Review Question - QID 211663

This patient sustained a multi-traumatic injury and is suffering from hemorrhagic shock. The presence of tachycardia would favor the diagnosis of hemorrhagic shock over neurogenic shock.

In initial hypovolemic shock (stage I, <15% blood loss), heart rate, blood pressure, urine output, pH, and mental status are largely unaffected, as the body can typically compensate for this amount of volume loss. With increasing blood loss, tachycardia, hypotension, low urine output, decreased pH, hemoconcentration, cool clammy skin, and altered mental status can be observed. This patient sustained a splenic injury and T12 and L3 vertebral injuries. Both hemorrhagic and neurogenic shock may result in a decrease in cardiac output and hypotension; however, neurogenic shock may also present with warm dry skin, vasodilation, loss of sympathetic tone, and paradoxical bradycardia.

Schouten et al. review the initial management of the spinal column and spinal cord injury (SCI) in the emergency room. The authors discuss that acutely, deep tendon reflexes are absent and paralysis is flaccid, but that this transitions to hyper-reflexia and spasticity with time. They conclude that spinal shock is a temporary physiologic state of the acutely traumatized spinal cord, evident by the transient absence of reflexive function caudal to the spinal cord injury followed by gradual return of reflex activity. Additionally, the diagnosis of a "complete" spinal cord injury cannot be made until the neural "shock" resolves.

Spector et al. review cauda equina syndrome. They report on the characteristic findings such as varying patterns of low back pain, sciatica, lower extremity sensorimotor loss, and bowel and bladder dysfunction. Classical findings include urinary retention, saddle anesthesia of the perineum, bilateral lower extremity pain, numbness, and weakness. The authors conclude that there should be a high index of suspicion in the postoperative spine patient with back and/or leg pain refractory to analgesia, especially in the setting of urinary retention.

Hadley et al. review the presentation of acute SCI. The authors report that hypotension has been associated with an increased risk of mortality following spinal cord injuries. They conclude that hypotension (systolic blood pressure <90 mm Hg) should be avoided after acute SCI, with the maintenance of mean arterial blood pressure at 85 to 90 mm Hg for the first 7 days after acute spinal cord injury in order to improve spinal cord perfusion.

Sekhon et al. review the epidemiology, demographics, and pathophysiology of SCI. They discuss primary and secondary injury, with the mediators of secondary injury including vascular mechanisms, excitatory amino acids, calcium, sodium, free radicals, inflammation, and apoptosis.

Figures A is a sagittal CT image demonstrating T12 and L3 vertebral fractures.
Figure B is an axial CT image demonstrating a splenic injury with hematoma. Figure C is a clinical photograph demonstrating left abdominal flank injury. Illustration A shows the classification of hemorrhagic shock.

Incorrect Answers:
Answer 2: Bradycardia is a paradoxical response that occurs with spinal cord injury. In the setting of hypovolemia, there should be a responsive tachycardia, as seen with hemorrhagic shock
Answer 3: Decreased cardiac output occurs in both hemorrhagic and neurogenic shock.
Answer 4: Vasodilation is a response seen following the loss of sympathetic tone with spinal cord injuries. This finding would favor neurogenic shock over hemorrhagic shock.
Answer 5: Warm dry skin is also a response that occurs with the loss of sympathetic tone seen with spinal cord injury. With a hemorrhagic shock, the skin is usually cool, clammy and pale.