Introduction

In 2020, a series of updates to the TCCC guidelines occurred as approved by the Committee on Tactical Combat Casually Care (CoTCCC). Theses updates in the trauma guidelines can be viewed here (see red text), and they went live on 05 November 2020 on the Deployed Medicine website. There were a total of six separate changes to the TCCC guidelines that included five updates and one new addition to the following topics below. Our aim is to provide a summary of key highlights of these TCCC guideline changes and their relevance to wilderness medicine.

1. Tourniquets - update
2. Hypothermia prevention and management - update
3. Tranexamic acid - update
4. Fluid resuscitation – update
5. Prehospital analgesia – update
6. Eviscerating abdominal injuries – new addition

Recommended Limb Tourniquets in TCCC

The tourniquet working group from the CoTCCC completed a comprehensive review of limb tourniquets employable in Tactical Combat Casualty Care. This was the first update for new tourniquet recommendations since 2005. Based on the evidence, the CoTCCC ultimately recommended six nonpneumatic tourniquets and two pneumatic tourniquets. The goals of this extensive tourniquet review were to: 1) review the previously recommended tourniquets; 2) determine if additional commercial tourniquets warrant CoTCCC recommendation; and 3) identify commercial tourniquets that require further review or do not currently warrant recommendation - see Table 1 for a tourniquet guideline update and publications. These new tourniquet additions have direct translation to both civilian tactical and wilderness medicine application.

Management of Hypothermia in TCCC

When combat casualties incur hemorrhage and shock, the effects of trauma-induced hypothermia result in significantly increased mortality. Consequently, hypothermia prevention and rewarming are an essential component of prehospital trauma care guidelines. In both civilian and military trauma, it has been reported that 100% mortality occurs when core temperature is <32°C (89.6F). Thus, the CoTCCC decided to review hypothermia prevention and management guidelines and update them - see Table 1 for summary on hypothermia management and prevention guidelines and publications. The recommended hypothermia rewarming enclosure systems have direct application to wilderness medicine.

Use of Tranexamic Acid in TCCC

Tranexamic Acid (TXA) is an inexpensive, antifibrinolytic agent shown to reduce morbidity and mortality in patients with significant bleeding. Questions about the use of TXA persist regarding the optimal medical and tactical/logistical use, timing, and dose of this medication. Thus, the CoTCCC working group examined these questions and the strength of evidence for potential guideline updates. As a result, CoTCCC agreed to update the TXA dosing and administration, and add traumatic brain injury as a new indication - see Table 1 for a summary on the TXA guideline update and publications. The recommendations for TXA dosing have direct application to advanced providers in wilderness medicine.

Administration of Analgesia and Sedation in TCCC

Pain is one of the most common complaints from trauma victims. Reports from recent military conflicts suggest that early pain control may reduce the incidence of long-term deleterious outcomes. There are several studies that demonstrate a relationship with poor management of acute and chronic pain with PTSD, and other mental health issues. The current approach to analgesia at the point of injury is based on the severity of the injury and utilizes a single drug/single dose, and then repeat when necessary. There are medical interventions now offered at the point of injury and during prolonged field care that may require ongoing analgesia and/or dissociative sedation. See Table 2 for the reason to update the analgesia and sedation guidelines and pending publications. The recommendations for analgesia and sedation have direct application to the advanced provider in wilderness medicine.

Fluid Resuscitation for Hemorrhagic Shock in TCCC

In severely wounded military casualties, time to prehospital transfusion initiated within 30 minutes of injury is associated with improved 24-hour and 30-day survival. Consequently, both civilian Fire/EMS and military operational units are now conducting whole blood transfusion at the point of injury. Ongoing research demonstrates that time to transfusion, and maybe more importantly what is being transfused, has a greater impact on mortality. Thus, current research focuses on the optimal fluid resuscitation for trauma victims in hemorrhagic shock. The CoTCCC has made several updates to the fluid resuscitation section, e.g., in 2011, 2014, and now recently in 2020. Since the last 2014 fluid resuscitation TCCC update, newer concepts in resuscitation from hemorrhagic shock continues to evolve. Since 2014, the preferred fluids for resuscitation of casualties in hemorrhagic shock has been the following top three options: 1) whole blood; 2) 1:1:1 plasma, RBCs, and platelets; and 3) 1:1 plasma and RBCs.

The use of whole blood for damage control resuscitation continues to gain broad acceptance for battlefield use. Based on the evidence, the use of cold-stored low titer O whole blood (LTOWB) is now the preferred resuscitation fluid for trauma victims in hemorrhagic shock. Based on the 2020 TCCC approved changes, the top three preferred trauma resuscitation fluids are presented below in order of preference:

1. Cold stored low titer O whole blood
2. Pre-screened low titer O fresh whole blood
3. Plasma, RBCs, and platelets in a 1:1:1 ratio

See Table 2 for the reasons to update the fluid resuscitation guidelines and pending publications. The recommendations for fluid resuscitation have direct application to the advanced provider in wilderness medicine.

Management of Abdominal Evisceration in TCCC

About 20% of combat wounds are abdominal injuries including evisceration that may complicate about 1/3 of battle-related abdominal wounds. Evisceration is an injury with potential for improved outcomes if managed appropriately in the prehospital setting. Traditionally, initial management of abdominal evisceration consists of assessing for and controlling associated hemorrhage, covering the eviscerated abdominal contents with a moist, sterile barrier, and carefully reassessing the patient. However, the CoTCCC has not specifically addressed this issue previously in the trauma guidelines. The intent is to reduce hemorrhage, increase intra-abdominal organ viability, reduce hypothermia, and reduce complications related to sepsis. See Table 2 for the reason for the new addition on the management of abdominal evisceration and pending publications. The recommendations for evisceration management have direct application to the wilderness medicine provider.

Future TCCC Guideline Changes

The CoTCCC airway working group is finalizing their enormous review of the evidence for making a series of proposed updates to the TCCC guidelines. The airway topics that have proposed changes at the point of injury are patient positioning, nasopharyngeal airway, extraglottic airways, and cricothyrotomy procedures and equipment. All of the proposed TCCC airway changes will have direct translation to civilian prehospital care including wilderness medicine education and training. A future article in the Wilderness Medicine Magazine will summarize all CoTCCC approved airway management changes. Other topics with pending future TCCC updates: Traumatic Brain Injury; Extremity Tourniquets; Junctional Tourniquets; and Hemostatic Agents.

Final Thoughts

It is important to reiterate that all of these six TCCC topics are now fully integrated into the TCCC guidelines and teaching curricula. The application of analgesia and fluid resuscitation TCCC guideline updates is beyond the scope of the typical wilderness medicine provider not carrying a robust medical kit, and without appropriate advanced skills training. Consequently, these updates are more applicable to advanced providers serving with search & rescue teams, wilderness expeditions, or disaster response medical teams that have delayed medical evacuation to definitive care. Finally, managing eviscerations in the wilderness/austere environment is very rare, but may be seen with a mechanism of injury causing abdominal penetration from, for example, gunshot wound during hunting, wild animal attack, fall from height, or a deterrent explosive device used to keep individuals away from illegal substances, e.g., hemp (cannabis sativa) or property.