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



METHODS
prospective study.


METHODS
University Hospital, Greece.


METHODS
17 patients undergoing abdominal aortic aneurismal (AAA) repair and 8 patients undergoing repair of aortoiliac occlusive disease.


METHODS
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.
Vretzakis
G
G
Department of Anaesthesiology, G. Gennimatas Hospital, Thessaloniki, Greece.
Papadopoulos
G
G
Koutsias
S
S
Papaziogas
B
B
Antoniadou
E
E
Pitoulias
G
G
Papadimitriou
D
D
D000368:Aged; D001012:Aorta, Abdominal / Q000601:surgery*; D017544:Aortic Aneurysm, Abdominal / Q000601:surgery*; D001157:Arterial Occlusive Diseases / Q000601:surgery*; D002245:Carbon Dioxide / Q000378:metabolism*; D003250:Constriction; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged
D002245:Carbon Dioxide