Advanced Search

Home > Journals > Minerva Anestesiologica > Past Issues > Minerva Anestesiologica 2006 June;72(6) > Minerva Anestesiologica 2006 June;72(6):543-9



A Journal on Anesthesiology, Resuscitation, Analgesia and Intensive Care

Official Journal of the Italian Society of Anesthesiology, Analgesia, Resuscitation and Intensive Care
Indexed/Abstracted in: Current Contents/Clinical Medicine, EMBASE, PubMed/MEDLINE, Science Citation Index Expanded (SciSearch), Scopus
Impact Factor 2,036

Frequency: Monthly

ISSN 0375-9393

Online ISSN 1827-1596


Minerva Anestesiologica 2006 June;72(6):543-9

SMART 2006 - Milan, May 10-12, 2006 


The ratio between arterio-venous PCO2 difference and arterio-jugular oxygen difference as estimator of critical cerebral hypoperfusion

Zanier E. R. 1, Rossi S. 2, Conte V. 1, Colombo A. 1, Nicolini R. 1, Caironi P. 1, Stocchetti N. 1, Gattinoni L. 1

1 Department of Anesthesiology and Intensive Care Ospedale Maggiore IRCCS University of Milan, Milan, Italy
2 Department of Anesthesiology and Intensive Care Civil Hospital, Vicenza, Italy

Aim. The aim of this study was to evaluate the arterio-venous difference in carbon dioxide tension (DPCO2) and the ratio between DPCO2 and arterio-jugular oxygen difference (AJDO2) as indicators of compensated or uncompensated cerebral hypoperfusion.
Methods. Cerebral blood flow (CBF) was reduced stepwise in 6 pigs by inducing intracranial hypertension with consequently cerebral perfusion pressure (CPP) reduction: CBF 100%, 50-60 % of baseline, 20-30% of baseline. Intracranial pressure (ICP), mean arterial pressure (MAP), CPP and CBF (laser-Doppler method) were continuously recorded. Superior sagittal sinus was punctured for the determination of AJDO2 and DPCO2.
Results. CBF impairment was accompanied by changes in AJDO2 from 6.03±1.21 vol% to 7.32±1.30 vol%, up to 8.07±1.32 vol% (P<0.01), in DPCO2 from 12.17±3.25 mmHg to 16±4.12 mmHg, up to 26.5±6.41 mmHg (P<0.01), and DPCO2/AJDO2 ratio from 2.05±0.39 to 2.06±0.72 up to 3.41±1.09 in the 3 phases (P<0.05).
Conclusion. When CBF declines AJDO2 increases, indicating greater extraction of O2 to satisfy aerobic metabolism. However, this mechanism can no longer compensate once a critical CBF threshold is reached. DPCO2 rises slowly during moderate CBF reduction because of defective washout; the rise is steeper during marked CBF impairment when anaerobic metabolism takes place. During cerebral hypoperfusion the venous blood gases and acid base variables mirror the degree of cerebral perfusion. In particular the DPCO2, and the DPCO2/ AJDO2 ratio may be useful markers of critical brain hypoperfusion.

language: English


top of page