Document Detail


ED95 of phenylephrine to prevent spinal-induced hypotension and/or nausea at elective cesarean delivery.
MedLine Citation:
PMID:  19162468     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: The purpose of this trial was to determine the 95% effective dose (ED95) of phenylephrine by intermittent i.v. bolus, to prevent spinal-induced hypotension and/or nausea at elective cesarean delivery. METHODS: The study was conducted in a double-blinded fashion in 50 patients undergoing elective cesarean delivery under spinal anesthesia. The dose of phenylephrine was determined using up-down sequential allocation, modified by a variation of the Narayana rule. Systolic pressure and heart rate were assessed every minute until uterine incision. The first patient was assigned a 40-microg dose, and the dose to subsequent patients varied by 10-microg increments or decrements. An adequate response was defined as absence of hypotension (systolic pressure <80% of baseline) and nausea. The study solution was given immediately after spinal administration, without prior pressure measurement, and thereafter when the systolic pressure was <or=control values. fell below baseline. The ED95 was determined by a logistic model with non-log-transformed doses, using Firth's penalized maximum likelihood method with 95% confidence intervals based on penalized profile likelihood. RESULTS: The ED95 of phenylephrine was estimated as 159 microg (95% confidence interval: 122-371 microg), although the largest dose given in the study was only 120 microg. Hypertension (systolic blood pressure >120% of baseline) was observed in 14 cases, immediately after intrathecal injection and prophylactic phenylephrine administration in all cases. CONCLUSION: The ED95 of phenylephrine, administered as intermittent boluses to prevent pre-delivery spinal-induced hypotension and/or nausea at elective cesarean delivery, is at least 122 microg (lower limit of the confidence interval). The safety of this dose warrants further studies.
Authors:
M Tanaka; M Balki; R K Parkes; J C A Carvalho
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Publication Detail:
Type:  Journal Article; Randomized Controlled Trial     Date:  2009-01-21
Journal Detail:
Title:  International journal of obstetric anesthesia     Volume:  18     ISSN:  1532-3374     ISO Abbreviation:  Int J Obstet Anesth     Publication Date:  2009 Apr 
Date Detail:
Created Date:  2009-03-23     Completed Date:  2009-06-26     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9200430     Medline TA:  Int J Obstet Anesth     Country:  Netherlands    
Other Details:
Languages:  eng     Pagination:  125-30     Citation Subset:  IM    
Affiliation:
Department of Anesthesia and Pain Management, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada.
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MeSH Terms
Descriptor/Qualifier:
Adult
Anesthesia, Obstetrical / adverse effects*
Anesthesia, Spinal / adverse effects*
Blood Pressure / drug effects
Cesarean Section*
Dose-Response Relationship, Drug
Double-Blind Method
Electrocardiography / drug effects
Female
Humans
Hypotension / chemically induced*,  epidemiology,  prevention & control*
Infant, Newborn
Injections, Intravenous
Nausea / chemically induced*,  epidemiology,  prevention & control*
Phenylephrine / administration & dosage*,  therapeutic use*
Pregnancy
Pregnancy Outcome
Vasoconstrictor Agents / administration & dosage*,  therapeutic use*
Vomiting / epidemiology,  prevention & control
Young Adult
Chemical
Reg. No./Substance:
0/Vasoconstrictor Agents; 59-42-7/Phenylephrine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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