[Haemodynamic and respiratory effects of pentazocine. Studies on cardio-surgical patients (author's transl)].

The effects of different doses of pentazocine on circulation and respiration were investigated in 28 patients divided into three groups. The circulatory reactions occurred in two phases. In the first, immediately after the injection, ventilated patients showed vasodilation and therefore a decrease in the peripheral and pulmonary blood pressure due to the reduction in peripheral and pulmonary vascular resistance. In contrast, the second phase is characterized by a vasoconstriction with maximal alterations ten minutes after injection. As a consequence, the peripheral and pulmonary arterial pressure is increased by a raise in peripheral and pulmonary vascular resistance. These circulatory effects were more pronounced in the group receiving the higher dose of pentazocine. In spontaneously breathing patients pentazocine causes ventilatory depression indicated by a decrease in PaO2 and an increase in PaCO2. In these patients pulmonary vascular resistance and pulmonary arterial pressure are increased within the first minute after injection in contrast to the ventilated patients receiving the same dose. These increases are accompanied by the maximum of ventilatory depression. This change can be explained by the pulmonary hypoxic vasoconstriction.

RCT Entities:   Population Interventions Outcomes