Journal of neurosurgical anesthesiology
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J Neurosurg Anesthesiol · Jul 2009
Spectral analysis of heart rate variability during asleep-awake craniotomy for tumor resection.
Anesthesia during asleep-awake craniotomy should provide adequate analgesia and sedation whereas permitting language testing. In this work, we used the analysis of heart rate variability (HRV) to quantify the sympatho-vagal balance and better evaluate patient's stress response during asleep-awake craniotomy. Patients admitted to our hospital for tumor resection with language testing were studied (n=21, age range: 22 to 53 y ). ⋯ During T5, LF/HF ratio returned to preanesthesia level. HRV analysis confirmed the presence of moderate intraoperative stress response, indicating a significant increase in the LF/HF ratio during the awake phases. This information might help in tailoring the protocol and the duration of awake phase according to the individual autonomic response.
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J Neurosurg Anesthesiol · Jul 2009
Hemodynamic changes after administration of mannitol measured by a noninvasive cardiac output monitor.
Mannitol is the most commonly used hyperosmotic agent in neurosurgery. Being an agent that increases intravascular volume by withdrawing water from the brain, it may cause significant changes in stroke volume (SV), cardiac output (CO), systemic vascular resistance and blood pressure. In this study, we monitored the hemodynamic changes in response to a single dose of mannitol by using a noninvasive CO monitor based on the thoracic electrical bioimpedance technique, in patients undergoing craniotomy. ⋯ The overall fluid balance at the end of 120 minutes was -370+/-987 mL. In this study using noninvasive measurement of CO by thoracic bioimpedance plethysmography during craniotomy, a single bolus dose of mannitol 1.0 g/kg caused a significant but short duration changes in the hemodynamic variables. The changes in SV, and CO, lasted for only 15 minutes after the infusion.
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J Neurosurg Anesthesiol · Jul 2009
Comparative StudyEvaluation of the FloTrac uncalibrated continuous cardiac output system for perioperative hemodynamic monitoring after subarachnoid hemorrhage.
Early hemodynamic assessment is of particular importance for adequate cerebral circulation in patients with aneurysmal subarachnoid hemorrhage (SAH), but is often precluded by the invasiveness and complexity of the established cardiac output determination techniques. We examined the utility of an uncalibrated arterial pressure-based cardiac output monitor (FloTrac) for intraoperative and postoperative hemodynamic management after SAH. In 16 SAH patients undergoing surgical clipping, arterial pulse contour cardiac index, and stroke volume variation (SVV) were analyzed via the radial FloTrac system. ⋯ Better prediction of cardiac responsiveness to defined volume loading for increasing stroke volume index >10% was observed for SVV under mechanical ventilation with greater area under the receiver operating characteristics curve than that for global end-diastolic volume index or central venous pressure. These data suggest that the FloTrac underestimates the reference CI, and is not as reliable as transpulmonary thermodilution for perioperative hemodynamic monitoring after SAH. SVV is considered to be an acceptable preload indicator under mechanical ventilation.
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J Neurosurg Anesthesiol · Jul 2009
Randomized Controlled Trial Comparative StudyA randomized, double-blinded comparison of ondansetron, granisetron, and placebo for prevention of postoperative nausea and vomiting after supratentorial craniotomy.
Postoperative nausea and vomiting (PONV) are frequent and distressing complications after neurosurgical procedures. We evaluated the efficacy of ondansetron and granisetron to prevent PONV after supratentorial craniotomy. In a randomized double-blind, placebo controlled trial, 90 adult American Society of Anesthesiologists I, II patients were included in the study. ⋯ No significant correlation was found between neurosurgical factors (presence of midline shift, mass effect, pathologic diagnosis of tumor, site of tumor) and the occurrence of PONV. We conclude that ondansetron 4 mg and granisetron 1 mg are comparably effective at preventing emesis after supratentorial craniotomy. However, neither drugs prevented nausea effectively.