Journal of clinical monitoring and computing
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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.
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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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J Clin Monit Comput · May 1999
Comparative StudyTranscranial Doppler monitoring compared with invasive monitoring of intracranial pressure during acute intracranial hypertension.
To determine whether a simple transcanial Doppler waveform variable-pulsatility difference (systolic - diastolic blood flow velocity) can serve as a measure of critical changes in cerebral perfusion. ⋯ In pigs with induced diffuse intracranial hypertension, noninvasive transcranial Doppler waveform monitoring of pulsatility difference can identify increased cerebral oxygen extraction and dangerously decreased cerebral perfusion pressure.
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J Clin Monit Comput · May 1999
Randomized Controlled Trial Comparative Study Clinical TrialOn the dynamic performance of the Abbott Safeset blood-conserving arterial line system.
Critically ill patients frequently have indwelling arterial lines placed during their Intensive Care Unit stay. The lines are used to monitor blood pressure continuously, administer drugs and to draw blood for a variety of physiologic tests. Several blood-conserving arterial line systems have been developed to eliminate the need to discard blood in the process of obtaining undiluted and uncontaminated blood samples. The purpose of this study was to evaluate the dynamic performance of one such system the Abbott Clinical Care System Safeset blood conserving arterial line system - in comparison to a conventional arterial line system. ⋯ Because the Abbott Safeset blood-conserving arterial line system is underdamped and has a lower resonant frequency compared to the traditional arterial system, it may overestimate systolic blood pressure, particularly in patients with high heart rates.