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406 Head Trauma

○ Substantial decrease in ICP (15% with Modified Glasgow Coma Scale
craniotomy, additional 65% reduction Exam Findings* Score
VetBooks.ir • Hyperventilation (PaCO 2 < 30 mm Hg) Motor Activity 6
with durotomy); superior in this effect
compared with any medical therapy
Normal gait, normal spinal reflexes
○ Emergency therapy: lowers arterial CO 2 .
Resultant vasoconstriction decreases Hemiparesis, tetraparesis, or decerebrate rigidity 5
cerebral perfusion pressure and decreases Recumbent, intermittent extensor rigidity 4
ICP. However, decreased perfusion to
brain parenchyma may have deleterious Recumbent, constant extensor rigidity 3
consequences. Recumbent, constant extensor rigidity with opisthotonos 2
○ Current recommendation: ventilate patient Recumbent, hypotonia of muscles, depressed or absent spinal reflexes 1
such that PaCO 2 = 30-35 mm Hg. Brainstem Reflexes
• Hypothermia
○ Reduces cerebral metabolic rate, decreasing Normal pupillary light reflexes and oculocephalic reflexes 6
cerebral perfusion by reflex vasoconstric- Slow pupillary light reflexes and normal to reduced oculocephalic reflexes 5
tion, and consequently decreases ICP Bilateral unresponsive miosis with normal to reduced oculocephalic reflexes 4
○ May also limit secondary brain injury by
limiting neuroexcitatory activities and Pinpoint pupils with reduced to absent oculocephalic reflexes 3
suppression of local inflammatory response Unilateral unresponsive mydriasis with reduced to absent oculocephalic reflexes 2
○ Can result in coagulation abnormalities, Bilateral unresponsive mydriasis with reduced to absent oculocephalic reflexes 1
cardiac disturbances, and hypotension
○ Moderate hypothermia (90°F-91.4°F Level of Consciousness
[32°C-33°C]) has been efficacious in Occasional periods of alertness, responsive to environment 6
human trials and animal models of Depression or delirium, capable of responding to environment but response may be inappropriate 5
brain injury; clinical veterinary use is Stupor, responsive to visual stimuli 4
uncertain.
• Glucocorticoids: contraindicated in treatment Stupor, responsive to auditory stimuli 3
of head injury Stupor, responsive only to repeated noxious stimuli 2
Nutrition/Diet Coma, unresponsive to repeated noxious stimuli 1
Supplemental nutrition may be needed in Total score
severely compromised patients. Assessment of Prognosis
• Enteral route preferred if possible/safe (pp. Good 15-18
1106 and 1107); prevent sneezing during
tube placement Guarded 9-14
• Parenteral nutrition (p. 1148) may be needed Grave 3-8
in patients at risk for aspiration pneumonia.
*The modified Glasgow coma scale is based on the neurologic exam findings for the categories of motor activity, brainstem reflexes,
Behavior/Exercise and level of consciousness. Entries in each category are scored 1-6, with 1 indicating more severe dysfunction. The three category
scores are summed for the total score, which is interpreted as shown to establish the prognosis.
• Animals with severe neurologic deficits may
be recumbent with limited mobility. ○ Fair to good with minor, nonprogressive • Comprehensive nursing care is important to
• Range-of-motion exercises and physical injury prevent complications such as nosocomial
rehabilitation may be beneficial for these ○ Severely injured animals have poorer infection or aspiration pneumonia.
patients. short-term recovery rates and may have • Avoid jugular compression or jugular
longer rehabilitation/recovery periods if venipuncture in head trauma patients.
Possible Complications they survive.
• Infection (aspiration pneumonia, nosocomial • Modified Glasgow coma scale (MGCS) has Client Education
infection) been used for scoring injury severity in cases • Clients must be informed of the potential
• Seizures of head trauma and has been correlated with for long recovery periods for severely injured
• Kidney injury, oliguria/anuria, uremia outcome. animals.
• Persistent neurologic deficits • Clients should also be made aware of the
PEARLS & CONSIDERATIONS need for intensive treatment and monitoring
Recommended Monitoring of animals with head injury.
• Assess neurologic status. Comments • The MGCS may be helpful in quantitating
○ Repeated examination may aid in evaluat- • Head trauma is a common and serious injury injury severity to provide the client with a
ing the efficacy of therapy. in dogs and cats. prognosis.
○ Imaging (CT or MRI) may be helpful in • Clinicians must recognize the signs of
assessing injury. progressive neurologic injury. SUGGESTED READING
○ Therapy to decrease ICP if indicated ○ The MGCS may be helpful as a monitor- DiFazio J, et al: Updates in the management of the
• Monitor oxygenation (arterial blood gas/ ing tool. small animal patient with neurologic trauma. Vet
pulse oximetry). Clin North Am Small Anim Pract 43:915-940,
• Ensure adequate BP. Technician Tips 2013.
Diligent monitoring and nursing care are AUTHOR: Elizabeth M. Streeter, DVM, DACVECC
PROGNOSIS & OUTCOME important for an optimal outcome. EDITOR: Benjamin M. Brainard, VMD, DACVAA,
• Even subtle changes in neurologic assessment DACVECC
• Prognosis depends on severity and type of can be important and should be brought up
injury. with the veterinarian.

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