Journal of clinical monitoring and computing
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J Clin Monit Comput · Dec 2006
The influence of sevoflurane on the bispectral index, regional cerebral oxygen saturation, and propofol concentration during propofol/N2O anesthesia.
This study was undertaken to investigate the influence of sevoflurane on the bispectral index (BIS), regional cerebral oxygen saturation (rSO(2)), and serum propofol concentration during propofol/N(2)O anesthesia. This study tested the hypothesis that sevoflurane affect BIS values, rSO(2), and the pharmacokinetics of propofol during propofol/ N(2)O anesthesia. ⋯ We have shown that sevoflurane decreases BIS values during propofol/N(2)O anesthesia without affecting rSO(2) and that this change is accompanied by an increase in serum propofol concentration. Changes in propofol concentration may be due to, at least in part, hemodynamic changes such as decreased CO produced by sevoflurane.
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J Clin Monit Comput · Dec 2006
Neurophysiological identification of position-induced neurologic injury during anterior cervical spine surgery.
This study was a retrospective review of 3,806 patients who underwent anterior cervical spine surgery with multi-modality neurophysiological monitoring consisting of transcranial electric motor evoked potentials, somatosensory evoked potentials and spontaneous electromyography between 1999-2003. The objectives of this study were twofold: (1) to evaluate the role of transcranial electric motor evoked potential tceMEP and ulnar nerve somatosensory evoked potential (SSEP) monitoring for identifying impending position-related stretch brachial plexopathy, peripheral nerve entrapment/compression or spinal cord compression and (2) to estimate the point-prevalence of impending neurologic injury secondary to surgical positioning effects. Sixty-nine of 3,806 patients (1.8% showed intraoperative evidence of impending neurologic injury secondary to positioning, prompting interventional repositioning of the patient. ⋯ Brachial plexus stretch upon neck extension for optimal surgical access and visualization was second in frequency-of-occurrence. Evolving traction injury to the ulnar nerve attributed to tightly-wrapped or malpositioned arms was observed in 16% of alerted cases, whereas evolving spinal cord injury following neck extension accounted for an additional 19%. This study highlights the role of tceMEP and ulnar nerve SSEP monitoring for detecting emerging peripheral nerve injury secondary to positioning in preparation for and during anterior cervical spine surgery.
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J Clin Monit Comput · Oct 2006
ReviewIntraoperative motor evoked potential monitoring: overview and update.
Amidst controversy about methodology and safety, intraoperative neurophysiology has entered a new era of increasingly routine transcranial and direct electrical brain stimulation for motor evoked potential (MEP) monitoring. Based on literature review and illustrative clinical experience, this tutorial aims to present a balanced overview for experienced practitioners, surgeons and anesthesiologists as well as those new to the field. ⋯ The many advances in motor system assessment achieved in the last two decades undoubtedly improve monitoring efficacy without unduly compromising safety. Future studies and experience will likely clarify existing controversies and bring further advances.
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The purpose of this study was to develop an interactive software package of alarm sounds to present, recognize and share problems about alarm sounds among medical staff and medical manufactures. ⋯ We have developed an interactive software package of alarm sounds by integrating the database and the alarm sound simulator (URL: http://info.ahs.kitasato-u.ac.jp/tkweb/alarm/asdb.html ). The AlmSS was useful for replaying multiple alarm sounds simultaneously and designing new alarm sounds interactively.
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J Clin Monit Comput · Aug 2006
Randomized Controlled TrialResponse entropy is more reactive than bispectral index during laparoscopic gastric banding.
There is a potential use for spectral entropy or bispectral index (BIS) for controlling level of anesthesia, but it is not known how these EEG monitors relate during steady state anesthesia. We compared Response Entropy (RE) and BIS during anesthesia for laparoscopic gastric banding with RE targeted to 45. ⋯ Within the range of 41-44, RE and BIS are equal but the gain of RE is 0.5 greater than BIS with deeper or lighter anesthesia. This is not likely due to increased smoothing with BIS. Identifying periods of RE activation show that BIS, EMG and RE increase together.