Dataset Information

Cerebrospinal fluid and arterial acid-base equilibria in spontaneously breathing third-trimester pregnant women.

ABSTRACT:

Background

Acid-base status in full-term pregnant women is characterised by hypocapnic alkalosis. Whether this respiratory alkalosis is primary or consequent to changes in CSF electrolytes is not clear.

Methods

We enrolled third-trimester pregnant women (pregnant group) and healthy, non-pregnant women of childbearing age (controls) undergoing spinal anaesthesia for Caesarean delivery and elective surgery, respectively. Electrolytes, strong ion difference (SID), partial pressure of carbon dioxide ( [Formula: see text] ), and pH were measured in simultaneously collected CSF and arterial blood samples.

Results

All pregnant women (20) were hypocapnic, whilst only four (30%) of the controls (13) had an arterial [Formula: see text] <4.7 kPa (P<0.001). The incidence of hypocapnic alkalosis was higher in the pregnant group (65% vs 8%; P=0.001). The CSF-to-plasma Pco₂ difference was significantly higher in pregnant women (1.5 [0.3] vs 1.0 [0.4] kPa; P<0.001), mainly because of a decrease in arterial Pco₂ (3.9 [0.3] vs 4.9 [0.5] kPa; P<0.001). Similarly, the CSF-to-plasma difference in SID was less negative in pregnant women (-7.8 [1.4] vs -11.4 [2.3] mM; P<0.001), mainly because of a decreased arterial SID (31.5 [1.2] vs 36.1 [1.9] mM; P<0.001). The major determinant of the reduced plasma SID of pregnant women was a relative increase in plasma chloride compared with sodium.

Conclusions

Primary hypocapnic alkalosis characterises third-trimester pregnant women leading to chronic acid-base adaptations of CSF and plasma. The compensatory SID reduction, mainly sustained by an increase in chloride concentration, is more pronounced in plasma than in CSF, as the decrease in Pco₂ is more marked in this compartment.

Clinical trial registration

NCT03496311.

SUBMITTER: Zadek F

PROVIDER: S-EPMC9642833 | biostudies-literature | 2022 Nov

REPOSITORIES: biostudies-literature

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Publications

Cerebrospinal fluid and arterial acid-base equilibria in spontaneously breathing third-trimester pregnant women.

Zadek Francesco F Giudici Giorgio G Ferraris Fusarini Chiara C Ambrosini Maria T MT di Modugno Adriana A Scaravilli Vittorio V Zanella Alberto A Fumagalli Roberto R Stocchetti Nino N Calderini Edoardo E Langer Thomas T

British journal of anaesthesia 20220910 5

<h4>Background</h4>Acid-base status in full-term pregnant women is characterised by hypocapnic alkalosis. Whether this respiratory alkalosis is primary or consequent to changes in CSF electrolytes is not clear.<h4>Methods</h4>We enrolled third-trimester pregnant women (pregnant group) and healthy, non-pregnant women of childbearing age (controls) undergoing spinal anaesthesia for Caesarean delivery and elective surgery, respectively. Electrolytes, strong ion difference (SID), partial pressure of ...[more]

PMID: 36096944

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Dataset Information

Cerebrospinal fluid and arterial acid-base equilibria in spontaneously breathing third-trimester pregnant women.

Background

Methods

Results

Conclusions

Clinical trial registration

Publications

Cerebrospinal fluid and arterial acid-base equilibria in spontaneously breathing third-trimester pregnant women.

Similar Datasets

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