Computerized record keeping promises complete, accurate and legible documentation. Reliable measurements are a prerequisite to fulfill these expectations. We analyzed the physiological variables provided by bedside monitoring devices in 657 bedside visits performed by an experienced Intensive Care nurse during 75 Intensive Care rounds. We registered which variables were displayed. If a variable was displayed, we assessed whether it could be used for documentation or should be rejected. If a value was rejected the reason was registered as: the measurement was not intended (superfluous display), the current clinical situation did not allow proper measurement, or other reasons.

Basic variables (vital signs and respiration related variables) were displayed in more then 90%, specific variables (e.g. intracranial pressure) were displayed in less than 50% of the situations. Displayed variables were superfluous on an average of 11% because measurement was not intended.

Variables like heart rate, temperature, airway pressure, minute volume of ventilation, arrhythmia, pulmonary arterial pressure, non-invasive blood pressure, and intracranial pressure provide high quality measured values (acceptance of more than 90%). Invasive arterial pressure, central venous pressure, respiration rate and oxygen saturation (via pulse oximetry) provided lower quality values with a rejection rate higher than 10%. Inappropriate sensor technology to match the clinical environment seems to be the root cause. In future the request for automatic documentation will increase. In order to avoid additional staff workload and to ensure reliable documentation, sensor technology especially related to respiration rate, blood pressure measurements, and pulse oximetry should be improved.

Summary

The aims of this study were (a) to survey and evaluate the impact of information technology applications in High Dependency Environments (HDEs) on organizational, psychological and cost-effectiveness factors, (b) to contribute information and design requirements to the other workpackages in the INFORM Project, and (c) to develop useful evaluation methodologies.

The evaluation methodologies used were: questionnaires, case studies, objective findings (keystroke) and literature search and review. Six questionnaires were devised covering organizational impact, cost-benefit impact and perceived advantages and disavvantages of computerized systems in HDE (psychological impact).

The general conclusion was that while existing systems have been generally well received, they are not yet designed in such a developed and integrated way as to yield their full potential. Greater user involvement in design and implementation and more emphasis on training emerged as strong requirements. Lack of reliability leading to parallel charting was a major problem with the existing systems. It proved difficult to assess cost effectiveness due toa lack of detailed accounting costs; however, it appeared that in the short term, computerisation in HDEs tended to increase costs. It is felt that through a better stock control and better decision making, costs may be reduced in the longer run and effectiveness increased; more etailed longitudinal studies appear to be needed on this subject.

Little information is known concerning hemodynamic parameters of bypass grafts after open heart surgery during the postoperative period. As there is no easy to use bedside-method for monitoring, we developed a new implantable Doppler probe to measure blood flow velocity with a 20 MHz pulsed Doppler system. The accuracy of this method was proved in a circulatory model and in animal studies. Our conclusion is that the implantable pulsed Doppler system is a sensitive method for monitoring small vessel hemodynamics.

Summary

Since at least 1951 anesthesia journals have called for a more rigorous application of statistical methods in research reports (9, 14). This appeal for statistical excellence actually applies to the researcher, to the clinician journal reader, and to the editor. Thirty five years ago the obligations of these three groups was made clear in an unsigned editorial in Anesthesiology (9); there is now a widespread consensus on these responsibilities (1, 2, 21). The researcher must create valid science. The clinician reader must bring sufficient intellectual skills to understand a journal article; using these skills the reader must critique the research report to judge its applicability to his patients. The editor must decline manuscripts showing poor or absent application of the scientific method, experimental design, and statistical analysis.

Though the editors continue to exhort further improvements, even a casual persusal of their journals demonstrates a tremendous improvement in the handling of numeric data over the last four decades (3, 10, 11, 17, 19). With the increasing sophistication of statistical methods in journals, the reader must continue to expand his statistical understanding.

In this short review, a few highlights of statistical methods useful either in planning and accomplishing a research project or in reading a research report will be discussed; these include the planning of a study design, data collection, data analysis, and interpretation of the research. Comments about using these concepts to better understand a research article will be included. Also included will be an annotated reading list for further study and reference. Mathematical formulas have been avoided as much as possible. Actual use of statistics requires use of equations which can be found in the books of the reading list.

Summary

Two new portable infrared gas analysers, the Irina (Drägerwerke, Lübeck, Germany) and the Normac (Datex Instrumentarium Corporation, Helsinki, Finland), were tested and the results compared to those from such established methods as gaschromatography and the Beckman LB-2 (Beckman, USA) infrared gas analyser using exactly defined gas mixtures from a vaporizer developed in our laboratory. The analysers were evaluated for their accuracy and precision, noise, zero stability, gain stability and the impact of flow, overpressure, carrier gas and humidity. All three analysers showed good accuracy and precision. The noise level was acceptable except in the older version of the Normac, but this error has now been corrected by the manufacturer. Zero and gain stability are very good; gas flow and overpressure do not affect the measurement. The influence of carrier gases and humidity is negligible except for the strong N₂O effect on the Beckman. We conclude that this new generation of highly sophisticated and reliable but handy analysers will meet the clinical demands.

Summary

Many phases of modern anesthesia keep the anesthetist too busy to obtain and plot physiologic data or to record anesthetic events. Yet the anesthesia record serves as a log book, a clinical management tool, a trend and pattern plotter, as well as a medical-legal document. If these functions are important, an automated anesthesia recording system is needed for charting the data reliably and accurately. Automating the anesthesia record also lays the ground work for abstracting the data and generating records with specific information sought by the anesthetist, the physicians in the recovery room and intensive care unit, the administrators of the hospital, as well as representatives with interest in medical-legal problems.

It is possible to link a Laser-Doppler to a DOS-compatible personal computer in order to monitor microcirculation of the free flap after plastic surgery.

We connected such a system to a second computer by telephone modems, in order to control the Laser-Doppler via the telephone line from a distant location using only commercially available hardware and software. The aim was to develop a low-cost system which would not require the purchase or construction of any specialised equipment. Using this system, it was possible to show the Laser-Doppler waveforms to colleagues who were not at the patient site, for their (more experienced) opinions without any further delays.

Preliminary tests on five cases showed that it was indeed possible to transfer recorded information about the blood flow rate of free skin flaps from one computer to a remote one, without any loss of information. In these cases, the measured blood flow and clinical surveillance of the blood supply were adequate, thus making revision of the tissues not necessary.

This preliminary study suggests that standard ‘off-the-shelf’ personal computer tools may be useful in improving the monitoring of microcirculation after plastic surgery.

Summary

At University Hospital, interfaces are being designed to link-stand-alone patient care devices to Hospital Information System (HIS). The objective is to have an integrated HIS comprising of data from bedside patient monitors and from stand-alone devices such as infusion pumps, fetal monitors, and pulse oximeters. Interfaces are implemented with standard hardware and software design tools.

The feasibility of designing a general purpose interface hardware based on a common microprocessor has been demonstrated for an IMED model 960 infusion pump [1]. The present paper describes the implementation of the software component of the interface using standard microcomputer software packages. The device of choice was the Corometrics model 115 fetal monitor for implementing the software because it is used extensively at University Hospital and has built-in data communication hardware.

The Corometrics model 115 fetal monitor was interfaced to an IBM Personal Computer (PC) model XT. Data acquired from the fetal monitor was used to provide data tables and graphs. The feasibility of designing and implementing a software interface capable of acquiring and processing data received from a stand-alone device (fetal monitor) was demonstrated.

A description of the important aspects of the interface software design is presented in this paper. This design will eventually be part of the HIS. A brief discussion about the design modifications necessary to acquire data from multiple devices simultaneously is also included.

A knowledge-based alarm system for intensive care monitoring was designed, built, tested on-line, and evaluated. The system is a functional prototype of a highly specific patient monitor providing alarms on hypovolemia, hyperdynamic state, left ventricular failure and hypoventilation. These intelligent alarm functions aim to maintain the quality of patient monitoring even if nurses' attention is temporarily reduced or focused elsewhere. The alarm system has an electronic access to data available in a multichannel patient monitor and the patient data management system of the intensive care unit. Median filtering, trend estimation, and rule-based reasoning are applied when processing the measured variables and estimating the patient's state.