Journal of clinical monitoring and computing
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J Clin Monit Comput · Jan 1999
A single computer-controlled mechanical insufflation allows determination of the pressure-volume relationship of the respiratory system.
To evaluate and further develop a method for determination and mathematical characterisation of the elastic pressure-volume (Pel-V) relationship in mechanically ventilated human subjects during one single modified insufflation with simultaneous determination of resistance of the respiratory system. ⋯ Using one single modified insufflation allows a fast and accurate determination of respiratory mechanics. The Pel-V curves were determined with high reproducibility and were adequately described by a three-segment model of the curve incorporating a linear segment between two asymmetrical non-linear segments.
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Intensive care and operating room monitors generate data that are not fully utilized. False alarms are so frequent that attending personnel tends to disconnect them. We developed an expert system that could select and validate alarms by integration of seven vital signs monitored on-line from cardiac surgical patients. ⋯ Integration of information from several sources improved the reliability of alarms and markedly decreased the frequency of false alarms. Fuzzy logic may become a powerful tool for integration of physiological data.
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J Clin Monit Comput · Jan 1999
A simple strategy for faster induction and more cost-effective use of anesthetic vapor.
Inducing general anesthesia often involves mask ventilation using high fresh gas flow (FGF) to administer anesthetic vapor prior to endotracheal intubation. A common practice is to turn the vaporizer off when the mask is removed from the patient's face to avoid room contamination (VAPOff). An alternative approach is to leave the vaporizer on and turn the FGF to minimum to reduce the amount of vapor laden gas that can enter the room (FGFOff). The objective of this study is to compare the relative induction times and vapor costs associated with each induction strategy. ⋯ The strategy of turning the FGF to minimum and leaving the vaporizer on during intubation does not contaminate the room and speeds induction by fostering a greater alveolar concentration than the VAPOff method. Cost savings are derived using FGFOff since a higher alveolar concentration is achieved at the same vapor cost. Additional cost savings are demonstrated since a low flow technique is possible immediately after intubation when using FGFOff. The practice of turning off the vaporizer during endotracheal intubation while FGF remains high should be abandoned.
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J Clin Monit Comput · Jan 1999
Clinical investigation of a new combined pulse oximetry and carbon dioxide tension sensor in adult anaesthesia.
To test the accuracy of a new combined oxygen saturation and cutaneous carbon dioxide tension (SPO2-PCO2) sensor in a routine adult clinical environment. This probe provides a non-invasive and continuous monitoring of the arterial oxyhaemoglobin saturation, arterial carbon dioxide tension and pulse rate at the ear lobe. The sensor is intended to measure both relevant respiration/ventilation parameters in one single probe. ⋯ During general anaesthesia, postoperative recovery and critical care treatment, both monitoring of oxygenation and ventilation is important. Since pulse oximetry estimates only arterial oxygen saturation, periodic blood sampling is still necessary to determine the patient's arterial carbon dioxide status. We could demonstrate that the difference between cutaneous and arterial PCO2 was clinically unimportant, and therefore we conclude that the two methods of estimating the patient's carbon dioxide status may be used interchangeably. Our results demonstrated that 3 min after sensor placement, the new SpO2-PCO2 sensor prototype proved to be a reliable tool for continuous non-invasive monitoring of oxygenation and ventilation.
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J Clin Monit Comput · Jan 1999
Computerized monitoring of physical activity and sleep in postoperative abdominal surgery patients.
Assessment of early postoperative activity is important in the documentation of improvements of peri-operative care. This study was designed to validate computerized activity-based monitoring of physical activity and sleep (actigraphy) in patients after abdominal surgery. ⋯ Computerized activity monitoring by actigraphy is a reliable and easy method for monitoring physical activity and sleep-wake cycles after major abdominal surgery.