A clinical comparison of sodium thiopental (pentothal), sodium methitural (neraval), sodium buthalitone (transithal), and sodium hexobarbital (evipal).

Much ~ been written m recent years of the relative advantages and chsadvantages of new intravenous anaesthetics. Such comparisons are always difficult to make because of the many variables which ca~Lnot be easily controlled in a clinical series. For that reason, we attempted some time ago to compare a number of intravenous agents in human vol~mteers, a&a~inistering each drug consecutively to the same individuals under rigidly controlled condittons (1, 2). Double the sleep dose of each drug was given in a standard concentration and at a standard rate. For a variety of reasons the results obtained did not necessarily reflect each agent's usefulness in clinical practice. The standardization of concentration is a procedure open to criticasm. Also, it is very difficdlt to deterrmne equi-potent doses for each agent and the administration of doable the sleep dose is not an exact criterion since the sleep dose itself is hard to define. It was felt that a htrther controlled study should be undertaken, restricting the administration of each agent to patients undergoing a standard operative; procedure and using as the criterion of dosage the amount of drug req~Lired t:o permit the performance of the operation. The concentrations used in this study were the ones commonly employed in the chnical use of these agents. It was ho-Jed that the present clinical study would )4elcl additional information which wou_d enhance the value of our previous e,vperimental, results when considered side by side with them.