Hypotension, Spinal Anesthesia
Conditions
Keywords
phenylephrine, norepinephrine, cesarean delivery under spinal anesthesia
Brief summary
This study evaluate the ability of phenylephrine and of noradrenaline to maintain normal systemic arterial blood pressure and heart rate in healthy pregnant women submitted to cesarean section with spinal anesthesia. Half of participants will receive bolus of phenylephrine while the other half will receive bolus of noradrenaline.
Detailed description
This is a prospective, randomized, double-blind, comparative two-group clinical study to observe two vasopressor drugs, phenylephrine and noradrenaline, in the ability to maintain systemic arterial pressure in pregnant women after spinal anesthesia for cesarean section; based on the hypothesis that, since noradrenaline has a predominant alpha-adrenergic action and a weak 1- beta-adrenergic beta action, it could be as capable of maintaining blood pressure effectively as phenylephrine, but with a lower frequency of bradycardia; patients who meet the inclusion criteria will be randomly assigned to one of the groups to be studied: group F - phenylephrine at a dose of 100mcg bolus and N - noradrenaline at the dose of 5mcg. One of these drugs will be used whenever systolic blood pressure drops below 10% of the baseline, additional doses will be allowed whenever necessary, aiming at maintaining the systolic blood pressure at baseline values; the blood pressure will be measured non-invasively and the heart rate by pulse oximeter and electrocardiogram.
Interventions
DRUGPhenylephrine 100 mcg
Phenylephrine at a dose of 100 mcg bolus at a dilution containing 20 mcg / mL of the drug, 5 mL each bolus
Norepinephrine at a dose of 5 mcg at dilution containing 1 mcg / mL, 5 mL each bolus
Sponsors
Hospital dos Servidores do Estado do Rio de Janeiro
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Caregiver, Investigator)
Intervention model description
In a randomized, double-blinded study, 76 healthy patients having cesarean delivery under spinal anesthesia will be randomized, using an electronic system (the Randomizer App®, Version 3.2 Wisse Keizer program), to have systolic blood pressure maintained with bolus of phenylephrine at a dose of 100 mcg bolus (at a dilution containing 20 mcg / mL), or with norepinephrine at a dose of 5 mcg (at a dilution containing 1 mcg / mL).
Eligibility
Sex/Gender
FEMALE
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* Pregnant women, with single gestation, with cesarean programming to be performed under spinal anesthesia; * Age above 18 years; * Physical State American Society of Anesthesiologists (ASA) II and III; * Weight between 50kg and 120kg; * Height between 140cm and 180cm.
Exclusion criteria
* Refusal to participate in the study; * Pregnant women with fetus with known abnormalities; * Pregnant women with cardiovascular disease; * Pregnant women with pregnancy-specific hypertensive disease; * Allergy to any medication to be used in the study; * Users of monoamine oxidase inhibitors; * Users of tricyclic antidepressants; * Emergency caesarean section due to acute fetal distress; * Situations in which the sensory level after single intrathecal injection of the local anesthetic does not reach at least T6 within 5 minutes after spinal anesthesia.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Number of bolus required | during the procedure | Number of bolus doses of phenylephrine and noradrenaline to maintain systemic arterial pressure at 90% of baseline in pregnant women undergoing spinal anesthesia for cesarean |
| Heart rate | during the procedure | Number of episodes of heart rate under 60 bpm while using phenylephrine and noradrenaline in pregnant women undergoing spinal anesthesia for cesarean |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Neonatal gasometric outcome | during the procedure | To evaluate the neonatal outcome through the analysis of venous and arterial blood gases collected in the cord umbilical after birth. |
| Neonatal Apgar outcome | during the procedure | To evaluate the neonatal outcome through the classification given by the neonatologist responsible for the care to the newborn in the delivery room with the use of the Apgar Scale (0-10), 10 the better classification. |
| Nausea and vomiting | during the procedure | To evaluate the incidence of nausea and vomiting of the parturient during cesarean section |
Countries
Brazil
Outcome results
None listed