Colloid Co-hydration and Vasoconstrictor Infusion for Prevention of Hypotension During Cesarean Section

Study Overview
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Brief Summary
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This will be a double-blind randomized study, aiming at investigating a fixed rate phenylephrine infusion versus a fixed rate norepinephrine infusion versus placebo in combination with co-hydration with colloids for the prevention of maternal hypotension in elective cesarean section

Detailed Description
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Neuraxial techniques are the anesthetic techniques of choice in contemporary obstetric anesthesia practice, with a definitive superiority as compared to general anesthesia, since, by their use, serious complications involving the airway can be avoided.Spinal anesthesia has become the favorable technique for both elective and emergency cesarean section due to a quick and predictable onset of action, however, it can be frequently complicated by hypotension, with incidence exceeding 80% occasionally. The aim of the current randomized controlled double-blinded trial was to compare the effect of a fixed-rate norepinephrine infusion versus a fixed-rate phenylephrine infusion versus placebo in parturients subjected to elective cesarean section under combined spinal-epidural anesthesia. All parturients will also receive colloid co-hydration.

Official Title
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Colloid Co-hydration and Vasoconstrictor Infusion for Prevention of Postspinal Hypotension During Elective Cesarean Section. A Comparative Study

Conditions
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Hypotension Symptomatic, Vasoconstriction, Cesarean Section Complications, Obstetric Anesthesia Problems

Intervention / Treatment
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* Other: phenylephrine infusion
* Other: norepinephrine infusion
* Other: placebo infusion


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: adult parturients, American Society of Anesthesiologists (ASA) I-II, singleton gestation>37 weeks elective cesarean section Exclusion Criteria: Body Mass Index (BMI) >40 kg/m2 Body weight <50 kg Body weight>100 kg height<150 cm height>180 cm multiple gestation fetal abnormality fetal distress active labor cardiac disease pregnancy-induced hypertension thrombocytopenia coagulation abnormalities use of antihypertensive medication during pregnancy communication or language barriers lack of informed consent contraindication for regional anesthesia

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 48 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: phenylephrine infusion<br>fixed-rate phenylephrine infusion | Other: phenylephrine infusion<br>* in parturients allocated to the phenylephrine group, a phenylephrine infusion will be started as soon as spinal anesthesia is initiated<br>* Other names: medication used for blood pressure maintenance;|
| Active Comparator: norepinephrine infusion<br>fixed-rate norepinephrine infusion | Other: norepinephrine infusion<br>* in parturients allocated to the norepinephrine group, a norepinephrine infusion will be started as soon as spinal anesthesia is initiated<br>* Other names: medication used for blood pressure maintenance;|
| Placebo Comparator: placebo infusion<br>normal saline infusion | Other: placebo infusion<br>* in parturients allocated to the placebo group, a normal saline infusion will be started as soon as spinal anesthesia is initiated<br>* Other names: medication used for blood pressure maintenance;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| incidence of bradycardia | any incidence of maternal bradycardia (heart rate<60/min) will be recorded | intraoperative | 
| incidence of hypotension | any occurence of hypotension (systolic blood pressure<80% of baseline) throughout the operation will be recorded | intraoperative | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| need for vasoconstrictor | any need for vasoconstrictor during the operation will be recorded | intraoperative | 
| type of vasoconstrictor administered | phenylephrine versus ephedrine | intraoperative | 
| number of bolus doses of vasoconstrictor administered | number of interventions to maintain systolic blood pressure within the set limits will be recorded | intraoperative | 
| total dose of vasoconstrictor administered | total dose in mg for ephedrine or μg for phenylephrine administered | intraoperative | 
| incidence of hypertension | any incidence of systolic blood pressure>120% of baseline will be recorded | intraoperative | 
| need for atropine | any need for atropine during the operation because of bradycardia will be recorded | intraoperative | 
| modification or cessation of the infusion | any requirement for modification or cessation of the infusion due to reactive hypertension or bradycardia will be recorded | intraoperative | 
| incidence of nausea/vomiting | any occurence of nausea and/or vomiting during the operation will be recorded | intraoperative | 
| Neonatal Apgar score at 1 minutes | Neonatal Apgar score will be recorded at 1 minutes after delivery. The Apgar score is determined by evaluating the newborn baby on five simple criteria on a scale from zero to two, then summing up the five values thus obtained. The resulting Apgar score ranges from zero to 10. Scores 7 and above are generally normal; 4 to 6, fairly low; and 3 and below are generally regarded as critically low and cause for immediate resuscitative efforts. | 1 minute post delivery | 
| Neonatal Apgar score at 5 minutes | Neonatal Apgar score will be recorded at 5 minutes after delivery. The Apgar score is determined by evaluating the newborn baby on five simple criteria on a scale from zero to two, then summing up the five values thus obtained. The resulting Apgar score ranges from zero to 10. Scores 7 and above are generally normal; 4 to 6, fairly low; and 3 and below are generally regarded as critically low and cause for immediate resuscitative efforts. | 5 minutes post delivery | 
| neonatal blood gases | fetal cord blood analysis will be performed immediately post-delivery | 1 minute post delivery | 
| glucose in neonatal blood | glucose will be measured in the cord blood gas sample taken immediately post-delivery | 1 minute post delivery | 
| adrenaline in neonatal blood | an amount of the umbilical artery cord blood sampled from every neonate will be sent for lab measurements | 5 minutes post delivery | 
| noradrenaline in neonatal blood | an amount of the umbilical artery cord blood sampled from every neonate will be sent for lab measurements | 5 minutes post delivery |