Managing head trauma – the VN’s role in treating cases

Unfortunately, it is commonplace for patients with head traumas to be admitted to the emergency and general veterinary practice.

Various causes for head trauma exist, including road traffic collisions, being stepped on by owners and falling. Any animal that has had a head trauma must be advised to attend the veterinary practice straightaway, as it requires immediate medical attention.

Unfortunately, due to the nature of head injuries, other concurrent problems may present at the same time. It is paramount the animals are triaged, and admitted for treatment and stabilisation without delay.

Types of head trauma

Animals may be admitted with two types of head traumas:

• Primary brain trauma – this may be from impact with a direct source resulting in a skull fracture, or from cerebral haemorrhage. These forces include acceleration, deceleration and rotational forces (Freeman and Platt, 2012). The brain is sensitive to external trauma and forces due to its anatomical make-up.
• Secondary head trauma – this occurs following the primary trauma and is usually resulting from a cascade of metabolic changes (Brewer, 2022; brewerneurovet.com). It must be remembered that it is key to try to prevent the secondary head trauma from developing (O’Dwyer, 2018). Sometimes, it cannot be prevented, so reducing the level of injury is important.

Triage and initial assessment

It is important that triage and initial assessment of the head trauma patient is completed as soon as it arrives on the premises.

The initial assessment should evaluate the patient’s cardiovascular and respiratory systems (O’Dwyer, 2018). Using the pneumonic ABC will guide the key areas for triage of the patient. It is also important to remember that many patients with head traumas will have other injuries possibly relating to the spine, so they must be handled gently and with care.

• A – Airway: is the airway clear, is anything in the mouth that could be blocking the breathing? Is any swelling present in the oral cavity from the resulting head trauma? Remember to check for mucus and vomit, as this may need to be cleared from the airway.
• B – Breathing: is the patient breathing normally; is the pattern normal? Are any signs of disrupted breathing patterns present? Head trauma can result in unconsciousness, which could result in the patient suffering from apnoea or dyspnoea. This being the case, one must consider preparing ventilation equipment for the patient’s arrival.
• C – Checks: check the patient’s circulation, and monitor the heart rate and pulse rate. It is also important to check the blood pressure. When checking the pulse and heart, check for any evidence of a pulse deficit. If an electrocardiogram (ECG) device is available, complete a full ECG to check the heart rhythm and for any specific arrhythmias.

It is important to identify if any of the aforementioned is not within normal ranges, as the patient may require emergency intervention as directed by the vet (Terry, 2010). As part of the assessment, a modified Glasgow coma scale (MGCS; Bush Veterinary Neurology Service, 2016) should be completed on the patient.

Neurological assessment and MGCS

It is important to complete the neurological assessment and a recognised mentation assessment, such as MGCS, prior to providing any medication to the patient, as this can affect the assessment. However, it is important to remember these patients benefit from supplementary oxygen on admission and throughout the recovery period.

The MGCS is a method to assess the survival likelihood up to 48 hours in dogs with traumatic brain injury. The assessment looks at initial neurological status, as well as the changes in clinical signs.

Three areas are to be assessed, including level of consciousness, posture and pupillary size, and light response. The score ranges from 3 to 18, with the lower scores indicating severe neurological dysfunction (O’Dwyer, 2018). It is important to recognise that patients’ systemic problems can impact neurological functioning. (Fletcher, 2012).

The neurological assessment comprises of a physical assessment, which looks at the various neurological responses to stimulus. It is important the assessment be completed as soon as the patient is stable enough, but one must be aware that head trauma patients can have subtle changes and deteriorate quickly.

When assisting with the assessment, it is important to handle the patient gently, and ensure the head, neck and spinal cord are supported at all times. If any fractures are suspected, thorough discussion with the veterinary team should be completed so the safest way to handle the patient for the assessment can be planned. Careful positioning of the head and neck ensures no occlusion of the jugular vein, as this can decrease venous return from the brain, which can lead to increased intra-cranial pressure and can cause intra-cranial haemorrhage (O’Dwyer, 2018).

The physical examination will look at levels of consciousness, which should be reviewed regularly to monitor for improvement or decline.

The key definitions for levels of consciousness are:

• Awake and response – responds to stimuli and behaves as normal.
• Obtunded – the patient is showing signs it is awake, but response to stimuli is reduced.
• Stuporous – the patient only responds to painful stimulus, such as a pinch reflex.
• Comatose – the patient is defined as unconscious and does not respond to any stimulus, including pain stimuli.

While being assessed, the patient’s body position will enable the veterinary surgeon to assess the severity of the brain injury and prognosis. If the patient is presenting recumbent and defined as comatose, with all its limbs extended and the head dorsiflexed, this is classed as decerebrate rigidity and is indicative of severe brainstem injury, along with a grave prognosis.

Decerebellate is where the forelimbs are extended and the hindlimbs are flexed. This is less severe, and some patients will show some signs of consciousness and pupillary response (O’Dwyer, 2018; Rylander, 2013).

Monitoring the patient

The patient requires continuous monitoring, and the following clinical signs should be monitored and recorded accurately:

• Vital signs: temperature, pulse rate and quality, and respiration rate and character.
• Heart rate and character.
• Lung sounds, with specific placement for lung assessment.
• Mucous membrane colour and capillary refill time.
• Blood oxygen levels: this could be completed with a pulse oximetry or blood gas analysis.
• Pupillary size and response.

Any changes and regular recording should be immediately communicated with the veterinary surgeon.

Nursing the patient

A patient with head trauma will need extensive and continuous nursing care to be provided.

It should have a designated nurse who will monitor the patient, so any changes can be noted immediately and discussed with the veterinary surgeon. As discussed, patients suffering with head trauma can deteriorate quickly. Most patients will require supplementary oxygen therapy throughout their stay. They may also require artificial oxygen ventilation support.