Trauma

Neurogenic Shock = injury to the cervical or upper thoracic (above T6) spinal cord causes loss of sympathetic tone which presents as hypotension without tachycardia or cutaneous vasoconstriction.

Spinal Shock = flaccidity and loss of reflexes after spinal cord injury which may be temporary.

The body releases epinephrine in response to trauma.  Epinephrine acts on beta-adrenergic receptors to move potassium into cells (much like albuterol) resulting in hypokalemia that becomes detectable about 1 hour after trauma, and returns to normal about 24hrs later.

Abstract 1:Shock. 2007 Apr;27(4):358-63.A role for epinephrine in post-traumatic hypokalemia.Beal AL, Deuser WE, Beilman GJ.North Memorial Health Care, Robbinsdale, Minnesota 55422, USA.alan.beal@northmemorial.comWe have previously described a high incidence of admission hypokalemia in trauma patients at our institution. We subsequently performed a prospective study of 112 trauma patients to examine the possible etiologies of post-traumatic hypokalemia. Trauma patients >or=5 years old were evaluated within 6 h of injury with a variety of studies including catecholamines, cortisol, and insulin levels, with studies repeated 24 to 36 h after admission. No potassium replacement was given during this time. Demographic factors such as age, types of injury, and severity of injuries were collected. We found that the mean age of those with post-traumatic hypokalemia (<or=3.5 mEq/L) was significantly younger (29 vs. 37 years old; P = 0.004) and epinephrine levels were significantly higher (863 vs. 406 pg/mL; P = 0.01) when compared with normokalemic patients on admission. At 24 to 36 h, the hypokalemia group compared with the normokalemic patients showed a significant rise in the mean potassium levels (17.2% vs. 4.1%; P < 0.001), a significant fall in mean epinephrine levels (-86.6% vs. -81.4%; P < 0.001), and a significant rise in insulin levels (161% vs. 24%; P < 0.005). Finally, because our previous study had shown that post-traumatic hypokalemia was predictive of injury severity score, 4 trauma admission groups were compared with regard to potassium levels and injury severity score. Those trauma patients with both high injury severity and hypokalemia had significantly higher admission epinephrine levels (1222 vs. 290 pg/mL; P = 0.005), glucose levels (174 vs. 126 mg/dL; P = 0.001), and lower carbon dioxide levels (21.3 vs. 24.6 mEq/L; P < 0.03) than those trauma patients with less severe injury and normokalemia. We conclude that post-traumatic hypokalemia seems to be related to a rise in epinephrine levels, that this rise in epinephrine levels seems to be blunted in older patients, and that post-traumatic hypokalemia is rapidly reversible without specific therapy

• Vascular compromise of the spinal cord in the distribution of the anterior spinal artery.  Usually occurs after a hyperextension injury in a patient with preexisting cervical canal stenosis (forward fall with facial impact)
• May occur with or without spine fracture or dislocation

Recovery follows characteristic pattern: lower extremities, bladder function, proximal upper extremities, hands.

Infarction of the cord in the territory supplied by the anterior spinal artery.  Characterized by paraplegia and dissociated sensory loss with a loss of pain and temperature sensation.  Dorsal column function (position, vibration, and deep pressure sense) is preserved.

Poorest prognosis of the incomplete injuries.

Hemisection of the cord, usually as a result of penetrating trauma.  Characterized by ipsilateral motor loss (corticospinal tract), and loss of position sense (dorsal column) + contralateral loss of pain and temperature sensation beginning 1-2 levels below the injury (spinothalamic tract).

• up to 750ml blood loss (15% of blood volume)
• HR < 100
• SBP - normal
• PP - normal/increased
• RR - normal
• UOP - normal
• CNS/Mental Status - slightly anxious

Initial fluid replacement - crystalloid

• 750-1500ml blood loss (15-30% blood volume)
• HR 100-120
• SBP - normal
• PP - decreased
• RR - 20-30
• UOP - 20-30ml/hr
• CNS/mental status - mildly anxious

Initial fluid replacement - crystalloid

• 1500-2000ml blood loss (30-40% blood volume)
• HR - 120-140
• SBP - decreased
• PP - decreased
• RR - 30-40
• UOP - 5-15ml/hr
• CNS/mental status - anxious, confused

Initial fluid replacement - crystalloid & blood

• >2000ml blood loss (>40% blood volume)
• HR > 140
• SBP - decreased
• PP - decreased
• RR > 35
• UOP - negligible
• CNS/mental status - confused, lethargic

Initial fluid replacement - crystalloid & blood

< 50% of the circumferential bowel without vascular disruption in a hemodynamically stable pt

>50% of wall circumference injured, multiple injuries in a short segment, or both

Zone 1 - 

Zone 2 - 

Zone 3 - the area anterior to the SCM between the angle of the mandible and the base of the skull

• Angiography
• Cervical spine XR to rule out associated fx
• Flexible esophagoscopy
• Contrast-enhanced esophagogastric exam