Month: March 2011

Pre-hospital Expedition Medicine Series

Dr Amy Hughes, Medical Director of Expedition Medicine and Pre-Hospital Emergency Medicine Registrar and HEMS paramedic Dave Marshall, both part of the Kent Helicopter Emergency Medical Team, continue their series examining pre-hospital expedition trauma care and associated kit.

In the second article in the series, Dave Marshall gives an overview of managing pelvic fractures pre-hospitally and in an expedition environment, and introduces the use of the pelvic splint.

Edited by Dr Amy Hughes.

Pre hospital and Expedition management of pelvic trauma and use of the pelvic splint

Expeditions have become more and more adventurous over the past years, both in destination and the participants involved. As a result, the frequency and pattern of injury is changing and the demand on the medical team thus increased. Having a broad knowledge of fracture management, including mechanism of injury, clinical findings, reduction techniques and splinting is essential. Although one of the most enjoyable challenges of being a medic on an expedition team is improvisation regarding kit used to manage various ailments and injuries, practice and competence in the use of non-improvised kit such as the Pelvic Sam Splint is essential.

Mechanism of Injury

Pelvic fractures often result in extensive disruption of the bony structures and associated ligaments of the pelvis and are potentially life-threatening injuries. The fractures associated with the greatest morbidity and mortality involve significant forces such as motor vehicle crashes, motorcyclist crash, pedestrian versus car, falls from height and crush injuries. Early suspicion, identification and management of a pelvic fracture at the prehospital stage is essential to reduce the risk of death as a result of hypovolaemia, ⁽¹⁾. It is especially important to be able to identify, treat and minimize risk of further damage when in a remote area miles from the nearest medical facility.

Understanding the mechanism of injury is vital in being able to predict the potential for significant injury to the pelvis and its underlying structures, even in the absence of clinical signs. It is, therefore, essential that time is taken to evaluate the mechanisms involved in any accident resulting from significant force or where there is pain or injury to the spine, abdomen, pelvis or femurs.

In motor vehicle accidents – a not uncommon event on expeditions – learning how to ‘read’ the wreckage to help identify possible pelvic injury, in conjunction with clinical suspicion, can significantly aid diagnoses.

The intrusion into the passenger and drivers door is likely to result in massive lateral injury to the pelvis.

The intrusion into fuel tank shows the imprint of the riders pelvis. This would often result in significant fracture to the pelvis – often multiple, often ‘’open book’’ pelvis.

Anatomical structure of the pelvis 

The pelvic ring is often likened to a polo mint in that it is almost impossible to have a significant break in one place and not another. The most common area to be damaged in trauma is the pubic rami, acetabulum and the sacroiliac joint. There is extensive vasculature through and around the pelvic ring, most notably the iliac vessels. For imagery see > http://visualsunlimited.photoshelter.com/image/I0000kUOn3NJHcZU.

The greatest risk of a pelvic fracture is catastrophic haemorrhage and gentle handling of the patient in the initial and subsequent stages could literally be the difference between life and death. Whole blood clotting time is approximately 10 minutes, (depending on the environment). Expedition medics should be familiar with the ‘first clot best clot’ theory. In other words, a patient sustaining a traumatic injury resulting in haemorrhage will begin to form a clot using their own clotting factors. If this clot is disrupted they could easily bleed to death. A full fluid resuscitation will not be practical in the field as most expeditions carry a maximum of 2 litres of crystaloid. However it should be noted that overloading the patient with fluid can be equally harmful, and small boluses should be given to maintain a central pulse and cerebral perfusion. This is known as permissive hypotension and will be discussed in more detail in a future article. Disruption of this first clot in the prehospital setting could be fatal, and without access to blood and clotting agents the patient may die. Trauma will result in the patient becoming acidotic, hypothermic, and coagulopathic. ⁽³⁾

This coagulopathy cannot be easily reversed pre-hospitally, each factor contributes to the decline in the others. (see above diagram). Any disruption to the first clot will have devastating consequences. Ultimately, the patient requires definitive haemorrhage control, (surgery, angiography and embolisation), and replacement of blood and clotting agents.

The glass pelvis:  Think of the pelvis as being made of very fragile glass, and you can see the clot in the form of a cartoon jelly inside. The jelly is very delicate and unless movement is gentle and kept to a minimum, it will ‘wobble’ to the point of destruction very easily. The same applies to the blood clot! Early recognition of the potential for a pelvic injury, gentle handling and prompt stabilisation is vital to improve the outcome of a patient injured on an expedition.

Clinical Features of a pelvic injury:

• Management of pelvic fractures and clot preservation:
  Asymmetry of the pelvis – do not spring the pelvis. Visual alignment and gentle palpation of the Anterior Superior Iliac Spine may help demonstrate pelvic injury, but often the pelvis visually appears normal, thus mechanism of injury is vital in determining injury
• Shortening/rotation of the leg/s
• Inguinal pain
• Localised swelling/contusion
• Hematuria/urinary incontinence
• Bleeding PR/PV – PR examination not recommended to determine pelvic injury.
• MECHANISM, MECHANISM, MECHANISM! (albeit not a clinical feature!) – there may be no obvious clinical abnormality despite significant injury. Thus clinical suspicion is essential.

As we have already discussed, a patient with a suspected pelvic fracture must be handled very carefully. Whether in a medical facility or the most extreme expedition environment, the same principles apply to prevent worsening the injury and preserving the clot.

Log rolling the patient should be avoided at all costs!

The medical kit available on expeditions will be minimal. Stretchers may have to be improvised and transportation limited. However, all medical kits should have some sort of pelvic binder which should be applied carefully and correctly at the earliest opportunity,

Application of the pelvic SAM splint.

The casualty will inevitably have to be placed in the supine position, to evacuate them on whichever device is available. This can be achieved by a coordinated team approach utilising other members of the expedition.

One person should be at the head end of the patient maintaining in manual inline immobilisation, (MILS), and they will give clear commands to the team when moving the casualty, (“ready, brace, roll”). A pelvic binder such as the one shown can be applied using a minimal 10-15% roll, (enough to get a bum cheek off the ground!)  

Once in position the device can be tightened just enough to maintain anatomical alignment. Do not over tighten as this could cause significant further damage!

Log rolling patients.

Whilst sometimes useful in a controlled hospital environment following appropriate imaging, should be avoided in the pre hospital field. In simple risk versus benefit terms it could have catastrophic consequences. By using the hands available and correctly briefing the team about the amount of movement required (one cheek off!), it should be possible to optimise the care of the casualty prior to evacuating them to definitive care.

Improvised methods of pelvic splinting on expeditions

Much of the challenge of expedition medicine is improvisation. The medical kit you take out with you may not have SAM splints in them. Providing a support can be placed across the greater trochanter, then any sort of material could be used – for example clothing, a sheet, or a canvass of some kind.

Fluids

The approach to fluid management in trauma has changed. Two litres of fluid is not necessarily required for management of pelvic injury. Titrate fluid according to the presence of pulses or cerebration (alertness). The presence of a radial pulse, and even in certain circumstances (without associated head injury) presence of a femoral pulse signifies the blood pressure is sufficient to perfuse the necessary organs and promote clot preservation. Further details of permissive hypotension will follow in another article.

Analgesia

Essential – this depends on what is available. Intravenous opiates or a fentanyl lolly is ideal for analgesia, after the use of paracetamol or a NSAID.

Other injuries

Pelvic injuries are often present in conjunction with other significant injuries – spinal, femur, urological or abdominal as examples. Whether or not other injuries have been excluded, spinal precautions are essential in conjunction with good management of the pelvis.

References

1. Lee C, Porter K. The prehospital management of pelvic fractures, Emergency Medical Journal 2007;24:130-133
2. Maya A, Matinowitz U, Kluger Y. Coagulopathy in the critically injured patient, Yearbook of Intensive Care and Emergency Medicine 2006, Part 5,232-243
3. Crawford C, Pelvic Fracture in Emergency Medicine, available at: http://emedicine.medscape.com/article/825869-overview