Journal of neurosurgical anesthesiology
-
J Neurosurg Anesthesiol · Jan 2005
Randomized Controlled Trial Clinical TrialThe effects of intravenous fentanyl and intravenous fentanyl combined with bupivacaine infiltration on the hemodynamic response to skull pin insertion.
This study was conducted to compare the effects of intravenous fentanyl and intravenous fentanyl combined with bupivacaine infiltration on the hemodynamic response to skull pin insertion. 120 ASA I-II patients scheduled for elective craniotomy were included. The fentanyl group (group F, n = 60) received fentanyl during induction and prior to skull pin insertion (2 and 1 microg . kg, respectively). The fentanyl-bupivacaine group (group FB, n = 60) received the same doses of fentanyl as well as scalp infiltration with 0.25% bupivacaine. ⋯ The hemodynamic response to skull pin insertion was effectively suppressed with both methods. Still, the addition of scalp infiltration to fentanyl did not provide any additional benefit. Administering an additional dose (1 microg . kg) of fentanyl just before skull pin insertion is recommended as a simple and effective option that requires no extra time.
-
Perioperative visual loss (POVL) is a devastating injury that has been reported infrequently after nonocular surgery. The most common cause of POVL is ischemic optic neuropathy (ION). Increasing numbers of cases of ION are being reported after spine surgery, but the etiology of postoperative ION remains poorly understood. ⋯ However, levels of blood pressure and anemia intraoperatively were frequently at levels considered acceptable in anesthesia practice. The etiology of postoperative ION remains incompletely understood. Potential strategies to avoid this complication are discussed.
-
J Neurosurg Anesthesiol · Jan 2005
Progressive suppression of motor evoked potentials during general anesthesia: the phenomenon of "anesthetic fade".
Transcranial motor evoked potentials (MEPs) are useful for assessing the integrity of spinal cord motor tracts during major spine surgery. Anesthetic agents depress the amplitude of MEPs in a dose-dependent fashion. Anecdotal reports suggest that MEP responses degrade or "fade" over the duration of a surgery, despite unchanged anesthetic levels or other physiologic variables. ⋯ Prolonged exposure to anesthetic agents necessitates higher stimulating thresholds to elicit MEP responses, separate from the dose-dependent depressant effect. This retrospective study is limited and cannot explain the mechanism for this observed fade in signals. Recognition of anesthetic fade is essential when interpreting changes to the MEP response to avoid false-positive findings.
-
J Neurosurg Anesthesiol · Jan 2005
Trigemino-cardiac reflex during microvascular trigeminal decompression in cases of trigeminal neuralgia.
The trigemino-cardiac reflex (TCR) is a well-recognized phenomenon consisting of bradycardia, arterial hypotension, apnea, and gastric hypermotility during ocular surgery or other manipulations in and around the orbit. Thus far, it could bee shown that central stimulation of the trigeminal nerve during transsphenoidal surgery and surgery for tumors in the cerebellopontine angle can lead to TCR. In cases of microvascular trigeminal decompression for trigeminal neuralgia, no data of the possible occurrence of TCR are available. ⋯ After cessation of manipulation, HR and MABP returned (spontaneously) to levels before the stimulus. Risk factors of TCR were compared with results from the literature. In conclusion, the present results give evidence of TCR during manipulation of the central part of the trigeminal nerve during microvascular trigeminal decompression in cases of trigeminal neuralgia under a standardized anesthetic protocol.