Head trauma (main): Difference between revisions

Revision as of 23:12, 28 November 2019

This page is for adult patients. For pediatric patients, see: head trauma (peds)

Background

Also known as Traumatic Brain Injury (TBI): Impairment in brain function from a mechanical force

TBI Pathophysiology

Primary injury

Contusions
- Bruises to brain parenchyma
Hematomas
- Epidural hematoma
- Subdural hematoma
- Intraparenchymal
- Intraventricular
- Subarachnoid hemorrhage
Diffuse axonal injury
Direct cellular damage
- Neurons
- Axons
Tearing and shearing of tissues

Secondary injury

Brain swelling causes increased ICP which compresses the tissue causing ischemia with direct compression of the vasculature causing brain tissue herniation and brain death

Leads to expansion of the original injury (predominantly metabolic insult)
- Calcium and sodium shifts
- Mitochondrial damage
- Production of free radicals
Ultimately leads to damage to axonal integrity and axonal transport
- Enzyme activity leads to apoptosis
Microscopic structural injury is often unidentifiable on CT or MRI

Cerebral Blood Flow and Autoregulation

vasoconstriction
- HTN, Hypocarbia, alkalosis
No good way to measure cerebral blood flow
- Use CPP as surrogate
  - CPP is amount of pressure needed to perfuse the brain
  - CPP=MAP-ICP
    - When ICP elevates, CPP decreases
    - Normal ICP
      - 15 in adults
      - <10 to 15 in children
      - 1.5 to 6.0 in infants
Autoregulation allows the body to control the cerebral blood flow
- Autoregulatory mechanism is damaged in most TBI patients

Clinical Features

Adult patient with blunt head trauma

Differential Diagnosis

Head trauma

Neck Trauma

Evaluation

Adult GCS

Eye Opening	Verbal	Motor
		6: Obeys commands
	5: Oriented	5: Localizes to pain
4: Spontaneously opens	4: Confused speech	4: Withdraws from pain (normal flexion)
3: Opens to command	3:Inappropriate words	3: Decorticate posturing (abnormal flexion)
2: Opens to pain	2: Incomprehensible sounds	2: Decerebrate posturing (extension)
1: Does not open	1: No response	1: No response

14-15: Mild
9-13: Moderate
3-8: Severe

Workup

Workup is dependent on GCS severity, see:

Management & Disposition

Dependent on underlying diagnosis, see:

References

Authors:

@@ Line 1: / Line 1: @@
+{{Adult top}} [[head trauma (peds)]]
 ==Background==
-*Traumatic Brain Injury (TBI)
-**Impairment in brain function from mechanical force
-*Severe TBI defined as head trauma and GCS 3-8<ref>Teasdale G, Jennett B: Assessment of coma and impaired consciousness: A practical scale. Lancet. 1974, 2: 81-84.</ref>
 [[File:TBI GCS.jpg|thumb]]
+*Also known as Traumatic Brain Injury (TBI): Impairment in brain function from a mechanical force
-===Pathophysiology===
+{{TBI pathophysiology}}
-*vasoconstriction
-**HTN, Hypocarbia, alkalosis
-*No good way to measure cerebral blood flow
-**Use CPP as surrogate
-***CPP is amount of pressure needed to perfuse the brain
-***CPP=MAP-ICP
-****When ICP elevates, CPP decreases
-****Normal ICP
-*****15 in adults
-*****<10 to 15 in children
-*****1.5 to 6.0 in infants
-*Autoregulation allows the body to control the cerebral blood flow
-**Autoregulatory mechanism is damaged in most TBI patients
-*Cushing Reflex- more common in children than adults
-**Hypertension
-**Bradycardia
-**Respiratory Irregularity
 ==Clinical Features==
-{{GCS table}}
+*Adult patient with blunt head trauma
 ==Differential Diagnosis==
-{{Intracranial hemorrhage DDX}}
+{{Head trauma DDX}}
-{{Maxillofacial trauma DDX}}
 {{Blunt neck trauma DDX}}
-===Other===
-*[[Concussion]]
-*[[Severe traumatic brain injury]]
 ==Evaluation==
-{{Head trauma workup}}
+{{GCS table}}
-*Pertinent labs
-*Blood glucose
-*Venous blood
-*Hemoglobin assessment with consideration for transfusion with Hb < 7 mg/dL
-*PT/INR/PTT
-*Electrolytes
-**[[Hyponatremia]], hypomagnesemia, and hypophosphatemia may lower the seizure threshold
-*Miscellaneous labs
-**Beta-2 transferrin for CSF leak, needs 0.5 cc of fluid<ref>Arup Laboratories. https://arupconsult.com/content/cerebrospinal-fluid-csf-leak-beta-2-transferrin.</ref>
-===Monitoring===
-*Core temperature, Foley with bladder probe
-*ICP monitoring
-*Jugular venous oxygen saturation (SjvO2) by retrograde catherization of right IVJ associated with improved outcomes<ref>Cruz J: The first decade of continuous monitoring of jugular bulb oxyhemoglobin saturation: management strategies and clinical outcome. Crit Care Med. 1998, 26: 344-351.</ref>
-**Normal range 55-70%
-**Sustained desaturation < 50% requires aggressive treatment<ref>Robertson CS, Cormio M: Cerebral metabolic management. New Horiz. 1995, 3: 410-422.</ref>
-*Transcranial doppler around thinner walls of skull (insonation windows)<ref>de Freitas GR, Andre C: Sensitivity of transcranial Doppler for confirming brain death: A prospective study of 270 cases. Acta Neurol Scand. 2006, 113: 426-432.</ref><ref>Dosemeci L, Dora B, Yilmaz M, et al: Utility of transcranial Doppler ultrasonography for confirmatory diagnosis of brain death: Two sides of the coin. Transplantation. 2004, 77: 71-75.</ref>
-**Temporal region above zygomatic arch, through eyes, below jaw, behind occiput
-**Sensitivity for brain death is ~75%, specificity 98%
-==Management==
-===Main goals in management===
-*Prevent intracranial hypertension
-*Prevent secondary brain insults
-*Maintain Cerebral Perfusion Pressure (CPP) > 70 mmHg
-*Optimize cerebral oxygenation and blood flow
-*Monitor for increased ICP
+===Workup===
-*Monitor for [[Brain herniation syndromes|herniation]]
+''Workup is dependent on [[GCS]] severity, see:''
-*Maintain PaO2 > 60 mmHg
+*[[Mild traumatic brain injury]] ([[GCS]] 14-15)
-*Prevent hyperthermia
+**[[Clinical decision rules for head CT in trauma]]
-*Prevent hypotension
+*[[Moderate-to-severe traumatic brain injury]]  ([[GCS]] <14)
-*Correct coagulopathy (FFP, vitamin K, PCC, desmopressin)
-*[[Tranexemic acid]] may reduce progressive ICH<ref>Yutthakasemsunt S et al. Tranexamic Acid for Patients With Traumatic Brain Injury. BMC Emerg Med. 2013;13.</ref>
-**Loading dose 1 g over 10 min
-**Followed by maintenance dose of 1 g over 8 hrs
-{{Increased ICP treatment}}
+==Management & Disposition==
+''Dependent on underlying diagnosis, see:''
+*[[Intracranial hemorrhage]]
+*[[Moderate-to-severe traumatic brain injury]]
+**[[Elevated intracranial pressure]]
+*[[Mild traumatic brain injury]]
+*[[Post-concussive syndrome]]
 ==See Also==