Crush Injury
Objectives
To describe the assessment and management of crush injury and crush syndrome in the deployed setting.
Scope
This guideline provides a framework for the early assessment and management of a patient who has suffered a potential crush injury. In most circumstances, initial management should follow established trauma protocols. This guideline only describes considerations specific to crush injury.
Audience
This guideline is intended for the use of registered healthcare professionals fulfilling a general role in a forward medical location or in an Emergency Department on deployed operations.
Initial Assessment & Management
Crush injury is a direct injury resulting from compression.
While any part of the body may be injured by a crushing force, the term usually describes injury to the limbs and areas of muscle bulk. Injuries to the head, chest and abdomen should be managed in line with trauma principles and are not described further.
In addition to the immediate consequences of injury (e.g. bleeding), the patient with a crush injured limb may be at risk of developing compartment syndrome or Acute Kidney Injury (AKI, in this context part of “crush syndrome”, a consequence of myoglobin deposition).
Entrapment and extrication
In cases of entrapment, the earliest possible safe release of the compressing force should be a treatment priority. Analgesia should be given early to facilitate extrication and transfer to definitive care. Tourniquets should be applied if there is catastrophic haemorrhage, in line with trauma protocols. Loose pre-positioning of tourniquets prior to release of a compressing force should be considered to facilitate rapid application if catastrophic haemorrhage develops.
There is no evidence supporting the use of tourniquets to delay reperfusion and they should not be used for this purpose.
Not all entrapped patients will have suffered significant crush injury, although the risk should be considered.
Fluid resuscitation
Early IV/IO access should be established, if practicable, to facilitate prompt fluid resuscitation in case of deterioration, although this should not delay extrication. Fluid administration should be individualised based on injury (time, force, muscle mass), patient (hydration status, co-morbidities) and scene/system factors (time to definitive care, availability of renal replacement therapy).
Most patients in the first few hours after injury should be managed in accordance with standard trauma care (blood products, warmed saline titrated to BP). In austere settings with delayed extrication and delayed access to definitive care, more liberal fluid administration has been advocated to reduce the risk of AKI, although evidence to support this approach is limited. The use of sodium bicarbonate in crush injury is no longer recommended.
Monitoring
The incidence of clinically significant hyperkalaemia following a crush injury is unknown. Prophylactic treatment is not supported, however, early testing (VBG) may be helpful, if available. Confirmed hyperkalaemia or dynamic ECG changes consistent with it should prompt management in line with established protocols - see CGO on management of hyperkalaemia (link to follow).
Advanced Assessment & Management
Early blood tests (CK, renal function, electrolytes) may be useful to risk stratify patients with significant suspected crush injury but the trajectory may only be apparent with repeat testing over a few days. Myoglobin is detected as a positive result for haemoglobin on a urine dipstick. This, or dark (“coca-cola”) urine, should prompt a high suspicion of rhabdomyolysis, increasing the risk of developing AKI.
Acute kidney injury (“crush syndrome”)
In patients with significant crush injuries or deteriorating renal function, early consideration should be given to critical care review to facilitate access to renal replacement therapy, which will usually necessitate evacuation from the deployed setting. Renal replacement therapy should be initiated in line with the CGO for acute renal failure (link to follow).
Surgical Interventions
Patients are at risk of compartment syndrome following crush injuries; if suspected, prompt surgical review is required to allow this to be investigated and managed in line with the relevant guidance (link to follow). There is no role for “preventative” fasciotomies and fasciotomies should not be performed prior to surgical attention.
If the severity of damage to soft tissues, bone, vascular structures and or nerves renders the limb unsalvageable, then an early decision to amputate can reduce the systemic complications of crush injury, so a similarly prompt surgical review is essential.
Prolonged Casualty Care
The principles of good supportive care apply equally to crush injury as they do to any other traumatic injury. These include analgesia, maintaining hydration status and monitoring urine output.
Paediatric Considerations
The management of crush injury in children is the same as in adults.