Changes in central venous pressure with vasoactive drug injections in humans.

We tested whether central venous pressure (CVP) changes during vasoactive drug injections used for baroreflex assessment in humans. We measured CVP during sequential intravenous boluses of nitroprusside (NTP) and phenylephrine (PHE; modified Oxford technique). NTP caused a decrease in CVP of 1.9+/-0.2 mmHg from baseline (P<0.01) and PHE caused an increase in CVP of 0.3+/-0.2 mmHg above baseline. These changes in CVP may contribute to the observed integrated baroreflex responses.