Can Vena Cava Ultrasound Guided Volume Repletion Prevent Spinal Induced Significant Hypotension in Elective Patients?

Study Overview
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Brief Summary
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Aim of this study is to determine whether Inferior Vena Cava analyzed by trans-thoracic echocardiography is an effective method to guide titrated fluid repletion in non critical patients, in order both to decrease post procedural significant hypotension rate and to avoid unnecessary fluid overload in patients undergoing spinal anesthesia for elective surgical procedures

Detailed Description
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The setting is standard spinal anesthesia and corresponds to our first arm of the study, used as the control sample and statistical reference. During the induction phase, the patient is fitted with non-invasive blood pressure monitoring, three-lead ECG, pulse-oximetry and peripheral intravenous device. Data and vital signs are recorded and an infusion of crystalloid (NaCl 0.9% or Ringer's acetate) is given during the procedure until the beginning of the operation. Total amount of fluid is also recorded before and after the spinal anesthesia. In addition to the current clinical standard, for the second arm of the study, a trans-thoracic echocardiography is performed before spinal anesthesia, with the aim of assessing the patient's volume status; the exam is performed to assess size and collapsing of the Inferior Vena Cava during breathing cycle. According to different pre-established parameters, the patient is defined as fluid-responsive or unresponsive. If the patient is not responsive, investigators proceed to spinal anesthesia; otherwise they proceed to administration of crystalloid bolus (500 ml of NaCl 0.9% or Hartmann's solution). The patient may receive another bolus so as to reach a non-responsive pattern for echocardiographic evaluation.

Official Title
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Can Vena Cava Ultrasound Guided Volume Repletion Prevent Spinal Induced Significant Hypotension in Elective Surgical Patients? A Randomized, Case Control, Prospective Trial.

Conditions
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Fluid Overload, Anesthesia; Adverse Effect, Spinal and Epidural, Regional Anesthesia Morbidity

Intervention / Treatment
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* Device: Ultrasound-guided volemic repletion


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: both sexes grater than 18 year old requiring spinal anesthesia classified according to American Society of Anesthesiology (ASA) level as 1, 2 or 3 Exclusion Criteria: patients required invasive blood pressure monitoring (arterial/pulmonary catheter, thermodilution catheter), patients show signs of pre-procedural hypotension (defined as two measurements of systolic arterial pressure less than 80 mmHg and/or mean arterial pressure less than 60 mmHg), patients unable to give informed consent to language barriers, mental retard or any reduction in own ability to understand or give their informed consent, patient in which is not possible to perform spinal anesthesia for patient's refusal or technical difficulties in sampling, patients with International Normalized Ratio (INR) greater than 1.5 and/or activated Partial Thrombin Time in therapeutic range (more than 1.5 - 2 times the patient's normal values) and/or anti-factor X activity in therapeutic range patients with thrombocytopenia less than 50 G/l.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

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 |
| --- | --- |
| No Intervention: Wild-Type<br>The setting is standard spinal anesthesia and corresponds to our first arm of the study, used as the control sample and statistical reference. During the induction phase, the patient is fitted with non-invasive blood pressure monitoring, three-lead ECG, pulse-oximetry and peripheral intravenous device. Data and vital signs are recorded and an infusion of crystalloid (NaCl 0.9% or Ringer's acetate) is given during the procedure until the beginning of the operation. Total amount of fluid is also recorded before and after the spinal anesthesia. | |
| Experimental: Echocardiography<br>In addition to the current clinical standard, a Trans-Thoracic Echocardiography is performed before spinal anesthesia, with the aim of assessing the patient's volume status; the exam is performed to assess size and collapsing of the Inferior Vena Cava during breathing cycle. According to different pre-established parameters13, the patient is defined as fluid-responsive or unresponsive. If the patient is not responsive, investigators proceed to spinal anesthesia; otherwise they proceed to administration of crystalloid bolus (500 ml of NaCl 0.9% or Hartmann's solution). The patient may receive another bolus so as to reach a non-responsive pattern for echocardiographic evaluation. | Device: Ultrasound-guided volemic repletion<br>* After echocardiography analysis of Inferior Vena Cava, patient is repleted with a pre-established bolus of fluid (500 ml of crystalloid). After this repletion, patient is analyzed till the exam reach signal of non-responsiveness, previously defined as a reduction of Inferior Vena Cava diameter less than 36% from baseline level during normal breath<br>* Other names: IVCUS;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of Arterial Hypotension | To compare rates of arterial hypotension (previously define by international standard) after spinal anesthesia in patients who have undergone volemic optimization according to Trans-thoracic Echocardiography with patients who have been treated according to the current standard on the intention to treat population. | 30 minute after spinal anesthesia | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Total Amount of IV Fluid at the End of the Procedure | To assess if there is a difference between all treatments in the total quantity of fluids amount | 30 minutes after spinal anesthesia | 
| Percentage of Participants Administered Vasoactive Drug | Total amount of vasoactive drug administered for each group; for vasoactive drug we intended the use both of atropine than vascular amine | 30 minutes after spinal anesthesia | 
| Time of Procedures | Time employed to execute all procedure from the start of the study till 30 minutes after the end of the procedure | From time 0 to 30 minutes after spinal anesthesia | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Fluid replacement, Trans-Thoracic Echocardiography, Spinal Anesthesia, Empirical Volemic Repletion