International journal of clinical monitoring and computing
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Int J Clin Monit Comput · Jan 1987
Extravascular lung water measurement by double indicator dilution in shock and respiratory failure.
Clinical quantitation of water accumulation in the lungs is imprecise. The technique of measuring extravascular lung water (EVLW) with double indicator dilution utilizing cold indocyanine green dye has become practical with the addition of a microprocessor. The technique, insertion of a special thermistor tipped arterial catheter and potential problems are described. ⋯ On the other hand 19 patients with Adult Respiratory Distress Syndrome (ARDS) had marked increases in EVLW from normal of 5-8 ml/kg to 10.7 to 14.4 ml/kg. No further increases in EVLW were observed in eight ARDS patients requiring fluid resuscitation for associated hypovolemia and hypoperfusion. We feel that measurement of EVLW in critically ill patients offers an opportunity to study the pathophysiology of pulmonary failure.
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Int J Clin Monit Comput · Jan 1987
Carola, a computer system for automatic documentation in anesthesia.
A computer system has been designed for documentation and data acquisition during open heart surgery. This computer system (called 'Carola') processes all patient data during cardiac surgery. More than 50 analogue or digital signals are scanned. ⋯ From december 1983 the first prototype was used on a routine basis, followed by a second unit in June 1984 and a third in December 1985. Up to now more than 12.500 anesthetic hours have been recorded. Since then almost 100% of all anesthetics performed in our cardiothoracic unit have been documented by the computers, including all short procedures without invasive monitoring and all emergencies.
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Int J Clin Monit Comput · Jan 1987
Historical ArticlePulse oximetry: historical review and Ohmeda functional analysis.
Oximetry relies on the detection of the spectral properties of oxygenated and reduced hemoglobin. In vitro bench analysis capabilities have spurred the desire to accomplish accurate in vivo measurement through various techniques. The 1930-40s were a particularly active period for oximetry culminating in the development of pulse oximeters in the 1970s. ⋯ Arterial oxygen saturation readings are derived from the ratio of pulse-added signals of red and infrared light energy passed through tissue. Data manipulation that includes empirically derived constants produces numerical data that is clinically useful. A photo-plethysmographic waveform display of actual oximeter signal closes the loop between man and machine.
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Int J Clin Monit Comput · Jan 1987
Closed-loop control of blood pressure, ventilation, and anesthesia delivery.
Closed-loop control systems have been in use for over 4,000 years, yet applications in medicine have developed only recently. When compared with manual control, closed-loop controllers for blood pressure, ventilation, and anesthesia delivery provide more rapid and more precise control of mean pressure, end-tidal CO2, and end-tidal anesthetic concentrations. ⋯ It must be remembered however, that the best anesthesiologist may perform better than the controller, particularly in his ability to anticipate clinical events which effect control. Although the convenience, precision of control, and immunity to distractions are reason enough to further pursue their development, their final application to clinical care will depend on the inclusion of appropriate safeguards and supervisory software algorithms to protect the systems from failure.