Journal of neurosurgical anesthesiology
-
J Neurosurg Anesthesiol · Jan 2002
Treatment of transtentorial herniation unresponsive to hyperventilation using hypertonic saline in dogs: effect on cerebral blood flow and metabolism.
We tested the hypothesis that transtentorial herniation (TTH) represents a state of cerebral ischemia that can be reversed by hypertonic saline. Because of the high mortality associated with TTH, new therapeutic strategies need to be developed for rapid and effective reversal of this process. We produced TTH (defined by acute dilatation of one or both pupils) by creating supratentorial intracerebral hemorrhage with autologous blood injection in seven mongrel dogs anesthetized using intravenous pentobarbital and fentanyl. ⋯ TTH represented a state of ischemia in brainstem and supratentorial gray and white matter in the presence of adequate CPP, suggesting mechanical compression of vessels at the level of tentorium. Hypertonic saline reversed TTH, and restored both rCBF and CMRO2, although hyperemia was observed immediately after reversal of TTH. Administration of hypertonic saline may preserve neurologic function during the interim period between TTH and surgical intervention.
-
J Neurosurg Anesthesiol · Jan 2002
Case ReportsHazards of epinephrine in transsphenoidal pituitary surgery.
A 79-year-old woman with no history of myocardial ischemia presented with symptoms of pituitary apoplexy for which an urgent transsphenoidal resection of the pituitary gland was undertaken. The nasal passages were prepared with topical application of epinephrine followed by injection of what was presumed to be 1% lidocaine containing 10 microg/ml(-1) of epinephrine. ⋯ Postoperatively, she developed a myocardial infarction. The risks associated with the use of vasopressors are reviewed and suggestions for their safe use are presented.
-
J Neurosurg Anesthesiol · Jan 2002
Randomized Controlled Trial Clinical TrialEpidural administration of low-dose morphine combined with clonidine for postoperative analgesia after lumbar disc surgery.
This study evaluates the efficacy and side effects of a low dose of epidural morphine combined with clonidine for postoperative pain relief after lumbar disc surgery. In 36 of 51 patients who accepted the procedure, an epidural catheter was inserted (L1-L2 level). General anesthesia was induced with propofol and sufentanil, and maintained with sevoflurane in O2/N2O. ⋯ The occurrence of bladder catheterization was not significantly higher in that group. We conclude that a low dose of epidural morphine combined with clonidine offers a better postoperative analgesia than does bupivacaine-clonidine. The excellent analgesic conditions were obtained at the expense of a higher incidence of difficulties in initiating micturition.
-
J Neurosurg Anesthesiol · Jan 2002
Phenylephrine increases cerebral perfusion pressure without increasing intracranial pressure in rabbits with balloon-elevated intracranial pressure.
Using a rabbit model of intracranial hypertension, we studied the effects of infusion of phenylephrine on intracranial pressure (ICP) and cerebral perfusion pressure (CPP). Seven New Zealand white rabbits were anesthetized with isoflurane and normocapnia was maintained. An extradural balloon was used to raise ICP to 25 +/- 1 mm Hg. ⋯ The phenylephrine infusion was stopped after 45 minutes and MAP returned to baseline (76 +/- 8 mm Hg). We conclude that phenylephrine increased CPP because of its effect on MAP, but did not alter ICP. Phenylephrine may be used to increase CPP without raising ICP when autoregulation is intact.
-
J Neurosurg Anesthesiol · Jan 2002
Reverse Trendelenburg position reduces intracranial pressure during craniotomy.
Cerebral swelling and herniation pose serious surgical obstacles during craniotomy for space-occupying lesions. Positioning patients head-up has been shown previously to reduce intracranial pressure (ICP) in neurotraumatized patients, but has not been investigated during intracranial surgery. The current study examined the effects of 10-deg reverse Trendelenburg position (RTP) on ICP and cerebral perfusion pressure (CPP). ⋯ RTP appears to be an effective means of reducing ICP during craniotomy, thereby reducing the risk of cerebral herniation. CPP is not affected. Studies over longer periods of time are warranted, however.