[Circulatory effects of dihydrazinophthalazine (Nepresol) compared with sodium nitroprusside in controlled hypotension. A study of neurosurgical patients under neuroleptanesthesia].

In 32 neurosurgical patients in neuroleptanaesthesia and controlled hypotension the following hemodynamic parameters were studied. Blood pressure, heart rate, cardiac output in addition serial measurements of the blood gasanalysis, oxygen content were performed from the arterial and centralvenous blood samples. In the first collective of 12 patients a mean dosis of 45 +/- 12 mg dihydrazinophthalazine (Nepresol) decreased the blood pressure to a mean value of 55 +/- 7 mm Hg. In spite of this blood pressure drop the cardiac output increased by 62,4% in consequence to the increase of the heart rate by 27% and the stroke volume by 19,9%. A controlled hypotension to a mean value of 57 +/- 9 mm Hg was performed in 20 patients with sodiumnitroprusside. In contrast to the effects of Nepresol after medication of sodiumnitroprusside the cardiac output decreased by 16% the stroke index by 24% while the heart rate increased by 18%. Both drugs have a useful place in neuroanesthesia, but sodiumnitroprusside is the drug of choice for controlled hypotension, because after medication of Nepresol even in the higher dose range there is no dose-response-relationship and the onset of action is delayed.