Accuracy of totally implanted ports, tunnelled, single- and multiple-lumen central venous catheters for measurement of central venous pressure.

OBJECTIVE

To verify the accuracy of totally implanted ports, tunnelled central venous catheters (CVC), widely used in cancer patients, and multi-lumen catheters, used in intensive care units (ICUs), in measuring central venous pressure (CVP), using right atrial pressure (RAP) measured in a Swan-Ganz catheter as the reference standard.

DESIGN

A prospective study, over a 10-month period.

SETTING

A medical-surgical ICU in a comprehensive cancer centre.

PATIENTS AND PARTICIPANTS

Patients who had both (1) a Swan-Ganz catheter and (2) either a tunnelled catheter, a single or a multi-lumen catheter, or a totally implanted port.

INTERVENTIONS

RAP and CVP were measured simultaneously in each patient.

MEASUREMENTS AND RESULTS

Fifty-six pairs of RAP-CVP measurements were performed in 35 patients: 6 tunnelled catheters, 6 non-tunnelled single-lumen catheters, 26 multiple-lumen catheters and 18 totally implanted ports were studied. RAP measured in the Swan-Ganz catheter and CVP measured in the CVC were strongly correlated (r = 0.94, p < 0.01), whatever the type of catheter studied. The mean difference between RAP and CVP was -0.39 +/- 1.73 (SD) mmHg. In 51 cases (91%), the difference was within the limits of agreement (-3.78 to 3.00 mmHg, Bland and Altman method). For the five cases with a difference of 4 mmHg (three totally implanted ports, one double- and one triple-lumen catheter), CVP was greater than RAP.

CONCLUSIONS

CVP can be accurately measured in totally implanted ports, tunnelled or non-tunnelled single-lumen and multiple-lumen catheters. When the difference exceeds the limit of agreement, the discrepancy between the two measurements has limited significance in most cases.