PossibleEffects of Major Regional Blockade on Cardiotocographic Patterns.
| Uterine Contractions
|
Mechanism |
| Increased Frequency and intensity |
Analgesia decreases catechol amine leels |
| Decreased Frequency and intensity |
Decreased blood supply to uterus.
?Inhibition of motor nerve supply to uterus
?Direct effect of Local Anaesthetic on smooth muscle |
Fetal heart rate:
beat to beat variability |
|
| Increase |
Acute fetal hypoxia due to placental hypoperfusion |
| Decrease |
Direct effect of local anaesthetic agents.
Chronic hypoxia and acidosis from placental hypoperfusion |
Fetal heart rate:
Long term deceleations |
|
| Early |
Head compression from increased uterine tone. |
| Late |
Placental insufficiency worsened by placental hypoperfusion |
| Variable/td>
| Cord compression aggravated by
maternal hypotension and increased intensity
of uterine contractions. |