Journal of clinical monitoring and computing
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J Clin Monit Comput · Jun 2019
The importance of sensor contacting force for predicting fluid responsiveness in children using respiratory variations in pulse oximetry plethysmographic waveform.
Predicting fluid responsiveness is crucial for adequate fluid management. Respiratory variations in pulse oximetry plethysmographic waveform amplitude (ΔPOP) are used to predict fluid responsiveness, but show inconsistent results when used for children. Contacting force between the measurement site and sensor can affect the ΔPOP value, thereby hindering its reliability as an indicator. ⋯ A significant difference between the responders and non-responders was found only in ΔPOPs at 0.9-1.2N contacting force (P = 0.002) and individually adjusted contacting force (P < 0.000), while other contacting force groups did not show significant differences. ΔVpeak predicted a 15% increase in SVI (P = 0.008), whereas PPV did not. The ability of ΔPOP to predict fluid responsiveness depends on the contacting force in mechanically ventilated children. When contacting force is controlled to an adequate degree, the ability of ΔPOP to predict fluid responsiveness can be improved.
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J Clin Monit Comput · Jun 2019
Assessment of central hemodynamic effects of phenylephrine: an animal experiment.
Phenylephrine is an α1-adrenergic receptor agonist widely used to treat perioperative hypotension. Its other hemodynamic effects, in particular on preload and contractility, remain controversial. We, therefore, investigated the effect of continuously applied phenylephrine on central hemodynamics in eight mechanically ventilated domestic pigs. ⋯ Phenylephrine does not only affect cardiac afterload, but also increases effective preload. In contrast to CVP and Pmsfa, this effect can be monitored by GEDV. Further, phenylephrine affects contractility.
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Electronic medical records now store a wealth of intraoperative hemodynamic data. However, analysis of such data is plagued by artifacts related to the monitoring environment. Here, we present an algorithm for automated identification of artifacts and replacement using interpolation of arterial line blood pressures. ⋯ The average difference between manual review and algorithm in identifying the start of arterial line monitoring was 0.17, and 2.1 min for the end of monitoring. Application of the algorithm decreased the percent of time below 55 mmHg from 4.3 to 2.0% (2.1% with manual review) and time above 100 mmHg from 8.8 to 7.3% (7.3% manual). This algorithm's performance was comparable to manual review by a human anesthesiologist and reduced the incidence of abnormal MAP values identified using a sample analysis tool.
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J Clin Monit Comput · Jun 2019
Observational StudyTracheal sounds accurately detect apnea in patients recovering from anesthesia.
Apnea should be monitored continuously in the post anesthesia care unit (PACU) to avoid serious complications. It has been confirmed that tracheal sounds can be used to detect apnea during sedation in healthy subjects, but the performance of this acoustic method has not been evaluated in patients with frequent apnea events in the PACU. Tracheal sounds were acquired from the patients in the PACU using a microphone encased in a plastic bell. ⋯ The log-var apnea detection algorithm detected apnea with 92% sensitivity, 98% specificity, 46 PLR and 0.08 NLR. The performance of apnea detection in the PACU using the log-var tracheal sounds method proved to be reliable and accurate. Tracheal sounds could be used to minimize the potential risks from apnea in PACU patients.
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J Clin Monit Comput · Jun 2019
Effect of neuromuscular blockade on transcranial electric motor evoked potentials during surgical correction for idiopathic scoliosis under total intravenous anesthesia.
Transcranial electric motor evoked potentials (TCeMEPs) play an important role in reducing the risk of iatrogenic paraplegia. TCeMEPs could be obviously suppressed by neuromuscular blockade (NMB). The aims of this study were to examine the effects of NMB on TCeMEPs and to determine an appropriate level of partial neuromuscular blockade (pNMB) for TCeMEPs during surgical correction of idiopathic scoliosis under total intravenous anesthesia (TIVA). ⋯ Neither the amplitude and AUC nor the efficacy of TCeMEPs were affected at TOF4-5 of abductor halluces muscles TCeMEPs (AH-TCeMEPs) or at TOF3-5 of tibialis anterior muscles TCeMEPs (TA-TCeMEPs) compared with nNMB. However, the rate of unexpected movement was increased significantly at TOF5 and nNMB compared with TOF1 and TOF4. The application of pNMB with TOFR aimed at 26-50% for AH-TCeMEPs or 16-50% for TA-TCeMEPs seems to be an appropriate regimen for TCeMEPs during surgical correction for idiopathic scoliosis under TIVA.