ISSN:0898-4921    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

The objective of the first part of this study was to use an animal model to investigate the relationship between temperature in the cerebrovenous compartment and cerebral perfusion pressure. In the second part of the study, the objective was to examine the influence of hyperventilation and hypothermia on jugular bulb temperature and body temperature in patients undergoing elective neurosurgery. Intracranial pressure was increased artificially by inflating an infratentorial supracerebellar placed balloon catheter in nine pigs under general anesthesia. Temperature was monitored by thermocouples inserted in the sagittal sinus, white matter of the left lobe and abdominal aorta during the ensuing decrease in cerebral profusion pressure (CPP). Cerebrovenous blood temperature (jugular bulb) and body temperature (urinary bladder) were simultaneously monitored in 24 patients undergoing craniotomy. Moderate hyperventilation was performed in all patients. Cerebrovenous blood and core body temperature were recorded and differences between these two temperatures calculated at the beginning and the end of hyperventilation. At the beginning of the intracranial pressure (ICP), increase mean temperatures of cerebrovenous blood and cerebral tissue (left lobe) were lower than core body temperature. During CPP reduction the difference between core body temperature and cerebrovenous blood temperature increased significantly from 0.86 ± 0.44°C prior to ICP rise to 1.19 ± 0.58°C at maximum ICP. Before hyperventilation, cerebrovenous blood temperature was higher in 19 patients (±difference: 0.34°C ± 0.27) and equal or lower in five patients (difference: −0.08°C ± 0.11), than core body temperature. At the end of hyperventilation, the difference between cerebrovenous blood temperature and core body temperature increased (+0.42°C ± 0.24) in those 19 patients who had started with a higher cerebrovenous blood temperature and decreased (−0.10°C ± 0.18) in the other five patients. Both studies demonstrated that the temperature of cerebrovenous blood is influenced by maneuvers which are supposed to decrease cerebral blood flow.

ISSN:0898-4921    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

This study reports the collective effect of the positions of the operating table, head, and neck on intracranial pressure (ICP) of 15 adult patients scheduled for elective intracerebral surgery. Patients were anesthetized with propofol, fentanyl, and maintained with a propofol infusion and fentanyl. Intracranial pressure was recorded following 20 minutes of stabilization after induction at different table positions (neutral, 30° head up, 30° head down) with the patient's neck either 1) straight in the axis of the body, 2) flexed, or 3) extended, and in the five following head positions: a) head straight, b) head angled at 45° to the right, c) head angled at 45° to the left, d) head rotated to the right, or e) head rotated the left. For ethical reasons, only patients with ICP ≤ 20 mm Hg were included. Intracranial pressure increased every time the head was in a nonneutral position. The most important and statistically significant increases in ICP were recorded when the table was in a 30° Trendelenburg position with the head straight or rotated to the right or left, or every time the head was flexed and rotated to the right or left—whatever the position of the table was. These observations suggest that patients with known compromised cerebral compliance would benefit from monitoring ICP during positioning, if the use of a lumbar drainage is planed to improve venous return, cerebral blood volume, ICP, and overall operating conditions.

ISSN:0898-4921    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

For patients undergoing craniotomy, it is desirable to have stable and easily controllable hemodynamics during intense surgical stimulation. However, rapid postoperative recovery is essential to assess neurologic function. Remifentanil, an ultra-short-acting &mgr;-opioid receptor agonist, may be the ideal agent to confer the above characteristics. In this prospective randomized study, we compared the hemodynamic stability, recovery characteristics, and the dose of propofol required for maintaining anesthesia supplemented with an infusion of remifentanil, alfentanil, or fentanyl in 34 patients scheduled for supratentorial craniotomy. With routine monitors in place, anesthesia was induced with propofol (2–3 mg/kg), atracurium (0.5 mg/kg), and either remifentanil (1 &mgr;g/kg), alfentanil (10 &mgr;g/kg), or fentanyl (2 &mgr;g/kg). The lungs were ventilated with O2/air to mild hypocapnia. Anesthesia was maintained with infusions of propofol (50–100 &mgr;g/kg/min) and either remifentanil (0.2 &mgr;g/kg/min), alfentanil (20 &mgr;g/kg/h), or fentanyl (2 &mgr;g/kg/h). There were no significant differences among the groups in the dose of propofol maintenance required, heart rate, or mean arterial pressure. However, the time to eye opening (minutes) was significantly shorter in the remifentanil compared to the alfentanil group (6 ± 3; 21 ± 14;P= 0.0027) but not the fentanyl group (15 ± 9). We conclude that remifentanil is an appropriate opioid to use in combination with propofol during anesthesia for supratentorial craniotomy.

ISSN:0898-4921    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Neuroendoscopic procedures are increasing in frequency in neurosurgical practice. We describe the anesthetic technique and the perioperative complications found in 100 neuroendoscopic interventions performed at our institution. Cranial tumor biopsy or retrieval (62%) and cisternostomy for hydrocephalus (33%) were the most frequent indications for neuroendoscopy. The mortality rate was low (1%). Intraoperative complications occurred in 36 patients, with arterial hypertension being the most frequent (53%). Postoperative complications occurred in 52 patients; anisocoria (31%) and delayed arousal (29%) were the most frequent. The pressure inside the endoscope was monitored intraoperatively in the last 47 patients. A saline-filled catheter from a pressure transducer connected to the neuroendoscopy system was used for pressure monitoring. We recorded the highest peak of pressure values measured during each procedure. Twenty-three patients (49%) had peak pressure values >30 mm Hg, 12 patients (25%) >50 mm Hg, and 3 patients >100 mm Hg. Only one patient had hemodynamic changes occurring simultaneously with the pressure changes. We found an association between pressure inside the endoscope >30 mm Hg and postoperative (P= .003) but not intraoperative complications. A relationship was found between surgical duration and postoperative complications (P= .002). Neither the pressure inside the endoscope or the intraoperative morbidity were related to surgical duration. We conclude that there may be a high rate of postoperative complications after neuroendoscopies, namely, new neurologic deficits. High pressure levels inside the endoscope during neuroendoscopic procedures can occur without hemodynamic warning signs. Pressure values >30 mm Hg are associated with postoperative morbidity, especially unexpected delayed recovery. Measuring the pressure inside the endoscope is technically easy and might be beneficial if performed in all neuroendoscopic procedures. Reducing the incidence of episodes of high peak pressure values might decrease the rate of postoperative complications.

ISSN:0898-4921    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Urinary trypsin inhibitor (UTI) is a physiological protease inhibitor produced in the liver and excreted into urine. Urinary trypsin inhibitor-like antigen has been demonstrated on glial cells in the brain. This study measured cerebrospinal UTI levels in various conditions. Seven subjects in each of the following groups were studied: patients undergoing spinal anesthesia for minor surgery, spinal anesthesia for cesarean section, removal of meningioma, or at postoperative day 3 after ruptured intracranial aneurysm clipping. Cerebrospinal fluid was collected from a spinal needle, a needle puncturing the sylvian fissure, or a drainage tube from the optical carotid cistern. Urine was collected from a urinary catheter. Cerebrospinal and urinary UTI concentrations were measured by radioimmunoassay, and the urinary UTI concentration was divided by urinary creatinine concentration to give the systemic UTI concentration. The cerebrospinal UTI concentration in the brain tumor and postoperative state groups was significantly higher than in the spinal anesthesia and cesarean section groups. The systemic UTI concentration in the cesarean section and postoperative state groups was significantly higher than in the spinal anesthesia and brain tumor groups. The present results demonstrate that UTI can be detected in the cerebrospinal fluid, and suggest that cerebrospinal UTI increases in patients with a brain tumor or inflammation and is not affected by systemic UTI.

ISSN:0898-4921    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

This clinical report investigated the potential benefit of acute normovolemic hemodilution (ANH) as a blood-saving technique in the surgical repair of craniosynostosis. Over a 4-year period, 34 healthy children undergoing surgical repair of scaphocephaly or pachycephaly were randomly assigned to two groups of 17 patients each. Patients of the first group (ANH group) were submitted to ANH (target Ht: 25%) immediately before surgery and patients of the second group (Control group) were not. During surgery, estimated blood loss was compensated with a 5% albumin solution and no autologous or homologous blood was transfused. At the end of surgery, intraoperative blood loss (mean ± SD) calculated on the basis of the Ht value and the children weight was 21.3 ± 8% of the estimated blood volume (EBV) in the ANH group and 24 ± 6.6% in the Control group. Children of the ANH group received their autologous blood (18.9 ± 3.3% of EBV) systematically at the end of surgery. In the postoperative period, homologous blood was transfused when the Ht value was equal or less than 21%. Both groups were comparable regarding age, weight, type of craniosynostosis, duration of surgery, EBV, and preoperative Ht value. No difference was observed between ANH and Control groups in the number of patients who received homologous blood (15/17 and 14/17, respectively), in the amount of homologous blood transfused (17 ± 4.7% and 19.6 ± 6.3% of the EBV, respectively), and in the Ht value before hospital discharge (29.4 ± 5.0% and 30.7 ± 4.9%, respectively). In conclusion, this report suggests that ANH reduces neither the incidence of homologous transfusion nor the amount of homologous blood transfused in this series of children undergoing surgical repair of craniosynostosis.

ISSN:0898-4921    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Information on the effects of sevoflurane on the rate of cerebrospinal fluid (CSF) formation (Vf) and resistance to reabsorption of CSF (Ra) is incomplete, and no such information is available for remifentanil. The present study examined the dose-related effects of sevoflurane and remifentanil on Vf and Ra in rabbits. Eight rabbits were studied during isoflurane 1.4% (baseline) and sevoflurane 1.4%, 2.5%, and 3.7%, and eight were studied during isoflurane 1.4% (baseline) and remifentanil 0.30, 0.67, and 1.00 &mgr;g · kg−1· min−1in randomized order. Ventriculocisternal perfusion at two CSF pressure states for each experimental condition was used to determine Vf and Ra. There was no dose–response relation for Vf (10.4 ± 2.5, 9.0 ± 2.0, and 10.0 ± 3.0 &mgr;l · min−1) or Ra (0.81 ± 0.33, 1.35 ± 0.54, and 0.84 ± 0.27 cm H2O · &mgr;l−1· min) between the three sevoflurane concentrations. There also was no dose–response relation for Vf (7.8 ± 1.2, 8.8 ± 3.0, and 6.5 ± 2.3 &mgr;l · min−1) or Ra (1.07 ± 0.54, 1.23 ± 0.50, and 1.13 ± 0.51 cm H2O · &mgr;l−1· min) between the three remifentanil doses. Vf and Ra during either sevoflurane or remifentanil were not significantly different from Vf and Ra during the two isoflurane baseline conditions (Vf = 8.5 ± 2.5 and 9.8 ± 1.3 &mgr;l · min−1, and Ra = 0.97 ± 0.36 and 1.38 ± 0.55 cm H2O · &mgr;l−1· min, mean ± SD). Vf and Ra are of interest because they influence CSF volume, intracranial pressure, and/or intracranial elastance. In our model, sevoflurane or remifentanil did not significantly alter Vf or Ra.

ISSN:0898-4921    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Recently, the enzyme cyclooxygenase (COX) has been recognized to exist as constitutive (COX-1) and inducible isoforms (COX-2). In previous studies, drugs that were inhibitors of both COX-1 and COX-2 failed to decrease brain edema formation or improve Neurological Severity Score (NSS) after closed head trauma (CHT), although some did decrease prostaglandin-E2 (PGE2) formation. The present study examined whether or not a specific inhibitor of COX-2 (nimesulide) exerts a beneficial effect after CHT in rats. Halothane-anesthetized rats (n = 8 in each group) were randomly assigned to one of four groups: surgery, no CHT, no drug (group 1); surgery, no CHT, nimesulide 30 mg/kg intraperitoneally (IP) (group 2); surgery, CHT, no drug (group 3); and surgery, CHT, nimesulide 30 mg/kg IP (group 4). NSS was determined at 1 and 24 h, and brain tissue PGE2 concentration and water content were determined after killing at 24 h. Treatment with nimesulide did not improve NSS (NSS at 24 h = 11 ± 6 [median ± range] in group 3 and 12 ± 4 in group 4) or edema formation (brain water content at 24 h = 84.3 ± 1.8% [mean ± SD] in group 3 and 83.8 ± 1.9% in group 4). However, nimesulide did decrease cortical and hypothalamic PGE2 formation by 41% and 47%, respectively during the first hour of incubation after brain tissue sampling. The authors conclude that although nimesulide does reduce tissue PGE2 formation, it does not exert a beneficial effect on brain tissue edema or functional activity after CHT in rats.

ISSN:0898-4921    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Embolization procedure was performed for a 12-year-old boy with a left parietal arteriovenous malformation. Although provocative tests for the feeders to be occluded were considered very informative, the patient had to be sedated during microcatheter insertion. We used intermittent sedation with propofol during the interventional procedure, and obtained successful embolization.

ISSN:0898-4921    

出版商:OVID    

年代:2000

数据来源: OVID