Damon R. Kuehl

Neuroimaging after mild traumatic brain injury: review and meta-analysis.

This paper broadly reviews the study of mild traumatic brain injury (mTBI), across the spectrum of neuroimaging modalities. Among the range of imaging methods, however, magnetic resonance imaging (MRI) is unique in its applicability to studying both structure and function. Thus we additionally performed meta-analyses of MRI results to examine 1) the issue of anatomical variability and consistency for functional MRI (fMRI) findings, 2) the analogous issue of anatomical consistency for white-matter findings, and 3) the importance of accounting for the time post injury in diffusion weighted imaging reports. As we discuss, the human neuroimaging literature consists of both small and large studies spanning acute to chronic time points that have examined both structural and functional changes with mTBI, using virtually every available medical imaging modality. Two key commonalities have been used across the majority of imaging studies. The first is the comparison between mTBI and control populations. The second is the attempt to link imaging results with neuropsychological assessments. Our fMRI meta-analysis demonstrates a frontal vulnerability to mTBI, demonstrated by decreased signal in prefrontal cortex compared to controls. This vulnerability is further highlighted by examining the frequency of reported mTBI white matter anisotropy, in which we show a strong anterior-to-posterior gradient (with anterior regions being more frequently reported in mTBI). Our final DTI meta-analysis examines a debated topic arising from inconsistent anisotropy findings across studies. Our results support the hypothesis that acute mTBI is associated with elevated anisotropy values and chronic mTBI complaints are correlated with depressed anisotropy. Thus, this review and set of meta-analyses demonstrate several important points about the ongoing use of neuroimaging to understand the functional and structural changes that occur throughout the time course of mTBI recovery. Based on the complexity of mTBI, however, much more work in this area is required to characterize injury mechanisms and recovery factors and to achieve clinically-relevant capabilities for diagnosis.

Trends in emergency department management of skin abscesses

BACKGROUND Abscess is a distinct skin and soft tissue infection (SSTI) requiring incision and drainage (I&D). Previous national surveys combined all SSTIs to estimate abscess and evaluate management. We hypothesized that antibiotic rates are declining in response to evidence that antibiotics are unnecessary for most SSTIs requiring I&D. METHODS Emergency department (ED) patients included in the National Hospital Ambulatory Medical Care Survey from 2007-2010 with diagnosis codes for cutaneous abscess or SSTI were filtered using a procedure code for I&D available since 2007. The number of patients with SSTI, the percentage of patients receiving I&D, and the percentage of patients receiving antibiotics were determined. Antibiotics were characterized based on efficacy to methicillin-resistant Staphylococcus aureus (MRSA). RESULTS ED visits for SSTI increased from 3.55 million (95% confidence interval [CI], 3.24 million-3.86 million) in 2007 to 4.21 million (95% CI, 3.89 million-4.55 million) in 2010. Incidences of I&D rose from 736,000 (95% CI, 602,000-869,000) to 1.48 million (95% CI, 1.30 million-1.65 million) and comprised 32.2% of SSTI visits over the 4 years. In 2007, 85.1% (95% CI, 82.6%-87.7%) of patients received antibiotics after I&D with no change over 4 years. In 2010, 15.5% (95% CI, 12.1%-18.7%) received ≥2 antibiotics. Commonly prescribed antibiotics were trimethoprim-sulfamethoxazole (mean, 50.4%) followed by cephalexin (mean, 17.2%) and clindamycin (mean, 16.3%). CONCLUSION ED visits for SSTIs continue to rise. Despite mounting evidence, antibiotic use in SSTIs requiring I&D is high, and many patients receive multiple antibiotics, including drugs with no efficacy on MRSA.

Normal saline versus Normosol™-R in sepsis resuscitation: A retrospective cohort study

Objective To determine the effect of Normosol™-R as compared to normal saline on the outcomes of acute kidney injury and the need for renal replacement therapy in the resuscitation phase of sepsis. Design Our study is a retrospective before-and-after cohort study. Setting The study occurred at a 700-bed tertiary academic level 1-trauma center. Patients A total of 1218 patients were enrolled through emergency department admissions. The normal saline (before) cohort was defined as the dates between 1 March and 30 September 2014 and the Normosol™-R (after) cohort was assessed from 1 March to 30 September 2015. Interventions None. Measurements and main results Intravenous fluid volumes received during the first 24 h, 72 h, and total hospital stays were compared. Sodium, chloride, potassium, and bicarbonate levels at 72 h were also compared. The medical coded diagnosis of acute kidney failure, need for renal replacement therapy, hospital LOS, ICU admission, ICU LOS, in-hospital mortality, and need for mechanical ventilation were all compared. There was no significant difference in intravenous fluid volumes between groups. Regression modelling controlling for baseline characteristics and 24-h fluid intake volume found no differences between groups for the primary outcomes of acute kidney injury (P = 0.99) and renal replacement therapy (P = 0.88). Patients in the Normosol™-R cohort were found to have a lower rate of hyperchloremia at 72 h post-admission (28% vs. 13%, P < 0.0001). There was a trend toward a decrease in the hospital and ICU LOS in the Normosol™-R cohort; however, the data were not statistically significant. Conclusions This study was unable to detect any difference in outcomes between sepsis patients who received intravenous fluid resuscitation with either a balanced crystalloid (Normosol™-R) or normal saline, except for a decreased rate of hyperchloremia.

Hemostatic Matrix (FloSeal) as Treatment for Urethral Crush Injury After Failure of Traditional Hemostatic Technique

We report a case of traumatic arterial hemorrhage from the posterior urethral artery, refractory to traditional hemostatic technique, and successfully managed with intraurethral thrombin hemostatic matrix (FloSeal [Baxter Healthcare Corporation, Deerfield, Illinois, US]). We believe that this demonstrates a safe, effective therapy for urethral hemorrhage that may be accomplished by Emergency Physicians and may preclude the need for more invasive hemorrhage control strategies.