What is the prognosis and etiology of sympathetic storm in pediatric patients with Traumatic Brain Injury (TBI) in the Intensive Care Unit (ICU)?

From the Guidelines

Sympathetic storm in pediatric patients with Traumatic Brain Injury (TBI) is associated with increased morbidity and longer ICU stays, and its management should be prioritized in a pediatric trauma centre or an adult trauma centre with pediatric expertise. The etiology of sympathetic storm involves dysregulation of the autonomic nervous system following brain injury, particularly affecting the diencephalon, brainstem, or cerebral hemispheres 1. This condition is also known as paroxysmal sympathetic hyperactivity (PSH) and has a variable prognosis.

Key Factors

• The management of severe TBI children in a specialized centre is associated with reduced morbidity and mortality 1
• Inflicted trauma is a prominent cause of TBI in children < 2 years old, and this population is at risk for high ICP and poor outcome 1
• The incidence of raised ICP is high in TBI children < 2 years old, and there is a strong association between cerebral perfusion pressure and neurological outcome 1

Treatment Approach

Treatment of sympathetic storm typically involves a multi-drug approach, including:

• Beta-blockers (e.g., propranolol) to control symptoms
• Alpha-2 agonists (e.g., clonidine) to regulate blood pressure
• GABA-ergic agents (e.g., baclofen) to manage muscle spasticity
• Opioids (e.g., morphine) to control pain and discomfort
• Bromocriptine may be used in severe cases to help regulate symptoms

Important Considerations

• Early recognition of sympathetic storm using assessment tools like the PSH-Assessment Measure is crucial for improving outcomes
• Children with diffuse axonal injury or severe TBI are at highest risk of developing sympathetic storm
• Aggressive symptom management can reduce complications like weight loss, contractures, and secondary brain injury from physiologic stress 1

From the Research

Etiology of Sympathetic Storm in Pediatric Patients with TBI

• The etiology of sympathetic storm in pediatric patients with Traumatic Brain Injury (TBI) is related to the loss of cortical control after brain injury, leading to increased sympathetic activity and decreased parasympathetic activity 2, 3, 4.
• The condition is also known as Paroxysmal Sympathetic Hyperactivity (PSH) and is characterized by recurrent episodes of sympathetic hyperactivity, including tachycardia, systolic hypertension, hyperthermia, tachypnea, and diaphoresis 3, 4, 5.
• The pathophysiology of PSH remains controversial, with multiple theories proposed, but it is believed to be related to the primary and secondary injury caused by the TBI 4.

Prognosis of Sympathetic Storm in Pediatric Patients with TBI

• The prognosis of sympathetic storm in pediatric patients with TBI is generally poor, with increased mortality, longer ICU stay, and poorer functional outcomes 5, 6.
• The presence of PSH is associated with a higher risk of developing infections, longer recovery time, and poorer overall outcome 5.
• However, one study found that patients with PSH had lower PICU mortality, but longer PICU length of stay and lower likelihood of discharge home from the hospital 6.

Clinical Manifestations and Management

• The clinical manifestations of sympathetic storm in pediatric patients with TBI include tachycardia, hypertension, tachypnea, hyperthermia, and diaphoresis 2, 3, 4, 5.
• Management of PSH includes symptomatic treatment and the use of medications such as clonidine, bromocriptine, benzodiazepines, and gabapentin, although strict management guidelines are not established 5.
• Early use of propranolol after TBI may help control hemodynamics and blood sugar, and decrease catecholamine levels, which is associated with improved Glasgow Coma Scale (GCS) scores 2.