Published in:
01-07-2012 | Original
Transpulmonary thermodilution measurements are not affected by continuous veno-venous hemofiltration at high blood pump flow
Published in: Intensive Care Medicine | Issue 7/2012
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Purpose
To assess whether continuous veno-venous hemofiltration (CVVH) with high blood pump flow alters the measurements of cardiac index (CI), global end-diastolic volume indexed (GEDVI), and extravascular lung water indexed (EVLWI) performed by transpulmonary thermodilution.
Methods
Sixty-nine patients were included if they were monitored by a PiCCO2 device and received CVVH through a femoral (n = 62) or an internal jugular (n = 7) dialysis catheter. The blood pump flow was set at 250 mL/min (n = 31) or 350 mL/min (n = 38) and the filtration flow at 6,000 mL/h. A first set of data was collected with a first transpulmonary thermodilution (TDon). The blood pump was stopped and the continuous CI derived from pulse contour analysis was recorded (PCoff). A second data set (TDoff) was collected before and a last one (TDon-last) after restarting the blood pump.
Results
\( {\text{CI}}_{{{\text{TD}}_{\text{on}} }} \), \( {\text{CI}}_{{{\text{PC}}_{\text{off}} }} \), \( {\text{CI}}_{{{\text{TD}}_{\text{off}} }} \) , and \( {\text{CI}}_{{{\text{TD}}_{{{\text{on}} - {\text{last}}}} }} \) were not significantly different in patients with a femoral dialysis catheter (3.49 ± 0.96, 3.51 ± 0.96, 3.51 ± 0.99, and 3.44 ± 1.00 L min−1 m−2, respectively). This was observed with a blood pump flow at 350 mL/min and at 250 mL/min. In these patients with a femoral dialysis catheter, GEDVI did not significantly change when the blood pump was stopped. EVLWI significantly decreased when the blood pump was stopped but to a non-clinically relevant extent (−0.3 ± 0.8 mL/kg). No significant changes in CI, GEDVI, and EVLWI were observed in patients with an internal jugular dialysis catheter over the study period.
Conclusions
CVVH with a high blood flow pump does not alter the transpulmonary thermodilution measurements of CI, GEDVI, and EVLWI.