Norepinephrine To Prevent Hypotension After Spinal Anesthesia For Cesarean Delivery: A Dose Finding Study
Status:
Completed
Trial end date:
2016-04-01
Target enrollment:
Participant gender:
Summary
Spinal anesthesia is the most common anesthetic technique for elective Cesarean delivery
(CD), but the most frequent unwanted side effect is hypotension, which can cause nausea and
vomiting, as well as effects on the fetus. Prevention and treatment of maternal hypotension
includes intravenous fluids and vasopressors. Phenylephrine is the most common vasopressor
used for this purpose. However, it has been shown to reduce maternal heart rate and cardiac
output, which may be a concern in an already compromised fetus. Norepinephrine is commonly
used in high concentrations in intensive care and recent studies have suggested that in low
concentrations it may be a better alternative to phenylephrine in elective CD, as it does not
reduce the maternal heart rate or cardiac output. The optimum bolus dose of norepinephrine to
prevent hypotension after spinal anesthesia in elective CD has not been elucidated. The
investigators propose this study to determine the dose that would be effective in 90% of
patients (ED90).
A previous study by Ngan Kee et al, using continuous infusion of norepinephrine to prevent
hypotension in elective CD, suggested a potency ratio for norepinephrine to phenylephrine of
approximately 16:1. Hence, the investigators hypothesise that the ED90 will be approximately
6 µg, given that the current phenylephrine bolus dose at the investigators' institution is
approximately 100 µg.
Phase:
N/A
Details
Lead Sponsor:
Samuel Lunenfeld Research Institute, Mount Sinai Hospital