Lack of agreement between central venous pressure and pulmonary capillary wedge pressure in preeclampsia.

OBJECTIVE

To establish if agreement exists between central venous pressure (CVP) and pulmonary capillary wedge pressure (PCWP) measurements in severe hypertension in pregnancy as analyzed by tests of bias, precision, and 95% limits of agreement.

METHODS

In a prospective study, CVP and PCWP data in 30 patients were collected by means of a pulmonary artery catheter from initiation of therapy until delivery. Patients with a diastolic blood pressure of more than 110 mm Hg were included. Correlation and agreement between CVP and PCWP before and after treatment were evaluated.

RESULTS

The correlation coefficient (r) for CVP-PCWP data in 30 untreated patients was r = 0.64 (p = 0.0002) and for 256 pairs of posttreatment data, it was r = 0.53 (p < 0.0001). Linear regression and correlation for each individual patient in 29 patients with more than 3 measurements showed a significant correlation (p < 0.05) in 19 patients (66%). Correlation was poor (p > 0.05) in 10 patients (34%). The mean difference between PCWP and CVP was 3.5 +/- 2.6 mm Hg (limits of agreement: -1.6 to 8.7) in untreated patients. The mean difference between PCWP and CVP for 256 pairs of data derived posttreatment was 4.9 +/- 3.8 mm Hg (limits of agreement: -2.7 to 12. 5).

CONCLUSION

Invasive measurements of CVP and PCWP were found to agree poorly. Until a reliable noninvasive method is available to measure left ventricular preload, PCWP is the measurement of choice when invasive hemodynamic monitoring is necessary in patients with severe preeclampsia.