Diastolic Performance and Norepinephrine in Spinal-Induced Hypotension for Cesarean Delivery

Study Overview
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Brief Summary
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Background and rationale: The best agent to prevent spinal-induced hypotension is still uncertain but norepinephrine showed fewer effects on heart rate and cardiac output. In septic patients norepinephrine has been shown to produce an endogenous fluid challenge. Objective: We aim to assess if patients with impaired diastolic function (46% of pregnant women at term) are less able to maintain indexed cardiac output in response to norepinephrine infusion during spinal-induced vasoplegia. We also aim to assess if fetal wellbeing is related to maternal cardiac output during spinal anesthesia for cesarean delivery. Methods: We will assess by echocardiogram the diastolic function before surgery and will then start continuous non-invasive hemodynamic monitoring with a ClearSight® monitor (ClearSight®, Edwards Lifescience, Irvine, CA) and perform a fluid challenge to relate diastolic disfunction with fluid responsiveness. Hemodynamic monitoring will continue throughout the surgery. Norepinephrine infusion will start concomitantly to beginning of spinal anesthesia and will stop 5 minutes after uterotonic medication. Outcome: We aim to assess if patients with diastolic disfunction are less able to maintain cardiac output in response to norepinephrine infusion during spinal anesthesia induced vasoplegia. We also aim to assess if fetal wellbeing is related to maternal cardiac output during spinal anesthesia for cesarean delivery.)

Official Title
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Influence of Diastolic Performance on the Response to Norepinephrine for Prevention of Spinal Anesthesia-Induced Hypotension for Cesarean Delivery and Fetal Wellbeing

Conditions
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Hypotension

Intervention / Treatment
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* Drug: Norepinephrine
* Device: ClearSight®, Edwards Lifescience, Irvine, CA


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Pregnant women between the 36th and the 40th week of gestation undergoing spinal anesthesia for elective caesarian delivery. Exclusion Criteria: age < 18 yo; preeclampsia; eclampsia; atrial fibrillation and sinus tachycardia; cardiovascular diseases; neuromuscular disease; emergent or urgent cesarean delivery; coagulopathies; contraindications to spinal anesthesia.

Ages Eligible for Study
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Minimum Age: 18 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Normal Diastolic Function<br>Diastolic Function within normal values (defined in terms of E wave and A wave velocity and Deceleration Time according to the American Society of Echocardiography and the European Association of Echocardiography) | Drug: Norepinephrine<br>* Norepinephrine is administered as a continuous infusion at 0.05 mcg/kg/min and is kept to maintain systolic blood pressure within 90-120% of baseline during spinal anaesthesia. The infusion is started at the same time cerebrospinal fluid is obtained, immediately before injection of spinal medications, through a small-bore tubing connected directly to the peripheral intravenous catheter. It is stopped 5 minutes<br>Device: ClearSight®, Edwards Lifescience, Irvine, CA<br>* All patients are connected to a ClearSight® monitor (ClearSight®, Edwards Lifescience, Irvine, CA) by an inflatable finger cuff placed on the midphalanx of hand middle or ring finger with no radial artery catheter and its heart reference system (HRS) is zeroed at the level of the patient's midaxillary line. The ClearSight® monitoring is started in the pre-anaesthesia room and calibrated for 5 minutes before recording. The monitoring continues throughout the procedure until patient transfer in the recovery room. All data are anonymously collected on a USB pen for statistical analysis.<br>|
| Impaired Diastolic Function<br>Diastolic Function with pseudonormal pattern or impaired values (defined in terms of E wave and A wave velocity and Deceleration Time according to the American Society of Echocardiography and the European Association of Echocardiography) | Drug: Norepinephrine<br>* Norepinephrine is administered as a continuous infusion at 0.05 mcg/kg/min and is kept to maintain systolic blood pressure within 90-120% of baseline during spinal anaesthesia. The infusion is started at the same time cerebrospinal fluid is obtained, immediately before injection of spinal medications, through a small-bore tubing connected directly to the peripheral intravenous catheter. It is stopped 5 minutes<br>Device: ClearSight®, Edwards Lifescience, Irvine, CA<br>* All patients are connected to a ClearSight® monitor (ClearSight®, Edwards Lifescience, Irvine, CA) by an inflatable finger cuff placed on the midphalanx of hand middle or ring finger with no radial artery catheter and its heart reference system (HRS) is zeroed at the level of the patient's midaxillary line. The ClearSight® monitoring is started in the pre-anaesthesia room and calibrated for 5 minutes before recording. The monitoring continues throughout the procedure until patient transfer in the recovery room. All data are anonymously collected on a USB pen for statistical analysis.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Indexed Cardiac Output | We aim to study if the diastolic performance of the heart measured by transthoracic echocardiography in healthy pregnant women at term undergoing spinal anesthesia for caesarean delivery influences the effects of norepinephrine on indexed cardiac output (CI) measured by non-invasive continuous hemodynamic monitoring. | Baseline/after spinal anesthesia/after delivery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Indexed Stroke Volume | We will correlate diastolic performance measured by transthoracic echocardiography with the response to norepinephrine of indexed stroke volume (SVI) in ml, blood pressure (BP) in mmHg and heart rate (HR) in bpm measured by non-invasive continuous hemodynamic monitoring. | Baseline/after spinal anesthesia/after delivery | 
| Systolic Blood Pressure | We will correlate diastolic performance measured by transthoracic echocardiography with the response to norepinephrine of blood pressure (BP) in mmHg measured by non-invasive continuous hemodynamic monitoring. | Baseline/after spinal anesthesia/after delivery | 
| Heart Rate | We will correlate diastolic performance measured by transthoracic echocardiography with the response to norepinephrine of heart rate (HR) in bpm measured by non-invasive continuous hemodynamic monitoring. | Baseline/after spinal anesthesia/after delivery | 
| Apgar Scores | We ought to correlate the reduction of neonatal Apgar Scores with decreases of indexed cardiac output measured by non-invasive continuous hemodynamic monitoring. | Decreases of Indexed Cardiac Output after spinal anesthesia | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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norepinephrine, Cesarean section, spinal anesthesia