Some effects of premedication.

THE concept and practice of pre-anaesthetic medication were introduced by Claude Bernard (1869) and Labbe and Goujon (1872) who administered morphine before inducing anaesthesia with chloroform. A few years later Schafer (1880) and Dastre and Morat (1884) recommended giving atropine as well as morphine. Scopolamine was first used by Schneiderlin (1903) and papaveretum (Omnopon) by Leipoldt (1911). Despite the wide variety of agents which have since been introduced, these four drugs in various combinations remain among the most commonly used. The several desirable actions of these drugs are unfortunately accompanied by some disadvantageous ones, foremost among which is respiratory depression. Summation of this depression of breathing with that caused by the various hypnotics and analgesics employed in anaesthesia can produce a severe diminution of effective pulmonary ventilation with all its consequences. There have been very few studies of the action of these premedicant combinations on the respiration and the results are inadequate and sometimes conflicting. Nevertheless the findings form the basis of our present knowledge of the respiratory effects of these drugs and are authoritatively quoted in textbooks of pharmacology. The present investigation was undertaken to assess and compare the respiratory and other effects of the four combinations: morphine + atropine; morphine + scopolamine; papaveretum + atropine; and papaveretum + scopolamine; each given in a fixed dose per body weight under standard conditions.