Welcome to PICU Doc On Call, A Podcast Dedicated to Current and Aspiring Intensivists.
I'm Pradip Kamat and I'm Rahul Damania, and we are coming to you from Children's Healthcare of Atlanta - Emory University School of Medicine.
Welcome to our Episode a 24-month-old girl with increased seizure frequency.
Here's the case:
A 24-month old girl presents to the ED with h/o shaking/jerking episodes in her sleep. The patient was in the care of her aunt when this acute episode occurred. When the father arrived from work, he saw his daughter having episodes of her body shaking alternating with heavy breathing. The patient would not wake up in between episodes. There was pertinently no history of trauma. 911 was called and when EMS arrived, she was starting to arouse and respond to stimuli. The patient was transported to the ED. In the ambulance, the patient continued to have similar shaking and jerking episodes and was given rectal diazepam. On arrival to ED, the patient had a fever of 38.5 Centigrade. Due to ongoing seizures, the patient was loaded with Fosphenytoin, after having been given a total of two doses of IV Lorazepam. The patient was subsequently intubated for airway protection and respiratory failure. A respiratory viral panel was negative for SARS-COV-2 but positive for Rhino-enterovirus. The patient was admitted to the PICU with cEEG monitoring and placed on mechanical ventilation with fentanyl + dexmedetomidine infusions with as needed Midazolam administrations
Her physical examination on arrival to the PICU was unremarkable. She wasn't interactive as she had just received sedation after intubation. On her neuro-examination, Pupils are equal and punctiform. The face is symmetric. The tongue is midline. Normal bulk and tone. No spontaneous movements were noted. No withdrawal to painful stimuli. Tendon reflexes were equal throughout. No clonus is noted.
Rahul, to summarize key elements from this case, this patient has:
Absolutely, we will get to this later on in the episode; however, remember that Status epilepticus is historically defined as single epileptic seizure of >30 minutes duration or a series of epileptic seizures during which function is not regained between ictal events in a 30-minute period
OK to summarize, we have: 24-month-old girl who presented with prolonged seizures and acute respiratory failure
A 14-year-old girl is brought to the PICU from the floor with new-onset status epilepticus. She was admitted to the floor on her second day after a posterior spinal fusion surgery and is still receiving intravenous fluids. Her seizure is described as generalized tonic-clonic. After initial stabilization and maintenance of her airway and hemodynamics, which of the following is most likely to reveal the cause of her seizures?
Rahul, the correct answer here is A) serum electrolytes. Patients especially after posterior spinal fusion surgery are at risk for hyponatremia secondary to SIADH or even hypotonic fluids used for maintenance. Correction of hyponatremia in a child with seizures requires 3% hypertonic saline. The seizure threshold is typically a serum Na of 125meQ/L. Serum electrolytes will also reveal the serum glucose which is especially important to check in infants who have seizures. A stat MRI is not warranted in this patient especially if she is alert and awake prior to the seizure. Additionally, it would be dangerous to send an unstable patient for an MRI. As the patient is afebrile, LP is less likely to be illuminating about the cause of her seizures. LP could be needed especially if there is a strong suspicion of infection such as meningitis but can be delayed if the patient is unstable and antibiotics initiated. While a CEEG may be needed especially if the patient is intubated or comatose and there is a risk of non-clinical seizures, it is not the first-line diagnostic tool.
Excellent explanation Pradip, it is of utmost importance to make sure you assess for electrolyte disturbances or glucose abnormalities in your rapid diagnostics when patients are seizing. Remember hyponatremia, hypoglycemia, and hypocalcemia. If you have a child with Seizures
Let’s transition and highlight key definitions of status epilepticus:
Previously defined as a seizure lasting > than 30minutes or recurrent seizures lasting > 30minutes without patient regaining consciousness between seizures. The new definition refers to SE as 5minutes or more of either continuous seizure or 2 or more discrete seizures between which there is incomplete recovery of consciousness.
Refractory SE = SE that persists despite the administration of first and second-line anti-seizure medications with different mechanisms of action.
Super refractory SE refers to SE that continues 24 hours or more after the onset of anesthetic therapy for SE and includes recurrence during reduction or withdrawal of anesthetic therapy.
Pradip what is the most common cause of seizures in the pediatric population?
The majority of pediatric SE (30-50%) involved febrile seizures. About 9-17% involved either acute metabolic derangement or a CNS infection. 12% of first seizures in children present with status epilepticus (Shinnar, Pediatrics 1996)
What is the pathophysiology of seizures and its progression to status epilepticus?
There is an imbalance between excitation and inhibition. Ineffective recruitment of GABA neurons coupled with excessive excitatory NMDA neuronal stimulation leads to initiation and propagation of the electrical disturbance in SE. Prolonged seizures lead to selective neuronal loss in the hippocampus, cortex, and thalamus.
There is neurotoxicity due to excitotoxicity (via excess stimulation from glutamate on NMDA and AMPA receptors) as well as hypoxic-ischemic injury (imbalance between increased metabolic demand and cerebral blood flow/oxygenation). Hypoxia, acidosis, hypotension, and hypercarbia add to the ongoing damage.
There are early (< 30minutes) and late (> 30minutes) time-related complications of status epilepticus which are nicely elucidated in the LearnPICU status epilepticus-pathophysiology. (http://www.learnpicu.com/neurology/status-epilepticus)
The risk of subsequent epilepsy after status epilepticus is 26-36% (Barnard, J child Neurol 1999 and Eriksson, Develop Med Child Neurol 1997).
Would you also mind highlighting the way seizures are classified?
Seizures are classified as Partial or generalized based on clinical presentation or EEG FINDINGS. Partial Seizures arise in specific areas of the brain and are further classified as simple, local, or focal. Generalized seizures arise from diffuse cortical areas at one time. They involve both cerebral hemispheres and consciousness is typically impaired. Generalized can present as motor movements or absence seizures during which no convulsions are seen.
To summarize, these are the common causes of seizures in the PICU — AED withdrawal or change, drug toxicity or withdrawal, electrolyte problems, hypertensive encephalopathy, tumor, TBI, vasculitis, renal/hepatic dysfunction, fever, hypoxia/ischemia, and postoperative conditions. Pre-existing epilepsy, genetic and central nervous system disorders can also present with seizures. Intensivists should be vigilant about non-convulsive status especially in children who have hypoxic injury s/p cardiac arrest, submersion injury, TBI, and stroke.
Summary: IV Ativan and IV Midazolam if your patient has good access are equally effective