Pediatrics Advanced life support in exam oriented pattern for emergency physician

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Pediatric Advanced Life Support (PALS) - Exam-Oriented Review for Emergency Physicians

Sources: Rosen's Emergency Medicine (9e), Tintinalli's Emergency Medicine (9e)

1. EPIDEMIOLOGY & KEY CONCEPTS (High-Yield)

Feature	Pediatric (vs Adult)
Arrest etiology	Respiratory predominates (hypoxia/asphyxia), NOT primary cardiac
VF/pVT incidence	~10-15% (vs ~85% in adults)
Bystander CPR	Improves survival but underperformed
Survival (out-of-hospital)	~10%; in-hospital ~30-40%
Primary goal	Oxygenation + ventilation FIRST, then perfusion

Exam pearl: Because children arrest from respiratory causes, they benefit from conventional CPR (compressions + ventilations), unlike adults where compression-only CPR is acceptable. Compression-only CPR is inferior in pediatric arrests from asphyxia.

2. AGE DEFINITIONS (PALS)

Term	Age Range
Neonate	Birth to 28 days
Infant	<1 year
Child	1 year to puberty
Adult ACLS	Signs of puberty onward

3. RECOGNIZING ARREST / PRE-ARREST

Pediatric Assessment Triangle (PAT)

Appearance (TICLS: Tone, Interactiveness, Consolability, Look/Gaze, Speech/Cry)
Work of Breathing
Circulation to skin (color, mottling, pallor)

Normal Vital Signs by Age

Age	HR (beats/min)	RR (breaths/min)	SBP (mmHg)
Newborn	100-160	30-60	60-90
Infant (1-12 mo)	100-160	25-50	70-100
Toddler (1-3 y)	90-150	20-30	80-110
Preschool (3-5 y)	80-140	20-25	80-110
School-age (6-12 y)	70-120	15-20	90-120
Adolescent	60-100	12-20	100-120

Hypotension by age (PALS formula): Systolic BP < 70 + (2 × age in years) for ages 1-10

4. CPR - HIGH-QUALITY COMPRESSIONS

Key Parameters

Parameter	Value
Rate	100-120/min
Depth - Infants	1.5 inches (≥1/3 AP diameter)
Depth - Children	2 inches (≥1/3 AP diameter)
Recoil	Complete chest recoil
Interruptions	Minimize; switch compressor every 2 minutes
C:V ratio (no airway)	15:2 (pediatric; 30:2 for adults)
C:V ratio (advanced airway)	Continuous compressions + 1 breath every 2-3 sec (20-30 breaths/min)

Compression Technique by Age

Age	Technique
Infant (1-rescuer)	2-finger technique on sternum below nipple line
Infant (2-rescuer)	2-thumb encircling technique - preferred (generates higher cardiac output)
Child 1-8 years	1 or 2 hands, heel of hand on lower half sternum
Older child/adolescent	2 hands, same as adult

Exam pearl: For infants, the 2-thumb encircling technique generates greater cardiac output and coronary perfusion pressure than the 2-finger technique. Use it when a second rescuer is available.

ETCO₂ in CPR

Target ETCO₂ >20 mmHg to indicate adequate compressions
Sudden rise in ETCO₂ signals ROSC
If ETCO₂ consistently <10 mmHg despite optimal CPR, prognosis is poor

5. AIRWAY & VENTILATION

BVM vs Endotracheal Intubation

For pre-hospital arrest: 2019 PALS update recommends bag-mask ventilation - ETI does not improve survival and may worsen outcomes (delays compressions; OR 0.82 for survival, no benefit)
For in-hospital arrest: insufficient evidence to mandate ETI over BVM
If ETI performed: aim for 8-10 breaths/min without interrupting compressions

Airway Sizes (Exam Classics)

ET tube size = (Age/4) + 4 (uncuffed) or (Age/4) + 3.5 (cuffed)
Preferred: cuffed ETT in all ages (avoids multiple attempts)
Verify placement with waveform capnography

Jaw Thrust vs Head-Tilt/Chin-Lift

Jaw thrust preferred if cervical spine injury suspected
Head-tilt/chin-lift is standard for non-trauma

6. VASCULAR ACCESS

Priority order:

Peripheral IV (2 attempts max - 90 seconds)
Intraosseous (IO) - if IV fails; should be obtained within 60-90 seconds of arrest
Central venous access

IO sites:

Proximal tibia (most common)
Distal tibia
Distal femur
Humeral head (EZ-IO)

Exam pearl: IO is equivalent to IV for drug delivery in arrest. All resuscitation drugs can be given IO. If epinephrine is given via ETT: dose is 10× the IV dose (0.1 mg/kg of 1:1000).

7. PALS CARDIAC ARREST ALGORITHM (2020 AHA)

AHA 2020 Pediatric Cardiac Arrest Algorithm

The algorithm splits into two arms based on rhythm:

Shockable (VF / pulseless VT)

Start CPR + O₂ + attach monitor
Shock: 2 J/kg
CPR 2 min + IV/IO access
Shock: 4 J/kg
CPR 2 min + Epinephrine every 3-5 min
Shock: ≥4 J/kg (max 10 J/kg or adult dose)
CPR 2 min + Amiodarone or Lidocaine + treat reversible causes
Continue loops; check rhythm every 2 min

Non-Shockable (Asystole / PEA)

Start CPR + O₂
CPR 2 min + IV/IO access + Epinephrine ASAP (repeat every 3-5 min)
Consider advanced airway
Treat reversible causes (H's and T's)
Check rhythm every 2 min; if converts to shockable → go to shockable arm

8. DRUG THERAPY IN ARREST

Medications for Pediatric Cardiac Arrest

Drug	Indication	IV/IO Dose	Key Notes
Epinephrine	All rhythms	0.01 mg/kg (0.1 mL/kg of 0.1 mg/mL); max 1 mg	Repeat every 3-5 min; ET dose 0.1 mg/kg; HIGH doses (>0.01) do NOT improve survival
Amiodarone	VF/pVT, SVT	5 mg/kg bolus; up to 3 doses for VF/pVT	May repeat x3 for refractory VF; infuse over 20-60 min for SVT
Lidocaine	VF/pVT	1 mg/kg loading dose	Alternative to amiodarone; avoid in WPW
Atropine	Bradycardia (vagal/AV block)	0.02 mg/kg; min 0.1 mg, max 0.5 mg/dose	NOT for routine use in PEA/asystole
Adenosine	SVT	0.1 mg/kg (1st dose, max 6 mg); 0.2 mg/kg (2nd, max 12 mg)	1st-line for stable SVT; rapid IV push + flush; avoid in WPW/wide QRS
Procainamide	SVT (WPW), stable VT	10-15 mg/kg over 30-60 min	1st line for SVT in WPW; do NOT combine with amiodarone
Calcium chloride	Hyperkalemia, hypocalcemia, CCB OD	20 mg/kg	Not routine; central line preferred
Sodium bicarbonate	Hyperkalemia, TCA overdose	1 mEq/kg	Not routine use
Magnesium sulfate	Torsades de pointes	Max single dose 2 g	Not routine
Dextrose	Hypoglycemia	0.5-1 g/kg (max 25 g)	D10W: 5 mL/kg; D25W: 2 mL/kg; D50W: 1 mL/kg; Do NOT give empirically

Exam pearl: Epinephrine dose via ETT is 10× IV dose = 0.1 mg/kg of 1 mg/mL (1:1000) concentration. IV/IO dose uses 0.1 mg/mL (1:10,000) concentration.

9. H's AND T's - REVERSIBLE CAUSES

H's	T's
Hypovolemia	Tension pneumothorax
Hypoxia	Tamponade (cardiac)
Hydrogen ion (acidosis)	Toxins
Hypo/Hyperkalemia	Thrombosis (pulmonary)
Hypoglycemia	Thrombosis (coronary)
Hypothermia

Pediatric-specific emphasis: Hypoxia and hypovolemia are the most common reversible causes in children.

10. PEDIATRIC BRADYCARDIA ALGORITHM

Key steps:

Identify and treat underlying cause (O₂, airway, IO/IV access)
Is there cardiopulmonary compromise? (hypotension, AMS, shock)
- No → support ABCs, observe
- Yes → If HR <60/min with poor perfusion despite O₂/ventilation → CPR
If bradycardia persists:
- Epinephrine 0.01 mg/kg IV/IO (repeat every 3-5 min); or
- Atropine 0.02 mg/kg (for increased vagal tone or primary AV block); min 0.1 mg, max 0.5 mg
- Consider transcutaneous pacing
If pulseless arrest develops → Cardiac Arrest Algorithm

Exam pearl: In pediatrics, bradycardia is most commonly due to hypoxia - treat the airway first. Atropine is for vagal causes/AV block, NOT hypoxic bradycardia.

11. PEDIATRIC TACHYCARDIA ALGORITHM

Step 1: Evaluate QRS Duration

Narrow QRS (≤0.09 sec)
Wide QRS (>0.09 sec)

Step 2: Sinus Tachycardia vs SVT (Narrow Complex)

Feature	Sinus Tachycardia	SVT
History	Compatible with known cause (fever, pain, hypovolemia)	Vague, abrupt onset
P waves	Present/normal	Absent or abnormal
R-R interval	Variable	Fixed (non-variable HR)
Rate - Infants	Usually <220/min	Usually ≥220/min
Rate - Children	Usually <180/min	Usually ≥180/min
Treatment	Treat underlying cause	Vagal maneuvers → Adenosine → Cardioversion

SVT Treatment (Narrow Complex)

Vagal maneuvers (ice water to face in infants; Valsalva in older children) - first-line, no delays
Adenosine 0.1 mg/kg rapid IV bolus (max 6 mg); if ineffective → 0.2 mg/kg (max 12 mg)
Synchronized cardioversion 0.5-1 J/kg; if ineffective → 2 J/kg (sedate if possible, do NOT delay)

Wide Complex Tachycardia

Possible VT - evaluate for cardiopulmonary compromise
- With compromise → Synchronized cardioversion
- Without compromise + regular + monomorphic QRS → consider adenosine; consult expert; consider amiodarone or procainamide

Exam pearl - WPW: Avoid adenosine, digoxin, beta-blockers, calcium channel blockers in WPW. Use procainamide (first-line for SVT in WPW) or cardioversion.

12. DEFIBRILLATION & CARDIOVERSION

Intervention	Energy	Notes
Defibrillation (VF/pVT)	1st: 2 J/kg; 2nd: 4 J/kg; subsequent: ≥4 J/kg (max 10 J/kg or adult dose)	Unsynchronized
Synchronized cardioversion (SVT/unstable VT)	0.5-1 J/kg; repeat at 2 J/kg	Synchronize mode ON
AED for children <8 years / <25 kg	Prefer AED with pediatric dose attenuator	Use adult AED if no pediatric attenuator available
AED for children ≥8 years / >25 kg	Standard adult AED

Pad/Paddle placement:

One contact: right of sternum at 2nd intercostal space
Other contact: left midclavicular line at xiphoid level

13. POST-CARDIAC ARREST CARE (ROSC)

Goal	Target
Oxygenation	SpO₂ 94-99%; avoid hyperoxia (FiO₂ titration)
Ventilation	PaCO₂ 35-45 mmHg; avoid hypocapnia
Hemodynamics	MAP ≥5th percentile for age; treat hypotension aggressively
Glucose	Normoglycemia; treat hypo- AND hyperglycemia
Temperature	Targeted Temperature Management (TTM): 32-36°C; avoid fever
12-lead ECG	Obtain immediately to identify ST-elevation MI or arrhythmia
Neurological monitoring	EEG (especially if unresponsive post-arrest)

Exam pearl: Post-ROSC hypotension and hyperoxia are independently associated with worse neurological outcomes and mortality.

14. PEDIATRIC SEPTIC SHOCK

Recognition

Tachycardia + signs of decreased perfusion (delayed cap refill >2s, mottling, altered mental status)
Hypotension is a LATE sign in children (maintained by compensatory tachycardia/vasoconstriction)
"Compensated shock" = shock WITHOUT hypotension - critical to recognize

Management (Golden Hour Bundle)

0-15 min: Obtain IV/IO access; labs (CBC, BMP, lactate, blood culture, glucose); IV/IO fluid bolus
Fluid resuscitation: 10-20 mL/kg NS or LR bolus; titrate to signs of perfusion; reassess after each bolus
Antibiotics: Broad-spectrum IV within 1 hour of recognition
Vasopressors (if fluid-unresponsive): Norepinephrine or epinephrine for fluid-refractory shock
Hydrocortisone: for catecholamine-refractory shock with suspected adrenal insufficiency

Exam pearl: The 2020 Surviving Sepsis Campaign moved AWAY from mandating aggressive fluid resuscitation (no longer 3×20 mL/kg). Reassess after each bolus and stop if signs of fluid overload (crackles, hepatomegaly, worsening O₂).

15. TERMINATION OF RESUSCITATION

Pediatric CPA lasting >20 minutes without ROSC is associated with poor outcome
Exception: Hypothermic arrest - continue until rewarmed ("not dead until warm and dead")
If hypothermia is responsible and cardiac electrical activity is present, continue resuscitation

QUICK REFERENCE: PALS DOSE SUMMARY CARD

Drug	Dose	Route	Max
Epinephrine (arrest)	0.01 mg/kg	IV/IO q3-5 min	1 mg
Epinephrine (ETT)	0.1 mg/kg	ETT	-
Amiodarone (arrest)	5 mg/kg bolus (×3)	IV/IO	-
Lidocaine	1 mg/kg	IV/IO	-
Atropine	0.02 mg/kg	IV/IO	0.5 mg
Adenosine 1st	0.1 mg/kg	IV rapid	6 mg
Adenosine 2nd	0.2 mg/kg	IV rapid	12 mg
Cardioversion	0.5-1 J/kg → 2 J/kg	Synchronized	-
Defibrillation	2 → 4 → ≥4 J/kg	Unsynchronized	10 J/kg
Glucose (D10W)	5 mL/kg	IV/IO	25 g
Ca chloride	20 mg/kg	IV/IO	-
NaHCO₃	1 mEq/kg	IV/IO	-
MgSO₄	25-50 mg/kg	IV/IO	2 g

TOP 10 PALS EXAM TRAPS

C:V ratio = 15:2 (pediatric single/2-rescuer without advanced airway) - NOT 30:2
Minimum atropine dose = 0.1 mg - doses <0.1 mg can cause paradoxical bradycardia
ETT epinephrine dose = 0.1 mg/kg (10× the IV dose)
First defibrillation = 2 J/kg, not 1 or 3 J/kg
Bradycardia + hypoxia in children - treat airway FIRST before medications
CPR starts at HR <60/min with poor perfusion, not just HR <60
Adenosine is ineffective or potentially harmful in WPW - use procainamide
Compression-only CPR is inferior in pediatric asphyxial arrest
Hypotension is a LATE sign of shock in children
Hypothermia = continue resuscitation regardless of duration

Sources: Rosen's Emergency Medicine 9e, Ch. 158; Tintinalli's Emergency Medicine 9e, Ch. 109 - AHA 2020 PALS Guidelines

Stroke syndrome complete guide from Harrison, tintinaali and Rosen's emergency book

Stroke syndrome is a major topic - I'll pull all three textbooks simultaneously for maximum coverage.

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STROKE SYNDROME - Complete Emergency Medicine Guide

Sources: Rosen's Emergency Medicine 9e (Ch. 87), Tintinalli's Emergency Medicine 9e, Harrison's Principles of Internal Medicine 22e

1. EPIDEMIOLOGY & CLASSIFICATION

Type	Frequency	Key Features
Ischemic stroke	~87% of all strokes	Thrombotic, embolic, or lacunar
Intracerebral hemorrhage (ICH)	~10-15%	30-day mortality up to 50%
Subarachnoid hemorrhage (SAH)	~3-5%	"Worst headache of life"

Ischemic stroke subtypes:

Thrombotic (large vessel): ~1/3 of ischemic strokes; atherosclerotic plaque at vessel bifurcations, stenosis >90%
Lacunar (small vessel): Terminal arterioles; basal ganglia, thalamus, pons, internal capsule; strongly linked to hypertension (80-90%) and diabetes; range 2 mm to 2 cm; caused by lipohyalinosis
Cardioembolic: ~1/4 ischemic strokes; AFib = most common mechanism (5× increased risk); mural thrombus, endocarditis, cardiomyopathy
Cryptogenic: >1/3 cases - no clear cause identified

Exam pearl: Atrial fibrillation is the single most common identifiable cause of cardioembolic stroke.

2. PATHOPHYSIOLOGY (Harrison's)

CBF Level	Effect
Normal	40-60 mL/100g brain/min
<15-18 mL/100g/min	Brain becomes electrically silent; neurologic deficit appears; neurons still viable
<10 mL/100g/min	Membrane failure → intracellular Ca²⁺ rise → cell death

Ischemic penumbra: Surrounding at-risk tissue supplied by collaterals - this is the therapeutic target for reperfusion.

ICH injury mechanisms:

Mass effect from hematoma
Coagulation cascade activation
Inflammatory cytokines release
Blood-brain barrier disruption → perihematomal edema
Hematoma expansion (occurs in ~30-40% within first hours)

3. ANATOMY OF STROKE SYNDROMES

Anterior Circulation (80% of brain) - ICA territory

Artery	Territory	Stroke Features
Ophthalmic artery (1st branch of ICA)	Optic nerve, retina	Amaurosis fugax - sudden painless monocular blindness (identifies ipsilateral carotid pathology)
Anterior cerebral artery (ACA)	Medial frontal/parietal lobe	Contralateral leg weakness > arm (leg is cortically represented medially); abulia, personality change
Middle cerebral artery (MCA)	Lateral cortex, lenticulostriate	Contralateral arm/face > leg weakness; contralateral sensory loss; gaze deviation toward lesion; aphasia (dominant); neglect (non-dominant)
Lenticulostriate (MCA branches)	Basal ganglia, internal capsule	Pure motor/sensory lacunar strokes

Posterior Circulation (20% of brain) - Vertebrobasilar territory

Artery	Territory	Stroke Features
Posterior inferior cerebellar artery (PICA)	Lateral medulla, cerebellum	Wallenberg syndrome (lateral medullary syndrome): ipsilateral facial pain/numbness, contralateral body pain/temp loss (crossed pattern), ipsilateral Horner's, dysphagia, dysarthria, ataxia, hiccups
Basilar artery	Pons, midbrain	"Locked-in syndrome" (bilateral pontine infarct): quadriplegia, anarthria, intact cognition, eye movement preserved; "Top of basilar" syndrome
Posterior cerebral artery (PCA)	Occipital lobe, medial temporal	Contralateral homonymous hemianopia with macular sparing; memory loss; thalamic pain
Anterior inferior cerebellar artery (AICA)	Lateral pons, inner ear	Ipsilateral facial palsy, hearing loss, vertigo, contralateral body sensory loss

Classic Lacunar Syndromes

Syndrome	Location	Features
Pure motor hemiplegia	Posterior internal capsule or pons	Motor deficit alone (face + arm + leg) - NO sensory, NO cortical signs
Pure sensory stroke	Thalamus (VPL nucleus)	Sensory deficit alone - NO motor
Ataxic hemiparesis	Pons or internal capsule	Ipsilateral ataxia + contralateral leg weakness
Clumsy hand dysarthria	Pons	Dysarthria + hand clumsiness
Sensorimotor stroke	Thalamus + internal capsule	Motor + sensory combined

Exam pearl - Lacunar vs cortical: Cortical signs (aphasia, hemianopia, neglect, agnosia) are ABSENT in lacunar strokes. Their presence points to large vessel or cortical disease.

4. TRANSIENT ISCHEMIC ATTACK (TIA)

Definition (AHA tissue-based): "A transient episode of neurologic dysfunction caused by focal brain, spinal cord, or retinal ischemia, WITHOUT acute infarction."

Old definition (time-based, now abandoned): symptoms resolve within 24 hours
~240,000 TIAs/year in the United States
10% stroke risk within 3 months of TIA; 50% of those occur within the first 2 days
DWI-negative TIAs have a much lower recurrence risk

ABCD² Score (TIA risk stratification)

Feature	Points
Age ≥60 years	1
BP ≥140/90 on presentation	1
Clinical features: unilateral weakness	2
Clinical features: speech disturbance without weakness	1
Duration ≥60 min	2
Duration 10-59 min	1
Diabetes	1
Total max	7

Score 0-3: Low risk (~1% 2-day stroke risk)
Score 4-5: Moderate risk (~4%)
Score 6-7: High risk (~8%)

5. HEMORRHAGIC STROKE

Intracerebral Hemorrhage (ICH)

Classic presentation: Sudden onset headache + vomiting + severely elevated BP + focal neurologic deficits that progressively worsen (distinguishes from ischemic stroke, which is often maximal at onset).

Most common cause: Hypertensive vasculopathy (lipohyalinosis of small penetrating arteries) + Cerebral amyloid angiopathy (lobar, older patients)

Sites of Hypertensive ICH (Rosen's)

Location	Frequency	Clinical Presentation
Putamen	44%	Contralateral motor/sensory deficit
Thalamus	13%	Limb pain, speech difficulty, eye findings
Cerebellum	9%	Truncal/limb ataxia, vomiting, gait instability
Pons	9%	Pinpoint pupils, quadriplegia, hyperthermia, coma
Other cortical	25%	Variable

Exam pearl: Cerebellar hemorrhage = neurosurgical emergency. Patient can deteriorate rapidly with brainstem compression. Evacuate if deteriorating or hydrocephalus present.

ICH Score (Predicts 30-day mortality)

Feature	Points
GCS 3-4	2
GCS 5-12	1
GCS 13-15	0
ICH volume ≥30 mL	1
Intraventricular hemorrhage	1
Infratentorial origin	1
Age ≥80 years	1

Score 0 = 0% mortality; Score 5+ = ~100% mortality

6. STROKE RECOGNITION & SCALES

FAST Mnemonic (Prehospital)

Face drooping | Arm weakness | Speech difficulty | Time to call 911

Los Angeles Prehospital Stroke Scale (LAPSS)

Criteria: Age >45, no seizure history, new symptoms within 24h, ambulatory at baseline, glucose 60-400, unilateral facial/grip/arm weakness asymmetry.

Cincinnati Prehospital Stroke Scale

Facial droop (asymmetry)
Arm drift (one arm drifts down in 10 seconds)
Abnormal speech (slurred, wrong words, no speech)
Any one = 72% probability of stroke

NIHSS (National Institutes of Health Stroke Scale)

Score	Severity
0	No stroke
1-4	Minor stroke
5-15	Moderate stroke
15-20	Moderate-severe
21-42	Severe stroke

NIHSS Items (11 categories): 1a. Level of consciousness (0-3) 1b. LOC questions (0-2) 1c. LOC commands (0-2) 2. Best gaze (0-2) 3. Visual fields (0-3) 4. Facial palsy (0-3) 5. Motor arm L/R (0-4) 6. Motor leg L/R (0-4) 7. Limb ataxia (0-2) 8. Sensory (0-2) 9. Best language (0-3) 10. Dysarthria (0-2) 11. Extinction/inattention (0-2)

Exam pearl: NIHSS ≥6 with anterior circulation stroke suggests large vessel occlusion (LVO) and may be candidate for mechanical thrombectomy.

7. IMAGING IN STROKE

Non-Contrast CT Head (First-Line)

Available 24/7, fast, rules out hemorrhage - the critical first step
Sensitivity for hemorrhage >95%
Early ischemic changes (within 3-6 hours):
- Hyperdense artery sign - acute thrombus in vessel (hyperdense MCA sign)
- Loss of insular ribbon - loss of gray-white differentiation in insular cortex
- Sulcal effacement - early cerebral edema
- Loss of gray-white interface - basal ganglia obscuration
- Acute hypodensity - appears by 6-12 hours

Early CT changes in MCA stroke - (A) loss of gray-white interface at 2h50m; (B) acute hypodensity at 8h

CT Angiography (CTA)

Identifies large vessel occlusion (LVO) - required for thrombectomy planning
Can be obtained concurrently with non-contrast CT
Identifies dissection, stenosis, aneurysm, AVM

CT Perfusion (CTP)

Used for extended time windows (6-24h)
Identifies penumbra (salvageable tissue) vs core infarct
Generally not needed in first 6 hours if tPA criteria met

MRI/DWI-FLAIR

DWI (diffusion-weighted): shows acute infarction within minutes - most sensitive
FLAIR: negative within ~4.5h of onset
DWI-FLAIR mismatch = acute infarct on DWI but NOT on FLAIR → indicates stroke occurred within ~4.5 hours → supports tPA in wake-up strokes (WAKE-UP trial)

8. STROKE TIME GOALS (NINDS Targets)

Milestone	Target Time
Door to physician	10 minutes
Door to CT completion	25 minutes
Door to CT read	45 minutes
Door to treatment (tPA)	60 minutes
Access to neurology	15 minutes
Access to neurosurgery	2 hours

9. THROMBOLYTIC THERAPY (IV tPA)

Agents

Agent	Dose	Administration
Alteplase (first-line, FDA approved)	0.9 mg/kg (max 90 mg)	10% as IV bolus over 1 min; remaining 90% over 60 min
Tenecteplase (alternative, AHA 2022)	0.25 mg/kg (max 25 mg)	Single IV bolus - simpler to administer; preferred if thrombectomy planned

Time Windows for IV tPA (2019 AHA/ASA)

Window	Criteria
0-3 hours	Standard eligibility (broadest indication)
3-4.5 hours	Additional exclusions apply (see below)
4.5-9 hours	With CT perfusion mismatch (EXTEND trial)
Wake-up / unknown onset	DWI-FLAIR mismatch on MRI (WAKE-UP trial)

2019 AHA/ASA Eligibility for IV Alteplase

RECOMMENDED (within 3 hours):

Ischemic stroke with measurable neurological deficit
Age ≥18 years
Onset ≤3 hours

ADDITIONAL EXCLUSIONS for 3-4.5 hour window:

Age >80 years (relative)
NIHSS >25 (severe stroke)
Oral anticoagulant use regardless of INR
History of both prior stroke AND diabetes

ABSOLUTE CONTRAINDICATIONS:

Any ICH on CT
SBP >185 or DBP >110 (unless treated to below threshold before tPA)
Active internal bleeding
Recent cranial surgery/serious head trauma/prior stroke within 3 months
History of intracranial hemorrhage
Platelet count <100,000
Heparin within 48h with elevated aPTT
INR >1.7
Blood glucose <50 mg/dL
CT shows >1/3 MCA territory hypodensity
DOAC use within 48 hours (unless labs normal)

Symptomatic ICH after tPA

Risk: 2-7% overall; highest with most severe strokes
Usually occurs within 5-10 hours after infusion; very unlikely after 36 hours
If suspected: STOP tPA infusion immediately
Labs: fibrinogen, PT/INR, aPTT, CBC, type & crossmatch
Treat: Cryoprecipitate 10 units IV (target fibrinogen ≥150 mg/dL)
Neurosurgical consultation

10. BLOOD PRESSURE MANAGEMENT IN STROKE

Ischemic Stroke (Without tPA)

Scenario	BP Target	Agents
Not a tPA candidate	Withhold treatment unless SBP >220 or DBP >120 or MAP >130	Labetalol, nicardipine
Specific indications (MI, aortic dissection, HHE, LV failure)	Lower BP carefully	Individualize

Rationale: BP is auto-regulated and often elevated to maintain penumbral perfusion. Aggressive lowering can extend infarct.

Pre-tPA / Pre-thrombectomy BP Target

SBP ≤185 / DBP ≤110 before administration
Agents: Labetalol 10-20 mg IV over 1-2 min; or Nicardipine 5 mg/h IV (titrate to max 15 mg/h); or Clevidipine 1-2 mg/h IV

Post-tPA (First 24 hours)

Maintain BP <180/105 mmHg aggressively - risk of hemorrhagic transformation

Hemorrhagic Stroke (ICH) BP Management

Target SBP <140 mmHg within 1 hour (INTERACT2, ATACH-2 trials)
Reduces hematoma expansion
Use: Labetalol, nicardipine, clevidipine IV

Hypotension in Stroke

Low BP worsens ischemic stroke (decreased CPP)
Treat with fluid bolus; vasopressors if needed
Goal: maintain MAP appropriate to support cerebral perfusion

11. MECHANICAL THROMBECTOMY (Endovascular)

Indication: Acute ischemic stroke + anterior circulation large vessel occlusion (LVO) + presentation within 24 hours

Criteria (2018 AHA/ASA)

NIHSS ≥6
Prestroke mRS 0-1 (independent baseline function)
ICA or MCA M1 occlusion on CTA
Age ≥18 years
CT: ASPECTS ≥6 (Alberta Stroke Program Early CT Score - assesses early ischemic changes)

Time Windows

0-6 hours: Standard window, CT-based selection
6-16 hours: DAWN/DEFUSE 3 trials - CT perfusion mismatch required
6-24 hours: DAWN trial selection criteria

Exam pearl: Tenecteplase is preferred over alteplase when thrombectomy is planned because it is a single bolus (simpler, faster) and showed higher reperfusion rates (EXTEND-IA TNK trial).

12. ICH MANAGEMENT

Reversal of Anticoagulation in ICH

Anticoagulant	Reversal Agent
Warfarin (elevated INR)	Vitamin K 10 mg IV + 4-factor PCC (KCentra) - FASTER than FFP
Dabigatran (direct thrombin inhibitor)	Idarucizumab (Praxbind) - specific reversal agent
Rivaroxaban/Apixaban (factor Xa inhibitors)	Andexanet alfa (Andexxa)
Heparin	Protamine sulfate
t-PA induced ICH	Cryoprecipitate 10 units IV (target fibrinogen ≥150 mg/dL)

ICH General Management

Airway protection (GCS ≤8 or loss of protective reflexes → intubate)
BP target SBP <140 mmHg
Reverse anticoagulation urgently
Seizures: Treat if clinical or EEG evidence; No prophylactic anticonvulsants
ICP management: EVD if hydrocephalus + decreased LOC; mannitol or 3-23.4% hypertonic saline; target CPP 50-70 mmHg
Hyperglycemia and hypoglycemia both worsen outcomes - target normoglycemia
Fever (>38°C): identify source, antipyretics, avoid hyperthermia
DNR decisions: Defer new DNR orders until at least the 2nd full day (early DNR orders worsen prognosis due to self-fulfilling prophecy)

Surgical Indications in ICH

Cerebellar hemorrhage ≥3 cm or neurologic deterioration OR brainstem compression OR hydrocephalus → emergent surgical evacuation
Supratentorial ICH: generally not beneficial for surgery (STICH trials); consider in young patients with lobar hemorrhage <1 cm from surface
Hydrocephalus + decreased LOC → external ventricular drain (EVD)

13. SUBARACHNOID HEMORRHAGE (SAH)

Classic presentation: "Thunderclap headache" - sudden onset, worst headache of life (10/10), peaks within seconds to minutes; may be associated with brief LOC, meningismus, photophobia.

Hunt and Hess Grade (clinical)

Grade	Description	Mortality
1	Asymptomatic or mild headache, slight nuchal rigidity	<5%
2	Moderate to severe headache, nuchal rigidity, no neurological deficit except CN palsy	10%
3	Drowsiness, confusion, or mild focal deficit	30%
4	Stupor, moderate to severe hemiparesis	50%
5	Deep coma, decerebrate posturing, moribund	>80%

Diagnosis

Non-contrast CT head: Sensitivity ~98% within first 6 hours (decreases over time)
Lumbar puncture: If CT negative but clinical suspicion high - xanthochromia (yellow CSF from bilirubin) or > 2000 RBCs non-clearing across tubes
CT angiography or cerebral angiography: identifies causative aneurysm

Management

Secure the aneurysm (coiling preferred over clipping per ISAT trial)
Nimodipine 60 mg PO every 4 hours × 21 days (reduces vasospasm, improves neurological outcome)
Euvolemia (not hypervolemia)
Treat vasospasm: transcranial Doppler monitoring; induced hypertension/hypervolemia if symptomatic
Avoid fever, hypoxia, hypotension

14. STROKE MIMICS (Differential Diagnosis)

Mimic	Key Differentiating Feature
Hypoglycemia	Most common mimic; check glucose immediately; can cause sustained focal deficits lasting days
Todd's paralysis (post-ictal)	History of witnessed seizure
Complex migraine	Focal deficits with or without headache; young patient; prior migraines
Wernicke encephalopathy	Ophthalmoplegia + ataxia + confusion; mimics cerebellar/brainstem stroke; thiamine deficiency
Bell's palsy	LMN facial weakness (forehead involved); no other deficits
Subdural/epidural hematoma	Trauma history; progressive course; elder on anticoagulants
Brain tumor/abscess	Subacute onset; fever (abscess); history of malignancy
Air embolism	Scuba diving, iatrogenic; atmospheric pressure change
Hypertensive encephalopathy	Diffuse symptoms, papilledema; BP usually >200/130
Ménière disease	Episodic vertigo + tinnitus + hearing loss - mimics posterior circulation stroke
Giant cell arteritis	Elder; severe headache + ESR elevated; can cause visual symptoms and rarely aphasia/hemiparesis

Exam pearl: Check glucose on EVERY patient with suspected stroke. Hypoglycemia is the most treatable mimic and can be immediately fatal if missed.

15. STROKE MIMICS vs STROKE - KEY CT FINDINGS

Finding	Significance
Hyperdense MCA sign	Acute thrombus in MCA = large vessel occlusion
Subarachnoid hyperdensity (star pattern)	SAH
Intraparenchymal hyperdensity	ICH
Loss of insular ribbon	Early MCA territory ischemia
Hypodensity <1/3 MCA territory	Early infarct, tPA still appropriate
Hypodensity >1/3 MCA territory	Extensive infarct, increased ICH risk with tPA

16. SECONDARY STROKE PREVENTION

Antiplatelet Therapy

Aspirin 325 mg within 24-48 hours of ischemic stroke (not within 24h of tPA)
Aspirin + clopidogrel (DAPT): For minor stroke (NIHSS ≤3) or high-risk TIA (ABCD² ≥4) - given for 21 days (POINT/CHANCE trials)

Anticoagulation

Atrial fibrillation: Start oral anticoagulation within 4-14 days of ischemic stroke (depends on infarct size/hemorrhagic risk)
DOAC preferred over warfarin for nonvalvular AFib
Warfarin target INR 2.0-3.0 for mechanical valves

BP Control

Target <130/80 mmHg for secondary prevention

Statin Therapy

High-intensity statin (atorvastatin 40-80 mg) for all ischemic stroke/TIA patients

Carotid Disease

Symptomatic stenosis 50-99%: Carotid endarterectomy (CEA) within 2 weeks (greatest benefit)
Asymptomatic stenosis >60-70%: CEA or medical management depending on center expertise

17. QUICK REFERENCE: STROKE DRUG DOSES

Drug	Indication	Dose
Alteplase (tPA)	Ischemic stroke ≤4.5h	0.9 mg/kg (max 90 mg); 10% bolus, 90% over 60 min
Tenecteplase	Ischemic stroke ≤4.5h or pre-thrombectomy	0.25 mg/kg (max 25 mg) single IV bolus
Labetalol	BP lowering pre/post-tPA	10-20 mg IV over 1-2 min; repeat q10 min; max 300 mg
Nicardipine	BP lowering	5 mg/h IV; titrate by 2.5 mg/h q5-15 min; max 15 mg/h
Clevidipine	BP lowering	1-2 mg/h IV; double every 2-5 min; max 21 mg/h
Nimodipine	SAH vasospasm prevention	60 mg PO q4h × 21 days
Mannitol	Elevated ICP/cerebral edema	0.25-1 g/kg IV bolus
3% NaCl (HTS)	Elevated ICP/cerebral edema	Continuous infusion; target Na 145-155 mEq/L
4-factor PCC	Warfarin reversal in ICH	25-50 units/kg IV based on INR
Idarucizumab	Dabigatran reversal	5 g IV (two 2.5 g doses)
Cryoprecipitate	tPA-induced ICH	10 units IV over 10-30 min
Aspirin	Secondary prevention	325 mg (initial); 81 mg (maintenance)
Levetiracetam	Post-ICH seizures	1000-1500 mg IV

18. TOP EXAM TRAPS IN STROKE

Never start tPA if BP >185/110 - treat BP first, then reassess eligibility
Glucose check is mandatory before calling stroke - hypoglycemia is the #1 mimic
"Last known well" time, not "found" time determines tPA eligibility
Amaurosis fugax = ipsilateral carotid disease (ophthalmic artery is first ICA branch)
Cerebellar ICH = neurosurgical emergency - can herniate rapidly
Crossed findings = posterior circulation/brainstem (ipsilateral face + contralateral body)
Lacunar stroke = no cortical signs (no aphasia, no hemianopia, no neglect)
CT negative + thunderclap headache = LP for xanthochromia (SAH)
Do NOT lower BP aggressively in ischemic stroke without tPA - auto-regulation is impaired
Post-ICH DNR: defer until Day 2 - early withdrawal is associated with worse outcomes
Tenecteplase preferred if thrombectomy planned (single bolus, EXTEND-IA TNK)
DWI-FLAIR mismatch allows tPA in wake-up strokes

*Sources: Rosen's Emergency Medicine 9e Ch. 87 (Stroke), Tintinalli's Emergency Medicine 9e Ch. 109, Harrison's Principles of Internal Medicine 22e; AHA/ASA Guidelines 2019 (Ischemic Stroke), 2015 (ICH)*Here's a summary of what's covered in this complete guide:

What's Covered (18 Sections)

The guide integrates content from Rosen's Emergency Medicine 9e (Ch. 87), Tintinalli's Emergency Medicine 9e, and Harrison's Principles of Internal Medicine 22e, organized in exam-focused format:

Epidemiology - stroke types and frequencies
Pathophysiology - CBF thresholds, penumbra, ICH injury mechanisms
Anatomy of stroke syndromes - anterior/posterior circulation, lacunar syndromes with full tables (including Wallenberg, locked-in, ACA/MCA/PCA territories)
TIA - tissue-based definition, ABCD² score, risk stratification
Hemorrhagic stroke - ICH sites and frequencies, clinical presentations, ICH Score
Stroke recognition scales - FAST, LAPSS, Cincinnati, full NIHSS with scoring
Imaging - CT findings (hyperdense MCA, insular ribbon, etc.), CT with actual case images, CTA, CTP, DWI-FLAIR mismatch
Time goals - NINDS door-to-needle targets
IV thrombolysis - alteplase vs tenecteplase, time windows, full inclusion/exclusion criteria, sICH management
BP management - separate targets for ischemic/pre-tPA/post-tPA/ICH
Mechanical thrombectomy - LVO criteria, DAWN/DEFUSE3 extended windows
ICH management - anticoagulation reversal, surgical indications, ICP management
SAH - Hunt-Hess grade, diagnosis, nimodipine
Stroke mimics - 10+ conditions with differentiating features
CT findings table
Secondary prevention - antiplatelet, anticoagulation, statins, carotid surgery
Drug doses quick reference card
Top 12 exam traps

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