Prevention of Maternal Hypotension During Cesarean Section With Norepinephrine Infusion.

Study Overview
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Brief Summary
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This will be a randomized study aiming at investigating the combination of a norepinephrine infusion and colloid preloading versus the combination of a norepinephrine infusion and crystalloid co-loading for the prevention of maternal hypotension during 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. Recently, noradrenaline has been shown to be effective in maintaining blood pressure in obstetric patients. Another technique widely used to prevent hypotension is fluid administration. Current evidence suggests that the combination of fluid administration and vasoconstrictive medications should be the main strategy for prevention and management of hypotension accompanying neuraxial anesthesia procedures during cesarean section. Research is still underway in relation to the most appropriate timing for fluid administration, the most appropriate fluid volume as well as the type of fluid that should be administered. However, preloading of crystalloids seems to be inefficient as a sole strategy, while co-loading of colloids is more effective than co-loading of crystalloids for prevention of hypotension in the parturient. On the other hand, preloading and co-loading of colloids seem to be of equal effectiveness. Literature is rather scarce regarding the comparison of colloid preloading and crystalloid co-loading. The aim of this randomized study will be to investigate the combination of a norepinephrine infusion and colloid preloading versus the combination of a norepinephrine infusion and crystalloid co-loading for the prevention of maternal hypotension during elective cesarean section.

Official Title
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Prevention of Maternal Hypotension During Cesarean Section With Norepinephrine Infusion. Does Time and Type of Administered Fluids Matter?

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

Intervention / Treatment
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* Procedure: norepinephrine infusion and colloid preloading (NOR-COL)
* Procedure: norepinephrine infusion and crystalloid co-loading (NOR-CRYST)


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: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: norepinephrine infusion and colloid preloading (NOR-COL)<br>in parturients allocated to the NOR-COL group, a norepinephrine infusion will be started as soon as spinal anesthesia is initiated. This group will also receive colloid preloading (5 mL/kg) | Procedure: norepinephrine infusion and colloid preloading (NOR-COL)<br>* in parturients allocated to the NOR-COL group, a norepinephrine infusion will be started as soon as spinal anesthesia is initiated. This group will also receive 5 mL/kg of colloid infusion prior to the initiation of spinal anesthesia<br>|
| Active Comparator: norepinephrine infusion and crystalloid co-loading (NOR-CRYS)<br>in parturients allocated to the NOR-CRYST group, a norepinephrine infusion will be started as soon as spinal anesthesia is initiated. This group will also receive crystalloid co-loading (10 mL/kg) | Procedure: norepinephrine infusion and crystalloid co-loading (NOR-CRYST)<br>* in parturients allocated to the NOR-CRYST group, a norepinephrine infusion will be started as soon as spinal anesthesia is initiated. This group will also receive 10 mL/kg of crystalloid infusion simultaneously with the initiation of spinal anesthesia<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 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 | 
| 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 | 
| incidence of bradycardia | any incidence of maternal bradycardia (heart rate<60/min) 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 min | Neonatal Apgar score will be recorded at 1 min 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 min post delivery | 
| Neonatal Apgar score at 5 min | Neonatal Apgar score will be recorded at 5 min 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 min post delivery | 
| neonatal blood gases | fetal cord blood analysis will be performed immediately post-delivery | 1 min post delivery | 
| glucose in neonatal blood | glucose will be measured in the cord blood gas sample taken immediately post-delivery | 1 min post delivery |