11.2 Seizure Disorders, Encephalopathy & Delirium

Seizures in the Critically Ill Child

Seizures in the PICU may be provoked by fever, electrolyte imbalance, meningitis/encephalitis, TBI, stroke, hypoxic-ischemic injury, toxin exposure, or breakthrough in known epilepsy. Critically ill children also have a high burden of nonconvulsive seizures detectable only on continuous EEG — subtle eye deviation, autonomic swings, or unexplained coma should prompt EEG discussion, not dismissal as “just sedation.”

Classify what you see: focal versus generalized, motor versus nonmotor, and whether consciousness is impaired. Time the event. Protect the airway, turn to the side if vomitus is present, loosen restrictive clothing, and never force objects into the mouth. Check point-of-care glucose early; hypoglycemia is both a cause and a reversible contributor to ongoing seizures.

Status Epilepticus — Treat at Five Minutes

Status epilepticus (SE) is operationally defined as continuous clinical or electrographic seizure activity lasting 5 minutes or longer, or recurrent seizures without recovery to neurologic baseline between events. Waiting for a historical 30-minute definition delays therapy and increases neuronal injury, aspiration risk, and metabolic acidosis.

First-line pharmacologic rescue is a benzodiazepine (lorazepam IV, midazolam IM/IN/IV, or diazepam per access and protocol). If IV access is delayed, use an approved non-IV route rather than watching the clock empty. After benzodiazepines, second-line options commonly include levetiracetam, fosphenytoin (or phenytoin), or phenobarbital, chosen by etiology, cardiac status, and institutional pathway. Monitor for respiratory depression after benzos, hypotension/arrhythmia risk with phenytoin/fosphenytoin (especially with rapid infusion), and progressive sedation that may require airway support.

During and after SE, correct sodium, calcium, and magnesium when abnormal; treat fever; and obtain neuroimaging or LP when safe if a new structural or infectious cause is plausible. Document drug doses, times, and the exact clinical description — “jerking stopped at 11:42; still unresponsive” is more useful than “seizure resolved.”

Encephalopathy — A Syndrome With Many Drivers

Encephalopathy means a diffuse alteration in brain function: irritability, lethargy, confusion, or coma without necessarily implying a permanent lesion. In pediatrics, the differential is broad and time-sensitive:

Nursing priorities are simultaneous: protect airway and perfusion, reverse hypoglycemia immediately, escalate abnormal ammonia or sodium results, and avoid attributing a falling mental status solely to “tired after a procedure” without a differential. For infants with cyclic vomiting, lethargy, and neurologic change, metabolic disease including urea-cycle disorders must stay on the list until ammonia and specialty evaluation say otherwise.

Hepatic encephalopathy adds graded mental-status change, hyperammonemia, and risk of cerebral edema — minimize stimulation spikes, monitor for rising ICP signs, and partner on lactulose/rifaximin or dialysis strategies as ordered. Hypertensive encephalopathy demands controlled blood-pressure reduction without precipitous drops that steal cerebral perfusion.

PICU Delirium — Recognize, Screen, Prevent

Delirium is an acute disturbance of attention and awareness with a fluctuating course. In critically ill children it is associated with longer ventilation, longer length of stay, and post-ICU morbidity. Hypoactive delirium (quiet, withdrawn) is easy to miss and may be more common than the agitated hyperactive form. Mixed patterns fluctuate within a shift.

Validated pediatric tools include the Cornell Assessment of Pediatric Delirium (CAPD) and the Sophia Observation Withdrawal Symptoms–Pediatric Delirium (SOS-PD) scale, among others used by specific units. Screen on a schedule, especially after sedation changes, nights of poor sleep, or new infections.

Nonpharmacologic bundles are first-line. Antipsychotics or other pharmacologic treatments, when used, are adjuncts for severe agitation that threatens safety or device integrity after reversible causes are addressed — they are not a substitute for sleep hygiene and medication review. Always exclude hypoxia, hypercarbia, withdrawal, electrolyte chaos, and nonconvulsive seizures before labeling behavior as “just delirium.”

Integrating Seizure, Encephalopathy, and Delirium Care

A child may seize from meningitis, become encephalopathic from ammonia, then look delirious during weaning — the labels overlap. Your exam value is pattern recognition: time seizures and treat SE early; run a structured encephalopathy differential with glucose first; screen for delirium and strip away modifiable PICU toxins. Communication with families matters: explain that fluctuating awareness can be delirium or ongoing encephalopathy, and that parental presence is therapeutic, not optional fluff.