An 81#, nine year old male neutered Labrador Retriever presented to DoveLewis after being struck by a car. After the incident, he was not seen to rise. He had a history of an episode of immune mediated hemolytic anemia just over one year prior that resolved with treatment. The patient also suffered atopic dermatitis, hypothyroidism, and ventricular tachycardia and at the time of presentation was on regular treatment with levothyroxine, ketoconazole, cyclosporine, diltiazem, and azithromycin.
Initial Physical Examination
On initial physical examination, the patient was panting, tachycardic with a heart rate of 160, and had injected mucous membranes with appropriate capillary refill time. Bilateral foamy serosanguinous nasal discharge and left unilateral epistaxis were noted. Heart sounds were muffled and crackles were noted bilaterally on thoracic auscultation but femoral pulses were palpable and synchronous. SP02 was reported at 94% with flow-by oxygen supplementation. The patient’s abdomen was soft and non painful and several superficial abrasions were observed on the limbs and above the right eye. Diffuse muzzle swelling was appreciated. There were no palpable limb fractures or luxations and no evidence of pain on manipulation of the legs. However, conscious proprioception was absent in both pelvic limbs and deep pain perception was present in the left rear limb only. No other evidence of neurological deficits was noted. Mean arterial blood pressure was 80mmHg.
Initial Stabilization and Diagnostics
On presentation, 3mg hydromorphone was administered IV and ECG pads were placed for continuous monitoring. An 18g IV catheter was placed and a 400ml bolus of Plasmalyte - A was administered before the fluid rate was decreased to 60ml/hr. 60mg of furosemide was administered IV and the patient was placed in an oxygen cage at 40% oxygen. Lead II ECG revealed supraventricular tachycardia with a rate between 160-180 beats per minute. Lateral radiographs of the thorax and abdomen were examined. The radiographs showed a severe compression fracture involving the first lumbar vertebra, a suspected vertebral arch fracture involving the first lumbar vertebra, suspected mild pneumothorax, and probably a small quantity of pleural effusion. Due to radiographic findings and the acute nature of this patient’s presentation, methylprednisolone 800mg was administered intravenously along with an additional hydromorphone 2mg. Initial blood work showed mild anemia with a packed cell volume of 38% and a total solids of 8.9 g/dL.
At this time, this patient’s owner was faced with critical decisions. Treatment options included surgical stabilization of the spinal fracture or euthanasia. Complicating factors included the patient’s age, size, and concurrent medical conditions. There was no guarantee that surgical intervention would result in return of motor function to the pelvic limbs. If function does return to these patients, it can take several months and prolonged physical therapy will be required. After much deliberation, the patient’s owner elected to pursue surgical management of the fracture.
Surgery and Hospitalization
Once the owner decided on surgery, the dog was transferred to ICU for ongoing stabilization, surgery, and post operative care. Upon arrival in ICU, the patient’s mucous membranes were pink and capillary refill time was appropriate. Nasal discharge had resolved, heart rate and rhythm were unremarkable, and neurological examination was unchanged. Nasal oxygen prongs were placed and oxygen supplementation was started at 3L/minute. A fentanyl bolus (185ug) was administered and fentanyl (3ug/kg/hr), lidocaine (1mg/kg/hr), ketamine (0.12mg/kg/hr) continuous rate infusion was started. An 8fr Foley urinary catheter was placed and additional methylprednisolone (300mg IV) and dexamethasone (8mg IV) were administered to continue treatment for spinal shock and inflammation. An arterial catheter was placed to facilitate monitoring of arterial blood gases.
The patient was premedicated for anesthetic induction with midazolam and fentanyl and anesthesia was induced with propofol. After a dorsal approach, Lubra spinal plates were placed and secured on the spinous processes with stainless screws. These plastic plates are arranged on either side of the spinous process and bolted together to stabilize the fracture. The fracture was dissected and removed. Post operative placement radiographs show widening of the L13-T1 vertebral space with no evidence of compromise of the spinal canal.
The morning following surgery, the patient was able to move his head but Schiff-Sherrington posture was persistent. Deep pain was present in both pelvic limbs but conscious proprioception and motor function remained absent. Decreased anal tone was appreciated but some movement was noted in the distal tail. Through the day, fentanyl/lidocaine/ketamine continuous rate infusion was weaned to fentanyl alone and oxygen therapy continued. Urine output was 0.5 ml/kg/hr so the fluid rate was increased. Famotidine 40mg intravenously once daily was added to his treatments due to the administration of steroids and he was noted to eat a small amount. At this time his packed cell volume was significantly decreased at 16%. Due to this anemia, a coagulation profile was checked and was unremarkable. A FAST showed no evidence of abdominal or pleural effusion. The patient was typed and cross matched prior to administration of a unit of packed red blood cells. Throughout the day urine output improved and occasional persistent ventricular premature contractions responded to lidocaine boluses and a lidocaine continuous rate infusion was started.
As the day and night progressed, his fentanyl was weaned and changed by the second day post operatively to buprenorphine. Packed cell volume had improved to 24% post transfusion but the patient’s appetite had again waned. Due to his historical immune mediated hemolytic anemia, a complete blood count with pathology review was submitted. A moderate normocytic normochromic nonregenerative anemia was noted but morphology did not provide any further clues to determine the cause of the anemia. Recheck blood work showed stable packed cell volume, the albumin had dropped to 1.7g/dl and peripheral edema was noted so hetastarch was initiated. Polyethylene glycol, reported to seal axonal cellular membranes from leaking, was also administered intravenously on this date. The lidocaine continuous rate infusion was weaned and discontinued.
Three days post operatively the patient remained oxygen dependent and showed no significant improvement in neurologic function of his pelvic limbs. Due to ongoing inappetance and hypoalbuminemia, partial parenteral nutrition was initiated. Dolasetron was also started.
Four days post operatively, abdominal discomfort and distension with a palpable fluid wave was appreciated and ultrasound confirmed the presence of a moderate amount of free abdominal fluid. Abdominocentesis revealed serosaguineous fluid which total protein was 3.6g/dL with rare white blood cells seen on cytology. Thoracic limb movement was improving, anal tone normal, and tail tone and movement improving. He seemed more painful so gabapentin 300mg orally daily was added to his analgesia. In the evening, peripheral edema was worsening so he was started on a continuous rate infusion of furosemide. Additional doses of dexamethasone were administered on the fourth and fifth days post operatively before being discontinued.
Five days post operatively, passive range of motion exercises were initiated and he began to eat some food during his owner’s visits.
Six days post operatively, the patient was transitioned over to oral famotidine and tramadol and he was weaned from both oxygen and furosemide continuous rate infusion. His appetite was hearty and he was tentatively scheduled to be discharged into his owner’s care as soon as they were comfortable managing his physical therapy at home.
Seven days post operatively he removed his own urinary catheter but was unable to voluntarily urinate though his urinary bladder was easily expressed manually. Tail tone was noted on this date to be normal and he began to pull slightly against resistance with his left pelvic limb only on this date.
Eight days post operatively, it was noted that the patient had a weight loss of 5.2kg throughout his hospitalization and had significant pelvic limb and epaxial muscle atrophy. As he continued to show no evidence of vomiting or nausea, dolasetron was discontinued.
Nine days post operatively, the patient was seen slightly extending both pelvic limbs from a partially flexed position in his sleep. He was also noted to pull against resistance slightly with both pelvic limbs though both remained weak. On this date he was placed in a four-wheel cart to move around the hospital though he tired quickly.
Ten days post operatively he developed diarrhea with some frank blood and his appetite decreased slightly so hospitalization was extended. Neurological status was unchanged. Blood work was rechecked with normal albumin (2.9 g/dL), total protein (6.5 g/dL), and packed cell volume (44%).
Eleven days post operatively the patient’s appetite improved with appropriate positioning and no additional changes to his neurological status were appreciated.
Twelve days post operatively, the patient had a small amount of additional diarrhea. He was noted to have some trembling in his pelvic limbs intermittently. On this date recheck radiographs showed some compression of the disc space at T13-L1. These changes were anticipated and there was no evidence of failure of the Lubra plates. At this time the patient was discharged to the care of his family and recheck exams with the neurologist.
Any patient with a spinal fracture is likely to require extensive nursing care after surgical stabilization. While there is more care required for patients that suffer loss of sensory perception and motor function, this care is feasible for a committed pet owner. This patient required regular physical therapy and rechecks with his neurologist but did begin to show small signs of improvement while hospitalized. There is no way to know with certainty what degree of function will return but he was given a chance to recover. We often find it challenging to offer such options to pet owners because of the financial and emotional commitment required but we all must remember that these options are available.