Journal of clinical monitoring and computing
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J Clin Monit Comput · May 1999
Comparative StudyAssessment of short-term blood pressure variability in anesthetized children: a comparative study between intraarterial and finger blood pressure.
Continuous blood pressure (BP) measurement provides instantaneous information on hemodynamic status, and allows for assessment of sympathetic modulation of vasomotor tone using spectral analysis. As an alternative to intraarterial blood pressure (IABP) measurement, the Finapres, a photoplethysmographic device, allows for non-invasive continuous measurement of finger blood pressure (FBP). This study was designed to evaluate the accuracy of spectral measurements of FBP variability in children during anesthesia and recovery. For this purpose, reliability of BP measurement and short-term BP variability assessed by FBP were calculated and compared with IABP. ⋯ The differences evidenced between FBP and IABP spectral profiles might result from specific physiological properties of digital arteries, which are sympathetic effectors. This study supports the use of FBP in children to assess non-invasively the vascular sympathetic component of the autonomic nervous system during anesthesia and recovery.
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The Hb-Quick is a new portable hemoglobinometer that uses disposable cuvettes to measure the total hemoglobin concentration of capillary, venous, or arterial blood. Therefore, the objectives of this study were 1) to evaluate the performance of this compact, battery-powered hemoglobinometer by assessing its precision, accuracy, and linearity, 2) to determine whether its measurements suffer from interference by hemolysis, bilirubin, fetal hemoglobin, or hemodilution, and 3) to establish whether it can easily be used by clinical personnel with little or no laboratory training. ⋯ The new hemoglobinometer is fast and easy to operate. No sample preparation or pipetting is required. To operate the instrument, the user simply allows a drop of blood to fill the disposable cuvette by capillary action and inserts the cuvette into the instrument. The instrument analyzes the 10 microl sample and displays the results in less than 10 seconds. The interference caused by hemolysis, hemodilution with saline, fetal hemoglobin, and bilirubin were too small to be of any dinical importance. Tests in physician's offices indicated that clinical personnel with little or no formal laboratory training could successfully use this device. The observed precision, accuracy, linearity, and freedom from interference indicate that this hemoglobinometer is suitable for near-patient testing in a wide range of clinical settings including physicians' offices.
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J Clin Monit Comput · May 1999
Inter observer variability of the transcranial Doppler ultrasound technique: impact of lack of practice on the accuracy of measurement.
Published data on the observer variability with the transcranial doppler (TCD) ultrasound are limited by the use of the product moment correlation coefficient. This study was designed to quantify the intra and inter observer variability with the TCD in terms of the intra class correlation coefficient (ICC) and to assess the impact of lack of practice on the observer variability and the accuracy of data generated. ⋯ A high level of observer agreement is possible with the TCD for measurement of cerebral blood flow velocities. Lack of regular practice with the system reduces the accuracy of measurements and impacts on both measured and calculated indices.
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To design and evaluate a clinical monitor of respiratory drive (P0.1) and other respiratory variables in a simple way, using a commercial ventilator. ⋯ At rest, the ventilator introduced a minor influence on inspiratory time and P0.1, but not in ventilation, tidal volume, expiratory duration and respiratory frequency. During exercise, the influence was more evident. This effect could also be noticed in the coefficients of variation. The responses to mechanical loads were easily recorded and can be used as a simple test of central load-compensating mechanisms. CONCLUSIONS. The ventilator, with limitations, may be an alternative to conventional techniques, especially in clinical studies of the central inspiratory activity with and without respiratory loading.