[Experiences with an anesthesia protocol written by computer]

Since December 1983, we have used a computer system for charting and data logging in cardiac and thoracic anesthesia. These computers, designed as stand-alone units, were developed at our hospital based on Motorola 6809 microprocessor systems. All measurements derived from anesthetic monitoring, ventilator, and heart-lung machine are automatically sampled at regular intervals and stored for later data management. Laboratory results are automatically received from the hospital computer system. The user communicates with the system via a terminal and a keyboard; this also facilitates the entering of all comments, medications, infusions, and fluid losses. All data are continuously displayed on an A3 format anesthetic chart using a multi-pen, flat-bed plotter. The operation of the system has proved to be simple and needs less time than charting by hand, while the result, the display on the chart, is far clearer and more complete than any handwritten document. Up to now 3,200 operations (corresponding to 12,500 anesthetic h) have been documented. The failure rate of the system, defined as an interruption of the documentation for more than 30 min is 2.1%. Further development of the system is discussed. A data base for processing the stored data has been developed and is being tested at present.