Clinical trial NCT03851679: Pulmonary Echography and BNP Value Pre- and Post- Elective Cesarean Section in Spinal Anesthesia
Official title: Pulmonary Echography and BNP Value Pre- and Post- Elective Cesarean Section in Spinal Anesthesia
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Pregnancy Related
Keywords: pulmonary echography
B-Type natriuretic peptide
Spinal anesthesia
Lead sponsor: University of Udine
Sponsor class: OTHER
First posted: 2019-02-22
Enrollment: 80
Sex: FEMALE
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: RETROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Patients' anthropometric data were collected, data related to the anesthetic technique, pharmacological and intraoperative fluid therapy, sensory level reached after subarachnoid anesthesia, sensory level and motor blockade at discharge from the operating room. We also collected BNP serum values and pulmonary ultrasound images at 6 and 24 h after the intervention. Diuresis collection at 6 and 24 h after the intervention was registered as well as water balance.

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


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

Primary outcomes:
measure: Ultrasound pulmonary variations
timeFrame: pulmonary echography is made 30 minutes before Cesarean Section, 6 and 24 hours after surgery
Secondary outcomes:
measure: subclinical pulmonary echography variation
timeFrame: pulmonary echography is made 30 minutes before Cesarean Section, 6 and 24 hours after surgery
measure: B-type natriuretic peptide serum value variation
timeFrame: 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
measure: fluid administration and pulmonary echography variation
timeFrame: pulmonary echography is made 30 minutes before Cesarean Section, 6 and 24 hours after surgery
Other outcomes:
Locations:
Study officials:
References:
citation: Bamfo JE, Kametas NA, Nicolaides KH, Chambers JB. Maternal left ventricular diastolic and systolic long-axis function during normal pregnancy. Eur J Echocardiogr. 2007 Oct;8(5):360-8. doi: 10.1016/j.euje.2006.12.004. Epub 2007 Feb 23.
citation: Campos O, Andrade JL, Bocanegra J, Ambrose JA, Carvalho AC, Harada K, Martinez EE. Physiologic multivalvular regurgitation during pregnancy: a longitudinal Doppler echocardiographic study. Int J Cardiol. 1993 Jul 15;40(3):265-72. doi: 10.1016/0167-5273(93)90010-e.
citation: Lapinsky SE. Acute respiratory failure in pregnancy. Obstet Med. 2015 Sep;8(3):126-32. doi: 10.1177/1753495X15589223. Epub 2015 Jun 10.
citation: Pereira A, Krieger BP. Pulmonary complications of pregnancy. Clin Chest Med. 2004 Jun;25(2):299-310. doi: 10.1016/j.ccm.2004.01.010.
citation: Chappell D, Jacob M, Hofmann-Kiefer K, Conzen P, Rehm M. A rational approach to perioperative fluid management. Anesthesiology. 2008 Oct;109(4):723-40. doi: 10.1097/ALN.0b013e3181863117.
citation: Resnik JL, Hong C, Resnik R, Kazanegra R, Beede J, Bhalla V, Maisel A. Evaluation of B-type natriuretic peptide (BNP) levels in normal and preeclamptic women. Am J Obstet Gynecol. 2005 Aug;193(2):450-4. doi: 10.1016/j.ajog.2004.12.006.