The use of short-acting relaxants in E.C.T.

SINCE the introduction of curare to modify the contractions in E.C.T. , the use of relaxants has become standard psychiatric practice. These substances reduce the risk of fractures and enable treatment to be given to patients who would other wise be denied it owing to risks arising from concomitant physical disease. During recent years great efforts have been made to simplify the technique of muscle relaxation, in particular to evolve a method which is short in duration, free from undesirable side-effects and easy in use. In this short paper we give a description of our experience with three drugs recently introduced, namely, Suxamethonium Bromide or Brevidil †̃ â€M̃ †̃ â€w̃hich we used in r i i treatments, Suxethonium Bromide or Brevidil “ E “(@iotreatments), and Suxamethonium Chloride or Scoline (653 treatments) . These choline succinic ester derivatives have similar characteristics which can be considered together. According to experimental evidence (Bovet et al., 1949 and 1951) they produce a specific blocking action at the skeletal neuromuscular junction. Their initial, transient, acetyl-choline-like stimulation (Ginzel et al., 1951) (Von Dardel and Thesleff, †̃95')is followed by complete block which wears off quickly and is followed by a correspondingly rapid return to normal. In therapeutic amounts they appear to have little effect upon the autonomic or central nervous systems (Thesleff, 1951; Von Dardel and Thesleff, ,95,). Cholinesterases, especially serum pseudo cholinesterases (Glick, 1941 ; Bovet-Nitti, ,949) are thought to account for their rapid breakdown to the physiological metabolites succinic acid and choline (Castillo and De Beer, 195ob). Hence possibly their transient action and freedom from toxicity. In contrast, tubo-curarine, gallamine and decamethonium iodide are excreted unchanged. All these drugs produce muscular fasciculation within a few seconds of intra venous administration. The process starts in the face and spreads gradually to the trunk and limbs. The patient may experience muscular pain, and invariably shows respiratory distress while this is going on; therefore a quick-acting bar biturate given either before or with the relaxant, is essential. Considering the relaxants individually, Suxamethonium Chloride (sometimes known as succinyl-choline chloride, or Scoline) comes first. To begin with, we used this in the dosage recommended by the makers, based on the body-weight, and varying from 0@4to i@oml. (i6 mgm. to 40 mgm. active cation). The amount of thiopentone we used, also recommended by the makers, varied from o'15 gm. to O@4gm. Both substances were mixed in one syringe, as we were assured that Scoline lost only @oper cent. of its efficacy in 5 minutes when mixed with thio pentone. We found, however, that four-fifths of the recommended dosage produced adequate protection in women, possibly owing to their having less muscle tissue than men. This smaller dose resulted in more rapid restoration of breathing and therefore became our standard technique for women, the full dose being retained for men. We also found it possible, in some cases, to reduce the recommended dose of thiopentone. We gained the impression that this tended to shorten the period of apnoea.