Kareem R. AbdelFattah

Resveratrol decreases inflammation in the brain of mice with mild traumatic brain injury.

BACKGROUND Following a mild traumatic brain injury (TBI) event, the secondary brain injury that persists after the initial blow to the head consists of excitotoxicity, decreased cerebral glucose levels, oxidant injury, mitochondrial dysfunction, inflammation, and neuronal cell death. To date, there are no effective interventions used at decreasing secondary brain injury after mild TBI. METHODS In this study, male mice were treated with either placebo or resveratrol (100 mg/kg) at 5 minutes and 12 hours after mild TBI. The mice were injured using the controlled cortical impact device. In this closed-head model, a midline incision was made to access the skull and the impactor tip was aligned on the sagittal suture midway between the bregma and lambda sutures. The mice were injured at a depth of 2.0 mm, velocity of 4 m/s, and a delay time of 100 milliseconds. At 72 hours following injury, the animals were intracardially perfused with 0.9% saline followed by 10% phosphate-buffered formalin. The whole brain was removed, sliced, and stained for microglial activation (Iba1). In addition, using the enzyme-linked immunosorbent assay, tissue levels of interleukin 6 (IL-6) and IL-12 were measured in the cerebral cortex and hippocampus. RESULTS In this study, we found that in the placebo treatment group, there was a significant increase in Iba1 staining in the brain. The levels of microglial activation was reduced by resveratrol in the cerebral cortex (p < 0.001), corpus callosum (p < 0.001), and dentate gyrus (p < 0.005) brain regions after mild TBI. In addition to Iba1, resveratrol decreased the brain levels of IL-6 (p < 0.0001) and IL-12 (p < 0.004), which were observed in the hippocampus of the placebo group. In our model, no increase of IL-6 or IL-12 was observed in the cerebral cortex following TBI. CONCLUSION Resveratrol given acutely after TBI results in a decrease in neuroinflammation. These results suggest that resveratrol may be beneficial in reducing secondary brain injury after experiencing a mild TBI.

Detection of β-amyloid oligomers as a predictor of neurological outcome after brain injury

OBJECT Traumatic brain injury (TBI) is known to be a risk factor for Alzheimer-like dementia. In previous studies, an increase in β-amyloid (Aβ) monomers, such as β-amyloid 42 (Aβ42), in the CSF of patients with TBI has been shown to correlate with a decrease in amyloid plaques in the brain and improved neurological outcomes. In this study, the authors hypothesized that the levels of toxic high-molecular-weight β-amyloid oligomers are increased in the brain and are detectable within the CSF of TBI patients with poor neurological outcomes. METHODS Samples of CSF were collected from 18 patients with severe TBI (Glasgow Coma Scale Scores 3-8) and a ventriculostomy. In all cases the CSF was collected within 72 hours of injury. The CSF levels of neuron-specific enolase (NSE) and Aβ42 were measured using enzyme-linked immunosorbent assay. The levels of high-molecular-weight β-amyloid oligomers were measured using Western blot analysis. RESULTS Patients with good outcomes showed an increase in the levels of CSF Aβ42 (p = 0.003). Those with bad outcomes exhibited an increase in CSF levels of β-amyloid oligomers (p = 0.009) and NSE (p = 0.001). In addition, the CSF oligomer levels correlated with the scores on the extended Glasgow Outcome Scale (r = -0.89, p = 0.0001), disability rating scale scores (r = 0.77, p = 0.005), CSF Aβ42 levels (r = -0.42, p = 0.12), and CSF NSE levels (r = 0.70, p = 0.004). Additionally, the receiver operating characteristic curve yielded an area under the curve for β-amyloid oligomers of 0.8750 ± 0.09. CONCLUSIONS Detection of β-amyloid oligomers may someday become a useful clinical tool for determining injury severity and neurological outcomes in patients with TBI.

Estrone Is Neuroprotective in Rats after Traumatic Brain Injury

In various animal and human studies, early administration of 17β-estradiol, a strong antioxidant, anti-inflammatory, and anti-apoptotic agent, significantly decreases the severity of injury in the brain associated with cell death. Estrone, the predominant estrogen in postmenopausal women, has been shown to be a promising neuroprotective agent. The overall goal of this project was to determine if estrone mitigates secondary injury following traumatic brain injury (TBI) in rats. Male rats were given either placebo (corn oil) or estrone (0.5 mg/kg) at 30 min after severe TBI. Using a controlled cortical impact device in rats that underwent a craniotomy, the right parietal cortex was injured using the impactor tip. Non-injured control and sham animals were also included. At 72 h following injury, the animals were perfused intracardially with 0.9% saline followed by 10% phosphate-buffered formalin. The whole brain was removed, sliced, and stained for TUNEL-positive cells. Estrone decreased cortical lesion volume (p<0.01) and neuronal injury (p<0.001), and it reduced cerebral cortical levels of TUNEL-positive staining (p<0.0001), and decreased numbers of TUNEL-positive cells in the corpus callosum (p<0.03). We assessed the levels of β-amyloid in the injured animals and found that estrone significantly decreased the cortical levels of β-amyloid after brain injury. Cortical levels of phospho-ERK1/2 were significantly (p<0.01) increased by estrone. This increase was associated with an increase in phospho-CREB levels (p<0.021), and brain-derived neurotrophic factor (BDNF) expression (p<0.0006). In conclusion, estrone given acutely after injury increases the signaling of protective pathways such as the ERK1/2 and BDNF pathways, decreases ischemic secondary injury, and decreases apoptotic-mediated cell death. These results suggest that estrone may afford protection to those suffering from TBI.

A prospective evaluation of the use of routine repeat cranial CT scans in patients with intracranial hemorrhage and GCS score of 13 to 15

BACKGROUND Scheduled repeat head computed tomography after mild traumatic brain injury has been shown to have limited use for predicting the need for an intervention. We hypothesized that repeat computed tomography in persons with intracranial hemorrhage and a Glasgow Coma Scale (GCS) score of 13 to 15, without clinical progression of neurologic symptoms, does not impact the need for neurosurgical intervention or discharge GCS scores. METHODS This prospective cohort study followed all patients presenting to our urban Level I trauma center with intracranial hemorrhage and a GCS score of 13 to 15 from February 2010 to December 2010. Subjects were divided into two groups: those in whom repeat CT scans were performed routinely (ROUTINE) and those in whom they were performed selectively (SELECTIVE) based on changes in clinical examination. CT scanning decisions were made at the discretion of the neurosurgical service attending physician. RESULTS One hundred forty-five patients met the inclusion criteria (ROUTINE, n = 92; SELECTIVE, n = 53). Group demographics, including age, sex, and presenting GCS score were not significantly different. Of SELECTIVE patients, six (11%) required a repeat head computed tomography for a neurologic change, with one having a radiographic progression of hemorrhage (16%) versus 26 (28%) of 92 in the ROUTINE group showing a radiographic progression. No patient in either group required medical or neurosurgical intervention based on repeat scan. The number of CT scans performed differed between the two groups (three scans in ROUTINE vs. one scan in SELECTIVE, p < 0.001), as did the intensive care unit (2 days vs. 1 day, p < 0.001) and hospital (5 days vs. 2 days, p < 0.001) lengths of stay. Discharge GCS score was similar for both groups (15 vs. 15, p = 0.37). One death occurred in the SELECTIVE group, unrelated to intracranial findings. The negative predictive value of a repeat CT scan leading to neurosurgical intervention with no change in clinical examination was 100% for both groups. CONCLUSION A practice of selective repeat head CT scans in patients with traumatic brain injury admitted with a GCS score of 13 to 15 decreases use of the test and is associated with decreased hospital length of stay, without impacting discharge GCS scores. LEVEL OF EVIDENCE Diagnostic study, level II.

Thromboelastography and Rotational Thromboelastometry use in trauma

The appropriate resuscitation of patients in hemorrhagic shock is critical to improving survival. Current strategies for massive transfusions utilize fixed ratio protocols to rapidly deliver plasma and platelets to the patient. However, there is some concern that these larger volumes of transfusions can lead to untoward effects. Efforts are ongoing to provide patient-specific transfusion therapy in order to avoid excess transfusions. Thromboelastography (TEG) or Rotational Thromboelastometry (ROTEM) are two viscoelastic analyzers capable of providing Viscoelastic testing.

Large and Small Bowel

Along with control of hemorrhage, control of spill from the alimentary tract is the overriding goal for the first phase of an operation after penetrating abdominal injury. This is most easily accomplished with a rapid figure-of-eight suture. In the large majority of stable patients without shock, primary repair should be performed for non-destructive injuries and resection with anastomosis (including colocolonic) should be performed for destructive ones. In the setting of damage control, the whip stitches may be left in place or resection without anastomosis should be performed at the time of the first operation. Planned re-exploration may be done at the ICU bedside for profoundly ill patients. The general prejudice should be toward diversion after an initial damage control procedure, with only select patients or circumstances being considered for an anastomosis.

Advances in Burn Care

While management of burns has been taking place for thousands of years, it has been the last half-century that significant strides have changed the outcome of patients suffering from this devastating injury. The important technological changes that have played an integral part in these advances are many, and include codification of burn center transfer criteria and development of safe systems for transfer through transportation advances. Telemedicine has led to improved ongoing assessment of patients from distances from the burn center. Burn providers have also been leading the vanguard for the increasing use of decision support technologies in resuscitation, provision of nutrition, and detection and treatment of infection. Other recent technologic advances in burns include bioengineering approaches to determination of burn severity through wound depth determination and mapping, novel wound coverage techniques, and new grafting techniques to minimize morbidity in the severely ill. The clinical condition of burns lends itself easily to the development and utilization of new technologies because the clinical event is relatively homogenous and common, which we believe will continue well into the future. This work reviews recent advances and reports on new vistas which should be addressed in the future.

Do great teams think alike? An examination of team mental models and their impact on team performance

Background. Team mental models represent the shared understanding of team members within their relevant environment. Thus, team mental models should have a substantial impact on a teams ability to engage in purposeful and coordinated action. We sought to examine the impact of shared team mental models on team performance and to investigate if team mental models increase over time as teams continue to work together. Methods. New surgery interns were assigned randomly to 1 of 10 teams. Each team participated in one unique simulation every day for 5 days, each followed by video‐based debriefing with a facilitator. Participants also completed independently a concept similarity tool validated previously in nonmedical team literature to assess team mental models. All performances were video recorded and evaluated with a scenario‐specific team performance tool by a single, blinded junior surgeon under an institutional review board–approved protocol. Changes in performance and team mental models over time were assessed with paired samples t tests. Regression analysis was used to examine the extent to which team mental models predicted team performance. Results. Thirty interns (age 27; 77% men) participated in the training program. Percentage of items achieved (Symbol ± SD) on the performance evaluation was 39 ± 20, 51 ± 14, 22 ± 17, 63 ± 14, and 77 ± 25 for Days 1–5, respectively. Team mental models were 30 ± 5, 28 ± 6, 27 ± 8, 26 ± 7, and 25 ± 6 for Days 1–5 respectively, such that larger values corresponded to greater differences in team mental models. Paired sample t tests indicated that both average performance and team mental models similarity improved from the first to last day (P < .01, P < .05, respectively). Additionally, regression analyses indicated that team mental models predicted team performance on Days 2–5 (all P < .05) but not on the first day of simulations. Symbol. No caption available. Conclusion. These results demonstrate that greater sharing of team mental models among the teams leads to better team performance. Additionally, the increase in team mental models over time suggests that engaging in team‐based simulation may catalyze the process by which surgery teams are able to develop shared knowledge.

Porcine urinary bladder extracellular matrix activates skeletal myogenesis in mouse muscle cryoinjury

Abstract Background: Accelerated muscle regeneration is highly desirable after direct injury in trauma patients. Though the advantage of extracellular matrix extracted from porcine urine bladder (UBM) on tissue

Thromboelastometry analysis of severe North American pit viper-induced coagulopathy: A case report

Case details: A 51‐year‐old man presented with rapid onset encephalopathy and respiratory failure after a suspected intravascular envenomation from a North American pit viper. The patient received antivenom and was transferred to a tertiary care facility where he had cardiovascular collapse and persistent coagulopathy requiring 28 vials of Crotalidae polyvalent immune Fab antivenom for initial control and six vials for maintenance. The patients coagulopathy was monitored using “traditional” measures (platelets, fibrinogen, and prothrombin time/international normalized ratio) and rotational thromboelastometry (ROTEM®). The patient also subsequently developed intestinal necrosis requiring exploratory laparotomy with ileum and colonic resections, and anuric renal failure requiring continuous renal replacement therapy. After coordinated multidisciplinary management, he was discharged to an acute inpatient rehabilitation on hospital day 25 and has since made a full recovery. Discussion: In the setting of a severe intravascular pit viper envenomation, thromboelastometry correlated well with “traditional” measures. During recovery, ROTEM® demonstrated measurable improvements in the extrinsic coagulation pathway while the INR remained between 1.5 and 1.6. Patients intestinal necrosis may have resulted from microvascular thrombosis due to Crotalinae venom. The patients ultimate recovery necessitated a coordinated multidisciplinary effort. ROTEM® abnormalities after North American pit viper envenomation may be more sensitive than “traditional” measures and may have prognostic value to determine the severity of envenomation, but further research to define its utility is required. HighlightsA severe North American pit viper envenomation resulted in cardiovascular collapse, intestinal necrosis, and renal failure.Use of rotational thromboelastometry (ROTEM®) correlates well with measurements of fibrinogen and prothrombin time/INR.EXTEM specification may be more sensitive than INR alone in evaluating extrinsic pathway abnormalities.