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P Mark Li

Publications and source records attributed to P Mark Li.

2 recordsLinked to original sources

Use of admission Glasgow Coma Score, pupil size, and pupil reactivity to determine outcome for trauma patients.

BACKGROUND: Determination of nonsurvival in trauma patients is difficult because valid prognostic indicators are lacking. It was hypothesized that patients presenting with a Glasgow Coma Score (GCS) of 3 as well as fixed and dilated (FD) pupils do not have a reasonable chance of survival. METHODS: From 1999 through 2001, adult trauma patients (age, >14 years) admitted with a GCS of 3 were reviewed. Patients receiving paralytic agents before initial assessment were excluded from analysis. Fixed and dilated pupils were defined as being 4 mm or more in diameter bilaterally and nonreactive to light. In this study, the FD patients were evaluated for survival, resuscitative measures, surgical procedures, length of hospital stay, and organ donation. The non-FD patients were evaluated for survival and length of hospital stay. RESULTS: Of the 137 patients evaluated with a GCS of 3, 104 had FD pupils and 33 did not. In the FD group, there were no survivors. On arrival, 28 (37.3%) of the patients were declared dead, and no further interventions were undertaken. Of the 76 patients (62.7%) who underwent further resuscitation, which included 53 surgical procedures, 30 died in the resuscitation bay, 39 within 24 hours, 4 within 48 hours, 2 within 72 hours, and 1 on day 6. There were 18 (23.7%) organ donors. Of the 33 patients without FD pupils, 11 (33%) survived to discharge (mean hospital stay, 21.4 days). Of the 22 nonsurvivors (67%), 10 died in the resuscitation bay, 8 within 24 hours, 1 within 48 hours, 1 on day 4, and 2 on day 6. CONCLUSIONS: Patients presenting with a GCS of 3 and FD pupils have no reasonable chance for survival. A significant percentage of these patients can be salvaged for organ donation. This information should be used in deciding to pursue aggressive resuscitation efforts and in discussing prognosis with family. Patients with a GCS of 3 who are not FD should be aggressively resuscitated because many of these patients survive to discharge.

Adolescent↗

Cerebral activation during vagus nerve stimulation: a functional MR study.

PURPOSE: To study the short-term effects of vagus nerve stimulation (VNS) on brain activation and cerebral blood flow by using functional magnetic resonance imaging (fMRI). METHODS: Five patients (three women, two men; mean age, 35.4 years) who were treated for medically refractory epilepsy with VNS, underwent fMRI. All patients had a nonfocal brain MRI. The VNS was set at 30 Hz, 0.5-2.0 mA for intervals of activation of 30 s on and 30 s off, during which the fMRI was performed. Statistical parametric mapping (SPM) was used to determine significant areas of activation or inhibition during vagal nerve stimulation (p < 0.05). RESULTS: VNS-induced activation was detected in the thalami bilaterally (left more than right), insular cortices bilaterally, ipsilateral basal ganglia and postcentral gyri, right posterior superior temporal gyrus, and inferomedial occipital gyri (left more than right). The most robust activation was seen in the thalami (left more than right) and insular cortices. CONCLUSIONS: VNS-induced thalamic and insular cortical activation during fMRI suggests that these areas may play a role in modulating cerebral cortical activity, and the observed decrease in seizure frequency in patients who are given VNS may be a consequence of this increased activation.

Adult↗