Journal of clinical monitoring and computing
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J Clin Monit Comput · Apr 2018
Comparative Study Observational StudyFour-wavelength near-infrared peripheral oximetry in cardiac surgery patients: a comparison between EQUANOX and O3.
Near-infrared spectroscopy (NIRS) is a continuous and noninvasive technology that measures regional tissue oxygen saturation (rSO2). A new 4-wavelength generation of NIRS monitors is now available. We aimed to compare peripheral somatic rSO2 values given by the 4-wavelength EQUANOX™ 7600 device (Nonin Medical Inc., Plymouth, Mn) and O3™ device (Masimo Corporation, Irvine, CA). ⋯ Bias was 4.0% and limits of agreement were ±26.3%. Significant correlations were evidenced between EQUANOX and O3 rSO2 absolute values: rho = 0.758 (95% CI 0.701-0.806), P < 0.0001, and rSO2 percent maximum difference versus baseline: rho = 0.582 (95% CI 0.188-0.815), P = 0.007. While absolute values of rSO2 given by both devices were equivalent and well correlated, the clinical agreement is probably not acceptable, meaning that EQUANOX and O3 are not interchangeable in routine practice.
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J Clin Monit Comput · Apr 2018
A validation method for near-infrared spectroscopy based tissue oximeters for cerebral and somatic tissue oxygen saturation measurements.
We describe the validation methodology for the NIRS based FORE-SIGHT ELITE® (CAS Medical Systems, Inc., Branford, CT, USA) tissue oximeter for cerebral and somatic tissue oxygen saturation (StO2) measurements for adult subjects submitted to the United States Food and Drug Administration (FDA) to obtain clearance for clinical use. This validation methodology evolved from a history of NIRS validations in the literature and FDA recommended use of Deming regression and bootstrapping statistical validation methods. For cerebral validation, forehead cerebral StO2 measurements were compared to a weighted 70:30 reference (REF CXB) of co-oximeter internal jugular venous and arterial blood saturation of healthy adult subjects during a controlled hypoxia sequence, with a sensor placed on the forehead. ⋯ With informed consent, 24 subjects successfully completed the somatic validation study. The bias and precision of somatic StO2 compared to REF CXS was 0.04 ± 4.22% from the average of flank, quadriceps, and calf StO2 measurements to best represent the global whole body REF CXS. The NIRS validation methods presented potentially provide a reliable means to test NIRS monitors and qualify them for clinical use.
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J Clin Monit Comput · Apr 2018
Predicting fluid responsiveness in whom? A simulated example of patient spectrum influencing the receiver operating characteristics curve.
The influence of patient spectrum on the sensitivities and specificities of diagnostic methods has been termed spectrum bias or spectrum effect. Receiver operating characteristics curves are often used to assess the ability of diagnostic methods to predict fluid responsiveness. As a receiver operating characteristics curve is a presentation of sensitivity and specificity, the purpose of the present manuscript was to explore if patient spectrum could affect areas under receiver operating characteristics curves and their gray zones. ⋯ Simulated patient populations with stroke volume variation values between 5 and 15 or 3 and 25% had median (2.5th-97.5th percentiles) areas under receiver operating characteristics curves of 0.79 (0.65-0.90) and 0.93 (0.85-0.99), respectively. The gray zones indicating range of diagnostic uncertainty were also affected. The patient spectrum can affect common statistics from receiver operating characteristics curves, indicating the need for considering patient spectrum when evaluating the abilities of different methods to predict fluid responsiveness.
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J Clin Monit Comput · Apr 2018
Observational StudyCerebral oxygen desaturation occurs frequently in patients with hypertension undergoing major abdominal surgery.
Hypertensive patients are more likely to experience latent cerebral ischemia causing regional cerebral oxygen saturation (rSO2) decrease during general anesthesia. The aim of this prospective observational study was to assess the incidence of decreased rSO2 in hypertensive patients undergoing major abdominal surgery and the perioperative factors affecting this change in rSO2. A total of 41 hypertensive patients were enrolled and stratified according to their hypertension as controlled and uncontrolled. ⋯ Moreover, nine patients (45%) in group D occurred early postoperative cognitive function decline were more than three patients (14.3%) in group N (P = 0.031). This pilot study showed a large proportion of hypertensive patient experienced cerebral desaturation during major abdominal surgery and uncontrolled hypertension predisposed to this desaturation. NCT02147275 (registered at http://www.clinicaltrials.gov ).
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J Clin Monit Comput · Apr 2018
Randomized Controlled Trial Comparative StudyComparison of Univent tube and EZ blocker in one lung ventilation; airway pressures and gas exchange.
Univent tube (UT) and EZ-blocker were used for one-lung ventilation (OLV). UT is a single lumen tube with a small separate lumen containing a bronchial blocker. EZ-blocker differs with its unique y-shaped double-cuffed distal end. ⋯ ABG findings and haemodynamic variables were similar. EZ and Univent tube affected the airway pressures, oxygenation, ventilation and haemodynamic variables similarly during OLV in patients with normal respiratory function. These devices can be alternatives to each other based on clinical conditions.