for safe insertion of the Veress needle through the umbilicus in the first trimester?
A
uterus is still low in the pelvis
9
Q
at what week gestation does the uterus begin to interfere with visualization during laparoscopic procedures?
A
23 weeks
10
Q
what maternal value must be monitored very closely in pregnant mothers during laparoscopic procedures?
A
- PaCO2
- maintain slightly alkalotic - CO2 ~ 30 mmHg
11
Q
what position should be used for pregnant women undergoing laparoscopic procedures if > 16 weeks ?
A
30 degree left-uterine displacement
12
Q
intraperitoneal pressures should be kept less than what in pregnant women during laparoscopic procedures?
A
- 12 mmHg
- make sure to remind circulator and/or surgeon to keep pressures low
13
Q
what non-maternal monitoring should be done for pregnant mothers undergoing a laparoscopic procedure?
A
continuous fetal heart rate - via transvaginal ultrasound
ouch
14
Q
what are the four potential causes of major physiologic changes during laparoscopy?
A
- creation of the pneumoperitoneum
- potential for systemic absorption of carbon dioxide
- initial Trendelenburg position
- reverse Trendelenburg position
15
Q
what is the purpose of a pneumoperitoneum?
A
to create an environment that allows for the surgeon to see all intra-abdominal structures and successfully manipulate all of the instruments required for that procedure
16
Q
what is a pneumoperitoneum?
A
insufflation of the peritoneal cavity with CO2 (or air, nitrous oxide, helium, oxygen)
17
Q
what are the characteristics of the ideal gas to use for a pneumoperitoneum?
- Nagelhout
A
- colorlessness
- nonflammable in the presence of electrocautery
- physiologic inertness
- excretion via pulmonary route
18
Q
pros for the use of CO2 for pneumoperitoneum
A
- nontoxic *
- non-flammable *
- doesnāt support combustion
- blood solubility enhances tissue diffusion, decreasing risk of air emboli
- less hemodynamic effects vs other gases *
- easy to access
*Nagelhout
19
Q
cons for the use of CO2 for pneumoperitoneum
A
- more pain due to diaphragmatic irritation
- hypercarbia, respiratory acidosis
- cardiac dysrhythmias
20
Q
why are helium and argon not used for pneumoperitoneum?
A
they caused greater hemodynamic depression if embolized into venous vasculature and caused death at much smaller volumes
21
Q
why must extreme caution be used to make sure that CO2 tank is actually CO2?
A
- if the tank is > 7% CO2 it has the same pin index as oxygen
- if using oxygen there is the potential for combustion
22
Q
physiologic changes from a pneumoperitoneum result from what two things? (big picture)
*Nagelhout
A
- direct mechanical pressure
- stimulation of intrinsic neurocirculatory responses
23
Q
advantage of pneumoperitoneum for laparoscopic procedures
A
separates the abdominal wall from the contents of the peritoneal cavity to optimize visualization and access
24
Q
disadvantages of pneumoperitoneum for laparoscopic procedures
A
- limits surgeonās freedom of movement
- limits choice of instruments
- involves risk of significant complications related to the use of CO2
25
procedure for creating a pneumoperitoneum - closed procedure method
(kinda long, feel free to break it up)
1. inject local anesthetic into umbilical area
2. insert Veress needle via anesthetized area into peritoneal cavity - verify placement
3. insufflate the cavity with CO2 at a pressure less than 19 mm Hg (3 L)
4. once distended, insufflator placed in automatic mode to maintain pneumoperitoneum at 12 mm Hg
5. trocar then inserted blindly or under direct visualization (*Nagelhout)
26
an intra-abdominal pressure of less than what indicates correct placement of an umbilically placed Veress needle?
*Nagelhout
10 mmHg or less
27
what are intra-abdominal pressures maintained at during a laparoscopic procedure?
12-15 mmHg
28
at what time during a laparoscopic procedure is the patient at the highest risk for serious complications?
- insertion of Veress needle/trocars
| - abdominal insufflation
29
what pressures are used during a retroperitoneoscopic adrenalectomy?
15-20 mmHg
30
what is an open procedure for creating a pneumoperitoneum?
what are the benefits of this method?
*Nagelhout
- surgeon creates a 1-2.5 mm vertical incision that allows him to directly separate the abdominal wall from the underlying tissues
- minimizes risk of damage to the bowel and vasculature
31
percentage of injuries that occur during entry and insertion of trocars?
percentage of injuries that are not diagnosed intra-op?
- > 50% occur during entry
| - 30-50% not diagnosed intra-op
32
what can cause massive hemorrhage during the procedure for creating a pneumoperitoneum?
- penetration of vessels
| - rupture of the spleen with stretching of pre-existing splenic adhesions
33
what method is used to assess for urinary structure damage if injury is suspected/likely?
- urinary catheterization and instilling methylene blue
| - checking for blood in catheter
34
what is one way WE can help to prevent organ damage during trocar insertion?
turn off vent/place in bag mode during trocar insertion to avoid organ displacement during inspiration
35
what can we do to help decrease some amount of abdominal pressure and also at the same time probs decrease some aspiration risk?
- insert OG salem sump and suction/decompress stomach
| - can leave in until the end of case
36
risk factors for injury during laparoscopic procedures (7)
- body habitus
- anatomic anomalies
- prior surgeries
- surgical skill
- degree of abdominal elevation during trocar placement
- patient position
- volume of gas insufflation
37
what factors should alert the team to a potential vascular injury?
*Nagelhout
- blood on aspiration of Veress needle
- free intraperitoneal blood
- unexplained hypotension and tachycardia
38
which entry technique is associated with a lower incidence of unrecognized vascular and visceral injury?
*Nagelhout
open entry
39
what is the benefit of placement of the primary trocar under high pressure (25 mmHg)?
*Nagelhout
high pressure creates the safest distance between the anterior abdominal wall and underlying abdominal contents and minimizes injury from trocar insertion
40
what can cause subcutaneous emphysema?
~ not the long chart
- improper placement of the needle between fascial planes in the muscle
- high intra-abdominal pressures*
- movement of gas through defects in the peritoneum*
(*Nagelhout)
41
subcutaneous emphysema has been associated with what negative outcomes?
- airway issues
- severe hypercarbia*
- decreased chest compliance*
- hemodynamic instability*
(*Nagelhout)
42
how can we assess for subcutaneous emphysema in the airway?
- leak test
| - if present, consider leaving the patient intubated until reabsorbed
43
the magnitude of the patient's physiologic response to the pneumoperitoneum depends on? (8)
- intraabdominal pressure attained
- volume of CO2 absorbed
- position
- age/co-morbidities
- intravascular volume
- ventilatory technique
- surgical conditions / time
- anesthetic agents used
44
effect of pneumoperitoneum on SVR?
cause of early change?
cause of late change?
- increased SVR
- increase initially due to increased levels of vasopressin
- later, increase is due to increased catecholamines (more related to 20 torr v 10 torr)
*increase SVR whether 5 mmHg or 40 mmHg
45
effect of pneumoperitoneum on MAP?
cause?
- increased MAP
- due to catecholamines
*increase MAP whether 5 mmHg or 40 mmHg
46
effect of pneumoperitoneum on HR? (at normal pressures)
cause?
- increased HR
| - due to catecholamines
47
at what pressures is there a difference in the effect of pneumoperitoneum on HR?
- 5-20 mmHg: HR is increased
| - 40 mmHg: HR is decreased
48
effects of pneumoperitoneum on CVP?
causes?
- initial increase in CVP due to squeeze of spleen and liver (blood reservoirs) and redistribution of abdominal blood volume
- later decreased due to reduction in venous return, but filling pressures increase
49
what causes a bigger effect on central pressures, position or pneumoperitoneum?
patient position
50
T/F: the effect on HR, MAP, and SVR only occur for a short time after abdominal insufflation
*Nagelhout
false - lasts for the duration of the insufflation
51
effect of pneumoperitoneum on cardiac index?
cause?
- decrease - 50% of baseline, proportional to the intra-abdominal pressure achieved
- due to decrease venous return from pneumoperitoneum and reverse trendelenburg reducing stroke volume
52
what can be done to reduce the amount of decrease in cardiac output from pneumoperitoneum?
- adequate fluid load (normovolemia)
- compression stockings/SCDs
- changes in patient position
~decreases to only 20% reduction in cardiac output vs 50%
53
what is our #1 job on insufflation?
watch EKG!
vagal stimulation with insufflation can cause bradycardia that can lead to asystole
54
high pressure insufflation can cause what EKG change?
prolonged QT
55
what are the two main causes of bradycardia in laparoscopic procedures?
- high abdominal pressures
| - rapid insufflation
56
if bradycardia is seen on insufflation, what should be done?
- tell surgeon to relieve pressure - should automatically fix
- if it doesn't resolve with pressure relief give atropine
57
GFR and UOP effects seen from pneumoperitoneum at varying pressures
- 5 mmHg - no change
- 10 mmHg - decreased
- 20 mmHg and higher - significant decrease
58
venous return effects at different pressures
- 5 mmHg - no change or decreased
- 10 mmHg - no change or increased
- 20 mmHg - increased or decreased
- 40 mmHg - decreased
59
cardiac output effects at different pressures
- 5 mmHg - no change or decreased
- 10 mmHg - no change or increased
- 20 mmHg - no change or decreased
- 40 mmHg - decreased
60
what pneumoperitoneum pressures can show an increase in cardiac output?
10 mmHg can show no change or an increase
all other pressures are no change or are decreased
61
what pneumoperitoneal pressures start to potentially cause an increase in CO2?
10 mmHg and higher
62
what pneumoperitoneal pressures start to potentially cause a decrease in pH?
10 mmHg and higher
63
what causes the initial increased filling pressures with a pneumoperitoneum?
does this correlate with an increase in volume in the heart?
- compression of abdominal venous beds which pushes blood back into central circulation
- pressure numbers are increased, but volume is not
64
effects of pneumoperitoneum on cerebral blood flow and ICP?
both are increased
65
does hyper/hypoventilation have an effect on the pneumoperitoneum's effect on cerebral blood flow and ICP?
- hyperventilation does not effect
| - hypoventilation makes it worse
66
an abdominal pressure of ~16 mmHg and tredelenburg causes how much of an increase in ICP?
150%
67
what effect does abdominal insufflation have on CSF?
- reduced reabsorption
| - due to increased IVC pressure and impaired venous drainage of the lumbar venous plexus
68
other than direct compression of the renal vasculature due to abdominal pressures, what else can cause further decrease in renal blood flow?
sympathetic stimulation causes ADH and renin release --> more vasoconstriction to kidneys
69
effect of pneumoperitoneum on kidneys, liver, and splanchnic blood flow?
- decreased
| - bigger effects seen with pressures > ~14 mmHg
70
what three conditions place the patient at an increased risk of decompensation from abdominal insufflation?
*Nagelhout
- increased metabolic rate (sepsis)
- large dead space
- decreased cardiac output
71
what places a COPD patient at an increased risk of post-op complications after laparoscopic surgery?
higher level of CO2 retention and respiratory acidosis
72
what device might be useful for monitoring CO2 levels during insufflation/why?
what patient population might have a huge benefit from this?
*Nagelhout
- transcutaneous CO2 monitor (PTCO2)
- ETCO2 may underestimate PaCO2
- COPD patients would have big benefit from PTCO2 monitor
73
effect of pneumoperitoneum on pulmonary compliance
- decreased due to diaphragm shifting upwards
| - increased peak pressures
74
effect of pneumoperitoneum on lung volumes?
- decreased vital vapacity
| - decreased FRC
75
what patients are at higher risk for developing hypoxia from pneumoperitoneum?
- obese pts - due to V/Q mismatching
| - pre-existing pulmonary disease
76
is hypoxia typically seen in healthy patients with pneumoperitoneum?
nope
77
what percent increase can be seen to ETCO2 due to absorption?
0-30% increase
78
what amount of change in pulmonary compliance is seen in supine patients with pneumoperitoneum?
43% reduced pulmonary compliance
79
what reflex offsets the effects of atelectasis during pneumoperitoneum?
hypoxic pulmonary vasoconstriction
80
changes in oxygenation during laparoscopic procedures are most often due to what?
usually due to physiologic effects anesthetics blocking HPV rather than a result of the pneumoperitoneum itself
81
why is it important to make note of peak pressures before and after abdominal insufflation?
- can tell us if we have pneumothorax
| - can tell us if ETT has migrated R mainstem
82
CO2 absorption that causes a low pH is what type of acidosis?
respiratory acidosis
83
how can we offset the effects of CO2 absorption?
increasing minute ventilation, otherwise CO2 will continue to rise
84
what abd insufflation pressures result in the maximum CO2 absorption?
10 mmHg
85
does PaCO2 ever plateau after insufflation?
- yes
| - after approx. 40 min from start of insufflation
86
when do blood gas parameters return to baseline?
after discontinuation of CO2 insufflation
-- unsure exactly when bc when i tried to re-find this in the book i couldnt
87
what degree of trendelenburg allows small bowel and colon to move out of the pelvis and minimize needle or trocar perforation?
10 ā 20
88
CV effects of trendelenburg
- increased venous return
- increased systolic heart volume
- increased SVR
- increased CO
- increased ventricular systolic work
- combination may lead to MI for patient at risk
89
resp effects of trendelenburg
- reduced lung capacity
- decreased FRC
- can have inadvertent R mainstem intubation
90
steep trendelenburg causes how much decrease in pulmonary compliance?
50%
91
what position partially counteracts the effects of pneumoperitoneum on the diaphragm and improves diaphragmatic function?
reverse trendeleburg
92
how long until displacement of the ETT with creation of pneumoperitoneum?
- within 10 minutes if its going to occur
| - reconfirm tube placement after pneumoperitoneum is established
93
what causes an increased risk of aspiration with laparoscopic procedures?
- increased intra-abd pressure
| - gravity from trendelenburg position
94
if a gas embolism is suspected, what position do you place your patient in?
name, description, rationale
- Durant position
- trendelenburg with left lateral tilt
- prevent bubble from traveling to RV outflow tract and causing airlock
95
CV effects of reverse trendelenburg position?
- decreased venous return
- decreased LVEDV
- EF maintained in healthy patients/ decreased in unhealthy
96
what could help mitigate some of the CV effects from reverse trendelenburg position?
- fluid bolus prior to positioning
| - might need vasopressor to shrink compartment
97
what three factors determine the rate of CO2 absorption?
1. tissue solubility of the gas
2. diffusion pressure gradient across the containing membrane
3. blood flow across the cavity
98
which causes increased CO2 absorption- extraperitoneal or intraperitoneal?
why?
- extraperitoneal
| - due to lack of containment of CO2 allowing an increased area for gas exchange
99
patient starts experiencing dysrhythmias and surgeon isnt working anywhere near the heart. what should you consider?
- patient might be hypercarbic, and not reflecting on ETCO2 monitor
- hypercarbia causes increased catecholamines --> dysrhythmias
100
example of intentional extraperitoneal CO2?
unintentional?
* i only have one for each bc theyre the ones she said, so feel free to add if you have something else :)
- intentional: inguinal hernia repair
| - unintentional: misplaced trocar causing subcutaneous emphysema
101
T/F: EtCO2 accurately predicts changes in PaCO2 in healthy, mechanically ventilated patients
true
102
T/F: EtCO2 accurately predicts changes in PaCO2 in mechanically ventilated patients with cardiopulmonary disease
- false
- ETCO2 does not increase comparably
- these pts might benefit from PTCO2 (*Nagelhout)
103
how can we prevent/minimize the respiratory effects from hypercarbia?
- increase minute ventilation (20-30% increase in mv is necessary to maintain pre-pneumo CO2 levels and prevent resp acidosis)
- TV 5-8 ml/kg ideal bw
- increase RR to maintain CO2 34-45 mmHg
104
how can we prevent/minimize the CV effects of hypercarbia?
- minimize SNS stimulation
- prevent hypoxia
- premed with anxiolytic
- 100% O2 on induction`
105
what is the preferred method to increase minute ventilation during laparoscopy?
*Nagelhout
increase TV rather than RR
106
what interventions can be done to improve clinical outcomes and decrease pulmonary complications
- PEEP
| - recruitment maneuvers
107
most widely accepted technique for laparoscopies?
- GA
- deep NMB
- cuffed ETT *
- pressure control ventilation *
- recruitment maneuvers *
108
FYI: GA alters ventilatory response, so spontaneous ventilation under general anesthesia results in hypercarbia
:(
109
effects of RA when combined with GA for laparoscopic anesthesia
better pain relief, but no better pulmonary function
110
worst anesthetic plan for laparoscopies?
maybe even worse than LMA :/
local anesthesia
111
risks of using only LA for laparoscopic procedure (5)
- inability to control respiration if hypercarbia develops
- delay in treating complications
- risk of injury if patient moves unexpectedly
- anxiety
- N/V
112
why should you probs not use nitrous for laparoscopy?
- moves into air filled space causing distention
- expansion of air embolism
- increased vomiting
- no difference in nausea
113
what is the main reason that we want to use NMB for laparoscopy?
to avoid injury to organs or vessels (or umbilical hernia??? what?)
114
rationale for inserting salem sump prior to lap case?
- evacuate any air from stomach to minimize gastric distention
- helps avoid risk of injury during Veress needle insertion
115
what is one important teaching point for patients regarding laparoscopic procedures?
probs so much more than this but my brain feels like a cement block so sry
in increased risk of PONV
116
best management approach for lap PONV?
multi-modal
117
options for laparoscopic analgesia?
what are the negatives for some of these?
- pre-incisional local infiltration
- intraperitoneal instillation of local
TAP block
- NSAIDs - can increase bleeding risks
- opioids ā can cause spasm of the sphincter of Oddi, increased nausea and vomiting
118
what are the methods to antagonize a sphincter of oddi spasm?
which method is best?
- glucagon - best :)
- nitroglycerin - cant tell angina vs spasm
- Narcan - rude, bc now they're in pain
119
which opioids are more likely to cause sphincter of oddi spasm?
- morphine, demerol
| - fentanyls are not as causative
120
what causes shoulder pain post-op after laparoscopic case?
best way to prevent?
- deferred pain related to irritation of the diaphragm
- remove as much CO2 from abdomen prior to closure
- we can give big breath to push abd contents down to attempt to force some CO2 out ("valsalva breaths")
121
what causes the bradycardia and asystole that can be seen during insufflation?
reflex vagal stimulation from stretching and distention of the peritoneum
122
what can cause PEA during laparoscopy?
- compression of the IVC
- hemorrhage
- gas embolism
123
what s/s should make you consider that the patient might have retroperitoneal hemorrhage?
- super labile
- decreased BP
- increased HR
- all hemorrhage symptoms, but can's see any blood
124
mortality rate with significant CO2 embolism?
*Nagelhout
28.5%
125
how does a large CO2 embolism occur?
- open vessel that has an intravascular pressure below intra-abdominal pressure
- erroneus placement of a Veress needle or trocar directly into an abdominal vessel
-- details from Nagelhout
126
what is the most sensitive diagnostic tool for CO2 gas embolism?
TEE
can detect emboli as small as 0.02 ml/kg -- wowzas
127
what can result from a large volume CO2 embolus?
- may form "gas lock" in the RA or RV that impairs venous return and RV outflow
- may reach the pulmonary circulation, cause PHTN, and R sided HF
128
presenting signs of gas embolism
she's long...
- hypotension
- jugular venous distention
- tachycardia
- āmill-wheelā murmur
- rapid, but short-lived increase in EtCO2 followed by a decrease
- hypoxemia
- cyanosis
- increase ET nitrogen *
- chest pain *
- dyspnea *
- increased PA pressures *
- dysrhythmias *
- pulmonary edema *
- wheezing/rales *
- detection of air in heart via TEE*
*Nagelhout
129
s/s of a significant gas embolism - 3 main signs
*Nagelhout
- acute decrease or loss in ETCO2
- increase in ET nitrogen
- hypotension and/or hypoxia that cannot be explained by deep anesthesia or hypovolemia
130
treatment for CO2 embolism
- stop insufflation
- release pneumoperitoneum
- place in Durant position (L-lat tberg)
- hyperventilate to reduce CO2 levels
- insert CVL to aspirate bubble from RA
- raise CVP by giving IV volume (low CVP increases risk of VAE)
- support hemodynamics with pressors and volume as needed *
- 100% O2 *
- d/c nitrous if you're a dummy and using during a lap case *
- flood surgical field with saline *
*Nagelhout
131
what can cause pneumothorax/mediastinum during lap case?
- tracking of insufflated CO2 around the aortic and esophageal hiatuses of the diaphragm into the mediastinum and rupture of the pleural space
- rupture of lung bulla or bleb
132
s/s of pneumothorax/mediastinum to look for during lap case
- unexplained increased airway pressure
- hypoxemia
- severe cardiovascular compromise with hypotension
- subcutaneous emphysema
133
risk factors for developing pneumothorax during laparoscopic procedures (4)
*Nagelhour
- procedures involving laparoscopic mobilization of the esophagus
- operative times > 200 minutes
- ETCO2 > 50 mmHg
- operator inexperience
134
treatment of pneumothorax/mediastinum
- deflation of the abdomen
- chest tube decompression if hemodynamically unstable
- small pneumothoraces may be treated conservatively and allowed to be reabsorbed, can proceed with case
135
how long can pulmonary dysfunction last after lap case?
up to 24 hours
136
methods to prevent pulmonary dysfunction in laparoscopic procedures
- alveolar recruitment maneuvers
| - cough/deep breathe post-op
137
how can we prevent DVTs during lap case
- compression stockings/SCDs
| - early ambulation
138
factors that lead to subcutaneous emphysema (16)
M&M bby...... š°
- insufflator (high gas flow and high gas pressure settings)
- intra-abd pressure > 15 mmHg
- multiple abd entry attempts
- veress needle/trocar not placed in peritoneal cavity
- skin/fascial seal around cannula isnt strong
- use of > 5 cannulas
- laparoscope used as lever
- cannula acting as fulcrum (???)
- long arm of laparoscope is a force multiplier
- tissue integrity compromised by repetitive movements
- structural weakness caused by repetitive movements
- improper cannula placement causing stressed angulation
- soft tissue dissection and fascial extension
- gas dissection leading to more dissection
- procedures > 3.5 hrs
- ETCO2 > 50 mmHg
139
intra-abd pressures greater than what are a risk factor for subcutaneous emphysema?
15 mmHg
140
use of how many trocars is accociated with increased risk of subcutaneous emphysema?
> 5
141
subcutaneous emphysema should be suspected if what changes occur?
*Nagelhout
- repitus
- hypercarbia
- elevated ETCO2
- decreasing lung compliance
- cardiac dysrhythmias
- hypertension
142
what should be done prior to extubation to assess for possible subcutaneous emphysema obstructing airway?
leak test
143
patient positioning
| for prostatectomy
steep trendelenburg
144
patient positioning
| for pelvis procedure
lithotomy w/ steep trendelenburg
145
what nerve injuries are most associated with robotic-assisted lap procedures?
- brachial plexus
- ulnar
- lateral femoral cutaneous nerve
146
eye injuries associated with robotic assisted lap procedures
- corneal abrasion
| - ischemic optic neuropathy
147
fluid limit during robotic assisted lap?
rationale?
- 1-2 L of crystalloid
| - minimize facial and airway edema
148
average age for robotic assicted lap prostatectomy?
considerations from this?
- 60 yrs
| - increased incidence of CAD and renal abnormalities due to prostatic hypertrophy
149
peak inspriatory pressures > ___ cmH2O can result in barotrauma
50-60
150
positioning for thoracoscopy
lateral decubitus
151
anesthesia methods for thoracoscopy
- LA, RA, or GA
| - intercostal nerve block alone, or with spinal, or with epidural
152
airway technique used for thoracoscopy
- one lung ventilation
- double lumen ETT
- can right mainstem a single lumen ETT if working on left lung
- intensionally creating a pneumothorax
153
indications for Video Assisted Thoracic Surgery (VATS)
- lung nodules
- pleural effusions
- wedge resections
- lung resections
154
benefits of a gasless laparoscopy
- avoid effects of CO2 insufflation
- avoid effects of high intraabdominal pressures
- minimal changes in cardiopulmonary, renal functions and neuroendocrine responses
155
describe the technique of a gasless laparoscopy
- mechanical retractor lifts abdominal wall 10-15 cm
| - only 1-4 mm Hg intra-abd pressure
156
what ASA pts may benefit from gasless laparoscopy?
ASA III and IV
157
what is a hysteroscopy?
endoscopic examination of the endocervix and endometrial cavity
158
what are the indications of a hysteroscopy?
- diagnostic for infertility
- abnormal uterine bleeding
- localization of IUD
- resection of septae, adhesions or lesions
159
methods of distending uterus for hysteroscopy
- CO2
| - liquid distending media
160
best anesthesia method for hysteroscopy
rationale for why to avoid one method?
- paracervical block or regional best
| - not GA - absorbing fluid can cause shift in Na+, we need to be able to monitor LOC
161
what causes an increased risk of absorption of distending media for hysteroscopies?
uterus is a sinus, cant close down
162
what are the three distending medias used for resectoscope?
- CO2
- hyskon (32% dextran)
- glycine 1.5%
163
what are the negatives associated with using CO2 for resectoscope?
- can cause embolism
| - rarely used
164
what are the negatives associated with using hyskon for resectoscope?
can cause
- anaphylaxis
- fluid overload
- pulm edema
- renal failure
165
what are the negatives associated with using glycine for resectoscope?
can cause
- fluid overload
- hyponatremia
- hypo-osmolarity
- hyperammonaemia
- hyperglycinaemia
(TURP syndrome i think?)
166
which distending medias have the most potential for absorption?
- hyskon
| - glycine
167
what must be carefully monitored during resectoscopes?
volume in vs volume out
168
what lab must be drawn prior to resectoscope?
Na+ level
169
large volume of distending media absorption can lead to what?
- decreased Na+
- increased fluid volume
- decreased osmolarity
- leaking from vessels
- pulm edema
- cerebral edema
170
what is glycine metabolized into?
what toxic effects can be seen from this metabolite if large amounts are present?
- ammonia
| - toxicity = seizures, mental changes, lethargy
171
what is TURP syndrome?
hypo-osmolar hyponatremia that causes cerebral edema
172
s/s of TURP syndrome
- HTN (sys and dias)
- bradycardia (reflex)
- CNS changes
- N/V
- headache
- agitation and lethargy
- may lead to cardiac arrest
173
what must you absolutely avoid with resectoscope procedures?
GA
174
what practice change is leading to a decrease in TURP syndrome?
using saline vs glycine for distending media
175
what are the early signs of TURP syndrome?
- restlessness leading to confusion
- blurring of vision
- headache
- N/V
--- none of these can be assessed during GA
176
CV diagnostic signs of TURP syndrome
- unexplainable HTN followed by decreased BP
- refractory bradycardia
- nodal/junctional rhythm
- ST changes
- U waves
- widening of QRS
177
average rate of fluid absorption during resectoscope procedures?
20 ml/min
> 1 L/hr
178
how can TURP syndrome be prevented?
- regional anesthesia to be able to assess CNS changes
- use saline v. glycine
- minimize surgical resection time (> 1 hr increases risk)
- different surgical technique (laser vaporization - cutting and coagulating areas to lead to less absorption)
- communication w/ surgeon
179
perforation into what area greatly increases risk of TURP syndrome?
why?
- increased risk with capsular perforation
| - opens up more sinuses = increased area for absorption
180
procedures greater than how long are associated with increased risk of TURP syndrome?
> 1 hr
181
what labs should be drawn if TURP suspected?
- CBC
- lytes
- Na+
- serum osmolality
- maybe ammonia level?
182
what to administer if suspect TURP syndrome>
- NS (not LR)
| - lasix
183
anesthetic technique recommended for resectoscope
regional anesthesia
184
caution if giving 3% to correct Na+ from TURP syndrome to avoid what?
central pontine myelinolysis, with paresis, mutism, pseudobulbar palsy and other neurologic disorders
185
glycine deficits of 500 ml lead to decreases in Na of how much?
2.5 mEq/L
186
best anesthetic agent to use for endoscopy and why?
- propofol
- dont need opioids but need sedation, and need something that wears off quickly with no hangover effect
- midazolam and fentanyl not needed - overkill
