Prophylactic Norepinephrine Infusion for Spinal Hypotension and Inferior Vena Cava Collapsibility Index

Study Overview
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Brief Summary
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The purpose of this study is to investigate the preventive effect of norepinephrine on post-spinal hypotension and the effect of norepinephrine on inferior vena cava collapsibility index (IVC-CI).

Detailed Description
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Post-spinal hypotension is a frequent complication during spinal anesthesia for cesarean delivery. It affects nearly 50-60% of patients without appropriately treat. Vasopressors has been highly recommended for routine prevention and/or treatment of post-spinal hypotension. Norepinephrine is new vasopressor that has been suggested as a potential alternative to phenylephrine and was recently introduced in obstetric anesthesia because of the minimal cardiac depressant effect. The purpose of this study is to investigate the preventive effect of norepinephrine on post-spinal hypotension and the effect on inferior vena cava collapsibility index (IVC-CI).

Official Title
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Prophylactic Norepinephrine Infusion for Spinal Hypotension and Inferior Vena Cava Collapsibility Index During Cesarean Delivery: a Randomized Double Blinded Controlled Study

Conditions
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Adverse Effect

Intervention / Treatment
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* Drug: normal saline
* Drug: Norepinephrine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18-45 years American Society of Anesthesiologists physical status classification I to II Scheduled for elective cesarean delivery under spinal anesthesia Full-term, singleton, pregnant women Exclusion Criteria: Height of no more than 150 centimeters Body weight greater than 100 kg or BMI greater than 30 Labor analgesia had been performed Contraindication of spinal or epidural anesthesia Eclampsia or chronic hypertension or baseline blood pressure ≥160mmHg Hemoglobin <7g/dl Fetal distress or known abnormal fetal development Severe vascular disease Diabetes mellitus or cardiovascular disease or nervous system disease

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 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: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Normal saline<br>Simultaneous with subarachnoid block, a bolus of normal saline was given followed by normal saline infusion | Drug: normal saline<br>* a bolus of normal saline was given followed by normal saline infusion<br>* Other names: NS;|
| Experimental: Norepinephrine<br>Simultaneous with subarachnoid block, a bolus of norepinephrine was given followed by norepinephrine infusion | Drug: Norepinephrine<br>* a bolus of norepinephrine was given followed by norepinephrine infusion<br>* Other names: Vasopressors;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The incidence of hypotension | SBP decreased to <80% of the baseline value | 1 to 20 minutes after subarachnoid block | 
| Inferior vena cava collapsibility index | CI = (dIVCmax - dIVCmin)/dIVCmax | 5 to 20 minutes after subarachnoid block | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The incidence of nausea and vomiting | Presence of nausea and vomiting in patients after subarachnoid block | 1 to 20 minutes after subarachnoid block | 
| The incidence of bradycardia | Heart rate less than 55 bpm | 1 to 20 minutes after subarachnoid block | 
| Incidence of hypertension | Systolic blood pressure at or above 120% of baseline | 1 to 20 minutes after subarachnoid block | 
| Arterial base excess of fetal vein blood | From umbilical vein blood gases | Immediately after delivery | 
| Pressure of oxygen of fetal vein blood | From umbilical vein blood gases | Immediately after delivery | 
| pH value of fetal vein blood | From umbilical vein blood gases | Immediately after delivery | 
| Number of rescue norepinephrine | a bolus of norepinephrine was given when SBP decreased to <80% of the baseline value | Immediately to 20 minutes after subarachnoid block | 
| APGAR score | A= Appearance P=Pulse G=Grimace A=Attitude R=Respiration | 1min after delivery | 
| APGAR score | A= Appearance P=Pulse G=Grimace A=Attitude R=Respiration | 5min after delivery | 
| APGAR score | A= Appearance P=Pulse G=Grimace A=Attitude R=Respiration | 10min after delivery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Norepinephrine, Hypotension, Inferior Vena Cava Collapsibility Index, Cesarean Delivery