Journal of clinical monitoring and computing
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Traditionally, the study of CO2 and O2 kinetics in the body has been mostly confined to equilibrium conditions. However, the peri-anesthesia period and the critical care arena often involve conditions of non-steady state. ⋯ The lesser known area of non-steady state O2 kinetics is introduced, including the measurement of pulmonary O2 uptake per breath. Future directions include the study of the respiratory quotient per breath, where the anaerobic threshold during anesthesia is identified by increasing respiratory quotient.
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J Clin Monit Comput · Jan 2000
Hierarchical rule-based monitoring and fuzzy logic control for neuromuscular block.
The important task for anaesthetists is to provide an adequate degree of neuromuscular block during surgical operations, so that it should not be difficult to antagonize at the end of surgery. Therefore, this study examined the application of a simple technique (i.e., fuzzy logic) to an almost ideal muscle relaxant (i.e., rocuronium) at general anaesthesia in order to control the system more easily, efficiently, intelligently and safely during an operation. ⋯ The results showed that a hierarchical rule-based monitoring and fuzzy logic control architecture can provide stable control of neuromuscular block despite the considerable individual variation in neuromuscular block required among patients. Also, there was less variation in T1% error compared with that of previous study on mivacurium. Meanwhile, the consistent medium CV of the MIR of both rocuronium and mivacurium indicated a good controller activity which is able to withstand noise, diathermy effect, artifacts and surgical disturbances.
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J Clin Monit Comput · Jan 2000
Clinical TrialMonitoring of respiratory rate in postoperative care using a new photoplethysmographic technique.
Photoplethysmography (PPG) is a non-invasive optical technique that measures variations in skin blood volume and perfusion. The PPG signal contains components that are synchronous with respiratory and cardiac rhythms. We undertook this study to evaluate PPG for monitoring patients' respiratory rate in the postoperative care unit, using a new prototype device. We compared it with the established technique, transthoracic impedance (TTI). ⋯ Our results indicate that PPG has the potential to be useful for monitoring respiratory rate in the postoperative period.
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J Clin Monit Comput · Jan 2000
Partial CO2 rebreathing indirect Fick technique for non-invasive measurement of cardiac output.
Evaluation in animals of a non-invasive and continuous cardiac output monitoring system based on partial carbon-dioxide (CO2) rebreathing indirect Fick technique. ⋯ The partial CO2 rebreathing technique for measurement of cardiac output is non-invasive, automated, and based on the well accepted Fick principle. The limits of agreement between NICO and TDco is within the recommended value for NICO to be a clinically acceptable method for cardiac output measurement. The results of this canine study show that NICO performed as well, and in some cases better, than other currently available non-invasive cardiac output techniques over a wide range of cardiac outputs.
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J Clin Monit Comput · Jan 2000
A proposed method for the measurement of anesthetist care variability.
Some critical events in anesthesiology occur as seemingly preventable misadventures, their exact origins indeterminable. Inexperienced anesthetists, anesthesia machine malfunctions, lack of vigilance and human error inevitably initiate some incidents. Anesthesia training improves recognition and decision-making. Avoiding crisis initiation and amelioration of those that do occur is one role of the consultant anesthesiologist. Safe patient care requires medical and procedural knowledge, technical expertise, and control of resources in a complex milieu. Anesthesia simulators are clinical laboratories where anesthetists can sharpen both cognitive and manual skills. Dynamic scenarios allow opportunities for anesthetists to explore and experience crises as they develop and apply their knowledge while attempting to manage these events. Simulator-based scenarios are reproducible and large amounts of useful data can be collected and saved. The authors hypothesize these data can be utilized to compare performance of anesthetists and to measure improvement of individual anesthetists over time. ⋯ It is suggested that the use of the techniques mentioned here may be of value in the development of a standardized testing protocol for anesthetists.