Articles from Critical Care Medicine

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Greer, David M.
Multimodal magnetic resonance imaging for determining prognosis in patients with traumatic brain injury-Promising but not ready for primetime [Editorial]
Critical Care Medicine. 37(4):1523-1524, April 2009.

Baker, Stephen
Trauma computed tomography and radiation dose: A matter of concern [Editorial]
Critical Care Medicine. 37(4):1508-1509, April 2009.

Tollard, Eleonore MD; Galanaud, Damien MD, PhD; Perlbarg, Vincent et al
Experience of diffusion tensor imaging and 1H spectroscopy for outcome prediction in severe traumatic brain injury: Preliminary results
Critical Care Medicine. 37(4):1448-1455, April 2009.
Abstract
Objective: The objective of the study is to test whether multimodal magnetic resonance imaging can provide a reliable outcome prediction of the clinical status, focusing on consciousness at 1 year after severe traumatic brain injury (TBI).Design: Single center prospective cohort with consecutive inclusions.Setting: Critical Care Neurosurgical Unit of a university hospital.Patients: Forty-three TBI patients not responding to simple orders after sedation cessation and 15 healthy controls.Interventions: A multimodal magnetic resonance imaging combining morphologic sequences, diffusion tensor imaging (DTI), and 1H proton magnetic resonance spectroscopy (MRS) was performed 24 +/- 11 days after severe TBI. The ability of DTI and MRS to predict 1-year outcome was assessed by linear discriminant analysis (LDA). Robustness of the classification was tested using a bootstrap procedure.Measurements and Main Results: Fractional anisotropy (FA) was computed as the mean of values at discrete brain sites in the infratentorial and supratentorial regions. The N-acetyl aspartate/creatine (NAA/Cr) ratio was measured in the thalamus, lenticular nucleus, insular cortex, occipital periventricular white matter, and pons. After 1 year, 19 (44%) patients had unfavorable outcomes (death, persistent vegetative state, or minimally conscious state) and 24 (56%) favorable outcomes (normal consciousness with or without functional impairments). Analysis of variance was performed to compare FA and NAA/Cr in the two outcome groups and controls. FA and MRS findings showed highly significant differences between the outcome groups, with significant variables by LDA being supratentorial FA, NAA/Cr (pons), NAA/Cr (thalamus), NAA/Cr (insula), and infratentorial FA. LDA of combined FA and MRS data clearly separated the unfavorable outcome, favorable outcome, and control groups, with no overlap. Unfavorable outcome was predicted with up to 86% sensitivity and 97% specificity; these values were better than those obtained with DTI or MRS alone.Conclusion: FA and NAA/Cr hold potential as quantitative outcome-prediction tools at the subacute phase of TBI.(C) 2009 Lippincott Williams & Wilkins, Inc.

Salottolo, Kristin MPH; Bar-Or, Raphael BS; Fleishman, Matthew MD; Maruyama, Gen et al
Current utilization and radiation dose from computed tomography in patients with trauma
Critical Care Medicine. 37(4):1336-1340, April 2009.
Abstract
Objective: To quantify the cumulative effective dose of radiation received during hospitalization after traumatic injury and to compare the computed tomography (CT) utilization practices for two time periods in patients with trauma.Design: A retrospective analysis of radiologic and medical data.Setting: A level I trauma center.Patients: Consecutively admitted adult patients with trauma with moderate to severe injuries (injury severity score >8), an intensive care unit (ICU) length of stay of one or more days, who were directly admitted and not transferred to another acute care center.Measurements and Main Results: CT examination means and utilization were compared for April through August, 2003 and April to August, 2007. Cumulative effective doses were calculated for the 2007 period, and patients with a high radiation dose (>100 mSv) were identified. One hundred sixty-five adult patients with trauma were included. An increase in mean CT examinations per patient was observed in the 2007 period compared with the 2003 period, overall (4.41 vs. 3.44, p = 0.002) and among subsets of patients. The overall increase remained significant after adjustment for patient demographics (p = 0.05). The mean cumulative effective dose per patient was 11.13 mSv in 2007; 9% of patients received a dose >=100 mSv.Conclusions: Patients with trauma are at an increased risk of adverse effects from CT studies, because they receive high doses of radiation, and the number of CT examinations that patients receive is increasing with time. We recommend that risk of radiation be prospectively monitored and estimated by hospitals through the use of CT examination count per patient.(C) 2009 Lippincott Williams & Wilkins, Inc.