Nitroprusside‐ and nitroglycerin‐induced hypotension: Effects on hemodynamics and on the microcirculation

After a short summary of the effects and metabolism of sodium nitroprusside (SNP) and nitroglycerin (NTG), the influence of induced hypotension on hemodynamics and on the microcirculation is investigated. The continuous registration of the local tissue pO 2 in skeletal muscle, myocardium, and liver with the multiwire surface electrode provides the opportunity to recognize immediately a change in the microcirculatory bed. This new method shows in animal experiments that the local oxygen supply during SNP‐induced hypotension is dramatically reduced, while the arterial pO 2 remains in a normal range. These changes are not found during NTG‐induced hypotension. Electron microscopic examination of various organs, and especially of the myocardium, shows that the alterations of the oxygen supply found after application of SNP were connected with changes in the ultrastructure.