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69 Central Nervous System Trauma 745

Fluid administration is generally considered first‐line
VetBooks.ir therapy in this situation; however, a restricted heart rate
makes these patients susceptible to fluid overload. Early
consideration of vasoactive agents is recommended in
people and so should be considered in veterinary patients
where appropriate.

Specific Management Considerations
Medical Therapy
Pain Management Analgesic therapy is essential in the
management of the neurotrauma patient. The degree
of analgesia and sedation must be balanced with pres-
ervation of blood pressure and ventilatory status, as
depression of each of these parameters can contribute
to secondary injury, and if possible should not impede
Figure 69.6 Securing a dog or cat to a board in lateral reassessment of neurologic status.
recumbency can reduce vertebral movement prior to external or Opioids are the analgesic drugs of choice in critical
internal stabilization of a fracture luxation. care medicine, because of their ease of reversal and rela-
tive safety when titrated to effect. Several studies suggest
that bolus infusion of opioids should be avoided, and
At the time of stabilization, patients with SCI should be constant‐rate infusions (CRIs) are preferred. Because of
immobilized by stabilizing both the body and head using the ease of reversal, it is recommended that full agonist
a rigid spine board (Figure 69.6). opioids be used.
Table 69.1 lists the recommended analgesics and their
Airway respective doses.
Although airway and spine protection share top priority,
airway management takes precedence; risking iatrogenic Corticosteroids The use of corticosteroids in the treat-
SCI is justified in exceptional circumstance when ment of acute SCI remains controversial despite extensive
required to secure or protect the airway. clinical investigation. Proposed mechanisms supporting
the use of corticosteroids in SCI include free radical scav-
Breathing enging, antiinflammatory effects, and improved local
Respiratory insufficiency can be an important cause of blood flow. Unfortunately, there are no studies demon-
early mortality after SCI. Cervical injuries can paralyze strating a benefit of steroids in improving outcome after
the diaphragm and cause respiratory arrest. Lower cervi- SCI in humans or veterinary patients. Given the potential
cal injuries can affect the intercostal muscles, causing a for significant adverse side‐effects, such as gastrointesti-
paradoxical breathing pattern. Paralysis of the intercostal nal ulceration, immunosuppression, and compromise of
musculature is associated with a decrease in forced vital renal perfusion in hypovolemic patients, the routine
capacity and maximal inspiratory force because inspi- administration of high‐dose corticosteroids in the acute
ration can cause chest wall collapse. Patients who com- phase of injury is not recommended.
pensate initially can fatigue rapidly, and indeed, many
patients with cervical injuries can require intubation in Table 69.1 Analgesic drugs suggested for use in patients
the first 24 hours. It is thus useful to monitor vital capac- with spinal cord injury
ity in such patients where possible; intubation should be
considered in patients whose vital capacity is markedly Analgesic Recommended dose
reduced. Hypoxia is an important cause of secondary Fentanyl
SCI and must be avoided. Dogs: 2 μg/kg, then constant‐rate infusion
(CRI) at 2–5 μg/kg/h
Cats: 1 μg/kg, then CRI at 1–2 μg/kg/h
Circulation Morphine Dogs: 0.15–0.5 mg/kg slow, then CRI at
It is essential to avoid hypotension of any kind in patients 0.1–1 mg/kg/h
with SCI given its contribution to secondary injury. Care Ketamine 0.1–1 mg/kg, then CRI at 2–10 μg/kg/min
must be taken to ensure that hypotension from other
causes is excluded, especially that attributable to occult Lidocaine Dogs: 1–2 mg/kg, then CRI at
25–80 μg/kg/min
hemorrhage, which can be challenging to detect in
patients with sensorimotor deficits. Dexmedetomidine 0.5–1 μg/kg/h