Sunday, January 14, 2024

Ukraine: Bradley IFVs taking on T90 tanks

 



Several videos have emerged this week, showing Bradley Fighting Vehicles successfully taking on advanced Russian T-90 tanks.

From Special Kherson Cat on Twitter, video of Bradley IFV vs T-90 in Avdiivka


Saturday, January 13, 2024

Ukraine: Types of Missiles that Russia Commonly Fires at Ukrainian Cities

 


 


     












S-300 / S-400 a potent, long range, surface-to-air, anti-aircraft guided missile, S300 developed in 1978, S400 in 2007. Fully automated, or can be manually piloted. Launched form a command post, which include acquisition and guidance radar, transportation, and launch vehicles. May be used to intercept aircraft or other missiles. Possessed by a number of countries in Europe and the Middle East, and used in conflicts including Syria and Nagorno-Karabakh. Used extensively against ground targets in Ukraine. Image by By Tourbillon - Own work, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=6714828. 


Kh-47 Kinzhal hypersonic air-launched ballistic missiles, NATO name "Killjoy", entered service in 2017, design based on the older Iskander missile, uses standard ballistic missile technology at greater speeds. After launch, the missile rapidly reaches cruising speeds of Mach 4, and up to Mach 10 on a downward trajectory. Maneuverable, erratic flight path. Originally touted as "impossible to intercept" by Russia, Kinzhals have been used extensively in Ukraine, and a significant proportion of them were successfully shot down by Patriot air defense systems in 2023. They have also proven to be fairly inaccurate. Image from By kremlin.ru, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=68926303


Kaliber cruise missile, in service 1994, some models are capable of a supersonic terminal sprint, traves at ~70' over water, or ~150-350' over land, uses inertial guidance +terminal radar or satellite guidance, 


Iskander mobile ground-launched, short-range hypersonic ballistic missile, NATO name "Stone", first launched in 1996, as a replacement to the SCUD missile, uses inertial guidance or GPS, depending on model, can be re-targeted midflight, uses evasive maneuvers and decoys during terminal flight, travels at an altitude of 20,000-160,000 feet. Used in Syria, Georgia, Nagorno-Karabakh, and Ukraine wars. In the summer of 2023, an Iskander was used to destroy Ria Pizzeria, a restaurant in Kramatorsk, Ukraine, frequented by journalists, aid workers, and military members. The famous Ukrainian writer Victoria Amelina was killed, along with a pair of 14-year-old twin sisters, and 10 others. Dozens were injured.

Image from Vitaly V. Kuzmin - http://www.vitalykuzmin.net/Military/ARMY-2016-Demonstration/, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=52213498


Kh-101 / Kh-555 / Kh-55 family of air-launched subsonic cruise missiles, Nato name "Kent", in service 1983, inertial guidance with terminal radar/terrain map, capable of cruising at tree-top level, the original Kh-55 ran on a Ukrainian-made Sich motor, used in Syria and Ukraine wars


Kh-22 "Storm" missiles. NATO name "Kitchen". Large, long-range anti-ship missile developed in 1962. Climbs to either 89,000' (high-altitude mode) or 39,000' (low-altitude mode), then hits top speed while dropping towards target. Guided by radio altimeter and gyroscope-stabilized autopilot. A 1,000kg shape-charge load results in a 16' wide, 40' deep hole. First combat use was in May of 2022 in Ukraine. Use against targets in civilian areas of Ukraine has been criticized due to low accuracy. Image by By Антон Бородин - Музей авиационной техники, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=10658517


Kh-59 "Ovod" or "Gadfly" guided aerially-launched land-attack cruise missiles. Developed in the 1980's. Flies at about 22' above water, or 300-3,000' above ground, using a radio altimeter. Used in Chechnya and Ukraine.



Cost #USDWarhead SizeWarhead TypeMissile Length, SpeedEngineRange, AccuracyLaunch Platform
S300   1 millionup to  143 kg19,000-36,000 metal frag,s~25'
up to 250 nmvehicle-based
Kinzhal10 million480kgConventional or nuclear25'

Mach 10
solid-fuel rocket300nmTu-22
Mig-31
Kaliber1 million500kgConventional or nuclear~25'

Mach 3
solid-fuel rocket or turbojetup to 1300nmAir, ship, or sub launched
Iskander3 million480-700kgCluster, thermobaric, EMP, frag, bunker busting, nuclear25'


Mach 7
single-stage solid propellant300nm


3' - 100'
vehicle
Kh-10113 million400mgconventional or nuclear24'

Mach 0.7
turbofan jet3500nm

20-33'
bomber aircraft
Kh-221 million1,000 kgRDX or thermo - nuclear38'

Mach 4.6
liquid - fueled rocket320 nm             300-900'Tu-22  Tu-95
Kh-59



500,000320 kgCluster, Shape-Charge Frag18'

Mach 0.8
2-stage rocket60-160nmSukhoi and Mig jets


Notes: "hypersonic" missile is somewhat of a misnomer; nearly all ballistic missiles reach hypersonic speeds at some point during flight

"Kh" and "X" are both transliteration options for the same Russian letter, (X)

Info from Jane's Air-Launched Missiles





Friday, January 12, 2024

Ukraine: Drones and Dogwalking


While GPS, mass consumer production, and AI have revolutionized use of warfare drones in Ukraine, early drones were a feature of many 20th century conflicts. Radio-controlled planes flew in WWI, and the Warsaw Uprising Museum in Warsaw has a display featuring a WWII "Goliath tracked mine" unmanned ground vehicle. Drones have increasingly been utilized in small-scale conflicts of the pre-Ukraine-war 21st century. 

In Ukraine, large-scale use of surveillance and attack drones have complicated traditional combined arms warfare. Surprise attacks have become more difficult, and countermeasures, such as armor, avoiding vehicle travel near the front, and signals jamming, have become crucial. Development of ever-more sophisticated drone tactics and countermeasures will be a hallmark of the Ukraine war, throughout its duration. 

And, as we see in the video, drones are not just good for war. They are also great for dog-walking.

Thursday, January 11, 2024

Ukrainian Army Recruiting Posters

 Recruiting for the 3rd Storming Brigade




Wednesday, January 10, 2024

Ukraine: How Long can a Tourniquet be left in place before the limb must be amputated?

Prospects for limb salvage after tourniquet placement has become a crucial matter for thousands of soldiers and their surgeons in the Ukraine war. Near-peer fighting conditions, and lack of air superiority, can create extended evacuation times for casualties. Drone threats to moving vehicles have become so pervasive that, in many areas, the last few miles up to the zero line area only traversable on foot. Beyond this zone, mud, bombing damage, UXOs, and the impossibility of road maintenance make vehicle evacuation slow and bumpy. Patients must often wait for nightfall to evacuate, and dawn-dusk day length at the height of summer on the Eastern Front is 17 hours. Today, almost two years into the war, high attrition rates amongst experienced frontline medics means loss of TCCC tourniquet conversion knowledge along the frontline. 

For medics and doctors in forward casualty collection and stabilization points, who are receiving tourniqueted patients after prolonged evacuations from a near-peer conflict area, assessing patient candidacy for tourniquet conversion (i.e. removal and replacement with a simple pressure dressing) or movement of tourniquet to a more distal location is a critical outcome-changing skill. Just as important as assessing limb salvageability is 1) readiness to manage acute complications such as acidosis and dysrhythmias, and 2) ensuring that timely transfer to higher-level care is available for potential mediu-term complications, such as compartment syndrome and acute renal failure. 

Current TCCC guidance assumes that limb salvage becomes highly unlikely 6 hours or more after tourniquet placement. However, this guidance is unavoidably based on the extremely limited data pool available to date. Limb salvage after tourniquet placement is a young and weak science, which stands to benefit greatly from case reporting and retrospective studies originating from the Ukrainian conflict. If we look only at the small pool of my personal experience as a paramedic in Ukraine, several case examples of physician-directed conversions of tourniquets in place for over 6 hours have been performed, or given post-conversion management, by either myself or my immediate colleagues. Clearly, amputating every limb that has been touniqueted for more than 6 hours would result in unnecessary negative life impacts for patients.

Current tourniquet science is based on animal studies done in controlled environments, and a very small number of human case reports. Tourniquets are widely used in routine surgeries, but tourniquet use in traumatic wartime injuries is a completely different animal. The reality of warfare adds in a number of important and unforeseen variables, which defy efforts to cleanly categorize patients as <6 hours vs >6 hours:

1) initial tourniquet placement is likely to occur under extreme conditions. Often, the soldier placing the tourniquet has minimal medical training, may be physically and/or mentally exhausted (many Ukrainian soldiers have been deployed for nearly 2 years with little or no leave), he or she may be receiving and returning fire, and may be working in conditions of darkness, loud noise, and confusion. The soldier placing the tourniquet may have reduced fine motor control due to cold, exhaustion, or adrenaline, or may be injured themselves. Weather and fighting conditions may have led to heat exhaustion, dehydration, nutritional deficits, soaked clothing, icy gear, numb fingers, or cold injuries of feet and hands, and rapid assessment and tourniquet placement and/or other bleeding control measures may have to be performed over/through multiple layers of clothing and body armor. Tourniquet availability on the frontlines is limited and likely to consist of a mish-mash of tourniquet brands and styles. These factors often conspire to create "partial-tourniqueted" patients. Tourniquets may be tightened enough to slow, but not fully stop, bleeding and limb perfusion. Venous and capillary return may be cut off, without halting arterial inflow. 

2) Due to frontline conditions, time of original placement of tourniquets is frequently estimated, or missing altogether.

3) Environmental conditions and threats during evacuation may necessitate rapid movement and rough handling of the patient, which may lead to tourniquet loosening or temporary dislodgement. Poorly made or re-used tourniquets may stretch over time or fail, lead to placement of multiple tourniquets, and intermittent periods of reperfusion or partial reperfusion. 

4) Intentional attempts at tourniquet conversion may be made in the field. Due to fighting conditions, these field attempts may or may not be accurately recorded in the documentation that reaches field hospitals. Patients evacuation routes shift frequently, and patients may pass through multiple patient care teams, comprised of a shifting cast of medical providers.

5) The tourniqueted limb may be subjected to a variety of physiological and environmental conditions, including varying levels of external cooling, varying states of patient blood loss and shock, and varying levels of resuscitative care received.

Due to these variables, Ukrainian doctors cannot rely on hard-and-fast rules such as the 6-hour tourniquet rule. Many tourniquets were placed with good intent, but were never necessary in the first place. Doctors are often forced to decide, based on clinical observations and professional experience, whether tourniquet removal is in the patient's best interest. Does the probability of limb salvage outweigh potential systemic risks to patients? Objective numerical values from blood testing can inform these decisions, if lab services are available. But more often, the critical time for this decision occurs at minimally-equipped forward field treatment points, and thus it must be made based on time of injury, exposure to weather, limb skin color and temperature, injury patterns, and overall patient presentation. 

Here is an interesting case report from Kragh et al, published in Orthopedic Trauma in 2007, which represents the realities of tourniquet placement in conflicts, as well as variability in limb salvage times. The patient, an American helicopter pilot in Afghanistan, was shot in the hand and received RPG shrapnel to one leg. Hemorrhage from the hand was stopped 1 hour after injury by a combination of one purpose-built and one improvised tourniquet. Bleeding recurred 6 hours after injury, and was stopped by tightening the tourniquet. The pilot lay in a snowdrift, with temperatures at -15C, for a half-day after injury. After that, he was insulated by blankets made from cut-out aircraft insulation. Evacuation was delayed due to an ongoing firefight, mountainous terrain, and inclement weather. The patient arrived at a forward surgical facility after 16 hours of continuous tourniquet placement. He had severe soft tissue loss, irreparable radial artery damage, and compartment syndrome. He underwent surgical debridement and irrigation, radial artery ligation, and 3 dorsal + 2 ventral hand fasciotomies, and the operating surgeon deemed hand preservation was questionable. Repeated surgical debridement and irrigation took place over the next month, first at Landstuhl, Germany, then at Walter Reed, before primary wound closure was accomplished. Several more surgeries and physical therapy followed, to correct pain and stiffness. By three years after injury, the patient had recovered sufficiently to use the hand for activities of daily living, and to return to piloting Chinook helicopters.



Tuesday, January 9, 2024

Aug 2023: 'The Spectator' Article on military medicine in Ukraine

From The Spectator, 23 Aug 2023: 'Ukraine's Real Killing Fields: An Investigation into the War's First Aid Crisis'

In this article, Spectator reporters interview medics from the Hospitallers and the Ukrainian military. Challenges such as military bureaucratic hurdles for replacing medical equipment, corruption, and medical training and staffing shortcomings,

The Spectator is a politically conservative UK magazine. It is the oldest political affairs magazine in print, and its former editors include Boris Johnson and several former UK cabinet members. Until recently the Spectator, along with the Telegraph, was owned by the Barclay Brothers. Back in 2014, the Telegraph Group was criticized for taking Russian funds in exchange for publishing links and supplements of Russian propaganda on Telegraph Group venues. This included reports downplaying Russian involvement in shooting down Flight MH17. These links were later removed. Since the start of the full-scale invasion, the Spectator and the Telegraph have leaned pro-Ukrainian, and have provided a wealth of in-depth reporting on Ukrainian and Russian affairs. 


The Telegraph Ukraine reporting and daily hour-long Ukraine podcast

From The Spectator, 23 Aug 2023: 'Ukraine's Real Killing Fields: An Investigation into the War's First Aid Crisis'

Monday, January 8, 2024

Video of hospital in Pokrovsk, Ukraine, at moment of bomb impact

 


Here is a video posted to the english-language Telegram Channel Live:Ukraine on 9 Feb 2023, allegedly showing a hospital in Pokrovsk, Ukraine, at the moment of a bomb impact.

Friday, January 5, 2024

Ukraine: Air Raid!

 A fascinating feature of the Ukraine war is the amount of real-time information (and propaganda) available to civilians. Daily updates are put out on Telegram, Facebook, and other platforms by the Ukrainian Ministry of Defense, Russian Ministry of Defense, and an array of milbloggers. Civilians post videos of rockets and missiles impacting, or being shot down, which provide the opposing side with battle damage assessments and information of air defense locations. Various 3rd-party open-source intelligence groups collate data and publish up-to-date maps of reported Russian and Ukrainian positions. A network of Ukrainian observers and defense agencies provide instant reporting on Aerial threats via a variety of Telegram channels. This includes radar-detected movements and takeoffs of missile-launching platforms such as Tupolev bombers and MIG jets, launches, locations, and vectors of incoming missiles (including hypersonic ballistic Kinzhals and Iskanders, Kaliber cruise missiles, repurposed S-300 surface-to-air missiles, and Shahed drones. Here's a typical series of missile updates from this week, courtesy of the Telegram channel "Radar".


13:57     Attention!  There is activity of enemy tactical aviation in the eastern and south-eastern directions! Threat of aerial weapons launch! In case of air raid alarm announcement in your area, seek shelter.        - 39,000 views

14:02    Air alarm for Dnipropetrovsk Oblast!    - 38,000 views

14:02     Air alarm for Zaporizhya Oblast!        - 37,800 views

14:06    X-59 threat for areas where the Alarm is        - 38,900 views

14:18    X-59 headed towards Dnipro                - 38.600 views

14:19    Dnipro: take shelter!        - 39,100 views

14:19    Zaporizhya: take shelter!    - 39,600 views

14:19    X-59 Rocket approaching Dnipro Region    - 39.800 views

14:21    Dnipro: Explosions        - 41,000 views

14:24    The rocket has been destroyed! (by air defense)    -41,000 views



Thursday, January 4, 2024

Combat Medicine: Pelvic Fractures

The pelvis has major blood vessels running throug it; fracture or penetrating injury can easily lead to a fatal amount of massive hemorrhage. Pelvic fractures with hemodynamic instability have a 40% mortality.  26% US mil deaths in Afghanistan and Iraq had a pelvic fracture.

Pelvic fractures are generally caused by severe blunt force or blast trauma. Signs and symptoms include:

Pelvic pain and/or crepitus

Deformed or unstable pelvis, unequal leg lengths, or outward rotation of legs (open-book fracture)

Bruising at bony prominences of pelvic ring, anal/vaginal/urethral bruising or bleeding

Neurological deficits in lower extremities

Major lower limb amputation or near amputation

Unconsciousness

Shock

Pelvic binders help return the pelvis to its natural position and lessen bleeding and further damage. There are several purpose-made varieties; an improvised binder may also be made using a sheet or similar object. Pelvic binders should be placed low, at the level of the greater trochanters ("bottom of the patients' pocket openings"). Higher placement can actually leverage open lower-pelvic fractures, increasing damage. One assessment at a major UK trauma center found that 41% of pelvic binders were placed too high.  Outward rotation of legs may be observed in displacement pelvic fractures; in these cases legs should also be bound together, in order to prevent further displacement. 


An Assessment of Pelvic Binder Placement at a Major UK Trauma Center


Wednesday, January 3, 2024

TCCC

1996 CAPT Frank Butler formalizes concepts and experiences from lessons learned in prior conflicts into first TCCC guidelines, and publishes them as an article. These guidelines were presented to DoD leadership, but were not immediately implemented as a universal standard. However, they were adopted by the Naval Special Warfare Command, 75th Ranger Regiment, the Army Special Missions Unit, and Air Force pararescue community. 

Medical research efforts by the US Special Operations Command led to the initiation of the 42-member Committee on TCCC (CoTCCC). CoTCCC's mission is “To develop on an ongoing basis the best possible set of trauma care guidelines customized for the tactical environment and to facilitate the transition of these recommendations into battlefield trauma care practice.” CoTCCC membership includes representatives from all service branches, and includes surgical specialists, emergency physicians, combat medical educators, physicians assistants, nurses, and medical planners. At least 30% of the voting membership must be active or former combat medics, paramedics, or pararescuemen. TCCC guidelines are based on evidence-based medicine, not anecdotal instances. 

In 2013 CoTCCC was moved under the Joint Trauma System's jurisdication (JTS). JTS was put together in order to improve military care of trauma patients. It has 6 components:

1) DOD Trauma Registry Management

2) Defense Committee on Trauma

3) Performance Improvement

4) Combatant Command Trauma System Management

5) Joint Trauma Education and Training

6) Defense Medical Readiness Institute

JTS develops and maintains Clinical Practice Guidelines, recommending combat casualty care training requirements, evaluating new medical equipment, facilitating medical performance improvements, facilitating collection and sharing of combat casualty data, maintaining the DOD Trauma Registry, and improving the organization and delivery of trauma care. 

Some level of TCCC is required for all US service members. The levels are listed below; ASM is the most basic, and CPP is the most advanced.

ASM All Service Members

CLS Combat Lifesaver

CMC Combat Medic/Corpsman

CPP Combat Provider Paramedic

The latest version of TCCC was released in 2020 and can be found here.

Deployed Medicine.org by the US Defense Health Agency provides online combat medicine learning materials, including Combat Lifesaver, Medic, and Paramedic courses and Prolonged Field Care Guidelines

TCCC Tactical Casualty Care, full Combat Medic/ Corpsman Course, Prolonged Field Care, and other resources at tcc.org English and Ukrainian versions available 

Tuesday, January 2, 2024

Tourniquet Conversion



 So far, an estimated 25,000-50,000 amputations having already occurred on the Ukrainian side of the war. Patients with tourniquets may not reach definitive care for 24 hours or more after tourniquet placement. Tourniquet times of less than 2 hours have a negligeable impact on limb salvage rates; tourniquet times over 4 hours are associated with reduced limb salvage rates. Amputation of a tourniqueted limb is very likely after 24 hours. Therefore, assessing whether stable patients who arrive at our near-frontline medical facility are candidates for a tourniquet conversion is a priority. "Tourniquet conversion" refers to the process of replacing a tourniquet with a simple pressure dressing. 

While civilian prehospital medical personnel are generally taught to never remove a tourniquet once placed, in the US military tourniquet conversion is a basic-level medical intervention. The TCCC guideline, taught to all US military members, is "every effort should be made to convert tourniquets in less than 2 hours if bleeding can be controlled by other means". Temporary tourniquet placement of up to 3 hours, with no resulting tissue damage, is also a common technique used by surgeons.

The process for converting a tourniquet is:

1) pack the wound and apply pressure for 3 minutes

2) apply pressure dressing

3) slowly release tourniquet over 1 minute, watching for bleeding. If bleeding resumes, re-tighten the tourniquet. Re-attempt conversion in 2 hours, as long as it hasn't been more than 6 hours since original application.

4) If conversion is successful, note release time and leave loosened tourniquet on the limb, just above the wound, in case tourniquet re-application is needed later.

Tourniquet conversion is contra-indicated in patients who are in shock, have an amputation below the tourniquet, or who cannot be monitored closely for bleeding. Tourniquets that have been on for more than 6 hours should not be converted. Intermittent reperfusion (Loosening a non-covertable tourniquet temporarily at intervals in an attempt to preserve the limb), is a common surgical technique. However, in field situations without ability to replace lost blood, this is dangerous and ineffective, and not recommended by TCCC.

A 2019 study in rats found that tourniquet application reduced uptake of prophylactic antibiotics in the ischemic limb, both during tourniqueting, and for up to 72 hours after release. https://www.sciencedirect.com/science/article/abs/pii/S0020138319305431

Impact of time and distance on outcomes following tourniquet use in civilian and military settings: A scoping review




Monday, January 1, 2024

Ukraine: Combat TBIs


TBIs and their sequelae have long been associated with wars. 
Brain Neurotrauma: Molecular, Neuropsychological, and Rehabilitation Aspects: Chapter 2: Combat TBI History, Epidemiology, and Injury Modes* by Ralph G DePalma offers a brief and fascinating historic overview, starting with Iliad accounts of TBIs, PTSD, and post-war mental illness from the legendary Trojan War. This chapter contains a wealth of links to pieces on "shell shock" blast injuries of WWI and WWII.  

Between 2000-2012, 255,852 US military service members sustained TBIs. 83% of these were mild, and 80% were estimated to have occurred in non-deployed settings, for example during training, sports, or vehicle accidents. A New York Times investigation examined TBI rates amongst US artillery companies who conducted heavy shelling campaigns against ISIS during the 2016-2017 anti-ISIS offensive. Some soldiers fired over 10,000 artillery shells in the space of just a few months. A military-ordered study of Fox battery, 2nd Battalion, 10th Marines, found that half of the unit had sustained TBIs during artillery firing operations. Study of microscopic damage caused by repeated lower-level blast exposures, or "Chronic Traumatic Encephalopathy" (CTE) is a young science. Under pressure from Veteran's groups, between 2018-2022 Congress passed bills ordering the Pentagon to start a large "Warfighter Brain Health Initiative". This initiative will endeavor to measure blast exposure and create protocols to protect troops. A growing pool of data suggests that safe blast exposure levels may be much lower than was previously assumed. The issue of CTE recently featured in the headlines; the brain of Robert Card, a former military grenade instructor who had a sudden onset of psychosis at age 40 and committed a mass shooting in Maine, will be examined for signs of blast-related CTE.

Massive use of heavy artillery in the current Ukraine War (firing up to 7,000 shells/day by the Ukraine side, and up to 60,000/day by the Russians), along with increased blast survivability made possible by modern medicine and armor, has created potential for long-term TBI impacts on a scale not seen since WWII. Heavy use of thermobaric weapons increases the risk of blast-wave injury.

 Manpower shortages mean a lack of post-injury recovery time away from the front. Casualties with mild TBIs are often re-subjected to repeated blasts as soon as a day or two post-injury. As these challenges are likely to be seen in other potential future near-peer conflicts, it can be hoped that Ukraine will systematically work to gather data and implement measures to improve TBI outcomes, and share lessons learned with overseas medical practitioners.

In his book, Ralph G. DePalma postulates: "Closed blast TBI has been postulated to relate to vascular surge from the thorax through the neck vessels, air embolism, and piezoelectric currents generated between the skull and the shock wave (). Viscoelastic dynamic rippling of the skull secondary to the blast has been postulated based on modeling (). Interactions between the advancing shock wave and blast overpressure, the configuration of the skull, and the brain, including its meninges and cerebrospinal fluid, are complex and cause heterogeneous injury patterns including brain swelling, cerebral vasospasm (), and diffuse axonal injury (DAI) with disruption across attentional networks ()...  postulated a novel mechanism of primary nonimpact blast injury. Calculations show a dramatic shortening the linear scale of the blast shock wave as it passes through brain tissue. The example of a shock wave interacting with water was used, with the assumption that brain tissue’s physical properties, on the whole, are quantitatively similar to the properties of water. CSF is even closer to water in its physical characteristics. The proposed mechanism, based upon the dynamic behavior of phonons in water, predicts the length scale of damage to be ~30–200 nm. This phonon-based model recently has been shown to accurately describe failure waves in brittle solids (). A shock wave traveling through the brain is characterized by a shock front, which is a thermodynamic boundary between shocked and nonshocked states of water. The shock front thickness depends on several parameters and decreases in dimensions relative to the intensity of the shock or blast. For intense shocks, the shock wave front equals the interatomic spacing in the specific medium of propagation. The difference between the two states, the blast wave front and the blast wave pressure, is that some of the energy gets deposited behind the shock front, causing a change in thermodynamic parameters of pressure, volume (density), and temperature. For intense shocks, the change in these parameters becomes pronounced, predicting nanoscale damage occurring within microseconds, in contrast to acceleration injuries having durations measured in milliseconds."

A TBI can present as loss or alteration of consciousness at the time of the injury, a confused or disorientated state and/or memory loss during the first 24 hours, and/or abnormal brain imaging. GCS of 13-15 characterizes a mild TBI, 9-12 characterizes a moderate TBI, and 3-8 characterize a severe TBI. 

A growing body of evidence shows that prehospital care greatly affects outcomes in TBI patients. While the initial trauma sustained by the patient results in a certain level of irreversible brain cell death, additional secondary  injury due to hypotension and hypoxia may be preventable during pre-hospital care.

The EPIC project is a collaboration between the University of Arizona, Arizona Department of Public Health, and over 130 Arizona Fire Departments, and ground and air EMS transport services. The goal of the EPIC Project is to "dramatically increase the number of severe TBI victims who survive with good neurologic outcome by thoroughly implementing the national EMS TBI guidelines." EPIC trained 11,000 EMTs and Paramedics, with emphasis on avoiding hypotension and hypoxia, and maintaining eucapnia. 21,852 patients were included in the effort between 2009-2015. After implementation of the EPIC guidelines, patient survival-to-discharge doubled. Survival tripled amongst TBI patients who required intubation. 

A 2017 study published in the Annals of Emergency Medicine found that odds of death increased by 2.5x with a single episode of hypoxia <90%, by 3x with an episode of hypotension <90, and by 6.1x  in patient with at least one episode of both hypoxia and hypotension. EPIC guidelines call for pre-oxygenation, with the aim of maintaining an O2 level of 100%. This should be done by applying immediate and continuous high-flow O2 via NRB, starting prior to extrication if applicable. In TBI patients, the risks from short-term hyperoxia are dwarfed by the risks from potential hypoxia.

The target capnography reading is 35-45. It is crucial to avoid hyperventilation, which reduces blood flow and oxygenation of brain tissues. A possible exception is during active brain herniation. Current TCCC guidelines still recommend hyperventilation at 20/minute for patients with signs of brain herniation. However, EPIC guidelines recommend against hyperventilation in any situation, having found that it did not enhance survival to discharge in herniating patients, and caused active harm to non-herniating patients who presented with herniation-like signs.   
Opiate pain medications and benzodiazepines may cause blood pressure to drop suddenly in patients with compensated shock, and should be used with extreme caution. 


Sunday, December 31, 2023

Ukraine: Great PFC Podcast episode

 Ukrainian medic Henri talks with the Prolonged Field Care Collective about conditions in Ukraine: most common injury patterns, weather and exposure, access difficulties, Russian drone attacks on medics, trench foot, dressing complex wounds, penetrating pelvic trauma, prevalence of pneumo-hemothorax over tension pneumothorax, body armor selection factors, and more.



Saturday, December 30, 2023

Blood Loss and the Lethal Triad

Symptoms of blood loss:

500 mL - well tolerated, may produce slight tachycardia, equivalent to a typical                       blood donation volume.

1000 mL - tachycardia over 100

1500 mL - changes in mental status, weak radial pulse, persistant tachycardia,                         tachypnea

2000 mL - confusion, lethargy, weak radial, tachycardia over 120, tachypnea over                     35, might be fatal if not managed properly

2500 mL - unconsciousness, no palpable radial pulse, tachycardia over 140,                             tachypnea over 35, fatal without intervention




 In patients with blood loss, the "Lethal triad"- is a self-reinforcing cycle of acidosis, hypothermia, and coagulopathy.

Acidosis: Reduced circulating blood volume leads to shunting of blood from the periphery to vital organs in the core. Peripheral tissues resort to anaerobic metabolism, which creates lactic acid as a byproduct. This can be worsened by administration of large volumes of non-oxygen-carrying, acidic fluids, such as normal saline (pH 5.5).  

Hypothermia: Develops easily and rapidly in trauma patents, even in warm conditions. Anaerobic metabolism, immobility, and other physiological responses to blood loss reduce heat production. Evidence shows that even small drops in body temperature (to 36C / 96.8F) can significantly increase mortality in trauma and burn patients. At core temperatures below 30C / 86F, patients stop shivering and cannot warm up without application of external heat, even if they are well-insulated. It is far easier to prevent hypothermia than to correct it. 

Coagulopathy: Clot formation depends on a complex series of pH- and temperature-dependent chemical reactions. Loss of clotting factors due to bleeding, acidosis, and hypothermia all produce coagulopathy, which in turn further exacerbates blood loss, acidosis, and hypothermia. 

Preventing the Lethal Triad cycle is crucial; once established, it is difficult to interrupt. Field treatment of patients with significant blood loss should include oxygen, insulation from the ground, covering with blankets/space blankets/ready-heat systems, and placement in a heated environment if possible.


 

Friday, December 29, 2023

Antibiotics in trauma



Evidence from historical US conflicts makes it clear that early administration of antibiotics in the field improves outcomes for battlefield casualties. Safety profiles are good for field antibiotics used in US combat medicine, and adverse reactions are rare. Currently, moxifloxacin (4th generation flouroquinolone) is the US military oral antibiotic of choice. Ertapenem (a carbapenem) is the parenteral antibiotic of choice. Together, these drugs cover a wide spectrum of potential infectious microbes. 

The US Combat Wound Medication Pack contains 400mg moxifloxacin, along with 15mg meloxicam and 500mg acetominophen. The Ukrainian medication pack contains a similar assemblage of pills. 


TCCC Combat Medic/Corpsman Antiobiotics Administration, TCCC.org  https://tccc.org.ua/en/guide/module-16-antibiotics-administration-cmc