Journal of neurosurgical anesthesiology
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J Neurosurg Anesthesiol · Jan 2007
Randomized Controlled TrialBispectral index profile during carotid cross clamping.
This study aimed at investigating the Bispectral Index (BIS) profile during carotid cross clamping (CXC). The study involved a pilot group of 10 patients undergoing routine carotid endarterectomy with shunt insertion under total intravenous anesthesia, and a study group of 26 additional patients. In all patients, rates of propofol and remifentanil providing a steady-state level of hypnosis (BIS: 40-60) were maintained constant throughout a recording period ranging from 3 minutes before CXC to shunt insertion. ⋯ In conclusion, during CXC under a constant level of intravenous anesthesia, BIS may increase, decrease, or remain unchanged. The paradoxical BIS increase could be related to borderline ischemia, a change in brain anesthetic agent concentration, or a change in the nociceptive-antinociceptive balance associated with a CXC-elicited painful stimulation. Caution should be used when interpreting BIS value during CXC.
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J Neurosurg Anesthesiol · Jan 2007
Randomized Controlled TrialEffect of head position on postoperative chemosis after prone spinal surgery.
Conjunctival swelling is a common finding in patients positioned prone. The purpose of this study was to evaluate the effect of head position on postoperative chemosis after prone spinal surgery. On the basis of the head position, 108 patients scheduled for prone lumbar surgery were randomly allocated to 1 of 2 groups: head neutral group (n=54) versus head down (HD) group (n=54). ⋯ The severity of chemosis, which was graded as none, mild, moderate, and severe, showed statistically significant difference between the head neutral group [24 (44%), 25 (46%), 3 (6%), 2 (4%), respectively] and HD group [10 (19%), 23 (43%), 17 (31%), 4 (7%), respectively, P<0.01]. Positive fluid balance and duration of surgery were risk factors for the development of postoperative chemosis. This result suggested that neutral head position, smaller fluid administration, and shorter duration of surgery were useful in decreasing the development of postoperative chemosis after prone spinal surgery.