Clinical trial NCT01108874: Up-Down Determination of the ED90 of Metaraminol to Treat Hypotension During Cesarean Section
Official title: Up-Down Determination of the ED90 of Metaraminol to Treat Hypotension During Elective Cesarean Section
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE2
Conditions: Hypotension
Keywords: Cesarean section
Hypotension
Metaraminol
Vasoconstrictor Agents
Adult
Female
Pregnancy
Anesthesia, Obstetrical/adverse effects
Anesthesia,Spinal
Blood Pressure/drug effects
Nausea
Vomiting
Lead sponsor: Federal University of São Paulo
Sponsor class: OTHER
First posted: 2010-04-22
Enrollment: 48
Sex: FEMALE
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: SINGLE_GROUP
Primary purpose: TREATMENT

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.

Eligibility criteria: 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

Primary outcomes:
measure: The ED90 of Metaraminol to treat hypotension in elective cesarean section will be determined.
timeFrame: From spinal induction until delivery (on average 30-60min)
Secondary outcomes:
measure: Maternal Demographics (Age, Height, Weight and Gestational Age)
measure: Incidence of Nausea and Vomiting
timeFrame: From spinal induction until delivery (on average 30-60min)
measure: Time between skin incision and delivery
measure: Time between uterine incision and delivery
measure: Total dose of metaraminol
measure: Number of Participants with Hypertension or Bradycardia as a Measure of Safety and Tolerability
timeFrame: From spinal induction until delivery (on average 30-60min)
measure: Umbilical blood gases
measure: Fetal well-being with Apgar scores
Other outcomes:
Locations:
city: São Paulo
country: Brazil
facility: Hospital São Paulo
Study officials:
affiliation: Disciplina de Anestesiologia, UNIFESP
name: Jefferson Clivatti, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Tanaka M, Balki M, Parkes RK, Carvalho JC. ED95 of phenylephrine to prevent spinal-induced hypotension and/or nausea at elective cesarean delivery. Int J Obstet Anesth. 2009 Apr;18(2):125-30. doi: 10.1016/j.ijoa.2008.09.008. Epub 2009 Jan 21.
citation: Pace NL, Stylianou MP. Advances in and limitations of up-and-down methodology: a precis of clinical use, study design, and dose estimation in anesthesia research. Anesthesiology. 2007 Jul;107(1):144-52. doi: 10.1097/01.anes.0000267514.42592.2a.
citation: Ngan Kee WD, Lau TK, Khaw KS, Lee BB. Comparison of metaraminol and ephedrine infusions for maintaining arterial pressure during spinal anesthesia for elective cesarean section. Anesthesiology. 2001 Aug;95(2):307-13. doi: 10.1097/00000542-200108000-00009.
citation: Ngan Kee WD, Lee A. Multivariate analysis of factors associated with umbilical arterial pH and standard base excess after Caesarean section under spinal anaesthesia. Anaesthesia. 2003 Feb;58(2):125-30. doi: 10.1046/j.1365-2044.2003.02888.x.