Difference between revisions of "Neurogenic shock"

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==Pathophysiology==
+
==Background==
 +
*Do not confuse with [[Spinal Shock]]
 +
*Diagnosis of exclusion
 +
**Never presume hypotension in trauma patient is due to neurogenic shock
 +
*Injury to cervical or thoracic vertebrae causes peripheral sympathetic denervation
 +
**Above T1:  full sympathetic denervation
 +
**T1-L3:  Partial sympathetic denervation
 +
**Below L4:  no sympathetic denervation
 +
*Lasts 1-3 wk
  
 +
==Evaluation==
 +
*[[Hypotension]](well tolerated)
 +
*Bradycardia
 +
*Peripherally vasodilated (warm extremities)
 +
**However, this leads to hypothermia
 +
**Ensure monitoring of core temperatures and warming of patient
  
Hypotension & bradycardia
+
==Differential Diagnosis==
 +
{{Shock DDX}}
  
*Results from disrupted sympathetic flow w/ overriding vagal tone
+
==Management==
 +
#Exclude other causes of shock
 +
#Supplemental O2 to perfuse injured spinal cord
 +
#Mechanical ventilation and oxygenation if spinal perfusion is compromised
 +
#Prevent hypothermia
 +
#Judicious IVF, with UOP > 30 cc/hr
 +
#Norepinephrine first line, with '''MAP goal of 85-90 for the first 7 days after spinal cord injury'''
 +
##Consider '''adding''' phenylephrine if BP refractory to first line agent
 +
##Phenylephrine alone without beta-1 stimulation will cause reflex bradycardia
 +
##Atropine if needed, keeping HR 60-100 bpm in NSR
 +
##May titrate down on norepinephrine and atropine, to favor more phenylephrine α agonism in ICU setting
 +
#High risk of VTE in paraparesis or tetraparesis
 +
##Up to 40% in non-prophylaxed
 +
##Must weigh benefits of VTE prophylaxis and risk of bleed from LMWH
 +
##Low dose SC heparin at 500 units q8hrs plus SCDs may be alternative
  
+
==References==
 +
*Chin LS et al. Spinal Cord Injuries Treatment & Management. Jul 7, 2015. http://emedicine.medscape.com/article/793582-treatment#showall.
 +
*Coplin WM. Traumatic Spinal Cord Injury. 2013 Neurocritical Care Society Practice Update. http://www.neurocriticalcare.org/sites/default/files/pdfs/09.SCI.final.pdf.
 +
<references/>
 +
*Orlando Regional Medical Center. Vasopressor and Inotrope Usage in Shock. 4/19/2011. http://www.surgicalcriticalcare.net/Guidelines/Vasopressors%20and%20Inotropes%20in%20Shock.pdf.
  
Sympathetic Disruption
+
==See Also==
 +
*[[Spinal Cord Trauma]]
 +
*[[Spinal Cord Compression (Non-Traumatic)]]
 +
*[[Autonomic Dysreflexia]]
 +
*[[Spinal Shock]]
  
Above T1: full
+
[[Category:Neurology]]
 
+
[[Category:Trauma]]
T1-L3:  Partial (higher=more)
 
 
 
Below L4:  none
 
 
 
Lasts = 1-3 wks
 
 
 
*beware of hypothermia
 
 
 
 
 
 
==Diagnosis==
 
 
 
 
 
(high thoracic or cervical injury)
 
 
 
-mild hypotension
 
 
 
-bradycardia
 
 
 
-warm periferal extremities
 
 
 
-loss of neuro func below injury level
 
 
 
-Flaccid paralysis/Areflexia
 
 
 
-priapism, Horner's, & abd breathing
 
 
 
 
 
 
==Treatment==
 
 
 
 
 
1)  EXCLUDE other causes of shock (i.e. hemorrhage, PNTX, tampand)
 
 
 
2)  IVF (SBP goal >70)
 
 
 
    -use neosynephrine/ Levophed
 
 
 
3)  Atropine (if sypm brady)
 
 
 
4)  Keep warm
 
 
 
 
 
 
==Prognosis==
 
 
 
 
 
If cord is contused and not transected, bulbocavernosus refex should return w/in 24-48 hrs
 
 
 
 
 
 
==Source ==
 
 
 
 
 
2/06 DONALDSON (Adapted from Tintinalli)
 
 
 
 
 
 
 
 
 
[[Category:Neuro]]
 

Latest revision as of 01:13, 24 July 2017

Background

  • Do not confuse with Spinal Shock
  • Diagnosis of exclusion
    • Never presume hypotension in trauma patient is due to neurogenic shock
  • Injury to cervical or thoracic vertebrae causes peripheral sympathetic denervation
    • Above T1: full sympathetic denervation
    • T1-L3: Partial sympathetic denervation
    • Below L4: no sympathetic denervation
  • Lasts 1-3 wk

Evaluation

  • Hypotension(well tolerated)
  • Bradycardia
  • Peripherally vasodilated (warm extremities)
    • However, this leads to hypothermia
    • Ensure monitoring of core temperatures and warming of patient

Differential Diagnosis

Shock

Management

  1. Exclude other causes of shock
  2. Supplemental O2 to perfuse injured spinal cord
  3. Mechanical ventilation and oxygenation if spinal perfusion is compromised
  4. Prevent hypothermia
  5. Judicious IVF, with UOP > 30 cc/hr
  6. Norepinephrine first line, with MAP goal of 85-90 for the first 7 days after spinal cord injury
    1. Consider adding phenylephrine if BP refractory to first line agent
    2. Phenylephrine alone without beta-1 stimulation will cause reflex bradycardia
    3. Atropine if needed, keeping HR 60-100 bpm in NSR
    4. May titrate down on norepinephrine and atropine, to favor more phenylephrine α agonism in ICU setting
  7. High risk of VTE in paraparesis or tetraparesis
    1. Up to 40% in non-prophylaxed
    2. Must weigh benefits of VTE prophylaxis and risk of bleed from LMWH
    3. Low dose SC heparin at 500 units q8hrs plus SCDs may be alternative

References

See Also