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head_computed_tomography_for_traumatic_brain_injury

Head computed tomography for Traumatic Brain Injury

Indications

1. presence of any moderate or high risk criteria which include: GCS ≤ 14, unresponsiveness, focal deficit, amnesia for injury, altered mental status (including those that are significantly inebriated), deteriorating neuro status, signs of basal or calvarial skull fracture

2. assessment prior to general anesthesia for other procedures (during which neurologic exam cannot be followed in order to detect delayed deterioration).


The gold standard for diagnosis of Traumatic Brain Injury (TBI) is Computerized tomography (CT).

The results of a study of Bodanapally et al. from Department of Radiology , Department of Diagnostic Radiology and Imaging Sciences and Nuclear Medicine, Neurosurgery Baltimore, Maryland, Department of Diagnostic Radiology and Imaging Science Atlanta, Georgia, indicate that virtual high monochromatic (190 keV, thin-section) images combined with standard 120 kV images may provide optimal diagnostic performance for evaluation of patients suspected of TBI 1).

A delay of diagnostics or medical care is the strongest independent predictor of mortality of TBI patients-particularly in the case of a surgically treatable intracranial hematoma 2) 3).

Computerized tomography (CT) is the routine imaging modality used to assess structural lesions in acute Traumatic Brain Injury (TBI), due to its accessibility and speed.

The information supplied by the admission CT scan not only allows for diagnostic screening for potential intracranial injuries requiring acute neurosurgical interventions, but also provides important prognostic information. If better implemented, outcome prediction models could help prioritize resources in the emergency setting. Better outcome prediction could also have the potential to improve TBI research by providing baseline risk stratification in trials and to optimize standardization of cohorts in comparative effectiveness research 4).

Classification

Follow-up CT

1. Many facilities perform a repeat head CT at 24 hours for patients who are clinically stable but had findings on initial head CT of: traumatic subarachnoid hemorrhage SAH, small subdural hematoma or epidural hematoma, cerebral contusions

2. For patients with severe head injuries:

a) for stable patients, follow-up CTs are usually obtained between day 3 to 5, (some recommend at 24 hrs also) and again between day 10 to 14.

b) some recommend routine follow-up CT several hours after the “time zero”CT(i.e.initial CT done within hours of the trauma) to rule-out delayed EDH, SDH, or traumatic contusions

3. for patients with mild to moderate head injuries:

a) for those with an abnormal initial CT, the CT scan is usually repeated prior to discharge b) stable patients with mild head injury and normal initial CT do not require follow-up CT Urgent follow-up CT: performed for neurological deterioration (loss of 2 or more points on the GCS, development of hemiparesis or new pupillary asymmetry), persistent vomiting, worsening H/A, seizures or unexplained rise in intracranial pressure (ICP) in patients with an ICP monitor.


Whether repeated cCT should be done by routine in every patient with TBI or ordered by individual decision remains unclear and is the topic of an ongoing discussion 5) 6) 7) 8).

Retrospective data show that routine CT scanning (in the absence of any clinical deterioration) after mild traumatic brain injury or moderate TBI had no therapeutic (interventional) consequences 9) 10).

On the other hand there is a trend towards routine use for patients with severe TBI but the evidence to support this concept is low. Some authors recommend a cCT scan if clinical signs of neurological deterioration occur 11) , other findings suggest that routine cCT might be beneficial in some subgroups of patients 12) 13). In particular patients with multiple trauma and severe TBI and patients who are endotracheally intubated, mechanically ventilated, and sedated might benefit from routine repeated cCT 14). There is only a single study which investigated the role of a follow-up cCT scan exclusively in unconscious, sedated, and mechanically ventilated patients with severe TBI 15). In those patients early clinical signs of neurologic deterioration are potentially difficult to detect. A change in pupils' status, signs of brain herniation, and seizures are commonly clinical signs of severe brain damage and therapeutic intervention might be too late 16).

Discharge after a repeat head CT and brief period of observation in the Emergency Department allowed early discharge of a cohort of mild TBI patients with traumatic ICH without delayed adverse outcomes. Whether this justifies the cost and radiation exposure involved with this pattern of practice requires further study 17).

The proper classification of these patients is of major importance in situations where a CT is not accessible.

A portable screening device that uses near-infrared spectroscopy (NIRS) technology allows a preliminary estimate of an intracranial hematoma.

The use of the device in a military medical rescue center (Kunduz, Afghanistan) is easy to learn and can be repeatedly used even under emergency room conditions. The technique can be applied in penetrating and blunt TBIs in the absence of an immediately available CT scan in rural areas, preclinically, under mass casualty conditions (e.g., in disaster situations) as well as in humanitarian crises or war zones. Nevertheless, further studies to assess the validity of this device are necessary 18).

References

1)
Bodanapally UK, Archer-Arroyo K, Dreizin D, Shanmuganathan K, Schwartzbauer G, Li G, Fleiter TR. Dual-energy CT Imaging of Head: Virtual High Energy Monochromatic (190keV) Images are More Reliable Than Standard 120 kV Images for Detecting Traumatic Intracranial Hemorrhages. J Neurotrauma. 2018 Oct 17. doi: 10.1089/neu.2018.5985. [Epub ahead of print] PubMed PMID: 30328766.
2)
Cushman JG, Agarwal N, Fabian TC, et al. Practice management guidelines for the management of mild traumatic brain injury: the EAST practice management guidelines work group. Journal of Trauma. 2001;51(5):1016–1026.
3)
Bratton SL, Chestnut RM, Ghajar J, et al. Guidelines for the management of severe traumatic brain injury. Journal of Neurotrauma. 2007;24(supplement 1):S37–S44.
4)
Maas AI, Murray GD, Roozenbeek B, Lingsma HF, Butcher I, McHugh GS, Weir J, Lu J, Steyerberg EW; International Mission on Prognosis Analysis of Clinical Trials in Traumatic Brain Injury (IMPACT) Study Group. Advancing care for traumatic brain injury: findings from the IMPACT studies and perspectives on future research. Lancet Neurol. 2013 Dec;12(12):1200-10. doi: 10.1016/S1474-4422(13)70234-5. Epub 2013 Oct 17. PubMed PMID: 24139680; PubMed Central PMCID: PMC3895622.
5)
Stippler M, Smith C, Robb McLean A, et al. Utility of routine follow-up head CT scanning after mild traumatic brain injury: a systematic review of the literature. Emergency Medicine Journal. 2012;29:528–532.
6) , 12) , 14)
Wang MC, Linnau KF, Tirschwell DL, Hollingworth W. Utility of repeat head computed tomography after blunt head trauma: a systematic review. Journal of Trauma. 2006;61(1):226–233.
7) , 9) , 11)
Kaups KL, Davis JW, Parks SN, et al. Routinely repeated computed tomography after blunt head trauma: does it benefit patients? Journal of Trauma. 2004;56(3):475–481.
8) , 13)
Brown CVR, Zada G, Salim A, et al. Indications for routine repeat head Computed Tomography (CT) stratified by severity of traumatic brain injury. Journal of Trauma. 2007;62(6):1339–1344.
10)
Chao A, Pearl J, Perdue P, et al. Utility of routine serial computed tomography for blunt intracranial injury. Journal of Trauma. 2001;51(5):870–876.
15)
Figg RE, Burry TS, vander Kolk WE. Clinical efficacy of serial computed tomographic scanning in severe closed head injury patients. Journal of Trauma. 2003;55(6):1061–1064.
16)
Chesnut RM, Temkin N, Carney N, et al. A trial of intracranial-pressure monitoring in traumatic brain injury. The New England Journal of Medicine. 2012;367:2471–2481.
17)
Kreitzer N, Lyons MS, Hart K, Lindsell CJ, Chung S, Yick A, Bonomo J. Repeat neuroimaging of mild traumatic brain-injured patients with acute traumatic intracranial hemorrhage: clinical outcomes and radiographic features. Acad Emerg Med. 2014 Oct;21(10):1083-91. doi: 10.1111/acem.12479. PubMed PMID: 25308130; PubMed Central PMCID: PMC4283790.
18)
Braun T, Kunz U, Schulz C, Lieber A, Willy C. [Near-infrared spectroscopy for the detection of traumatic intracranial hemorrhage : Feasibility study in a German army field hospital in Afghanistan.]. Unfallchirurg. 2014 Jan 18. [Epub ahead of print] German. PubMed PMID: 24435101.
head_computed_tomography_for_traumatic_brain_injury.txt · Last modified: 2019/07/04 15:11 by administrador