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Approach to the Critical Patient
Immediate stabilization
Initial priorities
Airway risk
Ongoing convulsions
Inability to protect airway
Persistent hypoxemia
Recurrent emesis
Breathing support
High flow oxygen
End tidal CO2 if available
Bag valve mask ventilation if apnea
Circulation support
Cardiac monitor
Two large bore IV or IO
Hypotension management
Isotonic crystalloid bolus 20 mL/kg
Vasopressor if shock persists
Immediate bedside checks
Point of care glucose
Core temperature
Pregnancy test if relevant
Status definition and timing
Operational definition
T1 threshold for convulsive SE 5 minutes
T2 threshold for neuronal injury risk 30 minutes
Time zero
Witnessed onset time
Last known well time
Early escalation
Resuscitation bay criteria
Ongoing generalized convulsions beyond 5 minutes
Recurrent seizures without baseline recovery
Airway compromise
Team activation
ICU early notification for refractory course
Neurology early notification if available
Anesthesia notification if intubation likely
Monitoring and access
Monitoring bundle
Vital sign frequency
Every 5 minutes during active management
Continuous pulse oximetry
Blood pressure strategy
NIBP cycling every 2 to 3 minutes
Arterial line if vasopressors or anesthetic infusion
Temperature strategy
Active warming if hypothermia
Active cooling if hyperthermia
Vascular access
IV access
Two peripheral lines preferred
Ultrasound guided peripheral if difficult access
IO access
If no IV within 2 minutes
Medication compatibility check for IO route
Immediate treatable causes
Reversible causes
Hypoglycemia
Dextrose therapy if low glucose
Thiamine before dextrose if malnutrition risk
Electrolyte derangements
Sodium disorders
Calcium disorders
Magnesium disorders
Toxicologic causes
Isoniazid concern
Bupropion concern
Tramadol concern
Sympathomimetic toxicity concern
CNS infection concern
Fever
Neck stiffness
Immunocompromised status
Eclampsia concern
Pregnancy beyond 20 weeks
Severe hypertension
Headache or visual symptoms
History
Key history elements
Core seizure history
Prior epilepsy
Baseline seizure type and frequency
Typical duration
Current event timeline
Time of onset
Continuous convulsions vs intermittent
Recovery between events
Semiologic clues
Focal onset features
Generalized onset features
Eye deviation
Cyanosis
Postictal course
Return to baseline
Persistent confusion duration
Medication and adherence
Antiseizure medications
Names and doses
Last dose time
Missed doses
Recent medication changes
Dose reduction
New interacting drugs
Benzodiazepine exposure
Home rescue meds
EMS meds and times
Provoking factors
Infection symptoms
Fever
Respiratory symptoms
GI symptoms
Sleep deprivation
Night shift
Insomnia
Substance use
Alcohol withdrawal risk
Stimulant use
Cannabis concentrates
Metabolic stressors
Vomiting
Diarrhea
Poor intake
Pregnancy related
Gestational age
Preeclampsia symptoms
Structural and vascular risk
Head trauma
Recent fall
Anticoagulant use
Stroke risk
Atrial fibrillation
Recent focal deficits
Brain tumor history
Known lesions
New headaches
PITFALLS
Common misses
Pseudoseizure concern
Do not delay benzodiazepines if ongoing convulsions and unstable
Early EEG for diagnostic uncertainty if stable
Nonconvulsive status after convulsive cessation
Persistent altered mental status
Subtle motor signs
Medication underdosing
Weight based benzodiazepine dose errors
Inadequate second line load
Physical Exam
Focused exam during stabilization
Neurologic domains
Level of consciousness
GCS trend
Persistent unresponsiveness
Pupils
Size and reactivity
Asymmetry
Motor findings
Ongoing rhythmic activity
Focal weakness after event
Asymmetric tone
Brainstem signs
Gag reflex status
Corneal reflex status
Respiratory and airway
Work of breathing
Apnea episodes
Aspiration signs
Oxygenation
SpO2 trend
Cyanosis
Cardiovascular and perfusion
Hemodynamics
Hypotension
Severe hypertension
Perfusion
Capillary refill
Skin temperature
Trauma screen
Head and face injuries
Tongue bite
Scalp hematoma
Musculoskeletal injuries
Shoulder dislocation concern
Vertebral tenderness
PEARLS
Exam interpretation
Focal deficits
Consider stroke
Consider intracranial hemorrhage
Persistent coma after cessation
Consider nonconvulsive status
Consider sedative effect
Consider hypoxic injury
Severe hypertension with pregnancy
Eclampsia until proven otherwise
Differential Diagnosis
Life threatening causes
High risk diagnoses
CNS hemorrhage
Intracerebral hemorrhage
Subarachnoid hemorrhage
Ischemic stroke with seizure
Large vessel occlusion
Cortical infarct
CNS infection
Meningitis
Encephalitis
Toxicologic
Isoniazid toxicity
Tricyclic antidepressant toxicity
Organophosphate toxicity
Metabolic
Hypoglycemia
Hyponatremia
Hypocalcemia
Uremia
Eclampsia
Generalized tonic clonic seizure in pregnancy
Severe hypertension
Mimics and related entities
Alternative explanations
Psychogenic nonepileptic seizures
Prolonged fluctuating course
Asynchronous movements
Syncope with myoclonus
Prodrome
Rapid recovery
Rigors
Febrile illness context
Movement disorders
Dystonia
Chorea
Coding anchors
Standardized coding
ICD-10 G40.901 status epilepticus unspecified not intractable
ICD-10 G41.9 status epilepticus unspecified
SNOMED CT concept status epilepticus
SNOMED CT concept nonconvulsive status epilepticus
Laboratory Tests
Immediate point of care
Bedside tests
Point of care glucose
Hypoglycemia threshold local protocol
Repeat after treatment
Venous blood gas
pH trend
PCO2 mmHg for hypoventilation
Lactate mmol/L
Postictal elevation expected
Persistent rise suggests ongoing seizure or shock
Core bloodwork
Baseline labs
Electrolytes
Sodium mmol/L
Potassium mmol/L
Chloride mmol/L
Bicarbonate mmol/L
Renal function
Urea mmol/L
Creatinine umol/L local units
Calcium panel
Ionized calcium mmol/L if available
Magnesium mmol/L
Phosphate mmol/L
CBC
Infection clue
Anemia clue
Liver enzymes
Hepatic injury clue
Valproate planning context
Directed labs
Antiseizure drug levels when applicable
Phenytoin total level
Valproate level
Carbamazepine level
Toxicology
Acetaminophen level if overdose concern
Salicylate level if overdose concern
Ethanol level if withdrawal planning
CK
Rhabdomyolysis screening after prolonged convulsions
Troponin if chest pain or arrhythmia
Seizure related elevation possible
ACS differentiation as needed
Infectious workup triggers
Infection evaluation
Blood cultures
Fever
Hemodynamic instability
Urinalysis and culture
Older adults
Pregnancy
Lumbar puncture labs set
CSF cell count
CSF protein
CSF glucose
CSF Gram stain and culture
CSF HSV PCR when indicated
Diagnostic Tests
Scoring Systems
Classification and risk tools
Status subtype classification
Convulsive status epilepticus
Nonconvulsive status epilepticus
Refractory status epilepticus
Super refractory status epilepticus
Etiology framework
Acute symptomatic
Remote symptomatic
Progressive symptomatic
Unknown
Prognostic scores
STESS use in ICU planning
EMSE use in ICU planning
Limitation for ED decision making
Not validated for discharge decisions
MRI
MRI brain
Indications
New focal deficits with negative CT
Suspected encephalitis
Suspected tumor
Sequences
DWI for acute infarct
FLAIR for edema
Contrast when mass or infection suspected
Limitations
Time to acquisition
Need for airway control
Motion artifact risk
CT
CT head without contrast
Indications
First seizure with persistent altered mental status
Focal neurologic deficit
Head trauma
Immunocompromised state
Anticoagulation
Findings
Intracranial hemorrhage
Mass effect
Hydrocephalus
Timing principle
Do not delay benzodiazepines for CT
CT angiography head and neck
Indications
Suspected large vessel occlusion
Thunderclap headache with SAH concern after noncontrast CT pathway
Limitations
Contrast allergy
Renal risk assessment
Ultrasound (or US)
Point of care ultrasound
Airway and ventilation adjuncts
Lung ultrasound for aspiration pattern
Diaphragm motion if paralysis concern
Hemodynamic adjuncts
IVC assessment for volume status support
Cardiac views for tamponade if arrest
Pregnancy adjuncts
Intrauterine pregnancy confirmation if unstable
EEG
Electroencephalography
Indications
Persistent altered mental status after convulsions stop
Suspected nonconvulsive status epilepticus
Paralyzed and sedated patient
Timing
As soon as feasible for suspected NCSE
Continuous EEG for refractory status
Interpretation pearls
Electroclinical dissociation risk after neuromuscular blockade
Periodic discharges and ictal patterns need expert review
Disposition
Level of care
Admission criteria
Any status epilepticus episode
ICU if refractory or intubated
Stepdown if controlled but high recurrence risk
ICU criteria
Need for mechanical ventilation
Continuous anesthetic infusion
Vasopressors
Continuous EEG requirement
Ward criteria
Fully awake baseline recovery
Clear reversible trigger corrected
Neurology plan in place
Transfer criteria
Need for continuous EEG not available
Refractory status requiring anesthesia support
Suspected encephalitis needing specialty care
Discharge considerations
Rare discharge pathway
Not status epilepticus after reassessment
Single brief seizure with full recovery
Normal neurologic exam
Safety prerequisites
Reliable supervision
Return precautions understood
Follow up arranged
Driving and activity restrictions
Jurisdiction specific guidance
Avoid swimming alone
Avoid heights and machinery
Treatment
First line benzodiazepines
Benzodiazepine strategy
Time based trigger
If convulsions at 5 minutes start benzodiazepine
If active convulsions after first dose repeat once
Preferred routes
IV if access established
IM if no IV
IN or buccal if no IV and IM delayed
Lorazepam IV
Adult dosing
0.1 mg/kg IV
Maximum single dose 4 mg
Repeat once after 5 minutes if ongoing
Pediatric dosing
0.1 mg/kg IV
Maximum single dose 4 mg
Repeat once after 5 minutes if ongoing
Midazolam IM
Adult dosing
10 mg IM single dose
Consider 0.2 mg/kg IM if weight based approach
Pediatric dosing
0.2 mg/kg IM
Maximum 10 mg
Midazolam IN or buccal
Pediatric dosing
0.2 mg/kg
Maximum 10 mg
Adult dosing
5 mg per nostril typical dosing pathway
Local protocol alignment
Diazepam IV
Adult dosing
0.15 to 0.2 mg/kg IV
Maximum single dose 10 mg
Repeat once after 5 minutes if ongoing
Pediatric dosing
0.2 mg/kg IV
Maximum single dose 10 mg
Second line antiseizure loading
Escalation trigger
If seizures persist 10 to 20 minutes after benzodiazepines start second line load
If recurrent seizures without recovery start second line load
Levetiracetam IV
Loading
60 mg/kg IV
Maximum 4500 mg
Infusion time 10 to 15 minutes
Advantages
Minimal hemodynamic effect
Few drug interactions
Valproate IV
Loading
20 to 40 mg/kg IV
Maximum 3000 mg
Infusion time 10 to 15 minutes
Avoidance
Pregnancy
Severe hepatic disease
Known urea cycle disorder
Fosphenytoin IV
Loading
20 mg PE/kg IV
Maximum 1500 mg PE
Infusion rate up to 150 mg PE per minute
Precautions
Arrhythmia risk
Hypotension risk
Narrow complex tachyarrhythmias concern
Phenytoin IV
Loading
20 mg/kg IV
Infusion rate up to 50 mg per minute
Precautions
Hypotension risk
Arrhythmia risk
Tissue injury risk with extravasation
Phenobarbital IV
Loading
20 mg/kg IV
Additional 5 to 10 mg/kg if needed
Use cases
Alcohol withdrawal refractory to benzodiazepines
Neonates and infants per protocol
Monitoring
Respiratory depression risk
Hypotension risk
Refractory status and anesthetic infusions
Refractory definition
Ongoing seizures after adequate benzodiazepine
Ongoing seizures after adequate second line load
Airway and ventilation
Intubation triggers
Persistent convulsions despite meds
Need for anesthetic infusion
Recurrent apnea
RSI considerations
Avoid long acting paralysis without EEG plan
Post intubation sedation plan before paralysis
Continuous infusion goals
EEG targets
Seizure suppression
Burst suppression target per neurology plan
Hemodynamic targets
Maintain MAP per age and comorbidity
Vasopressor support readiness
Midazolam infusion
Bolus
0.2 mg/kg IV
Repeat bolus 0.1 mg/kg if needed
Infusion start
0.05 to 0.2 mg/kg per hour
Titration
Increase 0.05 to 0.1 mg/kg per hour every 5 to 15 minutes
Typical upper range 2 mg/kg per hour
Adverse effects
Hypotension
Tachyphylaxis
Propofol infusion
Bolus
1 to 2 mg/kg IV
Infusion start
20 microg/kg per minute
Titration
Increase 5 to 10 microg/kg per minute every 5 minutes to suppression
Typical range 20 to 80 microg/kg per minute
Adverse effects
Hypotension
Hypertriglyceridemia
Propofol infusion syndrome risk
Ketamine infusion
Bolus
1 to 2 mg/kg IV
Infusion start
0.5 to 1 mg/kg per hour
Titration
Increase 0.5 mg/kg per hour every 10 to 20 minutes
Typical range 1 to 5 mg/kg per hour
Advantages
Less hypotension than GABA agents in some patients
Useful in super refractory status
Barbiturate coma option
Pentobarbital infusion
ICU only with continuous EEG
Profound hypotension risk
Immunosuppression and ileus risk
Etiology specific therapies
Hypoglycemia
Dextrose
Adult 25 g IV dextrose
Pediatric 0.5 g/kg IV dextrose
Thiamine
100 mg IV if malnutrition risk
Eclampsia
Magnesium sulfate
4 to 6 g IV loading over 15 to 20 minutes
Maintenance 1 to 2 g per hour
Repeat 2 g bolus for recurrent seizure
Blood pressure management
Severe range pathway per obstetric protocol
Isoniazid toxicity
Pyridoxine
Gram for gram replacement of isoniazid if known dose
If unknown dose 5 g IV adult
Pediatric 70 mg/kg IV maximum 5 g
Alcohol withdrawal
Benzodiazepines
High dose symptom triggered approach
Early phenobarbital pathway where used
Thiamine
100 mg IV before glucose containing fluids when possible
Evidence and guideline notes
Evidence grading
Benzodiazepines first line for convulsive status epilepticus
Class I recommendation in multiple society guidelines
Second line options
Levetiracetam
Valproate
Fosphenytoin
Similar seizure cessation efficacy in comparative trials
ACEP evidence language when referenced locally
ACEP Level B support for early benzodiazepine therapy in prolonged seizures
ACEP Level C support for early EEG when persistent altered mental status suggests NCSE
Special Populations
Pregnancy
Pregnancy specific priorities
Eclampsia pathway
Magnesium sulfate as first line antiseizure for eclampsia
Obstetrics involvement early
Medication safety
Avoid valproate when alternatives available
Benzodiazepines acceptable for maternal stabilization
Imaging considerations
CT head acceptable when indicated
MRI preferred when feasible for nonemergent etiologies
Geriatric
Older adult considerations
Etiology profile
Stroke and hemorrhage higher prevalence
Polypharmacy interactions
Medication sensitivity
Higher respiratory depression risk with benzodiazepines
Lower starting infusion rates for sedatives when used
Disposition bias
Lower threshold for admission and EEG
Pediatrics
Pediatric specific approach
Weight based dosing accuracy
Use kg weight actual or estimated
Dose caps applied to avoid adult overdose
Febrile seizure differentiation
Simple febrile seizure does not equal status
Complex febrile seizure may require broader workup
Airway strategy
Earlier desaturation risk
BVM proficiency emphasis
Etiology clues
Ingestion risk
CNS infection risk by age
Background
Epidemiology
Epidemiologic facts
Incidence
Status epilepticus annual incidence commonly reported 10 to 40 per 100000
Mortality
Higher mortality with acute symptomatic etiologies
Higher mortality with refractory status
Age distribution
Bimodal peaks in young children and older adults
Pathophysiology
Mechanisms
Time dependent receptor trafficking
Reduced GABA A receptor responsiveness over time
Increased excitatory transmission over time
Systemic consequences
Hyperthermia risk
Acidosis and hypercapnia risk
Rhabdomyolysis risk
Aspiration risk
Therapeutic Considerations
Treatment principles
Time sensitive benzodiazepines
Earlier administration linked to higher seizure termination
Delays increase refractory risk
Loading dose sufficiency
Underloading increases recurrence
Timely transition to second line reduces total benzodiazepine exposure
Continuous EEG role
Detect nonconvulsive seizures
Guide anesthetic titration
Hemodynamic tradeoffs
Sedative infusions often require vasopressors
Ketamine may preserve blood pressure relative to others
Patient Discharge Instructions
copy discharge instructions
Discharge instructions set
Return now criteria
Another seizure
Seizure lasting longer than 5 minutes
Trouble breathing
Blue lips or persistent low oxygen
Severe headache
New weakness or numbness
Fever with confusion
Pregnancy with headache or vision changes
Safety
No driving until cleared by clinician per local law
No swimming alone
No baths unsupervised
Avoid heights and power tools
Medication adherence
Take antiseizure meds exactly as prescribed
No sudden stopping of antiseizure meds
Triggers
Sleep regularity
Avoid alcohol binges
Avoid missed meals and dehydration
Follow up
Neurology or primary care follow up within 1 to 2 weeks
EEG and MRI scheduling if ordered
References
Clinical guidelines and evidence sources
Reference set
American Epilepsy Society guideline for convulsive status epilepticus
Benzodiazepines first line
Levetiracetam valproate fosphenytoin as second line options
Neurocritical Care Society guidance for refractory status epilepticus
Continuous EEG in refractory status
Anesthetic infusions for seizure suppression
Comparative trial evidence for second line agents
Similar efficacy of levetiracetam fosphenytoin valproate in established status epilepticus
ACEP evidence language integration
ACEP Level B and C style statements used where local pathways reference ACEP grading
Source file
SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.