Journal of clinical monitoring and computing
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J Clin Monit Comput · Oct 2016
The effects of advanced monitoring on hemodynamic management in critically ill patients: a pre and post questionnaire study.
In critically ill patients, many decisions depend on accurate assessment of the hemodynamic status. We evaluated the accuracy of physicians' conventional hemodynamic assessment and the impact that additional advanced monitoring had on therapeutic decisions. Physicians from seven European countries filled in a questionnaire in patients in whom advanced hemodynamic monitoring using transpulmonary thermodilution (PiCCO system; Pulsion Medical Systems SE, Feldkirchen, Germany) was going to be initialized as part of routine care. ⋯ In 54 % of cases physicians underestimated the actual CO by more than 20 %. The information provided by the additional advanced monitoring led 33, 22, 22, and 13 % of physicians to change their decisions about fluids, inotropes, vasoconstrictors, and diuretics, respectively. The limited clinical ability of physicians to correctly assess the hemodynamic status, and the significant impact that more physiological information has on major therapeutic decisions, support the use of advanced hemodynamic monitoring in critically ill patients.
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J Clin Monit Comput · Oct 2016
Investigation of peripheral photoplethysmographic morphology changes induced during a hand-elevation study.
A hand-elevation study was carried out in the laboratory in order to alter peripheral blood flow with the aim of increasing understanding of factors affecting the morphology of peripheral photoplethysmographic signals. Photoplethysmographic (PPG) signals were recorded from twenty healthy volunteer subjects during a hand-elevation study in which the right hand was raised and lowered relative to heart level, while the left hand remained static. Red and infrared (IR) PPG signals were obtained from the right and left index fingers using a custom-made PPG processing system. ⋯ Changes in hand position relative to heart level can significantly affect the morphology of the peripheral ac PPG waveform. These alterations are due to a combination of physical effects and physiological responses to changes in hand position, which alter vascular resistance. Care should be taken when interpreting morphological data derived from PPG signals and methods should be standardized to take these effects into account.
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J Clin Monit Comput · Oct 2016
Data clustering methods for the determination of cerebral autoregulation functionality.
Cerebral blood flow is regulated over a range of systemic blood pressures through the cerebral autoregulation (CA) control mechanism. The COx measure based on near infrared spectroscopy (NIRS) has been proposed as a suitable technique for the analysis of CA as it is non-invasive and provides a simpler acquisition methodology than other methods. The COx method relies on data binning and thresholding to determine the change between intact and impaired autoregulation zones. ⋯ The determination of the lower limit of autoregulation (LLA) was compared to a traditional binned data approach. Good agreement was found between the methods. The work highlights the potential application of using data clustering tools in the monitoring of CA function.
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J Clin Monit Comput · Oct 2016
Effect of controlled hypotension on regional cerebral oxygen saturation during rhinoplasty: a prospective study.
The aim of this study was to investigate the effect of controlled hypotension on cerebral oxygen saturation (rSO2) using near infrared spectroscopy (NIRS) and evaluation of postoperative cognitive function in patients undergoing rhinoplasty. Fifty adult patients who were scheduled for elective rhinoplasty surgery and required controlled hypotension were enrolled in this prospective study. Controlled hypotension was provided using a combination of propofol and remifentanil infusion supplemented with nitroglycerin infusion as necessary. rSO2 was evaluated during controlled hypotension by NIRS. ⋯ There was a 4 % decrease in the non-desaturated patients and a 7 % decrease in the desaturated patients when preoperative and postoperative MMSE scores were compared. A decline in cognitive function 1 day after surgery was observed in 23 patients (46 %) and in all patients with intraoperative cerebral desaturation. The current study showed that even if SpO2 is in the normal range, there might be a decrease of more than 20 % in cerebral oxygen saturation during controlled hypotension.