Assessment of volume preload on uteroplacental blood flow during epidural anaesthesia for Caesarean section.
OBJECTIVE
Epidural and spinal anaesthesia are the preferred mode of anaesthesia for Caesarean section. Volume preloading is recommended to prevent maternal hypotension and a reduction in uteroplacental blood flow, although positive effects of volume preloading on maternal cardiac output and arterial pressure are debatable. Doppler measurements of the umbilical artery beyond deriving pulsatility indices are not routinely performed.


METHODS
After Institutional Review Board approval and written informed consent, 14 consecutiVe women with epidural anaesthesia for Caesarean section received either hydroxyethyl starch 500 mL or gelatine 500 mL. Haemodynamic variables monitored were maternal arterial pressure, maximal blood flow velocity and pulsatility indices of the uterine artery derived from Doppler measurements.


CONCLUSIONS
Maternal arterial pressure and pulsatility indices in both groups did not change from baseline after intravenous colloid infusion. However, uterine blood flow increased significantly in both groups. The effectiveness of volume preloading may therefore be better described by changes in maximum uterine blood flow velocity than by pulsatility indices or maternal arterial pressure.
Gogarten
W
W
Universitätsklinikum Münster, Department of Anaesthesiology and Intensive Care, Münster, Germany.
Struemper
D
D
Gramke
H F
HF
Van Aken
H
H
Buerkle
H
H
Durieux
M
M
Marcus
M A E
MA
D000328:Adult; D000767:Anesthesia, Epidural / Q000379:methods*; D000773:Anesthesia, Obstetrical / Q000379:methods*; D001783:Blood Flow Velocity / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D001810:Blood Volume / Q000502:physiology*; D002585:Cesarean Section / Q000379:methods*; D005260:Female; D005780:Gelatin / Q000627:therapeutic use; D006801:Humans; D006895:Hydroxyethyl Starch Derivatives / Q000627:therapeutic use; D021041:Placental Circulation / Q000187:drug effects*; D010952:Plasma Substitutes / Q000627:therapeutic use; D011247:Pregnancy; D011673:Pulsatile Flow / Q000187:drug effects; D012039:Regional Blood Flow / Q000187:drug effects; D013997:Time Factors; D018615:Ultrasonography, Doppler, Color / Q000379:methods; D014469:Umbilical Arteries / Q000000981:diagnostic imaging / Q000187:drug effects; D014599:Uterus / Q000098:blood supply* / Q000187:drug effects
D006895:Hydroxyethyl Starch Derivatives; D010952:Plasma Substitutes; D005780:Gelatin