Journal of neurosurgical anesthesiology
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J Neurosurg Anesthesiol · Oct 2007
Randomized Controlled TrialLighter general anesthesia causes less decrease in arterial pressure induced by epinephrine scalp infiltration during neurosurgery.
Scalp infiltration with epinephrine-containing lidocaine solution can elicit significant hypotension before craniotomy under general anesthesia. A prospective randomized controlled study was designed to observe whether a lighter depth of general anesthesia could prevent the unintentional hypotension induced by the epinephrine scalp infiltration during neurosurgery or not. Fifty patients undergoing scheduled neurosurgery involving craniotomy were randomly allocated into 2 groups. ⋯ The mean percentage of maximal decrease in MAP was group 1 (13%)
group 2 (4%) without significant difference (P>0.05). The results implied that keeping a lighter general anesthesia caused less decrease in arterial blood pressure and was a relative effective method to prevent hypotension episode induced by epinephrine scalp infiltration. -
J Neurosurg Anesthesiol · Oct 2007
Case ReportsAwareness during general anesthesia: analysis of contributing causes aided by automatic data capture.
The cause of the awareness under general anesthesia often cannot be definitely determined from retrospective reviews of handwritten records, examinations of equipment, or interviews with clinicians. Failure to deliver the intended concentrations of anesthetic agents to the patient is one possible contributing cause for awareness. An advantage of an automated Anesthesia Information Management System (AIMS) is its ability to electronically capture and preserve case data that might otherwise be lost. ⋯ The data captured by the AIMS revealed low levels of inspired or expired inhalation agents during the intervals correlating with apparent patient recall. The findings suggest that failure to deliver sufficient concentrations of anesthetic gases permitted awareness events in these cases. Thus data from automated anesthesia information management in the operating room may help identify causes of awareness, and means to prevent awareness can be instituted.
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J Neurosurg Anesthesiol · Jul 2007
Propofol and remifentanil effect-site concentrations estimated by pharmacokinetic simulation and bispectral index monitoring during craniotomy with intraoperative awakening for brain tumor resection.
Different anesthetic techniques have been suggested for craniotomy with intraoperative awakening. We describe an asleep-awake-asleep technique with propofol and remifentanil infusions, with pharmacokinetic simulation to predict the effect-site concentrations and to modulate the infusion rates of both drugs, and bispectral index (BIS) monitoring. Five critical moments were defined: first loss of consciousness (LOC1), first recovery of consciousness (ROC1), final of neurologic testing (NT), second loss of consciousness (LOC2), and second recovery of consciousness (ROC2). ⋯ At ROC2, predicted effect-site concentrations of propofol and remifentanil were, respectively, 1.2+/-0.5 microg/mL and 1.4+/-0.2 etag/mL (data are mean+/-SE). A significative correlation was found between BIS and predicted effect-site concentrations of propofol (r=0.547, P<0.001) and remifentanil (r=0.533, P<0.001). Multiple regression analysis between BIS and propofol and remifentanil predicted effect-site concentrations at the different critical steps of the procedure was done and found also significative (r=0.7341, P<0.001).