Changes in Ventilation Inhomogeneity and Respiratory Function Following Elective Caesarean Section Under Regional Anaesthesia

Pregnancy Clinical Trial

— VIRCA  

Official title:

Changes in Ventilation Inhomogeneity and Respiratory Function Following Elective Caesarean Section Under Regional Anaesthesia: a Prospective Observational Study

Clinical Trial Details — Status: Withdrawn

Administrative data

• NCT number: NCT02714556
• Other study ID #: VIRCA-2016
• Status: Withdrawn
• Phase: N/A
• First received: March 1, 2016
• Last updated: October 30, 2016
• Start date: May 2016
• Est. completion date: October 2016

Study information

• Verified date: October 2016
• Source: University Hospital, Geneva
• Contact: n/a
• Is FDA regulated: No
• Health authority: Switzerland: Ethikkommission
• Study type: Observational

Clinical Trial Summary

Pregnancy is associated with physiological changes affecting the cardiorespiratory system as a consequence of an increase in both cardiac output and intra-abdominal pressure. The aim of this prospective observational study is to examine the perioperative changes in ventilation inhomogeneity and respiratory function measured by the non-invasive nitrogen multiple breath washout and forced oscillation techniques.

Description:

Pregnancy is associated with physiological changes affecting the cardiorespiratory system as a consequence of an increase in both cardiac output and intra-abdominal pressure. These alterations lead to a ventilation/perfusion mismatch which is potentiated by a decrease in functional residual capacity (FRC). These effects explain why pregnant women are more prone to the occurrence of hypoxemia, particularly in the third trimester of their pregnancy. The importance of the ventilation inhomogeneity can be estimated from the lung clearance index (LCI) measured by the non-invasive nitrogen multiple breath washout (N2 MBW) technique. Moreover the loss in lung volume is associated with reduction in respiratory system compliance, which can also be assessed non-invasively by the forced oscillation technique (FOT).

To our knowledge, there is no existing data on LCI or FRC using the aforementioned techniques in pregnant women. Furthermore, existing data on respiratory function in pregnant women is largely restricted to spirometric and body plethysmographic measurements taken primarily in the 1970s-1980s. As such, the important roles of lung ventilation inhomogeneity as well as the potential changes following birth after caesarean section have yet to be completely characterised.

Recruitment information / eligibility

• Status: Withdrawn
• Enrollment: 0
• Est. completion date: October 2016
• Est. primary completion date: October 2016
• Accepts healthy volunteers: No
• Gender: Female
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Written informed consent

• Pregnant woman in the third trimester (37-40 weeks gestational age)

• Scheduled for elective caesarean section under regional (spinal or combined spinal-epidural) anaesthesia

Exclusion Criteria:

• Pregnant women outside 37-40 weeks gestational age

• Non-singleton pregnancy

• Previous history of =2 caesarean sections

• History or clinical signs of cardiopulmonary disease in the last 12 months (chronic hypertension, gestational hypertension, preeclampsia, asthma, acute or chronic bronchitis, others)

• Positive current smoking status

• Pre-pregnant body mass index (BMI) >30 kg/m2 (based on booking records)

• Respiratory infection <2 weeks prior to surgery

• Inability to perform the respiratory function tests

Study Design

Observational Model: Cohort, Time Perspective: Prospective

Related Conditions & MeSH terms

• Pregnancy

Intervention

Other:
• Physiologic measures of lung function
Respiratory function tests: Nitrogen multiple breath washout (N2MBW) measured with an ultrasonic flowmeter (Exhalyzer D with ICU insert, Eco Medics, Duernten, Switzerland) Forced oscillation technique (FOT) measured with a tremoFlo device (Thorasys, Montreal, Canada)

Locations

Country	Name	City	State
Switzerland	University Hospitals of Geneva	Geneva

Sponsors (1)

Lead Sponsor	Collaborator
Walid HABRE

Country where clinical trial is conducted

Switzerland, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Perioperative changes in ventilation inhomogeneity (LCI) following delivery by caesarean section	Nitrogen multiple breath washout technique	1-3 days prior to caesarean section until 5 days postoperative	No
Secondary	Alterations in FRC throughout the postpartum period	Nitrogen multiple breath washout technique	1-3 days prior to caesarean section until 5 days postoperative	No
Secondary	Changes in respiratory mechanics: respiratory system compliance (Crs)	Forced oscillation technique	1-3 days prior to caesarean section until 5 days postoperatively	No
Secondary	Changes in respiratory mechanics: airway resistance (Raw)	Forced oscillation technique	1-3 days prior to caesarean section until 5 days postoperatively	No
Secondary	Perioperative respiratory complications	Apnoea/bradypnoea, oxygen desaturation <90%/hypoxemia, hypoventilation/atelectasis, pulmonary embolism, incoercible cough	During caesarean section until 5 days postoperatively	No
Secondary	Perioperative respiratory interventions	Intubation, oxygen therapy, bronchodilator, adrenaline, continuous positive airways pressure (CPAP), respiratory physiotherapy	During caesarean section until 5 days postoperatively	No