EMS Canine Tourniquet Use

Summary / Explanation

Introduction

Extremity hemorrhage from an arterial source is traditionally managed by placing a tourniquet that circumferentially compresses tissue until arterial occlusion is achieved. Although simple and effective in humans, anatomical differences in canines make this approach less feasible. Law enforcement officers with canine partners, military canine handlers, and prehospital providers should understand the anatomical challenges of adequately managing the canine casualty. This article outlines key considerations for managing canine extremity hemorrhage in the prehospital setting, emphasizing the challenges of canine anatomy and effective tourniquet use. 

Massive hemorrhage is a preventable cause of death in canine patients, yet it remains a significant cause of death among military working dogs and civilian canines involved in trauma.[1] Miller et al analyzed military veterinary treatment records of canine deaths in overseas conflicts, revealing that that injuries were the primary cause of death for 77.2% of the canines, with the most frequent external injuries being gunshot wounds (31.5%) and explosions or blasts (26.1%).[2] Guidelines were established to aid the canine rescuer's care and address the lack of emergent veterinary care, particularly in the tactical setting. Palmer et al offer recommendations aimed at addressing the major causes of out-of-hospital preventable deaths in canines.[3] From these recommendations, the K9 Tactical Emergency Casualty Care (K9-TECC) training program was created by the Committee for Tactical Emergency Casualty Care (CoTECC), which serves as operational canine care guidelines for civilian high-risk operational canine caregivers.[4]

Understanding the anatomical differences between humans and canines is crucial for providing appropriate hemorrhage control in dogs, as standard human tourniquets are often ineffective when applied to canines.

Objectives

• Identify key anatomical differences between canine and human extremities and the types of tourniquets that can be used in the canine population.
• Describe the preparation, equipment, and technique for canine tourniquet placement.
• Review appropriate evaluation methods to determine the efficacy of a placed tourniquet.
• Explain strategies for improving tactical canine care, focusing on hemorrhage control.

Anatomy and Physiology

Canine extremities vary significantly in circumference from proximal to distal, creating a conical shape that makes the traditional tourniquet prone to slipping distally when tightened. According to the Committee for Tactical Combat Casualty Care (C-TCCC) and its published K9-TCCC guidelines, windlass limb tourniquets designed for humans—such as Combat Application Tourniquet (C-A-T) and SOF Tactical Tourniquet Wide (SOFTT-W)—tend to slip distally and generally fail in their efficacy. Therefore, the literature on canine casualty care recommends using malleable tourniquets for canine extremity hemorrhage. [5] The canine's pulse should be evaluated in all extremities. On the forelimb, the pulse can be palpated on the palmer aspect of the limb, between the carpal and metacarpal pads. The dorsal pulse can be palpated at the slightly medial aspect of the hind limb, at the proximal end of the metatarsal bones. 

Indications

Canine tourniquet placement is indicated for severe hemorrhage in an extremity or tail when other methods have failed, such as direct pressure. Indications include life-threatening hemorrhage from a traumatic amputation or hemorrhage refractory to direct pressure or pressure dressing application.

Contraindications

There are no absolute contraindications to tourniquet placement in the presence of a life-threatening hemorrhage. In many cases, the canine must be muzzled to protect providers. Muzzle placement is typically contraindicated in canine patients presenting with the following conditions:

• Upper airway obstruction
• Respiratory compromise
• Severe facial trauma or suspected head injuries
• Heat-related injuries
• Vomiting or following narcotic analgesia administration
• Unconscious or significantly decreased level of consciousness

Equipment

The following equipment options are essential for ensuring the safety of both the canine patient and the provider in an emergency situation:

• Muzzle: Fabric or leather muzzle or an improvised muzzle device such as a belt, triangular bandage, or roller gauze
• Tourniquet options:
• Elastic-style: Safeguard Medical Systems SWAT-T™, Rapid Medical RATS Tourniquet, or H&H Tourni-Kwik TK4™
• Canine-specific windlass-style tourniquet: TACMED™ K9 Tourniquet
• Improvised tourniquet device: Compression bandage, belt, triangular bandage, or necktie

Sedation may be necessary to facilitate treatment and should be discussed with the dog handler. Options may include benzodiazepines, hydromorphone, or ketamine.[6]

When indicated, sedation protocols ranging from mild to heavy should be considered in the canine to facilitate clinical assessment and procedures.[6] Mild sedation can be achieved by coadministering midazolam with hydromorphone or morphine. For deep sedation, ketamine can be added as a third drug, which typically results in a sedate but rousable canine. Furthermore, sedation with a general anesthetic, such as an intravenous propofol bolus, can be administered as a supplement for further casualty care.

Personnel

Tourniquet placement requires adequately trained personnel to identify indications for its use, determine its efficacy once placed, and implement alternative solutions when needed to achieve adequate hemostasis. 

The majority of out-of-hospital canine care literature is focused on the operational canine, which is a distinct subpopulation of elite civilian working canines (K9), military working dogs, and Search-and-Rescue (SAR) canines. These canines are specially trained to operate in high-threat, tactical, and austere environments and commonly serve federal and local law enforcement agencies, the United States military, private security contracting organizations, and SAR groups such as Federal Emergency Management Agency Urban Search and Rescue, and volunteer SAR teams. 

Preparation

Effective teamwork between the rescuer and the handler is essential. Team safety should be prioritized, and the K9 handler should care for the injured canine whenever possible. If feasible, encounters with the canine should be used during training events to develop mutual familiarity with the animal before actual missions.

Tourniquet Placement Technique

• Ensure scene safety.
• Restrain the casualty and apply a muzzle using a cravat, stretch gauze, or commercial muzzle device.
• Attempt direct pressure or pressure dressing for hemostasis.
• If hemorrhage continues, apply a wide elastic tourniquet proximal to the wound, at least 2 to 3 inches above, avoiding joints.
• Tighten until bleeding stops and distal pulses are absent.
• Record the time and date of application.
• Immobilize and elevate the extremity when possible.

Tourniquet Conversion

Tourniquet placement causes a mechanical stoppage of blood, referred to as ischemia, which consequently induces complications associated with pressure, pain, and hypoxia. To minimize the risk of complications related to tourniquet placement, tourniquets must be converted as soon as possible. Rescuers should perform tourniquet conversion during the first 2 hours following placement. The 3 tourniquet conversion methods are as follows:

• Tourniquet removal: Bleeding has been controlled, and an appropriate dressing has been placed.
• Tourniquet-to-tourniquet conversion: A second tourniquet is placed proximal to the original, after which the original tourniquet is released, and the wound is monitored for bleeding.
• Tourniquet-to-dressing conversion: The wound is exposed and packed, followed by pressure dressing placement. The tourniquet is slowly lowered, and the wound is monitored for bleeding.

Complications

Tourniquets left in place for more than 1 to 2 hours can cause tissue ischemia, leading to serious complications such as rhabdomyolysis, vascular injuries, or peripheral nerve damage.[7] Tissue ischemia from prolonged tourniquet placement can result in permanent damage or loss of the limb and acute kidney injury.[8]

In addition, tourniquet placement is often painful, particularly in an already injured patient. Efforts to manage pain should be made when feasible, in accordance with the scope of practice and organizational protocols.

Clinical Significance

Tourniquet use has been widely adopted in both military and civilian human healthcare settings. Research indicates that various rescuers, including laypersons and professional rescuers, frequently use this intervention. Law enforcement officers initiate half of the total community placement of tourniquets in humans.[9] This trend is likely generalizable to the canine population, where police officers and first responders should be targeted for canine-specific trauma training. Tourniquets are a life-saving tool, but their use in canines presents unique challenges due to anatomical differences. Ensuring that personnel are trained in canine-specific techniques can improve outcomes in trauma scenarios.

Enhancing Healthcare Team Outcomes 

Collaboration and shared decision-making are crucial in managing canine hemorrhage. Early intervention to control hemorrhage can prevent irreversible shock and improve survival rates in the canine population. The individual or heterogenous team that serves as the rescue resource for a wounded canine can provide hemostasis during massive extremity hemorrhage and help achieve the best possible outcomes.

Ongoing education, collaboration, and shared decision-making among prehospital providers are essential to achieving and maintaining hemostasis in canine patients. The sooner hemostasis is achieved in the canine patient, the greater the likelihood of preventing an irreversible state of shock.