Cerebrospinal Acid-base in Pregnant and Non-pregnant Fertile Women

Effects of Pregnancy on the Physico-chemical Characteristics of Cerebrospinal Acid-base Equilibrium

The third trimester of pregnancy is typically characterized by the development of a marked respiratory alkalosis. The possible role of pregnancy-induced variations of cerebrospinal fluid (CSF) acid-base characteristics on the development of hypocapnic alkalosis is still unknown.

Aim of this study is to characterize, according to Stewart's approach, the acid-base equilibrium of CSF and arterial plasma of pregnant women and compare the results with data obtained from fertile, non-pregnant women.

Study Overview

Detailed Description

The reduction in plasma PCO2 correlates with gestational age and was shown to be associated to plasma progesterone concentrations. We hypothesize that pregnancy-related haemodilution, inducing a reduction in CSF Strong Ion Difference (SID), might have a role in the development of pregnancy-related hypocapnic alkalosis.

Samples of CSF and arterial plasma of pregnant women with gestational age > 35 weeks undergoing spinal anesthesia for elective caesarean section will be analyzed for blood gases, pH, electrolytes, osmolality, albumin and haemoglobin concentration. In addition plasma copeptin levels will be analyzed. The same measurements will be performed in fertile, non-pregnant women undergoing spinal anesthesia for elective surgery.

Study Type

Observational

Enrollment (Anticipated)

40

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

      • Milan, Italy
        • Recruiting
        • Fondazione Irccs Ca' Granda Ospedale Maggiore Policlinico
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

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

Women undergoing spinal anesthesia either for elective cesarean section of for elective surgery.

Description

Inclusion Criteria:

  • Pregnancy with gestational age > 35 weeks
  • Scheduled elective cesarean section under spinal anesthesia

Exclusion Criteria:

  • known respiratory or neurologic disease
  • multiple pregnancies

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Pregnant Women
Pregnant women with gestational age > 35 weeks undergoing spinal anesthesia for elective cesarean section.
Samples of cerebrospinal fluid and arterial blood will be collected anaerobically to measure acid-base variables, electrolytes, albumin, progesterone and copeptin levels
Control Group
Fertile, non-pregnant women undergoing spinal anesthesia for elective surgery.
Samples of cerebrospinal fluid and arterial blood will be collected anaerobically to measure acid-base variables, electrolytes, albumin, progesterone and copeptin levels

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Strong Ion Difference
Time Frame: 1 day
Strong Ion Difference (expressed in milliequivalents per Liter [mEq/L]) of cerebrospinal fluid and arterial plasma
1 day

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Partial pressure of carbon dioxide (PCO2)
Time Frame: 1 day
PCO2 (expressed in millimeters of Mercury [mmHg]) of cerebrospinal fluid and arterial plasma
1 day
Sum of albumin (expressed in mmol/L) and Phosphates (expressed in mmol/L)
Time Frame: 1 day
The total amount of weak non carbonic acids, i.e. the sum of albumin and phosphates (both expressed in mmol/L) of cerebrospinal fluid and arterial plasma
1 day
Difference between cerebrospinal fluid and arterial plasma Strong Ion Difference (Delta SID)
Time Frame: 1 day
The difference between plasma and cerebrospinal fluid SID (expressed in mEq/L) will be calculated as marker of electrolyte inbalance between these two extracellular fluid compartments. Delta SID = SIDcsf - SIDplasma
1 day
Difference between cerebrospinal fluid and arterial plasma partial pressure of CO2 (Delta PCO2)
Time Frame: 1 day
The difference between cerebrospinal fluid and arterial plasma PCO2 (expressed in mmHg) will be calculated as a marker of acid-base equilibrium between these two extracellular fluid compartments. Delta PCO2 = SIDplasma - SIDcsf
1 day
Progesterone levels
Time Frame: 1 day
Plasma and CSF Progesterone levels (expressed in ng/mL) will be measured
1 day
Copeptin levels
Time Frame: 1 day
Plasma copeptin levels (expressed in pmol/L) will be measured as a marker of antidiuretic hormone activity
1 day

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
SID PCO2 correlation
Time Frame: 1 day
Correlation between CSF SID and PCO2
1 day
Osmolality PCO2 correlation
Time Frame: 1 day
Correlation between CSF osmolality and PCO2
1 day
Plasma progesterone PCO2 correlation
Time Frame: 1 day
Correlation between plasma progesterone concentration and plasma PCO2
1 day
CSF progesterone PCO2 correlation
Time Frame: 1 day
Correlation between CSF progesterone concentration and CSF PCO2
1 day

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Collaborators

Investigators

  • Principal Investigator: Thomas Langer, MD, University of Milan
  • Study Director: Antonio Pesenti, MD, University of Milan
  • Study Chair: Giorgio Giudici, MD, University of Milan
  • Study Chair: Mariateresa Ambrosini, MD, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico di Milano

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (ACTUAL)

April 13, 2018

Primary Completion (ANTICIPATED)

April 1, 2019

Study Completion (ANTICIPATED)

April 1, 2019

Study Registration Dates

First Submitted

March 29, 2018

First Submitted That Met QC Criteria

April 5, 2018

First Posted (ACTUAL)

April 12, 2018

Study Record Updates

Last Update Posted (ACTUAL)

April 17, 2018

Last Update Submitted That Met QC Criteria

April 16, 2018

Last Verified

April 1, 2018

More Information

Terms related to this study

Other Study ID Numbers

  • CSF acid-base in pregnancy

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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