International journal of clinical monitoring and computing
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Int J Clin Monit Comput · Aug 1996
Comparative Study Clinical TrialAnkle blood pressure measurement, an acceptable alternative to arm measurements.
The use of automatic noninvasive blood pressure (NIBP) devices has become a common technique to monitor blood pressure intraoperatively. The usual cuff placement for these devices on the upper arm sometimes poses problems. As an alternative, many clinicians place the cuff on the ankle. ⋯ The difference between the times necessary to obtain the readings from arm or ankle was not statistically significant. Eight of the paired readings (2.0%) represented artifact, arbitrarily defined as a difference in mean blood pressure readings of 15 mm Hg between the arm and the ankle. Since the mean blood pressure readings obtained at the arm and at the ankle were statistically equivalent, we concluded that the ankle cuff placement provided a reliable alternative to the placement of the cuff on the arm.
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Int J Clin Monit Comput · Aug 1996
Evaluation of dynamic performance in liquid-filled catheter systems for measuring invasive blood pressure.
Invasive blood pressure measurement is used in patients with unstable haemodynamics. The demand of the accuracy of these measurements is high. The reliability of the reproduced signal strongly depends on the measurement system's dynamic characteristic-its resonance frequency and damping factor. ⋯ E. parallel to the tubing. The resonance frequency remains the same, the damping factor increases to around 0.5. Systems with higher damping factors (0.5-0.7) have lower overshoot (1-2%), therefore the blood pressure measurements are more accurate.
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Int J Clin Monit Comput · Aug 1996
LetterDevelopment of a pharmacokinetic model-based infusion system for ketamine analgesia.
Model-driven infusion systems in anaesthesia overcome the difficulties in obtaining on-line measurements of controlled variables. A linear pharmacokinetic model for ketamine was used to achieve target blood concentrations and was implemented using a palmtop PC. Although the use of ketamine for analgesia in total intravenous anaesthesia with propofol has been reported, this is the first such application to spontaneously breathing patients. Preliminary results show this to be a useful system, which may easily be applied to other intravenous anaesthetic agents.
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Int J Clin Monit Comput · May 1996
Auditory alarms during anesthesia monitoring with an integrated monitoring system.
Alarms in the operating room remain a major source of annoyance and confusion. A previous study by Kestin et al. utilized a specific combination of distinct, separate monitors in 50 pediatric patients. He reported a mean of 10 alarms per case with a mean frequency of one alarm every 4.5 minutes. ⋯ Of the alarms, 67% occurred during the beginning and end of anesthesia. The end-tidal carbon dioxide accounted for 42% of the alarms, mostly during intubation and extubation. Suggestions are made for further improvement in alarm systems.