Lecture on Wound Ballistics

Introduction

• Presenter: Trauma surgeon currently working for the Royal Navy and NHS.
• Inspired by Sir Keith Porter to become a trauma surgeon.
• Topics to be covered: Explanation of the lecture title, wound ballistics (physics of projectiles and human body), tissue behavior upon bullet impact, treatment algorithms, and research work at Porton Down.

Disclaimers

• Presenter’s personal views, not representing the Royal Navy or Her Majesty's Government.
• Not representing Oxford University Hospitals Trust.
• Conflict of interest: Has written a book on ballistic trauma.

Lecture Title: 'Guns Don't Kill People, Rappers Do'

• Title borrowed from an early 2000s Newport hip-hop band.
• Aim: Shift focus from firearms to bullets and their interaction with the human body.
• Historical context and other related titles in literature suggesting that the wounding effects of bullets often misunderstood.

Firearms Overview

• Explanation of a standard rifle’s firing mechanism.
• Muzzle velocity: Fastest speed of the bullet when it exits the barrel.
• Importance of barrel's spiral groove for stability.

Relevance of Firearms

• Globally, about 1 billion serviceable firearms; most are privately owned.
• High frequency of firearm-related injuries and terrorist attacks necessitates readiness and resilience in medical systems.
• Military conflict often results in more casualties from explosive weapons than from firearms.

The Science of Wound Ballistics

• Wound ballistics are unpredictable compared to internal and external ballistics.
• Kinetic energy: Potential to damage tissue; high-velocity bullets impart greater kinetic energy.
• Complex interaction between bullet and tissue dependent on drag and rate of energy transfer.

History of Bullet Design

• Late 19th century British military developments: Transition from lead to full metal jacketed rounds due to new smokeless powders.
• Dum-Dum bullets: Soft nose design for greater wounding potential.
• Modern implications: Used by hunters and police for more severe wounds.
• Hague Convention: Outlawed expanding rounds for military use.

Interaction of Bullets with Human Tissue

• Permanent cavity: Direct tissue destruction along the bullet’s path.
• Temporary cavity: Radial tissue acceleration causing additional damage; concepts of cavitation.
• Shockwave: Controversial, minimal clinical significance.
• Tissue variability: Different tissues’ responses to trauma (e.g., muscle resilient, liver not so).

Factors Increasing Wound Severity

• Bullet instability and tumbling: Increased drag and energy transfer.
• Clothing: Causes destabilization of bullets, resulting in more severe wounds.
• Pathophysiology: Primary, secondary, and tertiary injuries.
• Greater energy transfer in military weapons leading to more severe injuries.

Management Protocols

• Classification into decision, incision, and excision.
• Decision: Assessing energy transfer; features of high energy transfer (fracture, bullet retention, fragmentation).
• Incision: Extending wounds for decompression and exploration.
• Excision: Removal of non-viable tissue and contamination.

Clinical Experience and Findings

• Not all gunshot wounds require surgery; some managed with antibiotics and splinting.
• High energy transfer wounds: Require aggressive exploration and debridement.
• Low energy transfer wounds: Possibly managed conservatively, especially in mass casualty situations.

Historical Perspectives

• WWII and First World War surgeons emphasized conservative approach; unnecessary operations could do more harm.
• Modern studies support conservative management for simple, uncomplex wounds.

Recommended Resources

• Book by the presenter: Clinically-oriented on ballistic trauma.
• Coupland, Rothschild, and Newball's book: Comprehensive and science-heavy on wound ballistics.

Ongoing Research

• Comparative studies using sheep tibia to understand bullet impacts.

Conclusion

• Open for discussion and questions.
• Emphasis on practical and historical findings in ballistic trauma management.