Midazolam was compared with thiopentone as an intravenous anaesthetic induction agent in children between four and twelve years of age undergoing elective minor surgical procedures. Successful induction of anaesthesia was achieved in both groups of patients. With midazolam induction time was longer than with thiopentone, but the difference was not statistically significant. The incidence of apnoea was greater with thiopentone, but not significantly so. lt is concluded that midazolam is effective and safe, and could prove a reasonable alternative to thiopentone as an intravenous induction agent in children undergoing elective minor operations.

A/fentanil was used as an adjuvant to midazolam for analgesia in thirty outpatients undergoing colonoscopy. A similar group of thirty outpatients receivedfentanyl. The operating conditions and recovery times of the two groups were compared. A/fentanil usage resulted in better operating conditions. Recovery time was similar. Patient acceptance was high. No patient suffered respiratory depression during or after the procedure.

It is difficult to classify methods of removing carbon dioxide (C0 2 ) from expired air. Many methods are possible. Some are impractical at present but rapid advances are being made in the fields of aviation, space, underwater and environmental medicine and those methods currently regarded as far-fetched may become accepted within a few years.One way of classifying methods of CO 2 removal is to divide them into: (a) non-regenerative, removing CO 2 alone; (b) non-regenerative, removing CO 2 and supplying oxygen (0 2 ); (c) regenerative, removing CO 2 ; (d) regenerative, removing CO 2 and producing O 2 , Another way is to classify compounds used to remove CO 2 into: 1. absorbents 2. adsorbents (a) carbonaceous adsorbents (b) liquid film sorbents (c) zeolite molecular sieves 3. biogenerators 4. other.Both classifications will be used in this article to clarify the present position in the midst of ongoing research by industry and in other fields of medicine. (a) Non-regenerative methods of CO 2 removalSolid absorbents include sodium, potassium, calcium, barium and lithium hydroxide which have all been used in rebreathing systems. Adsorbents include charcoal and other carbonaceous materials.Liquid and deliquescent absorbents are not used in anaesthesia or in personal portable rebreathing systems owing to the risk of caustic liquid entering and damaging the lungs.Anaesthetists use soda lime and barium lime to absorb CO 2 , Charcoal and Carbosieve also adsorb hydrocarbons, halogenated hydrocarbons and other

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The effects of halothane (0.5-2%) and enflurane (1-4%) on two Transoxode transcutaneous oxygen (TePO) electrodes (Hellige Servomed Oxymonitor SM.361 system) were serially tested in atmospheres of nitrogen, air and 50% nitrous oxide in oxygen. Both TeP0 2 electrodes reduced and "read" halothane but not enflurane. Calibration drift was significantly greater (p < 0.05) after electrode exposure to halothane; 5.40 s.e.m. 1.37 kPa vs enflurane; -0.60 s. e. m. 0.93 kPa. Halothane has a direct effect in rendering the Transoxode inaccurate, which is probably clinically less important than the indirect cardiovascularly medicated influence of both halothane and enflurane on TeP0 2 levels. A reduction in the electrode polarisation voltage is recommended to obviate the direct effect of halothane on Transoxode performance.