Hyperbaric Oxygen Therapy and the Unseen injuries of war
Hyperbaric Oxygen Therapy and the Unseen Injuries of War
The US and Canadian Military Forces have over 1.2 million that have seen the effects of the War on Terror over the last twenty years. Many have received injuries from their service that are unseen. Previously I have referred to them as the silent injuries of war. These are not silent, they are real but they are usually subordinated to more visible injuries when they happen. These injuries are the result to blast overpressure. They may occur after one exposure to a significant overpressure or the may be the cumulative result of a number of exposures to explosions, detonations or blast. Primary blast injuries are difficult to diagnose. The chronic effects of exposure significant deviations from ambient atmospheric are even harder to ascertain. Key factors determining the potential for injury include-proximity, magnitude of the explosion, reflective surface, enclosed space, blast amplifying personal protective equipment and pressure changes occurring after exposure such as non sea level evacuation flights.
To understand the potential for injury it would help use to look at the management of the effect of pressure on the human body. John Scott Haldane, physician, physiologist, developed the concept of staged decompression in the early 1900’s. This concept has been revised overtime. It is based on a relationship of time and pressure. As the pressure increases the time of exposure without incurring a decompression obligation decreases. According the US Navy Dive Manual, a 180 ft excursion with a total bottom time of 5 minutes allows you to return to ambient pressure without incurring a decompression obligation. This is just over 6 ATA. The pressure exposure experience by our military personnel exposed to IED could as high 70-75 ATA. At some point the measure of time is so small as to make it irrelevant. Yet there is an obligation for decompression that is not being address.
Hypobaric exposures (ie evaluation flights) make these individual worse. Multiple exposures to blast compound these injuries. Even the firing of the individual combat weapon in firefights has been documented to impair the veteran. This possibly could be explained by the number of rounds fired, the proximity of the head to ejection port of the weapon and number of firefights the warfighter was exposed to and other pressure exposures unique to the combat theatre (ie breaching operations and large caliber weapons firings).
In the largest study involving veterans treated with hyperbaric treatment significant improvement were seen in post-concussive symptoms and secondary outcomes, including PTSD (which most participants had, depression, sleep quality , satisfaction with life, physical, cognitive and mental health function.
Hyperbaric treatments were developed to treat extraordinary pressure changes on the human body. The effectiveness of hyperbaric oxygen in addressing these injuries make sense. The Walter Institute of Research assembled a multi-volume publication that recounts the lessons learned in previous conflicts. This text was reviewed and approved by the Army Surgeon General was entitled the Textbook of Military Medicine. Volume 5 is Ballistics, Blast and Burn Injuries. On page 313 an algorithm appears entitled Neurological Abnormalities in the Blast Casualty. Within this algorithm treatment with Hyperbaric oxygen is identified as a definitive treatment.
My question to those caring for these veterans Why the delay in providing definitive care? Study after study has shown this safe and effective treatment to provide significant and impressive results.