Journal of neurosurgical anesthesiology
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Core body temperature is normally rigidly regulated by effective thermoregulatory responses that are triggered by small deviations in core and skin temperature. All general anesthetics so far tested markedly impair thermoregulatory control, increasing the range of temperatures not triggering protective responses by approximately 20-fold. Inhibition of thermoregulatory control--and reemergence of protective responses--are major factors influencing intraoperative temperature. ⋯ Forced air appears to be the most effective clinically practical cooling method. Mild hypothermia is also associated with serious complications including myocardial ischemia, impaired resistance to surgical wound infections, coagulopathies, and postoperative shivering. Consequently, patients deliberately made hypothermic during neurosurgery should subsequently be actively rewarmed.
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J Neurosurg Anesthesiol · Jan 1995
Comparative StudyBrain edema and neurologic status with rapid infusion of 0.9% saline or 5% dextrose after head trauma.
We previously reported that intravenous (i.v.) administration of large volumes (0.2 ml/g) of either an isotonic dextrose-free solution or 5% dextrose solution given over 18 h after closed head trauma (CHT) in rats did not significantly affect neurological severity score or brain tissue specific gravity. However, it is possible that with more rapid administration, isotonic or 5% dextrose i.v. solutions may alter neurological outcome after CHT. Our study examined whether neurological severity score, brain tissue specific gravity and water content, and blood composition were significantly altered when 0.25 ml/g of either 0.9% saline or 5% dextrose was given i.v. over 0.5 h (rather than over 18 h) after CHT. ⋯ There were no statistically significant differences in neurologic outcome and brain edema between the untreated and the saline-treated groups. However, 5% dextrose i.v. increased mortality (group 6 and 11, 50 and 0% survivors, respectively), decreased specific gravity in the noncontused hemisphere, and worsened neurologic outcome with and without CHT. Blood osmolality remained stable in comparison to the baseline value of 291.9 +/- 7.4 mOsm/kg (mean +/- SD).(ABSTRACT TRUNCATED AT 250 WORDS)
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J Neurosurg Anesthesiol · Oct 1994
Comparative StudyCSF, sagittal sinus, and jugular venous pressures during desflurane or isoflurane anesthesia in dogs.
Previous studies to determine whether desflurane increases cerebrospinal fluid (CSF) pressure are inconclusive because none have included all of the following: multiple doses of desflurane, administration for at least several hours, examination at normo- and hypocapnia, a concurrent comparison group, direct measurement of both intra- and extracranial CSF pressures, and measurement of venous pressures that influence CSF pressure. The present study was designed to determine whether CSF pressure increases during 4.0 h desflurane anesthesia using a study design that included the above elements. Catheters were placed in the lateral cerebral ventricle, cisterna magna, sagittal sinus, and jugular vein of 12 dogs anesthetized with thiopental 12 mg.kg-1.h-1 and halothane 0.5 to 0.8%. ⋯ CSF and sagittal sinus pressures, but not jugular venous pressure, increased with both desflurane and isoflurane. The greater increase of CSF pressure with 4.0 h desflurane (to 40.2 +/- 12.7 cm H2O) than with 4.0 h isoflurane (to 26.2 +/- 11.5 cm H2O) was attributable to an increase of CSF pressure that was greater during 2.0 h desflurane and normocapnia than during 2.0 h isoflurane and normocapnia, and to an increase of CSF pressure during 2.0 h desflurane and hypocapnia that was similar to that during 2.0 h isoflurane and hypocapnia. The greater increase of CSF pressure during desflurane may have resulted, in part, from increased CSF volume as indicated by a positive CSF-sagittal sinus pressure gradient (in contrast, there was little or no CSF-sagittal sinus pressure gradient during isoflurane) and a steeper slope of the gradient to CSF pressure relationship.
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J Neurosurg Anesthesiol · Oct 1994
ReviewTotal intravenous anesthesia is best for neurological surgery.
We believe that today balanced TIVA represents the best anesthetic technique for neurological surgery. Freely acknowledging that this point of view is unproven (36) with regard to the hard criterion of patient outcome on leaving the hospital, we submit that the intermediate or surrogate criteria discussed make a convincing case for preferring TIVA to volatile-based anesthetic techniques. Until a study demonstrating hard outcome differences between the two techniques is achieved, we will continue to encourage the use of TIVA in neuroanesthesia, based on its practical (anesthetic depth, neuromonitoring, surgical field) and theoretical (homeostasis, metabolism, antinociception, neuroprotection) advantages.