Journal of clinical monitoring and computing
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J Clin Monit Comput · Feb 2013
Validation of continuous and noninvasive hemoglobin monitoring by pulse CO-oximetry in Japanese surgical patients.
We evaluated the accuracy of noninvasive and continuous total hemoglobin (SpHb) monitoring with the Radical-7(®) Pulse CO-Oximeter in Japanese surgical patients before and after an in vivo adjustment of the first SpHb value to match the first reference value from a satellite laboratory CO-Oximeter. Twenty patients undergoing surgical procedures with general anesthesia were monitored with Pulse CO-Oximetry for SpHb. Laboratory CO-Oximeter values (tHb) were compared to SpHb at the time of the blood draws. ⋯ In patients with adequate perfusion (PI ≥1.4) the correlation coefficient was 0.89. In vivo adjustment of SpHb significantly improved the accuracy in our cohort of Japanese surgical patients. The strongest correlation between SpHb and tHb values was observed in patients with adequate peripheral perfusion suggesting that low perfusion may affect the accuracy of SpHb monitoring.
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J Clin Monit Comput · Feb 2013
Comparative StudyComparison of two different generations of "NIRS" devices and transducers in healthy volunteers and ICU patients.
The purpose of this study is to compare Near Infrared Spectroscopy (NIRS) thenar eminence parameters obtained with 2 different devices from the same manufacturer (InSpectra Models 325 and 650, Hutchinson Tech, Min USA), and 2 different probes (15 vs. 25 mm spacing), in healthy volunteers (HV) and ICU patients. Prospective, observational study in ICU setting. Simultaneous, cross over NIRS inter-device comparison and comparison between different probes (25 vs. 15 mm spacing) were done at baseline and during vascular occlusion tests (VOTs). ⋯ StO(2) data obtained with NIRS model 650 and 15 mm probe differ from values obtained with the previous device (325 and probe spacing 25 or 15 mm). This difference is not related to the population tested, but to the device and probe spacing. As a consequence, despite similar trends for variations between HV and patients during VOT, threshold and predictive values for outcome should be revisited with the new device before the acceptance for routine clinical use.
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J Clin Monit Comput · Feb 2013
ReviewShedding light on mitochondrial function by real time monitoring of NADH fluorescence: I. Basic methodology and animal studies.
Normal mitochondrial function in the process of metabolic energy production is a key factor in maintaining cellular activities. Many pathological conditions in animals, as well as in patients, are directly or indirectly related to dysfunction of the mitochondria. Monitoring the mitochondrial activity by measuring the autofluorescence of NADH has been the most practical approach since the 1950s. ⋯ These studies were the basis for the development of clinical monitoring devices as presented in accompanying article. The encouraging experimental results in animals stimulated us to apply the same technology in patients after technological adaptations as described in the accompanying article. Our medical device was approved for clinical use by the FDA.
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J Clin Monit Comput · Feb 2013
Pulmonary artery pulsatility is the main cause of cardiogenic oscillations.
The genesis of cardiogenic oscillations, i.e. the small waves in airway pressure (COS(paw)) and flow (COS(flow)) signals recorded at the airway opening is under debate. We hypothesized that these waves are originated from cyclic changes in pulmonary artery (PA) pressure and flow but not from the physical transmission of heartbeats onto the lungs. The aim of this study was to test this hypothesis. ⋯ Manual heart massages reproduced COS but they disappeared when PA was clamped during this maneuver. The transmission of PA pulsatilty across the lungs generates COS(paw) and COS(flow) measured at the airway opening. This information has potential applications for respiratory monitoring.