Management of the mild traumatic brain injured patient using a multidisciplinary observation unit protocol.

OBJECTIVES: We developed an ED based multidisciplinary observation unit (OU) protocol for patients with mild traumatic brain injury (mTBI). We describe the cohort of patients who were placed in the ED OU and we evaluated if changes to our inclusion and exclusion criteria should be made. METHODS: We conducted a retrospective cohort study to evaluate subjects who were admitted to the mTBI observation protocol. We included adults within 24 h of sustaining an mTBI with a Glasgow Coma Scale (GCS) of 14 or 15 who had pre-specified head CT findings, and did not meet exclusion criteria. Predictors of need for hospital admission after completing the OU protocol were determined using multivariable logistic regression analysis. RESULTS: The mean age was 49 (SD 23), 58 (33%) were female, and 136 (78%) were Caucasian. No subjects discharged home required a surgical intervention or ICU admission, and there were no deaths in discharged or admitted subjects. 28 subjects (16%) were admitted to the hospital following their OU stay. Subjects admitted were older (mean age: 56 vs. 48, p = 0.1) and had a higher proportion of traumatic bleeds on head CT (85% vs. 76%, p = 0.3). In multivariable logistic regression, GCS of 15 (aOR 4.24), African-American race (aOR 5.84), and no comorbid cardiac disease predicted discharge home after the observation protocol (aOR 0.28). CONCLUSIONS: A period of observation for a pre-defined cohort of patients with mTBI provided a triage plan that could allow appropriate patient management without requiring admission in the majority of subjects.

Implementation of a Neurotrauma Hotline for post-hospital continuity of care.

BACKGROUND: There are 4.8 million emergency department (ED) visits for traumatic brain injury (TBI) annually in the United States. Many of these patients do not receive educational information or follow-up care. AIMS OF THE STUDY: Our institution implemented a Neurotrauma Hotline for TBI patients. This study describes our implementation and utilization of a Neurotrauma Hotline at a Level I trauma center. METHODS: Callers and outcomes of calls to the hotline over a 12-month period were analyzed. Correlation analysis was done to assess relationship between hotline calls and TBI clinic volumes. RESULTS: There were 1205 calls to the hotline. Calls were most commonly from internal providers or patients, with 338 repeat callers. The call reason was frequently an appointment (36.8%) or advice (32.1%). There were 334 TBI clinic visits, and however, there was no statistically significant correlation between number of hotline calls and number of clinic visits (r = .417; P = .177). CONCLUSIONS: There was widespread utilization of our hotline. Other institutions wishing to adopt similar practices can expect that the majority of calls will be for appointment scheduling or clinical advice. Further work is needed to determine whether implementation of a Neurotrauma Hotline improves resource utilization and patient outcomes.

The olfactory pathway mediates sheltering behavior of Caribbean spiny lobsters, Panulirus argus, to conspecific urine signals.

The "noses" of diverse taxa are organized into different subsystems whose functions are often not well understood. The "nose" of decapod crustaceans is organized into two parallel pathways that originate in different populations of antennular sensilla and project to specific neuropils in the brain-the aesthetasc/olfactory lobe pathway and the non-aesthetasc/lateral antennular neuropil pathway. In this study, we investigated the role of these pathways in mediating shelter selection of Caribbean spiny lobsters, Panulirus argus, in response to conspecific urine signals. We compared the behavior of ablated animals and intact controls. Our results show that control and non-aesthetasc ablated lobsters have a significant overall preference for shelters emanating urine over control shelters. Thus the non-aesthetasc pathway does not play a critical role in shelter selection. In contrast, spiny lobsters with aesthetascs ablated did not show a preference for either shelter, suggesting that the aesthetasc/olfactory pathway is important for processing social odors. Our results show a difference in the function of these dual chemosensory pathways in responding to social cues, with the aesthetasc/olfactory lobe pathway playing a major role. We discuss our results in the context of why the noses of many animals contain multiple parallel chemosensory systems.

Role of the olfactory pathway in agonistic behavior of crayfish, Procambarus clarkii.

Crayfish establish social dominance hierarchies through agonistic interactions, and these hierarchies are maintained through assessment of social status. Chemical signals influence several aspects of fighting behavior, but the specific chemosensory sensilla involved in detecting these signals in crayfish are unknown. The goal of our study was to examine the importance of aesthetasc sensilla--olfactory sensors on the antennules of decapod crustaceans--in regulating changes in fighting behavior in crayfish, Procambarus clarkii, over the course of repeated pairings. We selectively ablated aesthetascs from pairs of crayfish after the first day of trials and compared the behavior of these ablated animals to that of pairs of intact controls. Results show that unablated crayfish significantly decreased the number and duration of fights over repeated pairings, whereas crayfish lacking aesthetascs continued to engage in similar amounts of fighting across all three trial days. This difference shows that aesthetascs regulate fighting behavior in P. clarkii.

Source and specificity of chemical cues mediating shelter preference of Caribbean spiny lobsters (Panulirus argus).

Caribbean spiny lobsters display a diversity of social behaviors, one of the most prevalent of which is gregarious diurnal sheltering. Previous research has demonstrated that shelter selection is chemically mediated, but the source of release and the identity of the aggregation signal are unknown. In this study, we investigated the source and specificity of the aggregation signal in Caribbean spiny lobsters, Panulirus argus. We developed a relatively rapid test of shelter choice in a 5000-l laboratory flume that simulated flow conditions in the spiny lobster's natural environment, and used it to examine the shelter preference of the animals in response to a variety of odorants. We found that both males and females associated preferentially with shelters emanating conspecific urine of either sex, but not with shelters emanating seawater, food odors, or the scent of a predatory octopus. These results demonstrate specificity in the cues mediating sheltering behavior and show that urine is at least one source of the aggregation signal.

Dual antennular chemosensory pathways can mediate orientation by Caribbean spiny lobsters in naturalistic flow conditions.

Benthic crustaceans rely on chemical stimuli to mediate a diversity of behaviors ranging from food localization and predator avoidance to den selection, conspecific interactions and grooming. To accomplish these tasks, Caribbean spiny lobsters (Panulirus argus) rely on a complex chemosensory system that is organized into two parallel chemosensory pathways originating in diverse populations of antennular sensilla and projecting to distinct neuropils within the brain. Chemosensory neurons associated with aesthetasc sensilla project to the glomerular olfactory lobes (the aesthetasc pathway), whereas those associated with non-aesthetasc sensilla project to the stratified lateral antennular neuropils and the unstructured median antennular neuropil (the non-aesthetasc pathway). Although the pathways differ anatomically, unique roles for each in odor-mediated behaviors have not been established. This study investigates the importance of each pathway for orientation by determining whether aesthetasc or non-aesthetasc sensilla are necessary and sufficient for a lobster to locate the source of a 2 m-distant food odor stimulus in a 5000-liter seawater flume under controlled flow conditions. To assess the importance of each pathway for this task, we selectively ablated specific populations of sensilla on the antennular flagella and compared the searching behavior of ablated animals to that of intact controls. Our results show that either the aesthetasc or the non-aesthetasc pathway alone is sufficient to mediate the behavior and that neither pathway alone is necessary. Under the current experimental conditions, there appears to be a high degree of functional overlap between the pathways for food localization behavior.