Prophylactic Phenylephrine Infusion for Preventing Hypotension During Spinal Anesthesia
Status:
Completed
Trial end date:
2013-09-01
Target enrollment:
Participant gender:
Summary
Lower limb orthopedic surgery is commonly realized under spinal anesthesia. This
loco-regional anesthesia induces a peripheral vascular resistance decrease by vasodilatation
resulting in hypotension. A severe and prolonged hypotension can compromise regional
perfusion and worse outcome especially in very elderly patients. Moreover the venous
vasodilatation observed after spinal anesthesia decreases cardiac preload resulting in a
cardiac output decrease. Several authors had identified the prevention of hypotension as a
key role during spinal anesthesia although none prophylactic treatment has been identified.
Spinal anesthesia single injection (SA) with low dose of local anesthetic or continuous
spinal anesthesia with very low dose bolus injections cause fewer episodes of hypotension.
Despite these techniques, hypotension can occur. Phenylephrine is an alpha adrenergic agonist
and cause vasoconstriction preventing hypotension. Prophylactic phenylephrine infusion for
preventing hypotension has been demonstrated during spinal anesthesia for cesarean delivery.
The investigators want to assess for the first time the prophylactic phenylephrine infusion
for preventing hypotension in elderly patients undergoing orthopedic lower limb surgery under
spinal anesthesia single injection.