Hypotension
Conditions
Keywords
Cesarean section, Hypotension, Metaraminol, Vasoconstrictor Agents, Adult, Female, Pregnancy, Anesthesia, Obstetrical/adverse effects, Anesthesia,Spinal, Blood Pressure/drug effects, Nausea, Vomiting
Brief summary
The purpose of this study is to find the best dose of metaraminol to be used in patients during elective cesarean sections.
Detailed description
The purpose of this study is to determine the effective dose 90% (ED90) of metaraminol to treat hypotension after spinal anesthesia in elective cesarean sections (CS). It is a double-blind study that uses the biased-coin up-down sequential allocation method to determine the ED90 of metaraminol. Baseline systolic blood pressure (SBP) will be determined by three automated measures 3 minutes apart just before CS. During the period from induction of spinal anesthesia to fetal delivery SBP will be monitored every minute and metaraminol will be administered every time it is lower than baseline value. If SBP falls below 80% of baseline value, the treatment will be considered a failure. An adequate response will be defined as the absence of hypotension during the study period.
Interventions
DRUGMetaraminol
Patients will be given metaraminol every time SBP falls below baseline value.
Sponsors
Federal University of São Paulo
Study design
Allocation
RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
FEMALE
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* Elective CS under spinal anesthesia * Normal singleton pregnancy beyond 36 weeks gestation * ASA physical status I/II * Age over 18 years
Exclusion criteria
* Patient refusal * Allergy to metaraminol * Preexisting or pregnancy-induced hypertension * Cardiovascular or cerebrovascular disease * Fetal abnormalities
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| The ED90 of Metaraminol to treat hypotension in elective cesarean section will be determined. | From spinal induction until delivery (on average 30-60min) | Bolus doses of metaraminol will be used every time SBP falls below baseline values and maternal responses to doses will be used to build a dose response curve from where ED90 will be estimated. |
Secondary
| Measure | Time frame |
|---|---|
| Incidence of Nausea and Vomiting | From spinal induction until delivery (on average 30-60min) |
| Time between skin incision and delivery | — |
| Time between uterine incision and delivery | — |
| Maternal Demographics (Age, Height, Weight and Gestational Age) | — |
| Number of Participants with Hypertension or Bradycardia as a Measure of Safety and Tolerability | From spinal induction until delivery (on average 30-60min) |
| Umbilical blood gases | — |
| Fetal well-being with Apgar scores | — |
| Total dose of metaraminol | — |
Countries
Brazil
Outcome results
None listed