Effects of Pregnancy on the Physico-chemical Characteristics of Cerebrospinal Acid-base Equilibrium
Overview
- Phase
- Not Applicable
- Intervention
- Not specified
- Conditions
- Acid-Base Imbalance
- Sponsor
- Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico
- Enrollment
- 40
- Locations
- 1
- Primary Endpoint
- Strong Ion Difference
- Last Updated
- 8 years ago
Overview
Brief Summary
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.
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.
Investigators
Eligibility Criteria
Inclusion Criteria
- •Pregnancy with gestational age \> 35 weeks
- •Scheduled elective cesarean section under spinal anesthesia
Exclusion Criteria
- •known respiratory or neurologic disease
- •multiple pregnancies
Outcomes
Primary Outcomes
Strong Ion Difference
Time Frame: 1 day
Strong Ion Difference (expressed in milliequivalents per Liter \[mEq/L\]) of cerebrospinal fluid and arterial plasma
Secondary Outcomes
- Partial pressure of carbon dioxide (PCO2)(1 day)
- Sum of albumin (expressed in mmol/L) and Phosphates (expressed in mmol/L)(1 day)
- Difference between cerebrospinal fluid and arterial plasma Strong Ion Difference (Delta SID)(1 day)
- Difference between cerebrospinal fluid and arterial plasma partial pressure of CO2 (Delta PCO2)(1 day)
- Progesterone levels(1 day)
- Copeptin levels(1 day)