In 1949 Bovet and Ins colleagues (1) descnbed the ~paralysing action of the bls-ehohne esters of succmlC acid, showing that they produced rapid paralysis of short duration Concurrently Bovet-Nltti (2) showed that the des~uction of these compounds m the blood was due to enzymatic hydrolysis. Evans, Gray, Lehmann and Silk (3) further demonstrated that the pseudo-chohnesterase of the serum was cinefly responsible fol the hydrolysis, the true eholmesterase of the cells hawng httle effect.Ttmstages m the breakdown are first, hydrolysis at a fairly rapld rate !Lo succinylchohne and chohne, and then hydrolysis of succinylmoncholine more slowly to succmm acid and chohne, less than 3 per cent being excreted unchange, d m the urine (4) Tins breakdown usually occurs in three to five minutes, but numerous case reports of prolonged duralaon have appeared in the hterature (5--11).Scohne| (succmylchohne chloride dihydrate) was the br~Jad used in the following two instances of prolonged apnoea.Case 1 H B A 70-year-old woman was admitted with large bowel obstructl,on. When presented for operataon she was adequately hydrated, her B P was 120/80 and she was m a reasonably fit condllaonMorphm gr a/6 and atropme gr 1/10o were given one hour before operataon Induetaon was with Tinopentone 250 mg and Scohne| 50 mg A No. 8 Magdl's ruffed catheter was passed and resptrataons recomrnenced m four minutes. Maintenance was with 6 litres nitrous oxade and 2 htres oxygen An mtravenous infusion of Scollne| 0.1 per cent was commenced (12).The total operating tune was two hours, during which a short carcuit anastomosis was performed for carcinoma of the colon Secondaries were present in the hver Up to the t~me of commencement of closure of the pentoneum, periods of spontaneous respirations were permitted and adequately assisted where necessary In all 500 mg of Scoline| were used As relax~ation for closucre of the pentoneum was inadequate, 50 rug of Scohne| were given from a syringe. The operation was completed ta.venty minutes later, but apnoea still persisted There were, however, very troy movements of the rebreathmg bag.Nikethamide 10 cc was given without effect, m fact the faint movements of the rebreathing bag dlsappeared.,Controlled respu'ation was carried out using 100 per cent oxygen ~ for periods up to ten minutes, and both hypo-and hyperventflatmn were tried without successRespirations gradually began to retxtrn 1~ hours from the time when the last dose of Scoline| had been administered, but it was three-quaxters of an hour *Children's Hospital, Wmmpeg, /Vl[an Formerly Anaesthetast, Bromley Group Hospitals, Kent, Eng
268Canad Anaes Soc J, vol 2, no 3, July, 1955,