ORIGINAL ARTICLES  ANESTHESIOLOGY Free

Minerva Anestesiologica 2001 September;67(9):629-36

Copyright © 2009 EDIZIONI MINERVA MEDICA

language: English

Alterations in carbon dioxide release during abdominal aortic clamping for aneurysmal or occlusive repair

Vretzakis G., Papadopoulos G. *, Koutsias S. **, Papaziogas B. **, Antoniadou E. ***, Pitoulias G. **, Papadimitriou D. **

From the Department of Anaesthesiology “G. Gennimatas” Hospital, Thessaloniki, Greece *Anesthesiology Clinic University Hospital of Ioannina, Greece **Department of Vascular Surgery 2nd Surgical Clinic of the Aristoteles University of Thessaloniki, Greece ***Intensive Care Unit “G. Gennimatas” Hospital, Thessaloniki, Greece

Background. Application and remov­al of an infra­ren­al aor­tic ­clamp is asso­ciat­ed ­with chang­es in oxy­gen con­sump­tion, espe­cial­ly ­when col­lat­er­al per­fu­sion is lim­it­ed. Carbon diox­ide pro­duc­tion dur­ing abdom­i­nal aor­tic clamp­ing is expect­ed ­also to ­change. The aim of ­this ­study was to eval­u­ate the alter­a­tions of CO2 ­release dur­ing abdom­i­nal aor­tic sur­gery.
Methods. Design: pros­pec­tive ­study. Setting: University Hospital, Greece. Patients: 17 ­patients under­go­ing abdom­i­nal aor­tic aneur­is­mal (AAA) ­repair and 8 ­patients under­go­ing ­repair of aor­toi­liac occlu­sive dis­ease. Interven-­tion: intra­op­er­a­tive ­record or cal­cu­la­tion of PaCO2, PetCO2, ­PECO2, VD, VDalv, and VCO2. Patients ­with aneu­rysms ­were ran­dom­ly divid­ed to ­have con­stant ven­ti­la­tion (­group AA) or mod­i­fied ven­ti­la­tion to pre­serve nor­mo­cap­nia (­group AB) dur­ing clamp­ing. Ventilation was ­kept con­stant in the occlu­sive ­patients ­group (group OD).
Results. Patients ­with AAA ­showed a sig­nif­i­cant ­decrease of VCO2 dur­ing clamp­ing and an ele­va­tion ­after unclamp­ing in ­both ­groups (AA and AB), ­with no dif­fer­ence of sta­tis­ti­cal impor­tance ­between ­them. During clamp­ing, PetCO2/ PaCO2 ­ratio was ­decreased and VDalv was ­increased espe­cial­ly in ­group AA, ­while unclamp­ing pro­duced the oppo­site ­effect. Occlusive ­patients ­showed insig­nif­i­cant alter­a­tions.
Conclusions. Our ­results sug­gest ­that, the cal­cu­lat­ed alveo­lar ­dead ­space is ­only an indi­ca­tor of the ­true V/Q in ­patients ­with AAA, ­because it is strong­ly depen­dent on the CO2 ­load to the ­lungs, ­which is mark­ed­ly ­altered in the ­same peri­od. The mod­ifi­ca­tion of ven­ti­la­tion dur­ing clamp­ing ­based ­only on PetCO2 and not on arte­ri­al sam­pling, ­could pos­sibly ­lead to hyper­car­bia in ­these ­patients.