http://hdl.handle.net/2027.42/60130 2017-07-09T21:39:40Z 2017-07-09T21:39:40Z Anderson, Steven W. Todd, Michael M. Hindman, Bradley J. Clarke, William R. Torner, James C. Tranel, Daniel Yoo, Bongin Weeks, Julie Manzel, Kenneth W. Samra, Satwant http://hdl.handle.net/2027.42/55889 2015-05-05T17:58:58Z 2006-11-01T00:00:00Z

Effects of intraoperative hypothermia on neuropsychological outcomes after intracranial aneurysm surgery Anderson, Steven W.; Todd, Michael M.; Hindman, Bradley J.; Clarke, William R.; Torner, James C.; Tranel, Daniel; Yoo, Bongin; Weeks, Julie; Manzel, Kenneth W.; Samra, Satwant Objective Subarachnoid hemorrhage and surgical obliteration of ruptured intracranial aneurysms are frequently associated with neurological and neuropsychological abnormalities. We reported that intraoperative cooling did not improve neurological outcome in good-grade surgical subarachnoid hemorrhage patients, as assessed by the Glasgow Outcome Scale score or other neurological and functional measures (National Institutes of Health Stroke Scale, Rankin Disability Scale, Barthel Activities of Daily Living). We now report the results of neuropsychological testing in these patients. Methods A total of 1,001 patients who bled ≤14 days before surgery were randomly assigned to intraoperative hypothermia (t = 33°C) or normothermia (37°C). Outcome was assessed approximately 3 months after surgery. Patients underwent the Benton Visual Retention, Controlled Oral Word Association, Rey–Osterrieth Complex Figure, Grooved Pegboard, and the Trail Making tests. T -scores for each test were calculated from normative data. T -scores were averaged to calculate a Composite Score. A test result (or the Composite Score) was considered “impaired” if the T -score was two or more standard deviations below the norm. A Mini-Mental State Examination was also performed. Results Neurological outcome data were available in 1,000 patients. Sixty-one patients died. Of the 939 survivors, 873 completed 3 or more tests (exclusive of the Mini-Mental State Examination). Patients with poor neurological outcomes were less likely to complete testing; only 3.9% of Good Outcome (Glasgow Outcome Scale score = 1) patients were untested, compared with 38.6% of patients with Glasgow Outcome Scale scores of 3 and 4. There were no prerandomization demographic differences between the two treatment groups. For hypothermic patients, 16.8% were impaired from their Composite Score versus 20.0% of patients in the normothermic group ( p = 0.317). For patients in the hypothermic group, 54.5% were impaired on at least one test, compared with 55.5% of patients in the normothermic group ( p = 0.865). Similar results were seen in patients with baseline WFNS scores = I. Mini-Mental State Examination scores in the hypothermic and normothermic groups were 27.4 ± 3.8 and 26.8 ± 4.5, respectively. Interpretation This is the largest prospective evaluation of neuropsychological function after subarachnoid hemorrhage to date. Testing was completed in a high fraction of patients, demonstrating the feasibility of such testing in a large trial. However, the frequent inability to complete testing in poor-outcome patients suggests that testing may be best used to refine outcome assessments in good-grade patients. Many patients showed impairment on at least one test, with global impairment present in 17 to 20% of patients (18–21% of survivors). This was true even among the patients with the best preoperative condition (WFNS = 1). There was no difference in the incidence of impairment between hypothermic and normothermic groups. Ann Neurol 2006;60:518–527

2006-11-01T00:00:00Z Booth, Victoria Poe, Gina R. http://hdl.handle.net/2027.42/49532 2007-03-20T08:22:28Z 2006-02-01T00:00:00Z

Input source and strength influences overall firing phase of model hippocampal CA1 pyramidal cells during theta: Relevance to REM sleep reactivation and memory consolidation Booth, Victoria; Poe, Gina R. In simulation studies using a realistic model CA1 pyramidal cell, we accounted for the shift in mean firing phase from theta cycle peaks to theta cycle troughs during rapid-eye movement (REM) sleep reactivation of hippocampal CA1 place cells over several days of growing familiarization with an environment (Brain Res 855:176–180). Changes in the theta drive phase and amplitude between proximal and distal dendritic regions of the cell modulated the theta phase of firing when stimuli were presented at proximal and distal dendritic locations. Stimuli at proximal dendritic sites (proximal to 100 Μm from the soma) invoked firing with a significant phase preference at the depolarizing theta peaks, while distal stimuli (>290 Μm from the soma) invoked firing at hyperpolarizing theta troughs. The input location-related phase preference depended on active dendritic conductances, a sufficient electrotonic separation between input sites and theta-induced subthreshold membrane potential oscillations in the cell. The simulation results predict that the shift in mean theta phase during REM sleep cellular reactivation could occur through potentiation of distal dendritic (temporo-ammonic) synapses and depotentiation of proximal dendritic (Schaffer collateral) synapses over the course of familiarization. © 2006 Wiley-Liss, Inc.

2006-02-01T00:00:00Z Wahr, Joyce A. Lau, Wei Tremper, Kevin K. Hallock, Lucy Smith, Kaye http://hdl.handle.net/2027.42/43058 2015-01-16T19:18:24Z 1996-07-01T00:00:00Z

Accuracy and precision of a new, portable, handheld blood gas analyzer, the IRMA® Wahr, Joyce A.; Lau, Wei; Tremper, Kevin K.; Hallock, Lucy; Smith, Kaye Objective. The accuracy and precision of the new IRMA® (Immediate Response Mobile Analysis System, Diametrics, Inc.®, St. Paul, MN) handheld blood gas analyzer was compared with that of two benchtop blood gas analyzers. The IRMA consists of a notebook-sized machine and disposable cartridges, each containing a pH, a CO 2 and an O 2 electrode, and provides bedside (point-of-care) blood gas analysis. Methods. A total of 172 samples (arterial and mined venous) were obtained from 25 informed, consenting patients undergoing cardiopulmonary bypass. The pH, PCO 2 and PO 2 of each sample was determined on four blood gas analyzers: NOVA Statlabs Profile 5 (NOVA Biomedical, Waltham, MA), the ABL-50 (Radiometer, West Lake, OH), and two IRMA machines. Linear regression and bias ± precision were determined, comparing each of the analyzers with the NOVA. Results. All three machines showed a similar, high degree of correlation with the NOVA for pH, PCO 2 , and PO 2 . The bias and precision of the IRMA machines compared with the NOVA was similar to that of the ABL compared with the NOVA for pH (NOVA:ABL −0.005 ± 0.011; NOVA: IRMA 1 = 0.0026 ± 0.025; NOVA: IRMA 2 = 0.0021 ± 0.025), for PCO 2 (NOVA:ABL = −1.4 ± 1.3 mmHg; NOVA: IRMA 1 = −1.3 ± 1.9 mmHg; NOVA: IRMA 2 = −1.2 ± 2.1 mmHg) and PO 2 (NOVA:ABL = 3.6 ± 21.1 mmHg; NOVA: IRMA 1 = 3.4 = 19.9 mmHg; NOVA: IRMA 2 = 6.3 ± 20.9 mmHg). The bias found for pH, PCO 2 , and PO 2 was not affected by extremes of temperature (range 25.5–40°C) or hematocrit (range 11–44%) for any machine. Conclusions. The new technology incorporated in the IRMA blood gas analyzer provides results with an accuracy that is similar to that of benchtop analyzers, but with all of the advantages of point-of-care analysis.

1996-07-01T00:00:00Z Harrison, William Bauld, Thomas J. Tremper, Kevin K. http://hdl.handle.net/2027.42/43057 2014-11-17T21:35:31Z 1994-01-01T00:00:00Z

Convenient and cost-effective modification of neuromuscular blockade monitors Harrison, William; Bauld, Thomas J.; Tremper, Kevin K.

1994-01-01T00:00:00Z