Central venous pressure measurements: peripherally inserted catheters versus centrally inserted catheters.

OBJECTIVE

To determine whether central venous pressure measurements taken from a peripherally inserted central catheter (PICC) correlate with those from a centrally inserted central catheter (CICC).

DESIGN

A pilot bench study followed by a prospective, non-blinded, clinical comparison.

SETTING

A 16-bed medical coronary intensive care unit and a 30-bed surgical intensive care unit at a university hospital.

PATIENTS

Seven surgical intensive care unit patients and five medical coronary intensive care unit patients.

INTERVENTIONS

During the bench study, a simple manometer system was set up to test the catheters. During the clinical study, measurements of central venous pressure were recorded from patients who had an indwelling CICC and PICC concomitantly. Positions of the catheter tips in the chest were verified by radiography. Paired central venous pressure measurements were taken from 19-gauge dual-lumen PICCs and from 7-Fr, 16-gauge, 18-gauge, and pulmonary artery catheter CICCs, all with continuous pressure infusion devices.

MEASUREMENTS AND MAIN RESULTS

Bench work showed that PICCs, because of their longer length and narrower lumen, have a higher inherent resistance, which can be overcome with a continuous infusion device. During the clinical study, three to 12 paired, digital, central venous pressure measurements were recorded from each of 12 patients for a total of 77 data pairs. Measurements were recorded at end-expiration. Mean central venous pressure from the CICCs was 11 + 7 mm Hg, and from the PICCs was 12 + 7 mm Hg. PICC pressure versus CICC pressure correlated (r = 0.99) for all data pairs. Analysis by repeated measures showed PICC central venous pressure more than CICC central venous pressure by 1.0 + 3.2 mm Hg (p = 0.02).

CONCLUSIONS

PICCs can be used to measure central venous pressure and to follow trends in a clinical setting when used with a pressure infusion device to overcome the natural resistance of the PICC. Central venous pressure recorded via PICCs is slightly higher, but the difference is clinically insignificant.