Journal of clinical monitoring and computing
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J Clin Monit Comput · Dec 2019
Case ReportsOxygen reserve index (ORi™) contributes to prediction of hypoxemia and patient safety during tracheal stent insertion using rigid bronchoscopy: a case report.
The oxygen reserve index (ORi™) is a new noninvasive and continuous variable, which represents a moderate hyperoxygenation status, with a unitless scale between 0.00 and 1.00. When percutaneous oxygen saturation (SpO2) exceeds 100%, arterial blood oxygen partial pressure cannot be evaluated without performing arterial blood gas analysis. Because of significant air leakage during rigid bronchoscopy, it is difficult to monitor respiration using capnography, which does not measure end-tidal carbon dioxide (ETCO2) accurately. ⋯ General anesthesia (total intravenous anesthesia) through continuous administration of 6-10 mg/kg/h of propofol and intermittent administration of 50 µg of fentanyl (total 200 µg) preserved spontaneous breathing. During tracheal stent insertion, disconnection between the oxygen supply system and rigid bronchoscopy, and tracheal stent expansion, the ORi tended to decrease before SpO2 decreased. Thus, measuring ORi could prevent hypoxemia during tracheal stent insertion using rigid bronchoscopy.
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J Clin Monit Comput · Dec 2019
Observational StudyPreoperative cerebral and renal oxygen saturation and clinical outcomes in pediatric patients with congenital heart disease.
We examined the predictability of preoperative cerebral and renal rSO2 values for outcomes in pediatric patients undergoing cardiac surgery under cardiopulmonary bypass (CPB). Patients who underwent pediatric cardiac surgery under CPB between September 2015 and September 2017 were enrolled in this study. Patients monitored with both cerebral and renal rSO2 at the beginning of surgery were included. ⋯ The cut-off value (66%) of cerebral rSO2 value was associated with risk of mechanical ventilator-free day [OR of 11.3 (95% CI 1.05-25.3, p = 0.0456)] and the cut-off value (66%) of renal rSO2 value was associated with risk of ICU-free survival day [ORs of 33.0 (95% CI 2.25-484.0, p = 0.0107)] in the noncyanotic patients. The preoperative low rSO2 values were associated with outcomes including 30-day mortality and might be reflective of the severity of cardiopulmonary function. Further studies are needed to confirm our results.
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J Clin Monit Comput · Dec 2019
Near-real-time pulmonary shunt and dead space measurement with micropore membrane inlet mass spectrometry in pigs with induced pulmonary embolism or acute lung failure.
The multiple inert gas elimination technique (MIGET) using gas chromatography (GC) is an established but time-consuming method of determining ventilation/perfusion (VA/Q) distributions. MIGET-when performed using Micropore Membrane Inlet Mass Spectrometry (MMIMS)-has been proven to correlate well with GC-MIGET and reduces analysis time substantially. We aimed at comparing shunt fractions and dead space derived from MMIMS-MIGET with Riley shunt and Bohr dead space, respectively. ⋯ MM-S and MM-VD correlated and agreed well with Riley shunt and with Bohr dead space. MM-S increased significantly after lung injury only in the lavage group, whereas MM-VD increased significantly in both groups. This is the first work evaluating and demonstrating the feasibility of near real-time VA/Q distribution measurements with the MIGET and the MMIMS methods.
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J Clin Monit Comput · Dec 2019
Optimizing intraoperative administration of propofol, remifentanil, and fentanyl through pharmacokinetic and pharmacodynamic simulations to increase the postoperative duration of analgesia.
Titrating an intraoperative anesthetic to achieve the postoperative goals of rapid emergence and prolonged analgesia can be difficult because of inter-patient variability and the need to provide intraoperative sedation and analgesia. Modeling pharmacokinetics and pharmacodynamics of anesthetic administrations estimates drug concentrations and predicted responses to stimuli during anesthesia. With utility of these PK/PD models we created an algorithm to optimize the intraoperative dosing regimen. ⋯ To dosing regimen from clinical scenario 2 greatly increased the fentanyl dosing regimen and greatly decreased the remifentanil infusion rate with no change to the propofol infusion rate. The results from this preliminary analysis of the optimization algorithm appear to imply that it can operate as intended. However a clinical study is warranted to determine to what extent the optimization algorithm determined optimal dosing regimens can maximize the postoperative duration of analgesia without delaying the time to emergence in a clinical setting.