Anesthesia c section Flashcards
Disadvantages of GA
- aspiration
- airway management
- fetal sedation and narcotizing
- awareness under light GA
possible class 1 emergencies or indications for GA
class 1 emergencies: massive hemorrhage, non reassuring FHR/fetal distress, abruption, eclampsia
indications: refusal of regional, contraindications of regional, coagulopathy
induction drug doses for GA
prop 2.5mg/kg; can be infused 6mg/kg/hr
etomidate 0.3 mg/kg
ketamine 1-1.5 mg/kg; fetal depression at 2mg/kg (decreased UBF)
sux 1 to 1.5mg/kg
physiological causes of neonatal depression
maternal hypoventilation/hyperventilation
reduced UP perfusion from aortocaval compression
neonatal acidosis increases when time between uterine incision and delivery exceeds 3 min
pharmacologic causes of neonatal depression
induction agents
NMBA
low O2 concentration
NO2 and other IAs
Duration of CS
15-120 min
Avg 40min
When is GA indicated for CS
Class I emergency without epidural, and spinal
Or either regional method takes too long
When is local anesthesia indicated for CS
- for life threatening fetal compromise
- anesthesia providers are not present
- mom consents
- supplementation of patchy epidural
What sensory level is necessary for adequate regional anesthesia for CS
T4
Which anticoagulant is not contraindicated while patient has an indwelling neuraxial catheter
Heparin
Minimal time between last dose and spinal injection/catheter placement
Warfarin 12-24 hours
Heparin aPTT<40; 6 after last dose for 5000u TID or higher
Heparin 5000 units BID no contraindication
Minimal time between spinal injection/catheter removal and next dose of anticoagulant
Warfarin 2 hours
Heparin 1 hour
Lovenox 24 hours; 6-8 hours
Spinal anesthesia contraindications
Specific cardiac lesions, technical problems, short stature, obese, neurological d.o
What is the preop prophylaxis for aspiration when doing a CS
Sodium citrate 30ml
Gastrokinetic such as reglan 10mg
What positions can you perform a spinal on
Lateral preferred but sitting more common
Preferred sites for spinal/epidural for CS
L2L3 L4L5
Solution for spinal for CS
Hyperbaric bupi 0.75% (7.5-15mg) with 6.25 to 25 mcg of fentanyl and or 0.1-0.3 morphine mg)
BUPI dose for spinal CS and DOA
7.5-15mg
60-120min
Fentanyl dose for Spinal CS and DOA
10-25 mcg
DOA 180-240min
Morphine dose and DOA for spinal CS
0.1-0.2 mg
720-1440
Epi dose for spinal CS
0.1-0.2 MG
True or false epidural anesthesia for CS is a less dense block, greater chance of failure, and has an increased complexity of the technique
True
How much cc of LA for each level anesthetic blockage
1cc
How many cc’s do you give with an epidural and how long between doses
5cc and 2 min between doses
What can you add to an epidural
Epi and sodium bicarb
Fentanyl/morphine
Which LA can be used in an epidural for fastest onset, no fetal transfer, acidotic fetus
2 chloro
Which LA is most frequently used for CS epidural if not urgent/emergent
Bupi
What do you add to epidural LA in case of emergency
2% lidocaine with epi and sodium bicarb
10-20 ml of lido
2ml of pedi bicarb (1ml of sodium bicarb with 9ml of 2% lidocaine)
Which cocktail for epidural CS has the fastest onset and longest duration
50/50 lido/bupi with sodium bicarb
Dose and DOA for Lidocaine 2% with epi 5mg/ml dose for Epidural CS
300-500 mg
DOA 75-100min
Dose and DOA for 3% 2-chloro
Epidural CS setting
450-750mg
40-50 min
Bupi 0.5% dose and DOA for epidural CS setting
75-125 ming 120-180 min
Ropi 0.5% dose and DOA for epidural CS
75-125mg 120-180 min
Fentanyl dose and doa for epidural CS
50-100 mcg 120-240 min
Morphine epidural cs dose and doa
3-4mg
720-1440min
How do you perform a sequential block
Inject 10ml of saline through epidural to help rostral spread of spinal
Squeezes dural sac
Smaller initial spinal dose - less hypotension
Why is spinal after failed epidural controversial
Risk of high or total spinal
How much of the OB spinal dose is recommended after a failed epidural
75%
Causes of total spinal
Epidural injection into subarachnoid (too much volume)
Epidural dose into subdural (subdural space low volume space)
Spinal after failed epidural
S/S and management for total spinal
Presents 10+25min after
Rapid progression of motor and sensory block
Sx: dyspnea, difficulty phonating, significant hypotension, LOC
Tx: IVF LUD, vasopressors, elevation of legs, intubate, r/o eclampsia, fluid embolism, anaphylactic shock
Acid Prophylaxis tx against aspiration for GA CS
Sodium citrate
H2 antagonist (-tidine)
Prokinetic - reglan
Is patient prepped and draped before induction of GA for CS
YES
Patient position considerations for RSI
15 degree at least of LUD
Cricoid 44 newtons
BURP
Head and neck elevated
How much MAC with GA CS
0.5-0.8 MAC with nitrous
Higher than 0.5 MAC run the risk of uterine relaxation and decreases sensitivity to oxytocin
What happens if you can’t intubate for cs
Ventilate through cricoid
Awaken, fiberoptic intubation
LMA fast track
Which induction drug has less histamine release and myocardial depression compared to thiopental
Etomidate
T or F
Decreased cholinesterase does not prolong sux
True
T or F defasiculation dose and repeat dose not necessary with sux
T
What is ideal maternal PaCO2 with MV for GA CS
27-31
Why is hypoventilation with mom bad
Eliminating UV/M gradient, limiting CO2 transfer - fetal respiratory acidosis
What is NDMR prolonged by
MAG
Central acting post CS analgesia
Ofermiv 1g IV q6h
Oral 650mg q6h
Which is the gold standard for neuraxial opioids
Morphine
Additional adjuncts for post CS analgesia (part of ERAS)
Ketamine 10mg or .15mg/kg after neuraxial anesthesia
TAP block
.25%-.375% bupi and ropi
Gabapentin 600mg 1hr prior to sx
