Vehicular Polytrauma in a Cavalier King Charles Spaniel Puppy Ariel Kravitz Senior Seminar March 5, 2014 Basic Science Advisor: Dr. Marnie FitzMaurice Clinical Advisor: Dr. Chelsie Estey

OUR PATIENT Signalment Not vaccinated 13 wo FI CKCS Not vaccinated Previously diagnosed with Bordetella Day 2 of Amoxicillin/Clavulanic acid

1 DAY PRIOR TO PRESENTATION TO CUHA Unsupervised outside Good Samaritan witnessed the vehicular trauma and brought her to an ER/CC center Treated for shock and cerebral edema Kept overnight - no improvement

PRESENTATION TO CUHA EMERGENCY Initial assessment Vocalizing in pain when moved → methadone Mild hypoxemia (SpO2: 21%: 92-93%) Hypotensive (96/58) (MAP 72) → fluid bolus T FAST → negative A FAST → negative Parvovirus SNAP test → negative

PRESENTATION TO CUHA EMERGENCY Neurologic examination Mental Status: Bright, Alert, Responsive Attitude/Posture: Slightly hunched posture Conformation/Muscularity: Normal Gait: Non ambulatory paraparesis (with minimal motor) Cranial Nerves: Normal Proprioception: Absent in pelvic limbs Spinal Reflexes: normal thoracic limb reflexes; decreased withdrawal reflexes bilaterally in the pelvic limbs; decreased patellar reflexes on the right and absent on left; normal cutaneous trunci reflex on the right but cutoff at L3 on the left Nociception: lumbar discomfort

PRESENTATION TO CUHA EMERGENCY Neurologic examination Mental Status: Bright, Alert, Responsive Attitude/Posture: Slightly hunched posture Conformation/Muscularity: Normal Gait: Non ambulatory paraparesis (with minimal motor) Cranial Nerves: Normal Proprioception: Absent in pelvic limbs Spinal Reflexes: normal thoracic limb reflexes; decreased withdrawal reflexes bilaterally in the pelvic limbs; decreased patellar reflexes on the right but absent on left; normal cutaneous trunci reflex on the right but cutoff at L3 on the left Nociception: lumbar discomfort

PRESENTATION TO CUHA EMERGENCY Neurologic examination Mental Status: Bright, Alert, Responsive Attitude/Posture: Slightly hunched posture Conformation/Muscularity: Normal Gait: Non ambulatory paraparesis (with minimal motor) Cranial Nerves: Normal Proprioception: Absent in pelvic limbs Spinal Reflexes: normal thoracic limb reflexes; decreased withdrawal reflexes bilaterally in the pelvic limbs; decreased patellar reflexes on the right but absent on left; normal cutaneous trunci reflex on the right but cutoff at L3 on the left Nociception: lumbar discomfort Neurolocalization: T3-L3 and L4-S3 myelopathy

PRESENTATION TO CUHA EMERGENCY Plan Full body CT Restrained on a backboard in O2 cage Supportive care in ICU Transfer to the Neurology Service in the AM

FULL BODY CT- HEAD Transverse soft tissue window post-contrast Coronal bone window post-contrast

FULL BODY CT- HEAD Transverse soft tissue window post-contrast Coronal bone window post-contrast

FULL BODY CT- HEAD Transverse soft tissue window post-contrast Coronal bone window post-contrast

FULL BODY CT- CERVICAL VERTEBRAE Sagittal bone window

FULL BODY CT- CERVICAL VERTEBRAE Sagittal bone window

Transverse soft tissue window FULL BODY CT- THORAX Transverse soft tissue window

Transverse soft tissue window FULL BODY CT- THORAX Transverse soft tissue window

FULL BODY CT- LUMBAR VERTEBRAE Transverse bone window through L4 Sagittal bone window throughL3-L5

FULL BODY CT- LUMBAR VERTEBRAE Transverse bone window through L4 Sagittal bone window throughL3-L5 Transverse bone window through L3

PROBLEM LIST Comminuted fracture of L4 vertebra Fissure fracture of C3 vertebra Bilateral pulmonary contusions Fractures of the right orbit Fractures of the frontal sinus with pneumocephalus and intracranial hemorrhage Hypoxemia Bordetella positive

VEHICULAR POLYTRAUMA High energy blunt injury Trauma - 2nd most common cause of death Most common cause of vertebral fractures 2nd spinal fracture/luxation - ~20% Additional injuries – 40-50% PE findings more sensitive than radiographs Figure 2 from Evaluation of vehicular trauma in dogs: 239 cases (January-December 2001)

SPINAL TRAUMA Pathophysiology 1o injury 2o injury Immediate result of the trauma Mechanical damage to the spinal cord → physical disruption of neuronal and glial cell membranes 2o injury Hours to days following trauma Biomechanical processes triggered by the primary injury → worsening spinal cord damage

SPINAL TRAUMA Pathophysiology 1o injury 2o injury immediate result of the trauma Mechanical damage to the spinal cord → physical disruption of neuronal and glial cell membranes 2o injury Hours to days following trauma Biomechanical processes triggered by the primary injury → propagated spinal cord damage

PRIMARY SPINAL CORD INJURY 3 compartment model Boney and soft tissue structures Dorsal Middle Ventral If 2 of the 3 compartments are affected → unstable injury Figure 12.1 from A Practical Guide to Canine and Feline Neurology

GOALS OF SPINAL MANAGEMENT Prevent ongoing primary injury and allay perpetuation to secondary injury Stabilization of a fracture is based on: The damaged structures The forces acting on them

VERTEBRAL FRACTURE REPAIR Goals Realign and stabilize the spinal column Decompress the spinal cord Surgical techniques Pins + PMMA* Locking plates * External fixators* Vertebral body plates Modified segmental fixation Tension band stabilization Spinous process plating

VERTEBRAL FRACTURE REPAIR Goals Realign and stabilize the spinal column Decompress the spinal cord Surgical techniques Pins + PMMA* Locking plates * External fixators* Vertebral body plates Modified segmental fixation Tension band stabilization Spinous process plating

L4 VERTEBRAL FRACTURE REPAIR Dorsal laminectomy Dorsal decompression Visualize L4 vertebral fracture Cortical screw placed transarticularly through the R articular facet joint of L4 4 screws placed bicortically through L3 and L5 Screws placed through the base of L and R transverse processes of L3 Screw placed through the base of the L transverse process of L5 Screw placed through the R transverse process and pedicle of L5 PMMA with cefazolin molded around the screws Fig. 35-6 from Small Animal Surgery

POST-OP CT Sagittal bone window through L2-L5 Transverse bone window through L5 Sagittal bone window through L2-L5

POST-OP CT

POST-OP TREATMENT Treatment 40% O2 Plasmalyte + 1.5% dextrose Fentanyl CRI Ampicillin/Sulbactam Ceftazidime Ondansetron, Pantoprazole and Sucralfate

DAY 1 POST-OP PROGRESS Neurologic examination – Day 1 post-op Ambulatory paraparesis with voluntary motor function in all limbs Absent placement in the hindlimbs bilaterally Intact withdrawal, patellar and perineal reflexes Cutaneous trunci reflex cutoff at the level of L3 on the left; normal on the right Continue to improve in hospital Oxygen independent day 3 post-op Fluids tapered and switched to all oral medication

DAY 5 POST-OP TGH Medications Exercise restriction Cefpodoxime Amoxicillin/Clavulanic acid Pregabalin Tramadol Metronidazole Exercise restriction At home rehabilitation

PROGNOSIS Fair to good Comminuted fracture - L4 Vertebra Failure of perfect anatomical alignment - potential for the spinal cord to be compressed if the fragments dislodge from their current locations 60-70% chance to return to normal function Fissure fracture - C3 Vertebra Not at issue at this time Potential for neurologic deficits in the future Growing Trauma

PROGNOSIS Bilateral pulmonary contusions – improving Fractures of the right orbit Not at issue at this time Unknown in future Fractures of the frontal sinus with pneumocephalus and intracranial hemorrhage Predisposed to seizures

RECHECK 1 4 weeks post-op Neurolocalization: Thoracolumbar spine (T3-L3) Mild hindlimb spinal ataxia Absent postural thrust on the right, delayed on the left, normal placing in all four limbs Pain elicited on head palpation, cranial cervical and thoracolumbar spine Spinal radiographs

RECHECK 1- SPINAL RADIOGRAPHS

RECHECK 1 Prognosis Recommendation: Still fair to good Medications Pregabalin Tramadol Exercise restriction At home rehabilitation

RECHECK 2 10 weeks post-op Neurolocalization: Thoracolumbar spine (T3-L3) Mild hindlimb spinal ataxia Delayed hopping on the right pelvic limb, normal hopping in other limbs, normal placing in all four limbs No pain elicited on palpation Spinal radiographs

RECHECK 2 - SPINAL RADIOGRAPH

RECHECK 2 Prognosis Recommendation: Good! Medications Pregabalin (tapered dose for 1 week) Tramadol Exercise restriction

COST IN HOSPITAL Initial Stay ECC exam $113.00 Full body CT $733.00 Surgery + Anesthesia $2078.26 Supportive therapy +maintenance in ICU x 9 days $4254.34 Total $7178.60 4 Week Recheck Exam + Radiographs $220.40 10 Week Recheck Exam + Radiographs $200.00 Total Cost $7599.00

SELECTED REFERENCES Dewey, C. A Practical Guide to Canine & Feline Neurology. 2nd ed. pp 405-414. Wiley-Blackwell, 2008. Ames, Iowa. Fleming J.M. et al. Mortality in north american dogs from 1984 to 2004: an investigation into age-, size-, and breed-related causes of death. Journal of Veterinary Internal Medicine. 2011 Mar. 25(2), pp 187-98. Fossum , T. Small Animal Surgery.   1st ed. pp 1118-1127. Mosby and Co., 1997. St. Louis, Missouri. Olby, N. The pathogenesis and treatment of acute spinal cord injuries in dogs. 2010 Sep. 40(5), pp791-80. Rockar, R.A et al. Development a Scoring System for the Veterinary Patient. Journal of Veterinary Emergency and Critical Care. 2007 Jul. 4 (2), pp 77-83. Streeter, E. et al. Evaluation of vehicular trauma in dogs: 239 cases (January–December 2001). JAVMA. 2009 Aug. 235 (4), pp 405-408. Tobias K, Johnston S: Veterinary Surgery: Small Animal. 1st ed. pp 487-496. Elsevier/Sauders, 2012. St. Louis, Missouri.

THANK YOU Dr. Chelsie Estey Dr. Marnie FitzMaurice Dr. Sofia Cerda-Gonzalez My family Class of 2014

QUESTIONS?