Journal of clinical monitoring and computing
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J Clin Monit Comput · Apr 2014
Reliable real-time calculation of heart-rate complexity in critically ill patients using multiple noisy waveform sources.
Heart-rate complexity (HRC) has been proposed as a new vital sign for critical care medicine. The purpose of this research was to develop a reliable method for determining HRC continuously in real time in critically ill patients using multiple waveform channels that also compensates for noisy and unreliable data. Using simultaneously acquired electrocardiogram (Leads I, II, V) and arterial blood pressure waveforms sampled at 360 Hz from 250 patients (over 375 h of patient data), we evaluated a new data fusion framework for computing HRC in real time. ⋯ Furthermore, the fusion of waveform sources produced better error density distributions than those derived from individual waveforms. The data fusion framework was shown to provide in real-time a reliable continuously streamed HRC value, derived from multiple waveforms in the presence of noise and artifacts. This approach will be validated and tested for assessment of HRC in critically ill patients.
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J Clin Monit Comput · Apr 2014
Lidocaine infusion adjunct to total intravenous anesthesia reduces the total dose of propofol during intraoperative neurophysiological monitoring.
Total intravenous anesthesia (TIVA) with propofol and opioids is frequently utilized for spinal surgery where somatosensory evoked potentials (SSEP) and motor evoked potentials (tcMEP) are monitored. Lidocaine infusions can contribute to antinociception and unconsciousness, thus allowing for a reduction in the total dose of propofol. We examined our recent experience with lidocaine infusions to quantify this effect. ⋯ No complications were associated with the use of the lidocaine infusion. The total estimated drug savings included 104 50 ml bottles of propofol and 5 5 ml ampules of sufentanil. These cases indicate that a lidocaine infusion can be effectively utilized in spine surgery with SSEP and tcMEP monitoring as a means to reduce propofol and sufentanil usage without a negative effect on the monitoring.
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J Clin Monit Comput · Apr 2014
A novel airway device with tactile sensing capabilities for verifying correct endotracheal tube placement.
We present a new device for verifying endotracheal tube (ETT) position that uses specialized sensors intended to distinguish anatomical features of the trachea and esophagus. This device has the potential to increase the safety of resuscitation, surgery, and mechanical ventilation and decrease the morbidity, mortality, and health care costs associated with esophageal intubation and unintended extubation by potentially improving the process and maintenance of endotracheal intubation. ⋯ It is intended to detect the presence or absence of tracheal rings immediately upon inflation of the airway occlusion cuff. The initial study detailed here verifies that a prototype device can detect contours similar to tracheal rings in a tracheal model.
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J Clin Monit Comput · Apr 2014
Letter Case ReportsAn abrupt reduction in end-tidal carbon-dioxide during neurosurgery is not always due to venous air embolism: a capnograph artefact.
Venous air embolism (VAE) is a well recognized complication during neurosurgery. Pre-cordial doppler and trans-esophageal echocardiography are sensitive monitors for the detection of VAE. A sudden, abrupt reduction in the end-tidal carbondioxide (ETCO2) pressure with associated hypotension during neurosurgery might suggest VAE, when more sensitive monitors are not available. We describe an unusual cause for sudden reduction in ETCO2 during neurosurgery and discuss the mechanism for such presentation.
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J Clin Monit Comput · Apr 2014
Clinical TrialPrediction of hypotension in the beach chair position during shoulder arthroscopy using pre-operative hemodynamic variables.
Since hypotension in beach chair position (BCP) can lead to catastrophic neurologic complications, the prediction of hypotension is a matter of concern in the BCP under general anesthesia. We investigated whether pre-induction values of mean arterial pressure (MAP), stroke volume variation (SVV), cardiac index (CI), and stroke volume index (SVI) can predict hypotension in BCP during general anesthesia. Forty healthy adult patients, aged 18-65 years, undergoing elective arthroscopic shoulder surgery, were enrolled. ⋯ The areas under the ROC curves for pre-induction values of MAP, CI, and SVI and post-induction value of SVV before a positional change were 0.556 (95% CI 0.373-0.739; p = 0.557), 0.735 (0.576-0.894; p = 0.014), 0.787 (0.647-0.926; p = 0.003), and 0.691 (0.525-0.857; p = 0.046), respectively. In this study, pre-induction values of CI and SVI and post-induction value of SVV before a positional change predicted hypotension in the BCP under general anesthesia. Our findings suggest that not only preload but also preoperative cardiac performances might be the important factors for the development of hypotension after a repositioning supine to the sitting during general anesthesia.