Effect of intravenous vasopressor on spread of spinal anaesthesia and fetal acid-base equilibrium

In contrast to its effect on spinal plain levobupivacaine, we did not find rostral spread of spinal hyperbaric bupivacaine to be less with prophylactic phenylephrine than with ephedrine. We observed an unexpectedly high incidence of fetal acidosis with ephedrine and found evidence that longer spinal-delivery intervals increase the risk of fetal acidosis developing with ephedrine, but not phenylephrine.