First experiences with Swan-Ganz measurements in patients with severe hypertension during pregnancy from an unselected population.

In 10 patients with severe hypertension during pregnancy (6 patients with preexisting hypertension and 4 with severe preeclampsia) Swan-Ganz measurements were done in order to detect and correct a reduced circulating volume and lower the blood pressure. It appeared that 6 patients had a reduced circulating volume (group I) and 4 patients a normal circulating volume (group II). In both groups there were 2 patients with severe preeclampsia; most patients were referred and had antihypertensive medication before and most infants had a birthweight less than the 10th centile. A difference was found in prolongation of pregnancy if counted from the first hemodynamic measurement (and start of therapy): on average 25 days in group I (despite careful volume correction and vasodilatation) versus on average 25 days in group II (vasodilatation only). Moreover, all infants but one were delivered by cesarean section, but fetal distress as indication for delivery was only noted in group I. Although Swan-Ganz measurements are very useful to determine filling state and effect of therapy it is concluded that once a reduced circulating volume is present one is too late to be able to prolong pregnancy considerably despite proper therapy of volume correction and vasodilatation. This makes Swan-Ganz measurements on "fetal indication" questionable.