Journal of neurosurgical anesthesiology
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J Neurosurg Anesthesiol · Jul 2015
Preischemic Administration of Sevoflurane Does not Exert Dose-dependent Effects on the Outcome of Severe Forebrain Ischemia in Rats.
We previously showed that preischemic administration of high-dose isoflurane worsened the outcome from severe forebrain ischemia in rats. Conversely, high doses of sevoflurane have been reported to improve the outcome from forebrain ischemia when the insult is moderate. To clarify the dose-dependent effects of sevoflurane on severe forebrain ischemia, we performed an outcome study using an identical protocol to that in our previous study with isoflurane. ⋯ Outcome evaluation at 5 days postischemia included seizure incidence, mortality rate, neuromotor score, and histologic injuries to the cerebral cortex and hippocampal CA1 and CA3. Different doses of sevoflurane did not statistically affect seizure incidence (10.0% to 18.2%), mortality rate (20.0% to 46.7%), cortical damage (mild to moderate degree), or hippocampal CA1 damage (93.7% to 96.7% neuronal necrosis) or CA3 damage (36.3% to 41.7%). Dose-dependent effects of sevoflurane were not observed for any of the outcome variables assessed in this rat model of severe forebrain ischemia.
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J Neurosurg Anesthesiol · Jul 2015
Randomized Controlled TrialDexmedetomidine as an Anesthetic Adjuvant in Patients Undergoing Transsphenoidal Resection of Pituitary Tumor.
Transnasal transsphenoidal (TNTS) resection of pituitary tumors involves wide fluctuation in hemodynamic parameter and causes hypertension and tachycardia due to intense noxious stimuli during various stages of surgery. None of routinely used anesthetic agents effectively blunts the undesirable hemodynamic responses, and therefore usually there is a need to use increased doses of anesthetic agents. Dexmedetomidine (DEX) an α-2 adrenergic receptor agonist, because its sympatholytic and antinociceptive properties may ensure optimal intraoperative hemodynamic stability during critical moments of surgical manipulation. In addition, DEX reduced the anesthetic requirement with rapid recovery at the end of surgery. The main aim of our study was to evaluate the effect of DEX on perioperative hemodynamics, anesthetic requirements, and recovery characteristics in patients undergoing TNTS resection of pituitary tumors. ⋯ DEX as an anesthetic adjuvant improved hemodynamic stability and decreased anesthetic requirements in patients undergoing TNTS resection of pituitary tumor. In addition, DEX provided better surgical field exposure conditions and early recovery from anesthesia.
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J Neurosurg Anesthesiol · Jul 2015
Cerebral Glucose Metabolism and Sedation in Brain-injured Patients: A Microdialysis Study.
Disturbed brain metabolism is a signature of primary damage and/or precipitates secondary injury processes after severe brain injury. Sedatives and analgesics target electrophysiological functioning and are as such well-known modulators of brain energy metabolism. Still unclear, however, is how sedatives impact glucose metabolism and whether they differentially influence brain metabolism in normally active, healthy brain and critically impaired, injured brain. We therefore examined and compared the effects of anesthetic drugs under both critical (<1 mmol/L) and noncritical (>1 mmol/L) extracellular brain glucose levels. ⋯ These findings suggest that the use of anesthetic drugs may be of limited value in attempts to influence brain glucose metabolism in injured brain tissue.
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J Neurosurg Anesthesiol · Jul 2015
Development of a Clinically Applicable Protocol for Assessment of Hypoxic Response Through Measurement of the Endogenous Gasotransmitter Hydrogen Sulfide in Human Plasma.
Gasotransmitters are endogenously made, biologically active gases with unique physiological properties. In addition to participation in the hypoxic respiratory reflex of the carotid body, the gasotransmitter hydrogen sulfide (H(2)S) is thought to play a role in more localized vasodilatory hypoxic tissue responses. This pilot project describes a methodology suitable to the clinical environment that allows for H(2)S gas capture in human plasma utilizing the fluorescent trapping agent dansyl azide. ⋯ To study the role of H(2)S as a marker of hypoxic response in humans, a reliable, robust, and safe protocol amenable to standard hospital laboratory procedures is needed. Through modification to methodologies described in the biochemistry literature, this pilot project demonstrates the feasibility of utilizing a fluorescent H2S gas trapping agent for assessment of hypoxic response in humans within the confines of a typical clinical collection and analysis environment.
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J Neurosurg Anesthesiol · Jul 2015
Measuring and Improving First Case On-Time Starts and Analysis of Factors Predicting Delay in Neurosurgical Operating Rooms.
We undertook an operating room (OR) process improvement project to increase first case on-time starts (FCOTS) in the neurosurgical ORs at a tertiary care academic medical center. We engaged the neurosurgical perioperative team which included neurosurgeons, neuroanesthesiologists, and nurses in a shared goal of improving FCOTS. ⋯ The quality improvement project, which was implemented in 2 phases, successfully increased the FCOTS rate in our neurosurgical ORs from 33% to 68%.