Journal of clinical monitoring
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The problem of accurate identification of alarm sounds in the operating room, recovery room, and intensive care environment has persisted for many years. Monitors made by different companies may have different alarm sounds for the same monitored variable, and similar alarm sounds for different variables. In an effort to illustrate universal alarms sounds, a system of six musical alarm tones was designed with musical themes from popular songs used for oxygenation, ventilation, cardiovascular monitoring, temperature monitoring, artificial perfusion, and drug administration systems. ⋯ The observed score on the second testing was 4.3 +/- 2.2 SEM, p = 0.001 compared with the first hearing. Indeed, 42 of 79 (53%) respondents got all six answers correct on the second testing, versus three respondents for the first testing. The implications of these findings are discussed in the context of integrated alarm systems used in complex medical environments such as the operating room.
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A system has been designed to determine cardiac output noninvasively. The system's main component is a closed breathing circuit and it measures oxygen uptake (VO2), carbon dioxide elimination (VCO2), and end-tidal CO2 partial pressure (PET). As an integral part of the system, periods of CO2 rebreathing can be automatically implemented. ⋯ The bias between the noninvasive estimates of Svo2 and the directly measured values was 1.1% (SD = 9.3%). For double determination with the noninvasive technique the bias was -0.9% (SD = 4.7%). It is concluded that in mechanically ventilated pigs the proposed method produces good estimates of CO and SVO2 also in the presence of significant ventilation/perfusion mismatch.
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The objective of this study was to evaluate a new reflectance pulse oximeter sensor. The prototype sensor consists of 8 light-emitting diode (LED) chips (4 at 665 nm and 4 at 820 nm) and a photodiode chip mounted on a single substrate. The 4 LED chips for each wavelength are spaced at 90-degree intervals around the substrate and at an equal radial distance from the photodiode chip. ⋯ Student's t test was used to determine the significance of each correlation. The mean and standard deviation of the differences were also computed. In the animal study, pulse amplitude levels increased concomitantly with skin temperature (at 665 nm, r = 0.9424; at 820 nm, r = 0.9834; p < 0.001) and SpO2(r) correlated well with SaO2(IL) (r = 0.982; SEE = 2.54%; p < 0.001).(ABSTRACT TRUNCATED AT 400 WORDS)
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Randomized Controlled Trial Comparative Study Clinical Trial
Radial artery cannulation: a comparison of 15.2- and 4.45-cm catheters.
Eighty-nine patients were studied prospectively to compare the incidence of postdecannulation arterial thrombosis and ischemic complications associated with percutaneous insertion of two different radial artery catheters. Patients scheduled for peripheral vascular surgery were randomized to receive a 15.2-cm (6 in, Argon Medical Corp.) or 4.45-cm (1.75 in, Arrow International, Inc.) 20-gauge, Teflon catheter. Extremity blood flow was evaluated prior to cannulation and again after decannulation with the modified Allen's test, pulse-volume plethysmography, and Doppler ultrasound. ⋯ Of the 8 patients with positive modified Allen's test who underwent radial artery cannulation, one suffered arterial occlusion. Radial artery cannulation with a 15.2-cm catheter was associated with a lower incidence of postdecannulation radial artery thrombosis than cannulation with the 4.45-cm catheter. Radial artery cannulation with longer catheters (greater than 5.0 cm) appears to be a safe practice.