The Ideal Haemostatic Dressing

Email: paul.parker@stees.nhs. uk Introduction The problem of haemorrhage is well recognised by the deploying military medical community. In 1970 Maughon, after examining the combat deaths of 2600 American servicemen in Vietnam, articulated the simple requirement that more be done on the battlefield to prevent death from haemorrhage: “The striking feature was to see healthy young Americans with a single injury of the distal extremity arrive at the magnificently equipped field hospital, usually within hours, but dead on arrival! ”[1] This was reinforced by Rocko in 1982, who wrote of the need to prevent “public exsanguination” in civilian trauma [2]. Leaving aside unsurvivable CNS trauma, the commonest cause of preventable death in combat remains haemorrhage [3]. In Vietnam 23.9% of casualties that survived to reach a hospital died of haemorrhagic shock [4]. Thirty eight percent of those who succumbed to haemorrhage in the pre-hospital setting bled to death from wounds where control could have been achieved simply by direct pressure [5]. In recent conflicts, extremity trauma has accounted for 54% of wounds by anatomical region [6] and deaths from extremity trauma remain as prevalent in recent conflicts as in Vietnam [7]. Analysis of autopsy data from American casualties sustained in Iraq and Afghanistan has shown that over 80% of casualties with potentially survivable wounds died from haemorrhage. Of these, approximately 20% died from wounds in the neck, axilla and groin [8]. As death from haemorrhage can occur within minutes of injury, prompt effective treatment of any haemorrhage is paramount [9]. In the Defence Medical Services (DMS) this has seen a re-design of the protocols issued to pre-hospital care providers, with specific indications as to when to employ techniques from an armamentarium of treatments that includes; pressure, elevation, elasticated field dressings, tourniquets and novel haemostatic dressings [10] (Figure 1). The efficacy and rationale behind the use of tourniquets has been discussed in this journal previously [11] and will not be repeated. However, significant numbers of wounds remain that have accessible bleeding points but are not suitable for tourniquet application. These wounds have been described as “nontourniquetable but compressible” [8]. In the tactical situation, application of sustained effective pressure is difficult. There is a poorly defined subgroup of traumatic wounds that due to location [7], complexity [9] or coagulopathy [12] require adjuncts to direct pressure in order to arrest bleeding. It is in dealing with these injuries, particularly in the pre-hospital and transport environment that novel haemostatic dressings have the greatest role to play. It may be where we can have the greatest effect on mortality and morbidity by reducing blood loss and the need for haemostatic resuscitation. Whilst often controversial, it is always appropriate to regularly examine the scientific basis upon which novel products, techniques and developments are introduced and delivered to the battlefield. The American model has seen a variety of products developed via different research and funding streams and despite frequent joint force operations, there has been a confusing adoption of several different dressings within the individual American uniformed services. This has not occurred within the DMS. The UKs initial choice of dressing was simply based on pragmatism [13]. It was also, for that reason, to be subject to annual review [11]. DMS clinicians and Medics are happy with the training they receive in utilising all the products currently fielded within the DMS [14], but it is unclear whether the dressings are effective? Forty four unexpected survivors among British service personnel wounded since 2003 have been reported[15]; it is unknown whether novel haemostatics have played a significant part, or any role at all, in these successes. It may represent a defect in the application injury coding scores unused to severe military blast and ballistic trauma. In written evidence to the Select Committee on Defence, the introduction of several enhanced haemostatic products and devices (HemCon, QuikClot, CAT tourniquet and the new FFD (in addition to the team medic)) were credited with saving “over three lives by 2006” [16]. This review examines the scientific evidence that led to the adoption of these novel haemostatic dressings and the clinical evidence as to their effectiveness now available. It will concentrate on those products currently available or recently used within the military environment. Novel Haemostatic Dressings