Seatbelt Sign of the Neck in Pediatric Trauma

HPI/ROS:

The patient is a 11 y.o. male with no past medical history who presents as trauma activation after MVC. Patient was the restrained front seat passenger in a head on collision. Denies LOC. Per EMS, patient was found in police cruiser on arrival, patient states he walked at scene. +Seatbelt sign. Vitals stable. Patient states his pain is worst in his neck, rates pain 6/10. Denies numbness/tingling.

 Vital Signs:  

BP 116/47  | Pulse (!) 115  | Resp 19  | Wt 37.5 kg  | SpO2 100%

Pertinent physical exam:

AIRWAY: intact  

BREATHING: non-labored Breath sounds: Clear to auscultation bilaterally

CIRCULATION: pulse palpable: Bilateral Radial, DP and PT pulses are normal and symmetric

Capillary refill: normal; less than 2 seconds

Head: normocephalic / atraumatic no hematoma, no abrasions

ENT: tympanic membranes bilaterally clear

Neck: trachea appears midline, there is a cervical collar in place. Abrasion/seatbelt sign over R neck. +midline c-spine ttp without stepoffs

Respiratory: clear to auscultation bilaterally

Cardiovascular: regular rate and rhythm. Seat belt sign across L anterior chest

Rectal: normal tone

Abdomen: soft, non-distended, normal bowel sounds, nonperitoneal with tenderness to palpation in RLQ. Seatbelt sign across lower abdomen and L anterior thigh

Back: no tenderness to palpation in t-spine or l-spine. No step offs. No abrasions or bruises.

Pelvis: non-tender, stable to anterior-posterior/lateral compression

Genitourinary: normal genitalia

Musculoskeletal: no palpable long bone deformities, no bony tenderness to palpation

Skin: grossly intact

Neurologic: GCS: eyes 4, best verbal response 5, best motor response 6 TOTAL GCS SCORE: 15. Bilateral upper extremity strength 5/5 at deltoids, biceps, triceps, and handgrip. Bilateral lower strength at 5/5 at hip flexion, dorsi-/plantarflexion.

Should this patient receive a CTA of the neck?

 

Review of the literature 

Blunt cervical vascular injury

Blunt cervical vascular injury (BCVI) has an incidence of 0.03-0.9% in pediatric blunt trauma. BCVI may cause ischemia and other neurologic sequelae. Most BCVI are treated medically with aspirin or anticoagulation. Higher grade lesions may require intervention including endovascular stenting or ligation. The development of focal neurologic findings may be delayed up to 10-72 hours, complicating diagnosis in the acute setting.[1]

Currently, the Eastern Association for the Surgery of Trauma (EAST) recommends that pediatric patients should be screened by adult criteria, called the Denver or Memphis criteria. The Denver criteria include “focal neurologic deficit, arterial hemorrhage, cervical bruit/thrill (<50 yo), infarct on head CT, expanding neck hematoma, neuro exam inconsistent with head CT, midface fractures, c-spine injuries, basilar skull fractures, GCS <8, hanging with anoxic brain injury, seat belt abrasion or other soft tissue injury of the anterior neck resulting in significant swelling or altered mental status. Isolated seatbelt sign without other neurologic symptoms has not been identified as a risk factor.”[2]

Evaluation with computed tomography angiogram (CTA) of the brain and neck represents a dose of radiation 8 times higher (16.4 millisieverts) than compared to a noncontrast CT of the brain and neck (2 millisieverts).[1] Exposure to ionizing radiation in the pediatric population has been shown to increase risks of cancers, especially leukemia, breast, and thyroid cancer.[3]

A recent, large study identifying risk factors associated with blunt cervical vascular injury (BCVI) examined 11,446 pediatric blunt trauma patients, with 375 (3.3%) undergoing CTA imaging. Fifty-three patients (0.4%) had cerebrovascular injuries, representing 0.5% of all pediatric blunt trauma patients and 14% of all blunt trauma patients screened with CTA.[1]

They found a seatbelt sign on the neck did not predict vascular injury.[1] These findings are consistent with other studies which did not find an association between  a cervical seatbelt sign and BCVI.[2,4] Furthermore, they identified independent predictors of cervical vascular injury: presence of cerebral hemorrhage, infarct on head imaging, cervical spine fracture, and basilar skull fracture.[1] Other studies have found associations between BCVI and clavicular fractures,[5] fracture through the carotid canal,[6] petrous temporal bone fracture,[6] GCS < 8,[6] focal neurological deficit,[6] and stroke on initial CT.[6]

  

Case Resolution

Due to the patient’s c-spine tenderness, in addition to the presence of a seat belt sign, the patient underwent imaging with a CT c-spine and a CTA brain and neck. He also had a CT of his abdomen.

All of his imaging (CTA brain/neck, CT c-spine, and CT abdomen and pelvis were all negative. The patient was admitted to the surgical service for pain management and serial exams of his abdomen. His repeat exam was normal and patient was discharged the following day.

Based on the above guidelines, a CTA of the brain and neck was not indicated.

Children of a certain size and age should not be sitting in the front seat and need booster seats. Here’s more information on that: http://brownemblog.com/blog-1/2019/1/10/hey-kiddo-take-a-seat

 

Faculty Reviewer: Dr. Jane Preotle

References

  1. Irma T. Ugalde IT,  MD, Claibrne MK, Cardenas-Turanzas M, Shah MN, Langabeer JR, Patel R. Risk Factors in Pediatric Blunt Cervical Vascular Injury and Significance of Seatbelt Sign. West J Emerg Med. 2018 Nov; 19(6): 961–969.

  2. Denver screening criteria. WikEM

  3. Risk of Ionizing Radiation Exposure to Children: A Subject Review. Committee on Environmental Health, American Association of Pediatrics. Pediatrics. 1998; 101(4).

  4. Desai NK, Kang J, Chokshi FS. Screening CT Angiography for Pediatric Blunt Cerebrovascular Injury with Emphasis on the Cervical “Seatbelt Sign” American Journal of Neuroradiology September 2014, 35 (9) 1836-1840.

  5. Lew SM, Frumiento C, Wald SL Pediatric blunt carotid inury: a review of the National Pediatric Trauma Registry. Pediatr Neurosurg, 1999; 30(5): 239-44. 

  6. Ravindra VM, Bollo RJ, Sivakumar W, Akbari H, Naftel RP, Limbrick DD, JEa A, Gannon S, Shannon C, Birkas Y, Yang GL, Prather CT, Kestle JR, Riva-Cambrin J. Predicting Blunt Cerebrovascular Injury in Pediatric Trauma: Validation fo the “Utah Score.” J Neurotrauma. 2017; 34(2): 391-399.

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Pediatric Baclofen Overdose

Case

A 16 year-old male presented to the emergency department after intentional overdose of 200 mg of baclofen. The patient was found in his bedroom by family members approximately 10 hours after ingestion with reported twitching, vomiting, unresponsiveness, and possible seizure activity. On arrival to the emergency department, the patient was awake, alert, and oriented; tearful, but otherwise asymptomatic.

 

Physical Exam

Vital signs included blood pressure 150/76, heart rate 112, temperature 99.2 F (37.3 C), respiratory rate 26, SpO2 97%. Physical exam showed frequent bilateral upper greater than lower extremity myoclonic jerks. The patient’s neurologic exam and physical exam were otherwise unremarkable.

 

Labs/Imaging

The patient’s toxicological workup was pertinent for undetectable salicylate, acetaminophen, and ethanol levels. His urine drug screen was negative. EKG showed sinus tachycardia with normal QRS and QTc intervals. A head CT previously completed at an outside hospital was normal. The rest of his laboratory evaluation including CBC, electrolyte levels, and hepatic function tests, was unremarkable.

 

Discussion

Baclofen is a centrally-acting skeletal muscle relaxant which functions as a GABA-B receptor agonist, believed to inhibit synaptic transmission of signals to the muscle from the spinal cord. Baclofen is typically prescribed for symptoms related to severe muscle spasm, such as in spinal cord injury or chronic neurologic disease (e.g. multiple sclerosis.) The medication can be administered either orally, or via an intrathecal pump.

Baclofen is absorbed rapidly from the GI tract in a dose-dependent manner, with peak serum levels occurring after ~1 hour (with a range of 0.5-4 hours). However, this has been found to be highly variable in pediatric patients. Its volume of distribution is also highly variable among pediatric patients, with nearly 50% interindividual variability. The reason for this variability is not clearly understood.

Baclofen is primarily excreted renally, with a serum half-life of 4.5 hours in pediatric patients, and a CSF half-life of 1.5 hours in intrathecal administration.

Baclofen overdose typically manifests with neurologic symptoms and dysautonomia. Symptoms are variable and may include: CNS depression/coma, hypotonia, hyporeflexia, seizure, respiratory depression, tachycardia, bradycardia, hypertension, hypotension, and arrhythmia. In adults, ingestions of >200 mg appear to correlate with an increased risk of respiratory failure, mechanical ventilation requirement, and ICU admission time.

 In an unfortunate case series, a group of teenagers overdosed on 60-600 mg of baclofen for recreational purposes. Patients displayed symptoms of overdose in 1-2 hours. 9 of 14 were intubated. Of 8 that were followed longitudinally: 7 were comatose, 6 were hypothermic, 5 were bradycardic, 4 were hypertensive, 8 were hyporeflexic, 3 had PVCs, and 2 had tonic-clonic seizures. The mean time of intubation was 40 hours. All patients recovered.

 

Treatment

Treatment of baclofen overdose is primarily supportive with IV fluids, hemodynamic and respiratory support, and antiepileptics as needed. Activated charcoal may also be considered. There are case reports of physostigmine being effective in low/moderate overdoses; however, its use is controversial. Finally, hemodialysis does shorten clearance time and resolution of toxicity in patients with normal and impaired renal function.

 

Disposition

Patients should be monitored until symptoms resolve. Depending on the dose ingested, the length of time since ingestion, clinical status, and laboratory analysis, they may be monitored either on the floor with telemetry or in the ICU.

 

Conclusion

The patient was treated with a 1 liter normal saline bolus and 1 mg of lorazepam IV; his hemodynamics normalized, his myoclonic twitching resolved, and he remained stable without seizure or complication throughout emergency department stay. He was admitted to the pediatric ICU for overnight monitoring, where he remained asymptomatic and had normal vital signs. The patient was then transferred to inpatient psychiatry for mental health treatment.

 

Summary

Baclofen overdoses typically present with a combination of altered mental status and or seizure, hypotonia, and dysautonomia. Treatment is primarily supportive and most patients recover with IV fluids, hemodynamic and respiratory support, and antiepileptics as-needed (usually benzodiazepines.) Activated charcoal should be considered. Patients should be admitted either to medical floor with telemetry or ICU depending on clinical status; they should remain admitted until symptoms resolve (typically several days, depending on ingested dose).

Faculty Reviewer: Dr. Jane Preotle 

References

  1. https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1742-6723.2006.00805.x

  2. http://ajcc.aacnjournals.org/content/15/6/611.full.pdf%2Bhtml%20

  3. https://emj.bmj.com/content/22/9/673

  4. https://www.mdpoison.com/media/SOP/mdpoisoncom/ToxTidbits/2012/February%202012%20ToxTidbits.pdf

  5. https://pediatrics.aappublications.org/content/101/6/1045

  6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2841240/

  7. https://www.acep.org/how-we-serve/sections/toxicology/news/september-2015/baclofen/

  8. https://www.uptodate.com/contents/baclofen-drug-information?search=baclofen&source=panel_search_result&selectedTitle=1~82&usage_type=panel&kp_tab=drug_general&display_rank=1