Pulmonary Echography and BNP Value Pre- and Post- Elective Cesarean Section in Spinal Anesthesia

Study Overview
=================
Brief Summary
-----------------
Pregnancy is characterized by many biohumoral changes: circulation, respiratory mechanics, oncotic pressure, vascular permeability and many other systems are affected. Vascular permeability is controlled by endothelial glycocalyx. Several factors such as sepsis, ischemia / reperfusion, inflammatory mediators, trauma, surgery including the Cesarean Section and fluid overload can increase vascular permeability due to a glycocalyx damage. During Cesarean Section under subarachnoid anesthesia, hypotension may occur. It is a common side effect caused by reduced preload due to aortocaval compression by the uterus. Furthermore, subarachnoid anesthesia causes block of the sympathetic preganglionic fibers which is associated with vasodilation. These changes often require the use of vasopressors and fluids. A fluid overload associated with the physiological and pathological factors discussed earlier might cause an increased risk of pulmonary edema and acute respiratory failure (IRA) in women undergoing cesarean section under arachnoid anesthesia. IRA occurs in less than 0.2% of total pregnancies but it is one of the most common cause of admission to intensive care unit in pregnant women. Among the causes that can lead to IRA in the last trimester of pregnancy we find pneumopathies such as asthma, pulmonary embolism due to amniotic fluid and pulmonary edema related to severe preeclampsia. Diagnosis of pulmonary edema can be clinical or sub-clinical through laboratory tests such as BNP (b-type natriuretic peptide). It might also be necessary to execute instrumental examinations such as chest radiography (contraindicated in pregnancy) or trans-thoracic ultrasound. Hypothesis: correlation between subarachnoid anesthesia, fluidic therapy and BNP values and ultrasound pattern

Official Title
-----------------
Pulmonary Echography and BNP Value Pre- and Post- Elective Cesarean Section in Spinal Anesthesia

Conditions
-----------------
Pregnancy Related

Intervention / Treatment
-----------------
* Diagnostic Test: B-Type natriuretic peptide (BNP) serum values
* Device: Pulmonary echography
* Other: urine collection


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: woman submit elective Cesarean Section: age > 18 years American Society of Anesthesiologists (ASA) physical status classification system > 2 > 37 gestational age arterial pressure >/ = 140/90 mmHg and proteinuria < 300 mmHg during anesthesia pre-examination no known cardiovascular/respiratory disease pre-partum pulmonary echography Exclusion Criteria: age < 18 years pulmonary echographic windows not satisfying blood loss during Cesarean Section more than 1000 mL and/or necessity to administer colloid postpartum hemorrhage within the first 24 hours following childbirth pre-eclamptic sign/symptoms within the first 5 days following childbirth twin pregnancy

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
Female

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| pregnancy woman<br>woman who are submitted to elective Cesarean Section in spinal anesthesia | Diagnostic Test: B-Type natriuretic peptide (BNP) serum values<br>* evaluation BNP serum values: pre- Cesarean Section (30 minutes before surgery) post- Cesarean Section (6 hour and 24 hour after surgery)<br>Device: Pulmonary echography<br>* Pulmonary echography: pre- Cesarean Section (30 minutes before surgery) post- Cesarean Section (6 hour and 24 hour after surgery)<br>Other: urine collection<br>* 6 hour and 24 hour urine collection after Cesarean Section<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Ultrasound pulmonary variations | The main goal of our study is to evaluate, preoperatively, the incidence of ultrasound pulmonary variations in pregnant women attending elective Cesarean Section | pulmonary echography is made 30 minutes before Cesarean Section, 6 and 24 hours after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| subclinical pulmonary echography variation | Evaluating the incidence of subclinical variations in ecographic lung characteristics at 6 and 24 hours after Cesarean Section | pulmonary echography is made 30 minutes before Cesarean Section, 6 and 24 hours after surgery | 
| B-type natriuretic peptide serum value variation | Finding if there is any correlation between preoperative b-type natriuretic peptide and ecographic lung characteristics in pregnants, before and 24 hours after Cesarean Section | B-type natriuretic peptide serum level is sampled 30 minutes before Cesarean Section, 6 and 24 hours after surgery 30 minutes before Cesarean Section, 6 and 24 hours after surgery | 
| fluid administration and pulmonary echography variation | Finding if there is any correlation between intraoperative fluids administered and ecographic lung characteristics | pulmonary echography is made 30 minutes before Cesarean Section, 6 and 24 hours after surgery | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
pulmonary echography, B-Type natriuretic peptide, Spinal anesthesia