A Trial Comparing Treatment With the Springfusor Infusion Pump to the IV Magnesium Sulfate Regimen

Inclusion Criteria: Exhibit systolic blood pressure \> 160mm Hg OR a diastolic pressure \> 110 mm Hg (at two times over 30 minutes) (A single higher pressure could be accepted if the clinical team felt that magnesium sulfate therapy should be initiated without waiting 30 minutes). Exhibit proteinuria \> 1+; Have not given birth, or be \<24h postpartum Be assessed by enrolling physician to benefit from magnesium sulfate therapy Agree to comply with study procedures Be \> 18 years of age Give informed consent for study participation Exclusion Criteria: Eclamptic or seizing at the time of enrollment Received magnesium sulfate therapy 24h prior to study enrollment Known serum creatinine \>1.2 mg/dL. (Subject may be enrolled prior to knowledge of serum creatinine but would be withdrawn if \>1.2 mg/dL in order to have a proper dose adjustment.