To the Editor:—
Epidural hematoma formation following lumbar regional anesthesia is a rare complication, with incidences of 1 in 220,000 after spinal anesthesia and 1 in 150,000 after epidural anesthesia. 1While severe lower back pain that is enhanced by percussion or movements of the spine typically represents the initial clinical symptom of a large epidural hematoma, 2cauda equina syndrome with paraparesis and dysfunctions of the bladder and bowel may develop after a delay of several hours.
We report the case of an 83-yr-old woman who underwent spinal anesthesia for minor gynecologic surgery. Preoperative evaluation revealed an ASA physical status of III with atrial fibrillation, discrete pretibial edema, and chronic rheumatoid pain in both legs. Blood chemistry values and coagulation status were normal. Daily medication, including 1,000 mg naproxen, was discontinued on the evening before surgery.
Due to degeneration of the spine, puncture of the lumbar subarachnoid space required multiple attempts at intervertebral spaces L2–L3 and L3–L4, with use of a 27-gauge Quincke needle. After appearance of clear cerebrospinal fluid without shooting pain or paresthesia, 75 mg hyperbaric lidocaine was injected.
In the early postoperative period, the patient reported her typical rheumatoid pain in the legs, and diclofenac was administered topically. Seventeen hours after surgery, a neurologic examination revealed monoparesis of the right leg in the absence of back pain. Sensory functions were reduced in radicular segments L4–L5 and S1–S4 on the right side. The right patellar tendon reflex was reduced, and ankle tendon reflexes were absent on both sides. There were no signs of bladder or bowel dysfunction. Primarily, a pressure palsy of the lumbar plexus or the femoral and sciatic nerves was assumed.
Lumbar computed tomographic images were obtained and revealed high-grade compression of the dural sac by a large, hyperdense mass. Subsequent magnetic resonance imaging (MRI) of the lumbar spine (fig. 1) demonstrated a subtotal obstruction of the spinal canal at the L2 and L3 levels. As imaging findings were highly suggestive of a large epidural hematoma, the patient underwent urgent decompressive laminectomy of L2–L4, and the hematoma was removed.
Postoperatively, the patient initially showed no significant benefit from decompressive therapy, although MRI examinations 3 weeks after the procedure confirmed complete removal of the hematoma. Following a rehabilitation process of 3 months, neurologic function was recovered and the patient was able to walk independently.
Major risk factors for bleeding complications following spinal or epidural anesthesia include impaired coagulation, difficult or multiple punctures, 3and insertion of a catheter. 4
Naproxen, a nonsteroidal antiinflammatory drug, may also have played a causal role in the development of the epidural hematoma, because platelet aggregation is normal in only 50% of patients 2 days after withdrawal of naproxen, 5and in our patient naproxen was withdrawn 12 h before surgery.
The strictly unilateral sensorimotor dysfunction of a radicular pattern without lower back pain in our patient was certainly an atypical clinical presentation of a large epidural hematoma expanding from the lower thoracic to the lower lumbar spine. Furthermore, in view of the age of the patient, the absence of ankle tendon reflexes on both sides might, instead, have been attributed to mild polyneuropathy than to an impairment of the first sacral root on both sides.
Magnetic resonance imaging is the diagnostic procedure of choice to verify an epidural hematoma. 6Therapy consists of urgent decompressive surgery with removal of the hematoma, usually in combination with hemilaminectomy. 7,8While outcome is influenced mainly by the severity of neurologic impairment at the time of surgical intervention, data and clinical experience suggest that the length of the delay before surgery also is important to recovery. Minor neurologic disturbances and treatment within 12 h 9and up to 36 h 2are correlated with a better prognosis for recovery, 2but patients may continue to benefit from surgical therapy up to 3 weeks 10after damage.