Effects of fluid challenge on gastric mucosal PCO2 in septic patients.
OBJECTIVE
To determine the effects of fluid challenge on systemic hemodynamic variables and gastric intramucosal partial pressure of carbon dioxide (PCO(2)) in septic patients.


METHODS
Short-term interventional study.


METHODS
Medical-surgical intensive care unit in a university hospital.


METHODS
Twenty-four adult patients with severe sepsis or septic shock requiring volume replacement. All patients were studied within 24 h of onset of severe sepsis or septic shock.


METHODS
Five hundred milliliters of a 6% hydroxyethyl starch (HES) solution were administered in 30 min.


RESULTS
Complete hemodynamic data, blood samples, and gastric mucosal PCO(2) (automatic gas capnometry) determinations were obtained at baseline and 15 min after the end of fluid infusion. After fluid challenge, cardiac index (CI) increased from 3.8 (range 2.9-4.2) to 4.2 (range 3.1-4.9) l/min m(-2) ( p<0.05). The PCO(2) gap decreased from 9.8 (range 6.9-26.0) to 8.5 (range 6.6-17.4) mm Hg ( p<0.05), but important individual variations were observed. We failed to observe significant relationships between changes in CI and in PCO(2) gap, or between indices of preload (pulmonary artery occluded pressure, right atrial pressure, and pulse pressure variations) and changes in PCO(2) gap. In addition, changes in PCO(2) gap and in (v-a) CO(2) were not related; however, changes in PCO(2) gap were related to baseline PCO(2) gap ( p=0.003), PEEP ( p=0.02), and cumulative doses of vasopressors ( p=0.02).


CONCLUSIONS
The effects of fluid challenge on gastric mucosal PCO(2) are variable and related to baseline PCO(2) gap rather than to systemic variables. In general, rapid volume infusion decreases PCO(2) gap, but this effect is more pronounced in patients with presumably impaired mucosal perfusion.
Silva
Eliézer
E
Department of Intensive Care, Erasme University Hospital, Route de Lennik 808, 1070 Brussels, Belgium.
De Backer
Daniel
D
Creteur
Jacques
J
Vincent
Jean-Louis
JL
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002245:Carbon Dioxide / Q000378:metabolism*; D005260:Female; D005440:Fluid Therapy / Q000379:methods*; D005753:Gastric Mucosa / Q000378:metabolism*; D006801:Humans; D006895:Hydroxyethyl Starch Derivatives / Q000627:therapeutic use; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010313:Partial Pressure; D010952:Plasma Substitutes / Q000627:therapeutic use; D011446:Prospective Studies; D012772:Shock, Septic / Q000628:therapy*; D018746:Systemic Inflammatory Response Syndrome / Q000628:therapy*
D006895:Hydroxyethyl Starch Derivatives; D010952:Plasma Substitutes; D002245:Carbon Dioxide