anesthesia for L&D 5/13 Flashcards
- how many phases of the cervical stage? what are they?
2. how long does the cervical stage last in multipara? primapara?
- 2 phases; latent phase and active phase
2. 8 hours for primapara and 5 hours for multipara
what are the 3 stages of labor (actually 4)
- cervical stage
- pelvic stage
- placental stage
(4. 60 min post delivery)
characteristics of latent phase:
regular contractions, cervical softening and effacement; dilation to 2-3 cm
characteristics of active phase?
dilation from 4-9 cm; pain d/t stretch and contractions
what are 6 causes of pain during labor in stage 1?
- stretch of lower uterus
- dilation of cervix
- pressure on nerve endings
- ischemia to myometrium (causes release of bradykinin, serotonin and histhamine).
- vasoconstriction d/t sympathetic activity
- inflammation of uterus muscle
what nerves are stimulated (pain) during stage 1 of labor?
T10-T12, L1
epidurals were avoided in the day, what phase did they think they would prolong?
latent phase
What is stage 2 and how long does it last in prima and multip?
stage 2= pelvic stage
stage 2 lasts 50 minutes in primapara; 20 min in multipara
what nerves are stimulated during stage 2 of labor?
pudendal nerves S2-S4
- what is stage 3 called?
2. what happens here?
- Placental stage
2. delivery of infant and placenta
- what is stage 4?
2. what is parturient at risk for?
- stage 4 is the first 60 minutes post delivery
2. H/R for hemorrhage, uterine atony, increased C.O.
fetal heart monitoring:
- how is it done (what is the method)?
- how is it determined?
1a. can be done indirectly by placing a tocodynameter (on the mothers belly)
1b. or direct by placing a catheter in the amnionic fluid
2. monitors fetal R to R to detect beat to beat variability
- what is tachy and brady for a fetus?
tachy is >160 bpm
brady is <120 bpm
how does a fetus compensate for slow developing asphyxia?
increases heart rate
- what does beat to beat variablilty telll us?
- what is decreased beat to beat variability associated with?
3(a,b) what is short and long term variability
- fetal well being
- decreased beat to beat variability associated with fetal acidosis
3a. short term variability= 2-3 beats
3b. long term variability=5-20 beats
what diminishes beat to beat variability?
- drugs (atropine, beta blockers),
- cns depression d/t hypoxia
- what are decelerations caused by?
2. what causes this?
- uterine distress
2a. decreased maternal oxygenation
- b. uterine hyperactivity
- c. oligohydramnios
- d. cord entrapment
- e. maternal hypotension d/t sympathetic blockade (regional)
- are early decels normal or abnormal?
2. characteristics of early decels:
- normal
- begin with contraction
- rarely drop below 110 bpm
- return to baseline with uterine pressure curve
- probably vaginal in orgin
- secondary to fetal head compression
late decels:
- normal or pathological? how bad are late decels?
- what causes late decels?
- pathological; caused by hypoxia from decreased uterine blood flow
1b. (bad sign when combined with decreased or absent HR) - recurrent bradycardia that begins 20 seconds or more after onset of contraction
- deoxygenated blood is caried to fetal placenta (takes 20 seconds for fetal chemo receptors to sense high CO2 and cause a vagal (bradycardic) response).
variable decels:
- what causes variable decels?
- are they normal or pathologic?
- what are they a sign of when 4 things happen?
- correlate with insuffecient umbilical blood flow
- Pathologic:
- sign of fetal demise when:
- prolonged
- if HR drops below 70 for 60 seconds or longer
- are repetitive
- heart is slow to return to baseline.