Central venous pressure as an adjunct to flow-guided volume optimisation after induction of general anaesthesia

Background: Although the central venous pressure (CVP) is often used as a guide to volume status in major surgeryand intensive care, fluid therapy should be guided by the response of the stroke volume (SV) to a fluid bolus. Thepresent study evaluates whether the central venous pressure (CVP) can serve as an adjunct to decisions of whetheror not fluid should be infused. Methods: Stroke volume (SV) and stroke volume variation (SVV) was monitored with FloTrac/Vigileo and the CVPwere measured in 80 patients just before general anaesthesia was induced (baseline) and then, before each of threesuccessive bolus infusions of 3 mL kg-1 of 6% hydroxyethyl starch 130/0.4. A patient showed fluid responsiveness andwas denoted a “responder” if SV increased by ≥10% from the bolus infusion. Results: The CVP was higher in non-responders (mean 7.2 mm Hg) than in responders (mean 5.8 mm Hg, P <0.0001). In non-responders but not in responders, the absence or presence of a rise in CVP improved the predictionof whether the patient would show fluid responsiveness during the next fluid bolus. For example, if no rise in CVPoccurred the chance was 48% of subsequent fluid responsiveness, while this chance was only 9% for those who hadan increase in CVP (P < 0.004). There was only a fair concordance between fluid responsiveness as indicated by SVand SVV (Cohen´s kappa 0.28). Conclusions: A low CVP suggests that the patient is lower on the Frank-Starling curve than indicated by SV as measured by FloTrac/Vigileo.Background: Although the central venous pressure (CVP) is often used as a guide to volume status in major surgeryand intensive care, fluid therapy should be guided by the response of the stroke volume (SV) to a fluid bolus. Thepresent study evaluates whether the central venous pressure (CVP) can serve as an adjunct to decisions of whetheror not fluid should be infused. Methods: Stroke volume (SV) and stroke volume variation (SVV) was monitored with FloTrac/Vigileo and the CVPwere measured in 80 patients just before general anaesthesia was induced (baseline) and then, before each of threesuccessive bolus infusions of 3 mL kg-1 of 6% hydroxyethyl starch 130/0.4. A patient showed fluid responsiveness andwas denoted a “responder” if SV increased by ≥10% from the bolus infusion. Results: The CVP was higher in non-responders (mean 7.2 mm Hg) than in responders (mean 5.8 mm Hg, P <0.0001). In non-responders but not in responders, the absence or presence of a rise in CVP improved the predictionof whether the patient would show fluid responsiveness during the next fluid bolus. For example, if no rise in CVPoccurred the chance was 48% of subsequent fluid responsiveness, while this chance was only 9% for those who hadan increase in CVP (P < 0.004). There was only a fair concordance between fluid responsiveness as indicated by SVand SVV (Cohen´s kappa 0.28). Conclusions: A low CVP suggests that the patient is lower on the Frank-Starling curve than indicated by SV as measured by FloTrac/Vigileo