Journal of clinical monitoring and computing
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J Clin Monit Comput · Feb 2020
Randomized Controlled TrialHypoventilation patterns during bronchoscopic sedation and their clinical relevance based on capnographic and respiratory impedance analysis.
Capnography involves the measurement of end-tidal CO2 (EtCO2) values to detect hypoventilation in patients undergoing sedation. In a previous study, we reported that initiating a flexible bronchoscopy (FB) examination only after detecting signs of hypoventilation could reduce the risk of hypoxemia without compromising the tolerance of the patient for this type of intervention. We hypothesize that hypoventilation status could be determined with greater precision by combining thoracic impedance-based respiratory signals, RESP, and EtCO2 signals obtained from a nasal-oral cannula. ⋯ Hypoventilation status (as revealed by EtCO2 levels) could be further classified by RESP into central-predominant or non-central-predominant types. It appears that patients with central-predominant hypoventilation are more sensitive to propofol during the induction of sedation. RESP values could be used to tailor sedation management specifically to individual patients.
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J Clin Monit Comput · Feb 2020
Measuring arterial oxygen saturation from an intraosseous photoplethysmographic signal derived from the sternum.
Photoplethysmography performed on the peripheral extremities or the earlobes cannot always provide sufficiently rapid and accurate calculation of arterial oxygen saturation. The purpose of this study was to evaluate a novel photoplethysmography prototype to be fixed over the sternum. Our hypotheses were that arterial oxygen saturation can be determined from an intraosseous photoplethysmography signal from the sternum and that such monitoring detects hypoxemia faster than pulse oximetry at standard sites. ⋯ The sternal probe detected hypoxemia 28.7 s faster than a finger probe (95% CI 20.0-37.4 s, p < 0.001) and 6.6 s faster than an ear probe (95% CI 5.3-8.7 s, p < 0.001). In an experimental setting, arterial oxygen saturation could be determined using the photoplethysmography signal obtained from sternal blood flow after calibration with CO-oximetry. This method detected hypoxemia significantly faster than pulse oximetry performed on the finger or the ear.
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J Clin Monit Comput · Feb 2020
Comparative StudyComparison of the venous-arterial CO2 to arterial-venous O2 content difference ratio with the venous-arterial CO2 gradient for the predictability of adverse outcomes after cardiac surgery.
This study aimed to compare the prognostic performance of the ratio of mixed and central venous-arterial CO2 tension difference to arterial-venous O2 content difference (Pv-aCO2/Ca-vO2 and Pcv-aCO2/Ca-cvO2, respectively) with that of the mixed and central venous-to-arterial carbon dioxide gradient (Pv-aCO2 and Pcv-aCO2, respectively) for adverse events after cardiac surgery. One hundred and ten patients undergoing cardiac surgery with cardiopulmonary bypass were enrolled. After catheter insertion, three blood samples were withdrawn simultaneously through arterial pressure, central venous, and pulmonary artery catheters, before and at the end of the operation, and preoperative and postoperative values were determined. ⋯ However, postoperative Pv-aCO2 was the best predictor of MOMM (area under the curve [AUC]: 0.804; 95% confidence interval [CI] 0.688-0.921), at a 5.1-mmHg cut-off, sensitivity was 76.0%, and specificity was 74.1%. Multivariate analysis revealed that postoperative Pv-aCO2 was an independent predictor of MOMM (odds ratio [OR]: 1.42, 95% CI 1.01-2.00, p = 0.046) and prolonged ICU stay (OR: 1.45, 95% CI 1.05-2.01, p = 0.024). Pv-aCO2 at the end of cardiac surgery was a better predictor of postoperative complications than Pv-aCO2/Ca-vO2 and Pcv-aCO2/Ca-cvO2.
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J Clin Monit Comput · Feb 2020
Philips Intellivue NMT module: precision and performance improvements to meet the clinical requirements of neuromuscular block management.
The variability or inaccuracy of acceleromyographic measurements could interfere with the interpretation of the train-of-four (TOF) ratio during neuromuscular block (NMB) recovery. This study evaluated the precision and performance of the Philips Intellivue NMT module (NMT) before (part 1) and after (part 2) several technical upgrades (i.e., firmware upgrade, new cable, and hand adapter) that were recently available. Two cohorts of 30 patients who were scheduled to undergo rhino/septoplasty under general anesthesia were included in the study. ⋯ Initially, the NMT significantly overestimated NMB recovery at every stage. Conversely, in the second part of the study, no difference reached statistical significance. With the recent upgrades and the new hand adapter, the NMT provided similar results compared with the TWX, Their implementation should be recommended in clinical practice.