Neurogenic shock
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
- Cardiogenic
- Acute valvular Regurgitation/VSD
- CHF
- Dysrhythmia
- ACS
- Myocardial Contusion
- Myocarditis
- Drug toxicity (e.g. beta blocker, CCB, or bupropion OD)
- Obstructive
- Distributive
- Hypovolemic
- Severe dehydration
- Hemorrhagic shock (traumatic and non-traumatic)
Management
- Exclude other causes of shock
- Supplemental O2 to perfuse injured spinal cord
- Mechanical ventilation and oxygenation if spinal perfusion is compromised
- Manual in-line stabilization reduces cervical movement better than C-collar, but be careful of tracheal pressures inadvertently applied which can worsen laryngeal visualization[1][2]
- Direct laryngoscopy causes C-spine extension at atlanto-occipital junction, C1-C2, and C4-C7 in order from most to least
- Consider video laryngoscopy with hyperangulated stylet or bougie assisted DL to intubate higher-grade laryngoscopy views of vocal cords without C-spine overextension[3]
- 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.
- ↑ The effect of laryngoscopy of different cervical spine immobilisation techniques. Heath KJ. Anaesthesia. 1994 Oct; 49(10):843-5.
- ↑ Manual in-line stabilization increases pressures applied by the laryngoscope blade during direct laryngoscopy and orotracheal intubation. Santoni BG, Hindman BJ, Puttlitz CM, Weeks JB, Johnson N, Maktabi MA, Todd MM. Anesthesiology. 2009 Jan; 110(1):24-31.
- ↑ Cervical spinal motion during intubation: efficacy of stabilization maneuvers in the setting of complete segmental instability. Lennarson PJ, Smith DW, Sawin PD, Todd MM, Sato Y, Traynelis VC. J Neurosurg. 2001 Apr; 94(2 Suppl):265-70.
- Orlando Regional Medical Center. Vasopressor and Inotrope Usage in Shock. 4/19/2011. http://www.surgicalcriticalcare.net/Guidelines/Vasopressors%20and%20Inotropes%20in%20Shock.pdf.