Case 54 - Labor and Delivery Flashcards
Describe the stages of labor, the innervation, and modes of analagesia to tx pain based on stage of labor
Stage 1
- Define - onset of regular contractions, ends with complete cervical dilation
- T10 - L1
-
Pain - visceral Pain
- uterine contractions and cervical dilation
- tx - epidural, spinal, paracervical blocks
Stage 2
- Define - cervical dilation to deliver of baby
- T10 - L1 (uterine contraction) + S2-S4 (perineal stretching)
- Pain - Somatic + visceral
- tx - epidural, spinal, pudendal nerve blocks
Stage 3
- Define - delivery of baby to delivery of placenta
- T10 - L1 (uterus) + S2-S4 (perineal stretching, laceration, injury)
- Pain - Somatic
- tx - epidural, spinal, pudendal nerve block
What are advantages of spinal vs epidural analgesia?
Spinal
Advant
- reliable + rapid onset
Disadvant
- hypotension (precipitious)
- inability to control spread
- limited duration
- PDPH
Epidural
Advant
- Better control of spread
- gradual decreaes in BP
- unlimited duration
- can convert analgesia to anesthesia (emerg c/s)
Disadvant
- prolong time to achieve surigcal anesthesia
- higher LA dose needed -> risk of LAST
what are advantages to a CSE, how would you do it? Can you see fetal brady after intrathecal spinal admin?
CSE
- best of both worlds (rapid onset + prolong block with repeat doses)
- rapid onset of analgesia (3-5 min)
- if using SA opioids -rapid onset, intense analgesia, minimal changes in BP or motor function
- give opioid in CSE and LA in epidural infusion
- opioid - fentanyl 25 mcg or sufent 5 mcg
Fetal brady
- can occur after intrathecal spinal med admin
- reason: pain well controlled -> decrease materal catechoalmines
- decrease b-adrenergic response, but see unopposed alpha-adrnergic activity
- alpha adrenergic = assoc with uterine contractions -> dec blood flow to uterus -> fetal brady
How can you determine if a patient is a candidate for walking epidural?
Walking epidural
- ambulate during labor with a neuraxial block
Candidacy
- unremarkable peripartum course -> no problems with mother or fetus (reassuring fetal heart status)
- monitor BP and fetal HR q30-60 min
- asses motor function
- should be able to step up and down on a stool
What are advantages and contraindications to neuraxial anesthesia for C/S?
Advantages of neuraxial during c/s
1) decrease risk of material aspiration
2) avoid intubating (difficult intubation in preg pts)
3) minimize neonatal depression from maternal drug administratoin
Absolute contraindications
- patient refusal
- shock, severe hypotension, severe hypovolemia
- infection at site
- coagulation abnormalities
- increased ICP (will worsen ICP 2/2 adding LA solution into spinal or epidural space)
Relative contraindication
- systemic infection
- back surgery history
- MS
Describe how you will provide neuraxial anesthesia (spinal and epidural) for a parturinent coming for elective c/s. (describe from machine check to end of block with tx neuraxial assoc hypotension)
Neuraxial anes in elective c/s
1) Check machine
- different size blades, ETT, laryngoscope handles
- emergency meds ready: ketamine, etom, prop, sux, ephedrine, pheynylephrine
2) admin pre-op antacids
- metoclopramide
- H2 blocker
- sodium bicitrate
3) Left uterine displacement
4) ASA monitors + oxygen
5) neuraxial anesthesia:
- Epidural
- negative test dose
- 2% lido + 1:200,000 Epi - 5 cc aliquots every 5 min till T4 level achieved
- at end of surgery - morphine 4mg PF - post op pain
- spinal
- 1.5 mL of hyperbaric bupi 0.75 % (11-12mg)
- add PF morphine 250mcg - post op pain
6) Monitor vitals q1-2 min for 15 min, then q5min after if stable
7) Hypotension
- fluid bolus
- ephedrine or phenylephrine bolus
what is mech of action of PDPH, risk factors, what are sign and symp of PDPH?
PDPH
- persistent CSF leak from SA into epidural space
- decreased SA pressure causes tension on pain-sensitive blood vessels -> vasodilation
RF
- large needle
- cutting edge needle
- female
- pregnant
- number of attempts
S/Sx:
- occipto-frontal headache
- Positional (worse with sitting up or standing up)
- n/v, photophobia, tinnitus, diplopia
Tx of PDPH
conservative
- IVF
- caffinee
- bed rest
- analgesis (opioids, NSAIDS)
Invasive
- blood patch - usually successful
- prophylactic blood patch - not benefical
what are advantages and disadvantages of general anesthesia when compared to neuraxial anes for c/s?
General Anesthesia
Advant
- shorter prepatory time
- absence of sympathetcomy
Disdvant
- difficult airway
- high risk of aspiration
- neonatal depression from general anes meds
- no immediate maternal bonding
What will be your pre-op and induction plan for a pregnant patient undergoing general anesthesia for c/s? (start from checking machine + emergency equip to tube secured)
1) check machine
- different airway equpiment, blades, ETTs
- glidescope
- induction meds (prop, ket, etom, sux)
- emergency meds (ephe, phenyl)
- SUCTION ON AND READY
2) Left uterine displacement at all times
3) prophylactic antacids
- metoclopramide, sodium bicitrate, h2 blockers
- high risk for aspiration
4) ASA monitors
5) RSI&I (have help available)
- denitrogenation 100% O2 for 3-5 min
- cricoid pressure
-
IV induction (based on HD stability) + SUX
- NO defasciculating dose (prolongs RSI)
- SUX provides faster optimal intubating conditions than ROC
- secure ETT, verify correct placement, let go of cricoid
-
maintain anesthesia
*
pregnant patient is undergoing general anesthesia for c/s. How will you maintain anesthesia?
Anesthesia Mainteance - Prior to delivery
- Goals: prevent maternal recall, decrease risk of fetal depression, decrease risk of uterine relaxation
-
N2O 50% with o2 + low dose volatile anesthetic
- volatile anes more potent than N2O -> can cause neonatal depression and uterine relaxation more than N2O
Anesthesia Mainteance - After neonatal delivery
- Goal: Prevent maternal recall, decrease uterine relxation
- increase N2O to 80%, add opioids, reduce volatile anesthestic to < 0.5 MAC
pregnant patient undergoes general anesthesia for c/s. how will you plan for extubatoin?
extubation
- Goal - still at risk for aspiration. AWAKE EXTUBATION
- check TOF, reverse neuromuscular blockade
-
extubate pt fully awake
- make sure pt able to protect airway
what factors affect placental transfer of a medication from maternal to fetal circulation? What does fentanyl, sux, volatile anes, propofol do in terms of placental transfer
1) lipid solubility
- high lipid solubility transfers
2) ionization
- nonioninzed meds transfer
3) protein binding
- non-protein bound (free form) meds transfer
4) molecular weight
- low molecular weight transfer
5) concentration gradient
- high conc gradient faciliates transfer
Anes Meds
- Propofol + Volatile anes + Fentanyl - transfer - high lipid soluble, nonion, low weight
- Sux + Roc -> No Transfer -> ionized, large molecular weight, not lipid soluble
what techinques can be used for pain relief afte c/s?
- IV opiods
- neuraxial opiods
- epidural - PF morphine 3-4 mg
- spinal - PF morphine 0.1 to 0.25 mg (250mcg)
what is the DDx for postpartum hemorrhage?
- uterine atony - Most common
- retained products of conception
- placenta accreta, increta
- cervical/vaginal laceration
- coagulopathy
- pre-eclampsia (HELLP)
- amniotic fluid embolus (DIC)
