NEUROLEPTANALGESIA is based upon the use of a tranquilizer and a narcotic administered intravenously to produce a state of psychic withdrawal and profound analgesia.1Several series of tranquilizers and narcotics have been investigated in Europe; those currently available for investigation in the United States, droperidol2and fentanyl citrate,3represent the most evolved of these so far. Droperidol, a butyrophenone, is a potent tranquilizer which produces in the patient a state of calm, disinclination to move, and "disconnection" from the surroundings. It has an α-adrenergic blocking effect, which offers some protection against shock, leads to good peripheral perfusion, and "unmasks" hypovolemia. It also protects against epinephrine-induced arrhythmias, and has an antiemetic effect. Droperidol may cause hypotension by virtue of its α-adrenergic blocking effect and peripheral vasodilatation, particularly when the drug is administered rapidly and in the presence of hypovolemia. The hypotension is usually transitory in the former case,