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

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

Study Overview

• Status: Completed
• Conditions: Pregnancy Related
• Intervention / Treatment: Diagnostic test: B-Type natriuretic peptide (BNP) serum values; Device: Pulmonary echography; Other: urine collection

• Study Type: Observational
• Enrollment (Actual): 80

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Female

• 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.

Description

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

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Retrospective

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

pregnancy woman; woman who are submitted to elective Cesarean Section in spinal anesthesia

Diagnostic test: B-Type natriuretic peptide (BNP) serum values; evaluation BNP serum values: pre- Cesarean Section (30 minutes before surgery); post- Cesarean Section (6 hour and 24 hour after surgery); Device: Pulmonary echography; Pulmonary echography: pre- Cesarean Section (30 minutes before surgery); post- Cesarean Section (6 hour and 24 hour after surgery); Other: urine collection; 6 hour and 24 hour urine collection after Cesarean Section

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

Collaborators and Investigators

• Sponsor: University of Udine

Publications and helpful links

General Publications

• 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.
• 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.
• Lapinsky SE. Acute respiratory failure in pregnancy. Obstet Med. 2015 Sep;8(3):126-32. doi: 10.1177/1753495X15589223. Epub 2015 Jun 10.
• 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.
• 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.
• 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.

Study record dates

Study Major Dates

• Study Start (Actual): December 17, 2016
• Primary Completion (Actual): August 8, 2018
• Study Completion (Actual): November 1, 2018

Study Registration Dates

• First Submitted: February 20, 2019
• First Submitted That Met QC Criteria: February 20, 2019
• First Posted (Actual): February 22, 2019

Study Record Updates

• Last Update Posted (Actual): February 22, 2019
• Last Update Submitted That Met QC Criteria: February 20, 2019
• Last Verified: February 1, 2019

More Information

Terms related to this study

• Keywords: Spinal anesthesia; pulmonary echography; B-Type natriuretic peptide
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Natriuretic Agents; Natriuretic Peptide, Brain
• Other Study ID Numbers: BNP and pulmonary echography

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No