What causes swelling of the maternal airway?
Increased progesterone, estrogen, and relaxin combined with an increase in ECF.
These tissues also become very friable
Risk of difficult and failed intubation
8x higher than normal
What things make airway edema even worse in parturients?
Pre-eclampsia, tocolytics, and prolonged trendelenburg position
This hormone is a respiratory stimulant
Progesterone
Causes MV to increase by 50%
(40% increase in TV + 10% increase in RR)
Lung volume changes in pregnancy
Increased:
Decreased:
- FRC (d/t decreases in ERV and RV)
No changes in other lung volumes! It’s actually pretty easy to think this through.
CV changes in pregnancy
3 Major effects of progesterone
1) Increases RAAS activity
- Increased blood volume and CO
2) Vascular muscle relaxation
- Decreased SVR and increased flow
3) Increased MV
- Rightward shift of dissociation curve
With LUD, the right torso should be elevated ___ degrees
15 degrees
Heme changes in pregnancy
Overall, increasing circulating blood volume and preparing for hemorrhage in labor
Mom makes more clot, but breaks it down faster too
What happens to serum albumin?
Decreases
What happens to pseudocholinesterase?
Decreases (not enough to be clinically relevant though)
Drug characteristics that favor placental transfer
Stages of labor
Stage 1
Stage 2
Stage 3
- Delivery of placenta
2 Major effects of uncontrolled pain in labor
1) Catecholamine release
- Maternal HTN and reduced UBF
2) Hyperventilation (leftward shift and decreased O2 transfer to fetus)
Only LA that decreases efficacy of morphine
2-Chlorprocaine
How is chlorprocaine metabolized?
Pseudocholinesterase (minimal placental transfer)
Presentation of high spinal
Rapid sensory and motor block
Dyspnea
Difficulty phonating
Hypotension (hypotension leads to apnea)
Management of high spinal
Get her BP back up so she will start breathing on her own! (Overall pressers and increase venous return)
If unable to manage her own airway, then INTUBATE
Normal fetal heart rate (FHR)
110-160
Fetal and maternal causes of low FHR (
Fetal:
Maternal:
Fetal and maternal causes of high FHR (>160)
Fetal:
Maternal:
These things decrease FHR variability
Type of decels and what they mean
1) Early
- Occur with uterine contraction
- Compression of fetal head increased vagal tone
- Loss of variability with each deceleration
- NO RISK OF FETAL HYPOXIA (benign)
2) Late
- Deceleration occurs AFTER contraction
- Due to decreased placental perfusion leading to fetal compromise**
- GRADUAL decal that happens with each contraction
- Caused by maternal hypotension, hypovolemia, acidosis, and preeclampsia
3) Variable
- No pattern between contraction and FHR
- RAPID drop in FHR
- Variability is maintained during decel
- Often due to compression of cord (causing baroreceptor mediated reduction in FHR)
Three-tier system for evaluation of FHR
Category I
Category II
Category III