Mild Traumatic Brain Injuries Can Be Safely Managed without Neurosurgical Consultation: The End of a Neurosurgical "Nonsult".

In 2010, 2.5 million people sustained a traumatic brain injury (TBI), with an estimated 75 per cent being mild TBI. Mild TBI is defined as a Glasgow Coma Scale (GCS) of 13 to 15. Based on recent data and our institutional experience, we hypothesized that mild TBI patients, including patients on aspirin, could be safely managed by trauma surgeons without neurosurgical consultation. Trauma patients admitted to a single Level I trauma center from June 2014 through July 2015 aged 18 years or older were evaluated. Patients with a GCS ≥14, regardless of intoxication, with an epidural or subdural hematoma ≤4 mm, trace or small subarachnoid hemorrhage, and/or nondisplaced skull fracture were prospectively enrolled. The primary outcomes were needed for neurosurgical consultation and intervention. Secondary outcomes included readmission rate and neurologic morbidity and mortality rate. Of 1341 trauma admits, 77 were enrolled. No patients required neurosurgical intervention. Only 1/75 (1.3%) patients required neurosurgical consultation. Outpatient follow-up was achieved with 75/77 (97.4%) patients. No mortalities, major neurologic morbidities, or readmissions were observed (95% confidence interval 0-4%). None of the 21 patients on aspirin required neurosurgical intervention and only 1/21 (4.8%) patients required neurosurgical consultation with no mortalities observed at follow-up. Management of mild TBI can be safely accomplished by trauma surgeons without routine neurosurgical consultation. Larger multicenter prospective studies are required to evaluate our finding that this also may be safe in patients taking aspirin.

Kinetics and Role of Plasma Matrix Metalloproteinase-9 Expression in Acute Lung Injury and the Acute Respiratory Distress Syndrome.

Primed neutrophils that are capable of releasing matrix metalloproteinases (MMPs) into the circulation are thought to play a significant role in the pathophysiology of acute respiratory distress syndrome (ARDS). We hypothesized that direct measurement of plasma MMP-9 activity may be a predictor of incipient tissue damage and subsequent lung injury, which was investigated in both an animal model of ARDS and a small cohort of 38 critically ill human patients. In a mouse model of ARDS involving instillation of intratracheal lipopolysaccharide (LPS) to induce lung inflammation, we measured neutrophil-mediated inflammation, along with MMP-9 activity in the airways and lung tissue and MMP-9 expression in the plasma. Neutrophil recruitment, inflammation, and MMP-9 activity in the airways and lung tissue increased throughout the 72 h after LPS instillation, whereas plasma MMP-9 expression was greatest at 12 to 24 h after LPS instillation. The results suggest that the peak in plasma MMP-9 activity may precede the peak of neutrophil inflammation in the airways and lung tissue in the setting of ARDS. Based on this animal study, a retrospective observational cohort study involving 38 patients admitted to a surgical intensive care unit at a tertiary care university hospital with acute respiratory failure requiring intubation and mechanical ventilation was conducted. Plasma samples were collected daily, and MMP-9 activity was compared with lung function as determined by the PaO2/FiO2 ratio. In patients who developed ARDS, a notable increase in plasma MMP-9 activity on a particular day correlated with a decrease in the PaO2/FiO2 ratio on the following day (r = -0.503, P < 0.006). Taken together, these results suggest that plasma MMP-9 activity changes, as a surrogate for primed neutrophils may have predictive value for the development of ARDS in a selected subset of critically ill patients.