Laparoscopic Anesthesia Flashcards
advantages of laparoscopic procedures (7)
- 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
what two things have improved the safety of laparoscopic procedures dramatically?
*Nagelhout
- open entry trocar
- videoscopic imaging
what are the three main challenges associated with laparoscopic procedures?
*Nagelhout
- pneumoperitoneum
- positioning
- increasingly critical patients
indications for laparoscopic procedures
*huge list Iām never gonna memorize
- 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
absolute contraindications for laparoscopic procedures (6)
- bowel obstruction
- ileus
- peritonitis
- intraperitoneal hemorrhage
- diaphragmatic hernia
- severe cardiopulmonary disease/CHF
relative contraindications for laparoscopic procedure (8)
- 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
laparoscopic splenectomies are often at high risk for what intra-op complication?
bleeding
what allows for safe insertion of the Veress needle through the umbilicus in the first trimester?
uterus is still low in the pelvis
at what week gestation does the uterus begin to interfere with visualization during laparoscopic procedures?
23 weeks
what maternal value must be monitored very closely in pregnant mothers during laparoscopic procedures?
- PaCO2
- maintain slightly alkalotic - CO2 ~ 30 mmHg
what position should be used for pregnant women undergoing laparoscopic procedures if > 16 weeks ?
30 degree left-uterine displacement
intraperitoneal pressures should be kept less than what in pregnant women during laparoscopic procedures?
- 12 mmHg
- make sure to remind circulator and/or surgeon to keep pressures low
what non-maternal monitoring should be done for pregnant mothers undergoing a laparoscopic procedure?
continuous fetal heart rate - via transvaginal ultrasound
ouch
what are the four potential causes of major physiologic changes during laparoscopy?
- creation of the pneumoperitoneum
- potential for systemic absorption of carbon dioxide
- initial Trendelenburg position
- reverse Trendelenburg position
what is the purpose of a pneumoperitoneum?
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
what is a pneumoperitoneum?
insufflation of the peritoneal cavity with CO2 (or air, nitrous oxide, helium, oxygen)
what are the characteristics of the ideal gas to use for a pneumoperitoneum?
- Nagelhout
- colorlessness
- nonflammable in the presence of electrocautery
- physiologic inertness
- excretion via pulmonary route
pros for the use of CO2 for pneumoperitoneum
- 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
cons for the use of CO2 for pneumoperitoneum
- more pain due to diaphragmatic irritation
- hypercarbia, respiratory acidosis
- cardiac dysrhythmias
why are helium and argon not used for pneumoperitoneum?
they caused greater hemodynamic depression if embolized into venous vasculature and caused death at much smaller volumes
why must extreme caution be used to make sure that CO2 tank is actually CO2?
- if the tank is > 7% CO2 it has the same pin index as oxygen
- if using oxygen there is the potential for combustion
physiologic changes from a pneumoperitoneum result from what two things? (big picture)
*Nagelhout
- direct mechanical pressure
- stimulation of intrinsic neurocirculatory responses
advantage of pneumoperitoneum for laparoscopic procedures
separates the abdominal wall from the contents of the peritoneal cavity to optimize visualization and access
disadvantages of pneumoperitoneum for laparoscopic procedures
- limits surgeonās freedom of movement
- limits choice of instruments
- involves risk of significant complications related to the use of CO2
procedure for creating a pneumoperitoneum - closed procedure method
(kinda long, feel free to break it up)
- inject local anesthetic into umbilical area
- insert Veress needle via anesthetized area into peritoneal cavity - verify placement
- insufflate the cavity with CO2 at a pressure less than 19 mm Hg (3 L)
- once distended, insufflator placed in automatic mode to maintain pneumoperitoneum at 12 mm Hg
- trocar then inserted blindly or under direct visualization (*Nagelhout)
an intra-abdominal pressure of less than what indicates correct placement of an umbilically placed Veress needle?
*Nagelhout
10 mmHg or less
what are intra-abdominal pressures maintained at during a laparoscopic procedure?
12-15 mmHg
at what time during a laparoscopic procedure is the patient at the highest risk for serious complications?
- insertion of Veress needle/trocars
- abdominal insufflation
what pressures are used during a retroperitoneoscopic adrenalectomy?
15-20 mmHg
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
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
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
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
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
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
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
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
which entry technique is associated with a lower incidence of unrecognized vascular and visceral injury?
*Nagelhout
open entry
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
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)
subcutaneous emphysema has been associated with what negative outcomes?
- airway issues
- severe hypercarbia*
- decreased chest compliance*
- hemodynamic instability*
(*Nagelhout)
how can we assess for subcutaneous emphysema in the airway?
- leak test
- if present, consider leaving the patient intubated until reabsorbed
the magnitude of the patientās 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
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
effect of pneumoperitoneum on MAP?
cause?
- increased MAP
- due to catecholamines
*increase MAP whether 5 mmHg or 40 mmHg
effect of pneumoperitoneum on HR? (at normal pressures)
cause?
- increased HR
- due to catecholamines
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
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
what causes a bigger effect on central pressures, position or pneumoperitoneum?
patient position
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
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
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%
what is our #1 job on insufflation?
watch EKG!
vagal stimulation with insufflation can cause bradycardia that can lead to asystole
high pressure insufflation can cause what EKG change?
prolonged QT
what are the two main causes of bradycardia in laparoscopic procedures?
- high abdominal pressures
- rapid insufflation
if bradycardia is seen on insufflation, what should be done?
- tell surgeon to relieve pressure - should automatically fix
- if it doesnāt resolve with pressure relief give atropine
GFR and UOP effects seen from pneumoperitoneum at varying pressures
- 5 mmHg - no change
- 10 mmHg - decreased
- 20 mmHg and higher - significant decrease
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
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
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
what pneumoperitoneal pressures start to potentially cause an increase in CO2?
10 mmHg and higher
what pneumoperitoneal pressures start to potentially cause a decrease in pH?
10 mmHg and higher
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
effects of pneumoperitoneum on cerebral blood flow and ICP?
both are increased
does hyper/hypoventilation have an effect on the pneumoperitoneumās effect on cerebral blood flow and ICP?
- hyperventilation does not effect
- hypoventilation makes it worse
an abdominal pressure of ~16 mmHg and tredelenburg causes how much of an increase in ICP?
150%
what effect does abdominal insufflation have on CSF?
- reduced reabsorption
- due to increased IVC pressure and impaired venous drainage of the lumbar venous plexus
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 ā> more vasoconstriction to kidneys
effect of pneumoperitoneum on kidneys, liver, and splanchnic blood flow?
- decreased
- bigger effects seen with pressures > ~14 mmHg
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
what places a COPD patient at an increased risk of post-op complications after laparoscopic surgery?
higher level of CO2 retention and respiratory acidosis
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
effect of pneumoperitoneum on pulmonary compliance
- decreased due to diaphragm shifting upwards
- increased peak pressures
effect of pneumoperitoneum on lung volumes?
- decreased vital vapacity
- decreased FRC
what patients are at higher risk for developing hypoxia from pneumoperitoneum?
- obese pts - due to V/Q mismatching
- pre-existing pulmonary disease
is hypoxia typically seen in healthy patients with pneumoperitoneum?
nope
what percent increase can be seen to ETCO2 due to absorption?
0-30% increase
what amount of change in pulmonary compliance is seen in supine patients with pneumoperitoneum?
43% reduced pulmonary compliance
what reflex offsets the effects of atelectasis during pneumoperitoneum?
hypoxic pulmonary vasoconstriction
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
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
CO2 absorption that causes a low pH is what type of acidosis?
respiratory acidosis
how can we offset the effects of CO2 absorption?
increasing minute ventilation, otherwise CO2 will continue to rise
what abd insufflation pressures result in the maximum CO2 absorption?
10 mmHg
does PaCO2 ever plateau after insufflation?
- yes
- after approx. 40 min from start of insufflation
when do blood gas parameters return to baseline?
after discontinuation of CO2 insufflation
ā unsure exactly when bc when i tried to re-find this in the book i couldnt
what degree of trendelenburg allows small bowel and colon to move out of the pelvis and minimize needle or trocar perforation?
10 ā 20
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
resp effects of trendelenburg
- reduced lung capacity
- decreased FRC
- can have inadvertent R mainstem intubation
steep trendelenburg causes how much decrease in pulmonary compliance?
50%
what position partially counteracts the effects of pneumoperitoneum on the diaphragm and improves diaphragmatic function?
reverse trendeleburg
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
what causes an increased risk of aspiration with laparoscopic procedures?
- increased intra-abd pressure
- gravity from trendelenburg position
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
CV effects of reverse trendelenburg position?
- decreased venous return
- decreased LVEDV
- EF maintained in healthy patients/ decreased in unhealthy
what could help mitigate some of the CV effects from reverse trendelenburg position?
- fluid bolus prior to positioning
- might need vasopressor to shrink compartment
what three factors determine the rate of CO2 absorption?
- tissue solubility of the gas
- diffusion pressure gradient across the containing membrane
- blood flow across the cavity
which causes increased CO2 absorption- extraperitoneal or intraperitoneal?
why?
- extraperitoneal
- due to lack of containment of CO2 allowing an increased area for gas exchange
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 ā> dysrhythmias
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
T/F: EtCO2 accurately predicts changes in PaCO2 in healthy, mechanically ventilated patients
true
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)
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
how can we prevent/minimize the CV effects of hypercarbia?
- minimize SNS stimulation
- prevent hypoxia
- premed with anxiolytic
- 100% O2 on induction`
what is the preferred method to increase minute ventilation during laparoscopy?
*Nagelhout
increase TV rather than RR
what interventions can be done to improve clinical outcomes and decrease pulmonary complications
- PEEP
- recruitment maneuvers
most widely accepted technique for laparoscopies?
- GA
- deep NMB
- cuffed ETT *
- pressure control ventilation *
- recruitment maneuvers *
FYI: GA alters ventilatory response, so spontaneous ventilation under general anesthesia results in hypercarbia
:(
effects of RA when combined with GA for laparoscopic anesthesia
better pain relief, but no better pulmonary function
worst anesthetic plan for laparoscopies?
maybe even worse than LMA :/
local anesthesia
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
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
what is the main reason that we want to use NMB for laparoscopy?
to avoid injury to organs or vessels (or umbilical hernia??? what?)
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
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
best management approach for lap PONV?
multi-modal
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
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 theyāre in pain
which opioids are more likely to cause sphincter of oddi spasm?
- morphine, demerol
- fentanyls are not as causative
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 (āvalsalva breathsā)
what causes the bradycardia and asystole that can be seen during insufflation?
reflex vagal stimulation from stretching and distention of the peritoneum
what can cause PEA during laparoscopy?
- compression of the IVC
- hemorrhage
- gas embolism
what s/s should make you consider that the patient might have retroperitoneal hemorrhage?
- super labile
- decreased BP
- increased HR
- all hemorrhage symptoms, but canās see any blood
mortality rate with significant CO2 embolism?
*Nagelhout
28.5%
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
ā details from Nagelhout
what is the most sensitive diagnostic tool for CO2 gas embolism?
TEE
can detect emboli as small as 0.02 ml/kg ā wowzas
what can result from a large volume CO2 embolus?
- may form āgas lockā in the RA or RV that impairs venous return and RV outflow
- may reach the pulmonary circulation, cause PHTN, and R sided HF
presenting signs of gas embolism
sheās longā¦
- 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
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
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 youāre a dummy and using during a lap case *
- flood surgical field with saline *
*Nagelhout
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
s/s of pneumothorax/mediastinum to look for during lap case
- unexplained increased airway pressure
- hypoxemia
- severe cardiovascular compromise with hypotension
- subcutaneous emphysema
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
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
how long can pulmonary dysfunction last after lap case?
up to 24 hours
methods to prevent pulmonary dysfunction in laparoscopic procedures
- alveolar recruitment maneuvers
- cough/deep breathe post-op
how can we prevent DVTs during lap case
- compression stockings/SCDs
- early ambulation
factors that lead to subcutaneous emphysema (16)
M&M bbyā¦ā¦ 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
intra-abd pressures greater than what are a risk factor for subcutaneous emphysema?
15 mmHg
use of how many trocars is accociated with increased risk of subcutaneous emphysema?
> 5
subcutaneous emphysema should be suspected if what changes occur?
*Nagelhout
- repitus
- hypercarbia
- elevated ETCO2
- decreasing lung compliance
- cardiac dysrhythmias
- hypertension
what should be done prior to extubation to assess for possible subcutaneous emphysema obstructing airway?
leak test
patient positioning
for prostatectomy
steep trendelenburg
patient positioning
for pelvis procedure
lithotomy w/ steep trendelenburg
what nerve injuries are most associated with robotic-assisted lap procedures?
- brachial plexus
- ulnar
- lateral femoral cutaneous nerve
eye injuries associated with robotic assisted lap procedures
- corneal abrasion
- ischemic optic neuropathy
fluid limit during robotic assisted lap?
rationale?
- 1-2 L of crystalloid
- minimize facial and airway edema
average age for robotic assicted lap prostatectomy?
considerations from this?
- 60 yrs
- increased incidence of CAD and renal abnormalities due to prostatic hypertrophy
peak inspriatory pressures > ___ cmH2O can result in barotrauma
50-60
positioning for thoracoscopy
lateral decubitus
anesthesia methods for thoracoscopy
- LA, RA, or GA
- intercostal nerve block alone, or with spinal, or with epidural
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
indications for Video Assisted Thoracic Surgery (VATS)
- lung nodules
- pleural effusions
- wedge resections
- lung resections
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
describe the technique of a gasless laparoscopy
- mechanical retractor lifts abdominal wall 10-15 cm
- only 1-4 mm Hg intra-abd pressure
what ASA pts may benefit from gasless laparoscopy?
ASA III and IV
what is a hysteroscopy?
endoscopic examination of the endocervix and endometrial cavity
what are the indications of a hysteroscopy?
- diagnostic for infertility
- abnormal uterine bleeding
- localization of IUD
- resection of septae, adhesions or lesions
methods of distending uterus for hysteroscopy
- CO2
- liquid distending media
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
what causes an increased risk of absorption of distending media for hysteroscopies?
uterus is a sinus, cant close down
what are the three distending medias used for resectoscope?
- CO2
- hyskon (32% dextran)
- glycine 1.5%
what are the negatives associated with using CO2 for resectoscope?
- can cause embolism
- rarely used
what are the negatives associated with using hyskon for resectoscope?
can cause
- anaphylaxis
- fluid overload
- pulm edema
- renal failure
what are the negatives associated with using glycine for resectoscope?
can cause
- fluid overload
- hyponatremia
- hypo-osmolarity
- hyperammonaemia
- hyperglycinaemia
(TURP syndrome i think?)
which distending medias have the most potential for absorption?
- hyskon
- glycine
what must be carefully monitored during resectoscopes?
volume in vs volume out
what lab must be drawn prior to resectoscope?
Na+ level
large volume of distending media absorption can lead to what?
- decreased Na+
- increased fluid volume
- decreased osmolarity
- leaking from vessels
- pulm edema
- cerebral edema
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
what is TURP syndrome?
hypo-osmolar hyponatremia that causes cerebral edema
s/s of TURP syndrome
- HTN (sys and dias)
- bradycardia (reflex)
- CNS changes
- N/V
- headache
- agitation and lethargy
- may lead to cardiac arrest
what must you absolutely avoid with resectoscope procedures?
GA
what practice change is leading to a decrease in TURP syndrome?
using saline vs glycine for distending media
what are the early signs of TURP syndrome?
- restlessness leading to confusion
- blurring of vision
- headache
- N/V
ā none of these can be assessed during GA
CV diagnostic signs of TURP syndrome
- unexplainable HTN followed by decreased BP
- refractory bradycardia
- nodal/junctional rhythm
- ST changes
- U waves
- widening of QRS
average rate of fluid absorption during resectoscope procedures?
20 ml/min
> 1 L/hr
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
perforation into what area greatly increases risk of TURP syndrome?
why?
- increased risk with capsular perforation
- opens up more sinuses = increased area for absorption
procedures greater than how long are associated with increased risk of TURP syndrome?
> 1 hr
what labs should be drawn if TURP suspected?
- CBC
- lytes
- Na+
- serum osmolality
- maybe ammonia level?
what to administer if suspect TURP syndrome>
- NS (not LR)
- lasix
anesthetic technique recommended for resectoscope
regional anesthesia
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
glycine deficits of 500 ml lead to decreases in Na of how much?
2.5 mEq/L
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
