Human Severe Blast TBI isToo Heterogenous for One Animal Model Col Rocco A. Armonda, MD National Capital Neurosurgery Consortium Walter Reed Military Medical Center, Bethesda
Disclaimer/Disclosure • The views expressed in this presentation are those of the authors and do not reflect the official policy of the Department of the Army, Navy, Department of Defense, or U.S. Government.• No Disclosures applicable to this presentation
Objective • Delinate the Varied Patterns of Severe Human Blast Injury • Discuss the Prognosis of Severe Blast Injury • Identify Mean of Improving our Models for Predicting Injury/Outcome • Introduce Bayseian Modeling as a Means to improve our understanding of Human Blast Injury
Gaining Wisdom..." By three methods we may learn wisdom: First, by reﬂection, which is noblest; Second, by imitation, which is easiest; and third by experience, which is the bitterest. (Confucius)
‘the road to Ruin...’" There are three possible roads to ruin: women, gambling and technology. The most pleasant is with women, the quickest is with gambling, but the surest is with TECHNOLOGY! (Georges Pompidou)
Bayes Theorem • Initial Beliefs+ Recent Objective Data= New/ Improved Belief • English Clergyman Thomas Bayes (18th Century) • “The Theory That Would Not Die, How Bayes’ Rule Cracked the Enigma Code, Hunted Down Russian Submarines and Emerged Triumphant from Two Centuries of Controversy” by Sharon McGrayne
Variables of Severe Human Blast Injury• All Varies Depending on Characteristics of Explosion: Not one is alike!• “Time, Distance, Shielding, Enclosures, Flying Fragments”• Inﬂuence of Body Armour • Protection/Ampliﬁcation/Transmission of Energy Waves• Effects of Terminal Ballistics on the Skull, Skull Base, Brain, and Cerebrovasculature• Inﬂuence of Associated Pulmonary, Extremity, Abdominal Injuries
Demographic Characteris0cs NEUROSURGERY Consults:Severe Head Injury 513:357 Age 27 + 7.7 years (18-‐73) Sex (M:F) 350:7 Injury Type (CHI:PHI) 139:218 Mechanism: 207 Blast 17 GSW 123 Other Branch of Service:214 USA 8 USAF75 USMC 7 USN
Initial CT Scan: IED Explosion <15 Minutes from Injury Severe Cranial Base Injury
Terminal Ballistics of Severe Blast Injury In Humans: Observations• Edema is Diffuse• Onset of Edema is Late• Length of Increased ICP is PROLONGED!• High Association with Delayed Cerebral-Vasospasm.• Outcome is difﬁcult to predict!!!!!!
Predicting Patient OUTCOME• Poor Characteristics • Associated Large Vessel Infarction: Deﬁnes Disability • Penetration of Fragments/Injury Zone into Diencephalon: Deﬁnes Level of Independent Recovery • Multiple Lobes Involvement/Bihemisphere/Combined Infra/Supra tentorial involvement: Survival/Long Term Independenence • Severe Concomittant Pulmonary Dysfunction MAJOR MORTALITY!
Conclusions • Each Patient/Injury is Different! • Balancing the Brain vs Lungs for best overall outcomes • The Model Must Adapt to New Information: BAYSEIAN THEORUM • Prevention of Delayed Insults Occult Vascular Injury (Vasospasm, Dissection, TICA) Improves Outcomes. • Predict Based on combined Model + Real-Time Data (continual update!).