Journal of neurosurgical anesthesiology
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Spectral Entropy (SpEn) is an alternative tool to the bispectral index (BIS) for monitoring depth of hypnosis. SpEn measures response entropy (RE) and state entropy (SE). This open-label prospective study was designed to evaluate SpEn and BIS in 20 patients undergoing elective supratentorial neurosurgery with craniotomy and resection of brain tumors. ⋯ Stated that prediction probability or P(K) represents an indicator probability to predict correctly the rank order of an arbitrary pair of distinct observed indices of depth of hypnosis (ie, clinical settings and SpEn indices, or BIS, Ce, MAP, HR), PK of BIS, SE, RE, and Ce provided a better depth of hypnosis than MAP and HR; RE being the best for rapidity, SE for sensitivity, and BIS for specificity. There is good correlation between the 3 hypnosis indices and Ce. This study demonstrates that SpEn provides a reproducible hypnosis index for patients undergoing supratentorial neurosurgical procedures.
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J Neurosurg Anesthesiol · Jul 2006
Quantitation of ischemic events after severe traumatic brain injury in humans: a simple scoring system.
Cerebral ischemia is recognized as one of the most important mechanisms responsible for secondary brain damage following severe traumatic brain injury (TBI), contributing to an increased mortality and a worse neurologic outcome. ⋯ The ischemic score proposed here, may be determined during the acute intensive care unit period, and correlates closely with outcome, which can only be determined 3 to 6 months, after injury. It also shows a correlation with neurochemical analytes.
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J Neurosurg Anesthesiol · Apr 2006
Randomized Controlled TrialIntravenous magnesium sulfate after aneurysmal subarachnoid hemorrhage: a prospective randomized pilot study.
We performed a randomized, double-blind, pilot study on magnesium sulfate (MgSO4) infusion for aneurysmal subarachnoid hemorrhage (SAH). Sixty patients with SAH were randomly allocated to receive either MgSO4 80 mmol/day or saline infusion for 14 days. Patients also received intravenous nimodipine. ⋯ The incidence of adverse events such as brain swelling, hydrocephalus, and nosocomial infection was also similar in patients receiving MgSO4 or saline. In this small pilot study, MgSO4 infusion for aneurysmal SAH is feasible. On the basis of the preliminary data, a larger study recruiting approximately 800 patients is required to test for a possible neuroprotective effect of magnesium after SAH.
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J Neurosurg Anesthesiol · Apr 2006
Randomized Controlled TrialThe effects of volatile anesthetics on intraoperative monitoring of myogenic motor-evoked potentials to transcranial electrical stimulation and on partial neuromuscular blockade during propofol/fentanyl/nitrous oxide anesthesia in humans.
The aim of the present study was to compare the influence of volatile anesthetics on transcranial motor-evoked potentials (tcMEP) in humans anesthetized with propofol/fentanyl/nitrous oxide and on partial neuromuscular blockade (NMB). The authors studied 35 ASA I and II patients who were undergoing elective craniotomy and brain tumor resection. The patients were randomized to one of three groups to receive halothane (HAL), isoflurane (ISO), or sevoflurane (SEV). ⋯ Both SEV and ISO at 1.0 MAC significantly decreased train-of-four ratio from 38.4+/-18.1 at control to 19.0+/-9.7 and from 35.3+/-12.4 to 26.1+/-13.7, respectively (P<0.001), but not HAL at 1.0 MAC. The amplitudes of tcMEPs were significantly reduced by all agents at 1.0 MAC, with the effect being less in HAL at 0.5 MAC. We have shown that HAL had a lesser suppressive effect on MEPs than either ISO or SEV at 0.5 MAC, which was partially due to a lesser degree of NMB.