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

Not Applicable

Completed

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

Brief Summary: 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: 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.

Recruitment & Eligibility

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.

Arm && Interventions

Group	Intervention	Description
Echocardiography	Ultrasound-guided volemic repletion	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.

Primary Outcome Measures

Name	Time	Method
Rate of Arterial Hypotension	30 minute after spinal anesthesia	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.

Secondary Outcome Measures

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