Traumatic events, such as motor vehicle accidents, penetrating injuries, animal bites, are common presentations in small animal emergency medicine.

Initial Assessment

Every trauma patient that is brought to your practice requires proper and immediate triage to determine the urgency and severity of the problems. Traumatic injuries will often affect more than one body system. Common problems in multitrauma patients that require immediate attention and treatment include respiratory distress, shock, brain and spinal trauma, acute abdomen and bleeding. It is important not to get distracted by less life-threatening abnormalities that have to be addressed in second instance, such as an open fracture, open wounds on the limb, or proptosis of an eye. They will not affect the survival of the patient in the acute phase.

A rapid and systematic approach to the trauma patient will allow the emergency clinician:

 To rapidly assess these patients so that the urgency and severity of the underlying problems can be determined

 To recognize any life-threatening condition so that aggressive treatment and stabilisation can be initiated

 To decide the best timing of any additional diagnostic examinations and to closely monitor them for any further complication or deterioration in their clinical condition.

The initial triage and initial assessment should follow the ABCD's approach.

Airway/Breathing Assessment

Oxygen should always be administered in every traumatised patient, especially in patients that are dyspnoeic. Multitrauma patients can suffer commonly from chest injuries (pulmonary contusions, pneumothorax and haemothorax) or penetrating chest injury. A careful examination of the respiratory system should help us identify the presence of these abnormalities. Our triage and initial assessment should focus on evaluation of the respiratory rate, effort and lung auscultation. Often, multitraumatised patients are too unstable to be able to undergo extensive diagnostics, so our initial physical examination should already allow us to localize and identify what the underlying cause of the dyspnoea in that patient is.

Recently, the use of ultrasound in trauma patient (TFAST) to evaluate the presence of lung and pleural space disease has gained popularity in the emergency room as a noninvasive, quite sensitive diagnostics to identify pneumothorax, pleural effusion, and pulmonary contusion. Penetrating chest injury should be initially cleaned and covered. Pneumothorax and haemothorax that cause severe dyspnoea should be addressed immediately with a thoracocentesis. If pulmonary contusions are suspected, we should be more careful in administering fluids in the resuscitation phase.

Shock

Multitrauma patients often present in a state of generalised hypoperfusion and they can suffer from different types of shock. Most patients in traumatic shock will be suffering from hypovolaemia secondary to external or internal haemorrhage or haemorrhage associated to long bone fractures and/or severe tissue trauma. Pain and severe injury to the spinal cord can contribute to the inability of the body to compensate to shock. Cardiogenic or arrhythmogenic shock may result as consequence of myocardial contusion and hypoxia. Septic shock may develop in later stages, because of wound infection or bacterial translocation from the gastrointestinal tract.

Rapid assessment of the cardiovascular perfusion parameters (heart rate, peripheral pulse quality, mucous membrane colour, and capillary refill time) will allow the emergency clinician to recognize the patient that suffers from different degree of hypoperfusion.

In human and recently in veterinary medicine, however, it has been demonstrated that many patients that suffer from shock have evidence of occult shock (i.e., ongoing tissue hypoperfusion) despite normalization of the cardiovascular parameters. For this reason, the evaluation, especially in traumatised patient, of base excess (BE), the shock index (SI the ratio between the heart rate and systolic blood pressure), the venous oxygen saturation (SvO₂) and the evaluation of the lactate clearance as markers of tissue hypoperfusion and injury, is becoming an accepted manner of evaluating perfusion, requirement for blood transfusion and some of these parameters have also shown to be predictive of mortality.

Neurologic System

Evaluation of the neurological system should include evaluation of mentation, postures, gait, and when necessary a complete neurological examination should be performed. Signs of head injury include bleeding or wounds involving the head, altered mentation (stupor or coma) associated to cranial nerve deficits and abnormalities in the pupil size. Scleral haemorrhage or blood in ear canals or from the nose could be signs of cranium fracture.

If spinal injury is suspected, the spine should be stabilised and supported on a blackboard and lateral radiograph of the spine performed before attempting to move the animal. A careful palpation of the spine for pain, crepitation, and abnormalities and a neurological examination with attention to spinal reflexes, withdrawal, and presence of deep pain should be performed in every patient with suspected spinal injury.

Abdominal Evaluation

The abdomen should be palpated for painful response, focal lesions, and the presence of a fluid thrill; the bladder should be identified. Frequent reevaluation of the abdomen for progressive distension is important. A significant volume (40 ml/kg) of free peritoneal fluid is necessary for a fluid thrill to be detected and palpation with the patient standing is most likely to be successful. If available, ultrasonography (AFAST) provides a much more sensitive and patient-friendly means of detecting peritoneal fluid. Occasionally, umbilical and peritesticular skin discoloration may be observed when significant intra-abdominal hemorrhage dissects through the abdominal muscle planes and subcutis. If abdominal effusion is suspected, abdominocentesis should be performed. The fluid collected should be evaluated and analysed for haematocrit, urea, creatinine potassium and cytology performed.

Pain Assessment

Dogs that have suffered from trauma are usually in considerable pain. Pain should always be assessed and addressed during the initial stabilisation.

Additional Care

All wounds should be evaluated and covered to prevent desiccation followed by placement of some form of dressing (preferably sterile). Once the patient is stable, the wounds should be clipped and cleaned and all penetrating wounds should be surgically explored.

Diagnostic Testing

In multitrauma, choosing and timing additional diagnostic examinations is difficult and controversial. With proper physical examination, the clinician should be able to initiate treatment and stabilise the animal. Further diagnostics such as radiographs of the thorax, complete ultrasound of the abdomen, CT of the head and spine, should only be considered in a stable animal. An early obtained blood sample can be useful to detect early internal haemorrhage and electrolytes abnormalities. A low packed cell volume (PCV) and total solids (TS) is very suggestive of blood loss; however, the initial presence of a normal or elevated PCV with concurrent low TS also may be the consequence of acute bleeding with splenic contraction and release of sequestered red blood cells. Termed 'acute traumatic coagulopathy' (ATC), this syndrome is believed to result from a combination of tissue damage and systemic hypoperfusion in multitraumatised patients, so coagulation parameters as well as platelet number should be evaluated, when possible, in a traumatized patient.

Monitoring

Careful monitoring of the physical examination parameters is the most reliable indicator of change in perfusion status. Evaluation of the respiratory pattern and neurological status should be frequently repeated. Further parameters that can provide information on perfusion status include arterial blood pressure, central venous pressure, oximetry (pulse and central venous), and urine output. Recording and identifying trends of change illuminate the need for intervention.

References

1.  Crowe DT. Assessment and management of the severely polytraumatized small animal patient. J Vet Emerg Crit Care. 2006;16(4):264–275.

2.  Simpson SA, et al. Severe blunt trauma in dogs: 235 cases (1997–2003). J Vet Emerg Crit Care. 2009;19(6):588–602.

3.  Driessen B, Brainard B. Fluid therapy for the traumatized patient. J Vet Emerg Crit Care. 2006;16(4):276–299.

4.  Sande A, West C. Traumatic brain injury: a review of pathophysiology and management. J Vet Emerg Crit Care. 2010;20(2):177–190.

5.  Herold LV, et al. Clinical evaluation and management of hemoperitoneum dogs. J Vet Emerg Crit Care. 2008;18(1):40–53.

6.  Lisciandro G. Abdominal and thoracic focused assessment with sonography for trauma, triage, and monitoring in small animals. J Vet Emerg Crit Care. 2011;21(2):104–122.

7.  Abelson AL, et al. Hypoperfusion and acute traumatic coagulopathy in severely traumatized canine patients. J Vet Emerg Crit Care. 2013;23(4):395–401.

8.  Porter AE, et al. Evaluation of the shock index in dogs presenting as emergencies. J Vet Emerg Crit Care. 2013;23(5):538–544.

9.  Stillion GR. Admission base excess as a predictor of transfusion requirement and mortality in dogs with blunt trauma: 52 cases (2007–2009). J Vet Emerg Crit Care. 2012;22(5):588–594.

10. Young BC. Decreased central venous oxygen saturation despite normalization of heart rate and blood pressure post shock resuscitation in sick dogs. J Vet Emerg Crit Care. 2014;24(2):154–161.