TY - JOUR PY - 2016// TI - Primary blast causes mild, moderate, severe and lethal TBI with increasing blast overpressures: Experimental rat injury model JO - Scientific reports A1 - Mishra, Vikas A1 - Skotak, Maciej A1 - Schuetz, Heather A1 - Heller, Abi A1 - Haorah, James A1 - Chandra, Namas SP - e26992 EP - e26992 VL - 6 IS - N2 - Injury severity in blast induced Traumatic Brain Injury (bTBI) increases with blast overpressure (BOP) and impulse in dose-dependent manner. Pure primary blast waves were simulated in compressed gas shock-tubes in discrete increments. Present work demonstrates 24 hour survival of rats in 0-450 kPa (0-800 Pa∙s impulse) range at 10 discrete levels (60, 100, 130, 160, 190, 230, 250, 290, 350 and 420 kPa) and determines the mortality rate as a non-linear function of BOP. Using logistic regression model, predicted mortality rate (PMR) function was calculated, and used to establish TBI severities. We determined a BOP of 145 kPa as upper mild TBI threshold (5% PMR). Also we determined 146-220 kPa and 221-290 kPa levels as moderate and severe TBI based on 35%, and 70% PMR, respectively, while BOP above 290 kPa is lethal. Since there are no standards for animal bTBI injury severity, these thresholds need further refinements using histopathology, immunohistochemistry and behavior. Further, we specifically investigated mild TBI range (0-145 kPa) using physiological (heart rate), pathological (lung injury), immuno-histochemical (oxidative/nitrosative and blood-brain barrier markers) as well as blood borne biomarkers. With these additional data, we conclude that mild bTBI occurs in rats when the BOP is in the range of 85-145 kPa.
Language: en
LA - en SN - 2045-2322 UR - http://dx.doi.org/10.1038/srep26992 ID - ref1 ER -