Journal of clinical monitoring and computing
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J Clin Monit Comput · Oct 2021
Trans-ocular brain impedance index for assessment of cerebral autoregulation in a porcine model of cerebral hemodynamic perturbation.
Cerebrovascular autoregulation (CA) is often impaired following traumatic brain injury. Established technologies and metrics used to assess CA are invasive and conducive for measurement, but not for continuous monitoring. We developed a trans-ocular brain impedance (TOBI) method that may provide non-invasive and continuous indices to assess CA. ⋯ Receiver operator curve test showed high predictive performance of DZx when compared to PRx with area under the curve above 0.86, with high sensitivity and specificity. Impedance indices appear to track changes in PRx and hemodynamics that affect cerebral autoregulation. TOBI may be a suitable less invasive surrogate to PRx and capable of tracking cerebral autoregulation.
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J Clin Monit Comput · Oct 2021
A simple method of mechanical power calculation: using mean airway pressure to replace plateau pressure.
The reference method for mechanical power (MP) calculation proposed by Gattinoni et al. is based on plateau pressure (Pplat) which needs an inspiratory hold. This study aims to introduce and validate a simple surrogate for MP calculation without any intervention in ventilated patients with or without acute respiratory distress syndrome (ARDS). The introduced equation is as:[Formula: see text]where Pmean is mean airway pressure, VE is minute ventilation, PEEP is positive end-expiratory pressure, and Te/Ti is expiratory-to-inspiratory ratio. 50 patients with ARDS and 50 post-operative patients without ARDS were enrolled. ⋯ At both Tplat levels, the Pmean-derived MP correlated well with the reference MP both in patients with or without ARDS (non-ARDS: slopes = 1.05, 0.94, R2 = 0.95, 0.93, bias + 0.76, + 0.51; ARDS: slopes = 1.03, 0.95, R2 = 0.96, 0.96, bias + 0.97, + 0.78. P < 0.0001 for all). In patients with or without ARDS, Pmean-derived MP allows rapid and dynamic estimation of mechanical power without any intervention at the bedside.
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J Clin Monit Comput · Oct 2021
LetterEndotracheal tube inflation tubing defect: an unusual cause of intraoperative volume leak.
Loss of endotracheal cuff pressure can lead to airway compromise and loss of volume delivery in mechanical ventilation requiring immediate intervention. A 40 years old male posted for bilateral interpositional arthroplasty was intubated nasally with 7.5 mm flexometallic endotracheal tube. In the intraoperative period airway leak was detected due to loss of cuff pressure even after repeated attempt of cuff inflation. After changing endotracheal tube, leak was detected from the inflation tubing distal to the cuff, which was apparent only when cuff pressure was increased above 30 cm of H2O.
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J Clin Monit Comput · Oct 2021
The influence of depth of anesthesia and blood pressure on muscle recorded motor evoked potentials in spinal surgery. A prospective observational study protocol.
For high-risk spinal surgeries, intraoperative neurophysiological monitoring (IONM) is used to detect and prevent intraoperative neurological injury. The motor tracts are monitored by recording and analyzing muscle transcranial electrical stimulation motor evoked potentials (mTc-MEPs). A mTc-MEP amplitude decrease of 50-80% is the most common warning criterion for possible neurological injury. ⋯ This may contribute to fewer false positive warnings. By performing this study after induction and prior to incision, this protocol provides a unique opportunity to study the effects of depths of anesthesia and blood pressure on mTc-MEPs alone with as little confounders as possible. Trial registration number NL7772.
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In anesthesia automation, one of the main important issues is the availability of a reliable measurement of the depth of consciousness level (hypnosis) of the patient. According to this value, the hypnotic drug dosage can be adequately calculated. One of the most studied hypnosis indexes is the bispectral index (BIS). ⋯ The objectives of this study are, first, to validate the accuracy of the PSI describing the hypnosis level during the maintenance phase of general anesthesia, by comparing with the BIS and, second, to model the relationship between propofol infusion rate and PSI values, obtained from a SEDLine monitor. For this, real data from patients undergoing general anesthesia simultaneously monitored with both BIS and PSI signals was used. Results obtained are interesting for a correct interpretation of PSI signal in clinical practice.