Hemodynamic Effect of Left Tilting in Cesarean Delivery

Study Overview
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Brief Summary
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The aim of this work is to investigate the effect of different angles of lateral tilt on the maternal hemodynamics before and after subarachnoid block

Detailed Description
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Aortocaval compression (ACC) by the gravid uterus is a known physiological phenomenon that is classically claimed to cause supine hypotension in full term pregnant women. ACC has been also mentioned as a possible cause of post-spinal hypotension (PSH) in parturients undergoing cesarean section (CS); however, the evidence for the value of left lateral tilting of parturient in improving hemodynamics is not clear. The aim of this work is to investigate the effect of different angles of lateral tilt on the maternal hemodynamics before and after subarachnoid block (SAB). Hemodynamic variables will be taken before SAB in three angles (zero angle, 15 degree angle, and 30 degree angles) of left lateral tilt. Patients will receive normal SAB after prophylactic vasopressor adminstration (either 15 mg ephedrine or 1.5 mcg/Kg phenylephrine intravenous bolus) then hemodynamic variables will measured again after SAB in the same three angles. The sequence of the tilting angles will be randomized. Another measure will be taken after delivery of the fetus. SAB will be done in sitting position under complete asepsis using 25 g spinal needle with crystalloid infusion of 500 mL. SAB will be achieved by intrathecal injection of 10 mg hyperbaric Bupivacaine plus 25ug fentanyl. Success of SAB will be tested within five minutes after drug injection. SAB will be considered successful if adequate block reached T4 dermatome. Cardiac output and stroke volume will be measured using electrical cardiometry device.

Official Title
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Hemodynamic Effect of Three Randomized Angles of Left Tilting After Spinal Anesthesia for Cesarean Delivery

Conditions
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Cesarean Section Complications, Spinal Anesthetic Complications

Intervention / Treatment
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* Other: left lateral tilting in 15 degrees
* Other: left lateral tilting in 30 degrees
* Other: supine position


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: full term parturients scheduled for cesarean delivery Exclusion Criteria: BMI > 35 Kg/m2, polyhydramnios, history of impaired cardiac contractility, valvular heart disease, cardiac arrhythmias, hypertensive pregnancy disorders

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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Design Details

Primary Purpose: Prevention
Intervention Model: Single Group Assignment
Interventional Model Description: The study will investigate the effect of different tilting angles on the hemodynamics of full term pregnants before and after spinal anesthesia
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: left lateral tilting arm<br>all patients will be put in three angles of left lateral tilt in randomized order (supine position - left lateral tilting in 15 degrees - and left lateral tilting in 30 degrees) and the hemodynamic data will be compared in the three angles. | Other: left lateral tilting in 15 degrees<br>* The mother will be placed in left lateral tilted position (15 degrees) using a standard wedge<br>Other: left lateral tilting in 30 degrees<br>* The mother will be placed in left lateral tilted position (30 degrees) using a standard wedge<br>Other: supine position<br>* The mother will be placed in standard supine position<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cardiac output | Cardiac output in liters per minute measured by electrical cardiometry | 30 minutes after spinal anesthesia in different angles of left lateral tilting | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| cardiac output | Cardiac output in liters per minute measured by electrical cardiometry | before spinal anesthesia in different angles of left lateral tilting | 
| mean arterial blood pressure | mean arterial blood pressure measured by non-invasive monitor | before spinal anesthesia in different angles of left lateral tilting | 
| mean arterial blood pressure | mean arterial blood pressure measured by non-invasive monitor | 30 minutes after spinal anesthesia in different angles of left lateral tilting | 
| stroke volume | stroke volume in milliliters measured by electrical cardiometry | before spinal anesthesia in different angles of left lateral tilting | 
| stroke volume | stroke volume in milliliters measured by electrical cardiometry | 30 minutes after spinal anesthesia in different angles of left lateral tilting | 
| systemic vascular resistance | measured in mmHg × min / mL by electrical cardiometry | before spinal anesthesia in different angles of left lateral tilting | 
| systemic vascular resistance | measured in mmHg × min / mL by electrical cardiometry | 30 minutes after spinal anesthesia in different angles of left lateral tilting | 
| heart rate | measured in beat per minute | before spinal anesthesia in different angles of left lateral tilting | 
| heart rate | measured in beat per minute | 30 minutes after spinal anesthesia in different angles of left lateral tilting |