Fluid Volume-hypotension Association in Cesarean Under Neuraxial Anesthesia

Study Overview
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Brief Summary
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Hypotension resulted from neuraxial block is a common problem, of which is a special issue in patients undergoing Cesarean section. A large number of studies and clinical guidelines suggest that fluid loading, pre- or co-anesthesia, is a promising manner in preventing hypotension. However, it is still a controversy because the fact of a relatively increased blood volume in parturients. In addition, although it is effective of fluid management, it's precise relationship between fluid (crystalloid or colloid) volume and the proportion of hypotension in Cesarean patients under neuraxial anesthesia is still unknown. The investigators designed this trial to clarify the accurate relationship between fluid volume in an escalated manner and the occurrence of hypotension analyzed with a non-linear regression, and wanted to present the 50% effective volume (EV50) of fluid including crystalloid and colloid in preventing hypotension in patients undergoing Cesarean section.

Official Title
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Fluid Volume-hypotension Association in Elective Cesarean Section Under Neuraxial Anesthesia

Conditions
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Cesarean Section

Intervention / Treatment
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* Drug: Ringer's Lactate
* Drug: Six percent hydroxyethyl starch


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 21-40 yr First time of delivery ASA status I-II No premature No genetic and infectious diseases Chinese Exclusion Criteria: < 21 yr > 40 yr Subjects with cardiac and pulmonary disorders Dislocation of placenta Pregnant hypertension Allergy to local anesthetics Unwilling to cooperation Need intraoperative administration of vascular active agents With significant delivery side effects With contradictions of neuraxial anesthesia

Ages Eligible for Study
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Minimum Age: 21 Years
Maximum Age: 40 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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Epidural crystalloid<br>Crystalloid (Ringer's Lactate) is given pre-, co- and post-epidural anesthesia in patients undergoing Cesarean section | Drug: Ringer's Lactate<br>* Ringer's Lactate 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 15 ml/kg is given to patients pre-, co- and post-neuraxial blocks<br>* Other names: Lactated Ringer's solution;|
| Active Comparator: Epidural colloid<br>Colloid (6% hydroxyethyl starch) is given pre-, co- and post-epidural anesthesia in patients undergoing Cesarean section | Drug: Six percent hydroxyethyl starch<br>* Six percent hydroxyethyl starch 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 15 ml/kg is given to patients pre-, co- and post-neuraxial blocks<br>* Other names: HES/HAES;|
| Active Comparator: Spinal crystalloid<br>Crystalloid (Ringer's Lactate) is given pre-, co- and post-spinal anesthesia in patients undergoing Cesarean section | Drug: Ringer's Lactate<br>* Ringer's Lactate 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 15 ml/kg is given to patients pre-, co- and post-neuraxial blocks<br>* Other names: Lactated Ringer's solution;|
| Active Comparator: Spinal colloid<br>Colloid (6% hydroxyethyl starch) is given pre-, co- and post-spinal anesthesia in patients undergoing Cesarean section | Drug: Six percent hydroxyethyl starch<br>* Six percent hydroxyethyl starch 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 15 ml/kg is given to patients pre-, co- and post-neuraxial blocks<br>* Other names: HES/HAES;|
| Active Comparator: CSEA crystalloid<br>Crystalloid (Ringer's Lactate) is given pre-, co- and post-CSEA anesthesia in patients undergoing Cesarean section | Drug: Ringer's Lactate<br>* Ringer's Lactate 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 15 ml/kg is given to patients pre-, co- and post-neuraxial blocks<br>* Other names: Lactated Ringer's solution;|
| Active Comparator: CSEA colloid<br>Colloid (6% hydroxyethyl starch) is given pre-, co- and post-CSEA anesthesia in patients undergoing Cesarean section | Drug: Six percent hydroxyethyl starch<br>* Six percent hydroxyethyl starch 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 15 ml/kg is given to patients pre-, co- and post-neuraxial blocks<br>* Other names: HES/HAES;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of hypotension |  | Anesthesia begin (0 min) to 120 min after anesthesia | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Recurrence of hypotension after ephedrine or phenylephrine |  | Anesthesia begin (0 min) to 120 min after anesthesia | 
| Consumption of ephedrine and phenylephrine |  | Anesthesia begin (0 min) to 120 min after anesthesia | 
| Duration of hypotension |  | Anesthesia begin (0 min) to 120 min after anesthesia | 
| Oxygen saturation during hypotension |  | Anesthesia begin (0 min) to 120 min after anesthesia | 
| One-min and 5-min Apgar scores |  | The first and fifth minute after cesarean successful delivery | 
| Low umbilical cord pH (artery < 7.20) |  | At the time of successful delivery (0 min) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Epidural anesthesia, Spinal anesthesia, Combined spinal-epidural anesthesia, Fluid therapy, Crystalloid, Colloid