Analgesic and respiratory effects of extradural sufentanil in volunteers and the influence of adrenaline as an adjuvant

The effects of extradural sufentanil 50 μg were investigated in 10 normal volunteers. Eight of these were studied at a second session when adrenaline 1: 200000 was added to the sufentanil. Well-defined segmental analgesia developed rapidly after plain sufentanil and lasted approximately 3 h. Respiration was depressed for about the same period and was greatest in the first 2 h, as shown by a 15% increase in PECO_2′ while the slope and VE₅₀ of the carbon dioxide response curve were depressed by 45% and 55%, respectively. Moderate drowsiness occurred in most subjects, while other side effects of itching, nausea and urinary retention occurred less frequently and were not severe. Addition of adrenaline 1: 200 000 intensified segmental analgesia and prolonged duration to 5 h, while side effects were lessened. It is concluded that extradural sufentanil shows considerable promise for clinical use, and that the risk: benefit ratio is improved by adding adrenaline 1: 200000.