Placental Perfusion Pressure
The driving pressure for blood flow across the placenta, calculated as the difference between maternal arterial pressure and uterine venous pressure.
Full Definition
Placental perfusion pressure represents the pressure gradient that drives maternal blood flow through the intervillous space of the placenta, ensuring adequate oxygen and nutrient delivery to the fetus. It is calculated as maternal mean arterial pressure minus uterine venous pressure (which approximates intraamniotic pressure during contractions). In obstetric anesthesia, maintaining adequate placental perfusion pressure is crucial when administering neuraxial blocks, as maternal hypotension can reduce this pressure gradient and compromise fetal well-being. Anesthesiologists must balance providing effective analgesia while preserving maternal blood pressure and, consequently, placental perfusion pressure through appropriate fluid management, positioning, and vasopressor use when necessary.
Usage
Usage note: Often discussed in context of maternal hypotension and fetal well-being.
In Context
- "Maintenance of adequate placental perfusion pressure was prioritized during epidural top-up administration." — Labor analgesia management
- "The anesthesiologist used phenylephrine to restore placental perfusion pressure after spinal-induced hypotension." — Cesarean delivery record