General Anesthesia for C-section – Flashcards
Unlock all answers in this set
Unlock answersquestion
How should all pregnant women be treated during intubation?
answer
treated as "full stomach"
question
Why is a pregnant pt more susceptible to regug into esophagus?
answer
incompetent lower esophageal sphincter
question
What are 3 meds you should give for aspiration prophylaxis before GA?
answer
1) reglan 2) Non-particulate antacid (bicitra) 3) H2 blocker (ranitidine)
question
What are 2 ways reglan helps dec aspiration risks?
answer
1) inc gastric motility 2) inc lower esophageal sphincter tone
question
How should reglan be administered? Why?
answer
SLOWLY (pushing too fast can cause temporary psychosis)
question
What effect might reglan have on NMB?
answer
inhibits psuedocholinesterase
question
What should you have pt do after taking bicitra?
answer
reposition (so it moves around in stomach)
question
How long does bicitra work?
answer
1 HOUR! (may need to re-dose if C-section doesn't happen right away)
question
Why should you give an H2 blocker before a C-section when it takes a while to work?
answer
can have prevent aspiration at end of case
question
What is the avg blood loss for C-section?
answer
~1L
question
Generally, blood loss has to be >_________L to affect mom's vital signs.
answer
>1.5L
question
Rank the 6 risk factors for greater than avg blood loss from highest to lowest risk?
answer
1) general anesthesia 2) amnionitis 3) preeclampsia 4) prolonged active phase of labor 5) 2nd stage arrest (same thing as prolonged active labor) 6) Hispanic ethnicity
question
General anesthesia has _____X more risk of greater than avg blood loss than regional anesthesia.
answer
3X
question
Why does a mom w/ prolonged active phase of labor have inc risk of blood loss?
answer
uterus has tired out and has less forceful contractions to prevent blood loss
question
What is the incidence of failed intubation in pregnant women?
answer
1:250
question
What are 4 ways to overcome the obstacle presented by large breasts during DL?
answer
1) have circulator hold breasts out of the way 2) use a laryngoscope handle that is shorter (1-celled handle) 3) rotate 90 degrees to keep from hitting chest 4) take blade off and insert it like a tongue blade, then reattach the handle
question
What should you do to all pregnant pts before intubation to maximize visualization?
answer
ramp them up! (place roll either perpendicular under shoulder or paralled under spine)
question
What are the 3 pt populations most at risk for recall?
answer
1) emergency C-section 2) trauma 3) cardiac
question
How should you adjust your dose of induction meds for a pregnant pt?
answer
use same dose
question
What is a good combo of drugs for induction in pregnant population?
answer
propofol and small dose of ketamine (balance out side effects)
question
What is the dose of ketamine recommended when used with propofol for induction?
answer
50mg
question
What is the dose of ketamine recommended when given alone for induction?
answer
1mg/kg
question
What is an alternate induction drug that can (but isn't often) used for induction?
answer
etomidate (0.3mg/kg)
question
What is the recommended way to preoxygenate/denitrogenate you pt before C-section? Why is this important?
answer
-give 2-3 vital capacity breaths w/ tight fitting mask of 100% FiO2 (faster than waiting 5 min of normal breaths with loose fitting mask) -important bc they have smaller FRC and inc O2 demand --> faster desat during intubation
question
What is the #1 cause of mortality in OB anesthesia?
answer
airway problems during general anesthesia
question
How does the timing of induction vary btwn pts undergoing C-section vs. other general surgeries?
answer
-in other surgeries, you induce GA, then position and prep pt, then wait (can be 30+ minutes btwn induction and incision) -in C-section, you position and prep first, then wait until right before skin incision to induce
question
What are 2 specific times you need to be sure to document during EVERY C-section?
answer
1) uterine incision-to-delivery time 2) time of umbilical cord clamping
question
What is 1 time you need to be sure to document during C-sections under GENERAL anesthesia?
answer
induction-to-delivery time
question
Studies show that as long as the induction-to-delivery interval lasts <_________minutes, you are not likely to cause clinically significant neonatal depression in a healthy fetus.
answer
<10minutes
question
Due to historical thought and "habit", we still continue to have induction-to-delivery intervals of about _______ minutes. What is the only POSSIBLE disadvantage to this and how can you prevent this risk?
answer
2minutes -only possible disadvantage=MAYBE inc risk of recall for mom (can dec this risk by adding 50mg ketamine to propofol for induction)
question
What is the NMB of choice for all general anesthesia C-sections unless there is a specific reason not to use it?
answer
succinylcholine
question
What are 2 reasons that Succ is the NMB of choice for GA C-sections?
answer
1) aspiration risk 2) risk for difficult airway/failed intubation
question
Should you or should you not give a defasiculating dose of NMB during GA C-sections? Why?
answer
should NOT; if you give a defasiculating dose of nondepol NMB, then you have to give 1.5mg/kg of succ (instead of 1mg/kg) which increases the duration of succ --> prob for risk of failed intubation
question
Approx how long after a 1mg/kg dose of Succ can the pt be "rescued" back to breathing after failed intubation?
answer
7-8 min
question
Approx how long after 1.5mg/kg (defasiculating) dose of Succ can the pt be "rescued" back to breathing after failed intubation?
answer
10-15 min
question
Approx how long after 0.3-0.4mg/kg (ED95) dose of Succ can the pt be "rescued" back to breathing after failed intubation?
answer
4-5 min
question
What is one disadvantage to using a smaller (0.3-0.4mg/kg) dose of Succ for intubation?
answer
gives you a much smaller window of opportunity where cords are open for intubation (want to DL and then wait for cords to open, then pass the tube)
question
What are 3 situations that (especially when seen together) can greatly prolong the duration of Succ?
answer
1) dec pseudocholinesterase in pregnancy 2) metoclopramine dec pseudocholinesterase 3) mag sulfate dec pseudocholinesterase (BIGGEST factor)
question
What should you ALWAYS do after using Succ for induction before you either redoes NMB or extubate the pt?
answer
check for recovery of twitches
question
In what 5 situations would you possibly choose to use a non-depolarizing NMB for induction?
answer
1) Risk of MH (most likely reason) 2) pseudocholinesterase deficiency 3) burn pt 4) spinal cord injury (depending on time frame) 5) muscular dystrophy
question
What is the FIRST thing you should do after you induce general anesthesia and you then realize you can't intubate?
answer
call for help
question
You should never try laryngoscopy more than _______ times before moving down the airway algorithm.
answer
2
question
What is the next step (after calling for help) that you should do after you induce GA and realize you can't intubate?
answer
mask ventilate (face mask OR LMA) while maintaining cricoid pressure
question
If you choose to place an LMA after failed intubation, what type of LMA should you use?
answer
one you can intubate through (and place the ETT as soon as possible)
question
If you choose to face mask ventilate after failed intubation, what else should you do?
answer
place an oral airway
question
Is the main reason you might not be able to ventilate well with an LMA after failed intubation?
answer
inability to place LMA correctly d/t cricoid pressure (may need to let up cricoid pressure JUST long enough to insert LMA)
question
What are 4 reasons you might not be able to ventilate well with a face mask after failed intubation? Which reason is most likely and how can you handle it?
answer
1) no good seal (may need to use 2 hands) 2) laryngospasm/bronchospasm (unlikely) 3) airway collapsing d/t upper airway swelling (treat w/ PEEP) 4) cricoid pressure might have collapsed airway (most likely--> treat by having person applying cricoid pressure slowly let up while you ventilate and as soon as you are able to ventilate, keep cricoid pressure at that level)
question
But doesn't letting up on cricoid pressure increase aspiration risk??? Why is it ok to do this during face mask ventilation?
answer
risk of no ventilation is MUCH greater and more serious than risk of aspiration
question
What is the next step on the algorithm if mask ventilation is NOT adequate after failed intubation?
answer
go to ASA difficult airway algorithm (emergency pathway)
question
What is the next step on the algorithm if you ARE able to provide adequate mask ventilation, either with an LMA or face mask?
answer
determine if there is fetal distress
question
If you ARE able to mask ventilate and determine that the fetus IS in distress, what are your 3 choices? Which is most often chosen?
answer
1) wake mom up and perform safe intubation 2) surgical airway 3) continue case w/ cricoid pressure and get baby out fast! (most often chosen)
question
What is the risk associated with waking mom up and performing safe intubation (awake FO, etc)?
answer
possible fetal demise
question
What is the risk associated with continuing case w/ cricoid pressure and delivering baby ASAP?
answer
aspiration (still better risk than immediate mother and/or fetal demise); once baby is out, you have more options for airway mgmt
question
What are 2 choices for surgical airway if mask ventilation is not adequate? What might be necessary to do in the mean time until surgical airway can be inserted?
answer
cricothyrotomy or tracheostomy (may need manual jet ventilation until trach can be placed)
question
What are 2 important things to remember when inserting a catheter in the cricothyroid membrane for jet ventilation?
answer
1) aspirate for air to confirm placement in trachea 2) point needle caudad to avoid hitting vocal cords
question
If mask ventilation IS adequate and there is NO fetal distress, what is the best next step?
answer
wake mom up and start process over with new plan (awake FO or call in the "airway pro" to try again)
question
What is the goal for uterine incision-to-delivery time in all C-section cases (not just under GA)?
answer
< 3 min
question
What happens at the time the last (if multiple babies) cord is clamped?
answer
Pitocin drip is started
question
What are 3 s/s of Pitocin overdose?
answer
1) vasodilation 2) hTN 3) skin flushing
question
What is the t1/2 of Pitocin in term pregnant women?
answer
5-15min (requires infusion for prolonged affect)
question
What are 2 alternatives to Pitocin to stimulate uterine contractions?
answer
1) ergot alkaloid (IM injection) 2) prostaglandin
question
What are 2 drug classes that should be avoided before cord is clamped?
answer
opioids or benzos (fetal depression)
question
After induction (with propofol and/or ketamine), what are 3 options to keep the pt asleep before delivery of baby?
answer
1) propofol drip (not used often) 2) volatiles 3) N2O
question
What cntn of volatiles is recommended for use UNTIL delivery of baby?
answer
< 2/3 MAC (b/c MAC is dec in pregnancy, 2/3 MAC is almost equivalent to 1MAC in a nonpregnant pt)
question
What is the only reason you would need to d/c volatile agent after delivery of baby?
answer
if you are not able to achieve adequate uterine contraction w/ volatiles still on (if uterus does not IMMEDIATELY begin to contract when you turn Pitocin on, you should immediately turn volatile off)
question
What are 5 options to add to opioid after delivery of baby to provide amnesia?
answer
1) N2O (very tricky when used alone w/ opioids) 2) ketamine 3) propofol drip 4) versed 5) IV scopolamine (not used often b/c wild on emergence)
question
True or False: If twitches return after succ induction before surgery is completed, it is necessary to redose NMB to allow surgeon ability to close.
answer
False (empty abdomen b/c no mo babe will not be hard to close) only need to redose NMB if pt starts trying to leave (moving arms or legs)
