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We held a computer software contest at 38th Congress of the JSA, held in March, 1991. The aim is to encourage the members of the Society to write softwares and to help distribute them, especially as Freewares. We received 25 entries for the contest; two-thirds of these are for computers of NEC PC9801 series and a third are for Macintosh. We received donations 3 million yen worth of instruments and goods for prizes plus some cash, which as prizes were distributed to those who made entries for the contest. Most of these programs have been registered as freewares at various computer networks, including our Ether-Net, one of the common computer network SIGBBS's among Japanese anesthesiologists.

A modified thermodilution catheter (KATS catheter) capable of monitoring continuous cardiac output by thermodeprivation and preserving its conventional function was devised. The KATS catheter has a thermistor incorporated closer to the tip of the catheter in addition to the usual thermistor used for conventional thermodilution. This additional thermistor is heated by a constant electric current but is capable of measuring its own temperature. The degree of heat deprivation is detected as the cooling of the thermistor, which is proportionally larger with larger blood velocity. Since blood flow is not the only source of heat deprivation, the actual formula was empirically derived by performing in vitro studies. Cardiac output can be determined by assuming the cross sectional area of the pulmonary artery is stationary. Calibration can be derived from a cardiac output measurement by the usual thermodilution method with the same catheter. The KATS catheter readings correlated significantly with conventional thermodilution values and electromagnetic flowmeter readings in anesthetized dogs. Continuous cardiac output measurement by the KATS catheter appears to be a promising technique.

Laryngeal mask airway (LMA) insertion was tried in 120 pediatric cases, from 2 months to 12 years of age. Initial indications for LMA were the same as for a face mask, except for two additional conditions; anticipation of difficulty with intubation and difficulty in management by a face mask. Size 2 LMA was used in the vast majority of cases. The insertion was successful on the first trial in 108 cases. More than one trial was necessary in 9 cases but only 3 cases required more than 3 trials. Insertion could not be completed in 3 cases. The relationship between the depth of LMA at the front teeth and age could be roughly described by "depth = 10 cm + 0.3 x Age". LMA was found to provide a better and more secure airway than the face mask without direct tracheal intervention. Heart rate did not increase with LMA insertion. It is easy to use and can be used in place of the face mask, but complications such as stomach air inflation due to too vigorous manual ventilation, slight pharyngeal injury, and airway obstruction due to kinking of LMA can occur. These complications can be avoided and must be kept in mind during it's use. LMA itself can be used to obtain a patent airway where an endotracheal airway is difficult to obtain. LMA-aided tracheal intubation can be extremely useful in obtaining endotracheal airways. Non-blind techniques can be used with LMA to increase safety. LMA is a very useful addition to pediatric anesthesia practice.