Antiepileptics

Antiseizure Medications (ASMs) – Quick Reference

• Dropdowns by class • Concise dosing & adjustments • Minimal inline styles.
• For clinical use, confirm in a trusted reference (e.g., labels/UpToDate/lexicomp) and patient specifics.

Voltage-Gated Sodium Channel Blockers

Drug (Brand)	Typical Adult Dose Range	Renal/Hepatic Adjustments	Key Interactions / Notes
Eslicarbazepine (Aptiom)	800–1600 mg PO daily (once daily). Titrate by 400–600 mg weekly.	CrCl <50 mL/min ↓ dose; severe hepatic impairment: caution (limited data).	↓ Hormonal contraceptives; additive hyponatremia with oxcarb/carb; induces UGT/CYP3A.
Carbamazepine (Tegretol)	800–1200 mg/day PO divided (ER often BID). Target by levels/response.	Hepatic disease: caution/avoid severe; autoinduction; no renal adj. typically.	Strong CYP3A4 inducer (↓ many drugs incl. OCPs, DOACs); ↑ by inhibitors (macrolides, azoles). HLA-B*1502 risk (SJS/TEN).
Oxcarbazepine (Trileptal)	600–2400 mg/day PO divided BID (ER once daily).	CrCl <30 mL/min: start 300 mg/day, slow titration. Hepatic: no adjustment (mild–mod).	↓ OCPs; less enzyme induction vs CBZ; hyponatremia common—monitor Na.
Phenytoin / Fosphenytoin	Phenytoin 300–400 mg/day PO (qHS or divided); individualized by levels (nonlinear).	Hypoalbuminemia/renal failure alter free levels; hepatic disease ↓ clearance.	CYP inducer; many DDIs (warfarin, OCPs, azoles). Monitor levels; long-term AEs.
Lamotrigine (Lamictal)	Maintenance ~100–400 mg/day (divided or once daily ER); titration depends on VPA/inducers.	Hepatic impairment: ↓ dose; renal failure: consider ↓ (metabolites).	↑ by valproate (halve/quarter dose); ↓ by enzyme inducers; rash risk—slow titration.
Lacosamide (Vimpat)	200–400 mg/day PO/IV divided BID (or once-daily ER).	CrCl ≤30 mL/min or mod–severe hepatic: max 300 mg/day; avoid severe hepatic.	PR prolongation/arrhythmias; additive with other Na+ blockers.
Rufinamide (Banzel)	800–3200 mg/day divided BID (take with food).	Hepatic impairment: ↓ dose; no renal adj. usually.	↓ by enzyme inducers; may ↓ OCPs; QT shortening (caution in short-QT).

Calcium Channel Modulators

Drug (Brand)	Typical Adult Dose Range	Renal/Hepatic Adjustments	Key Interactions / Notes
Ethosuximide (Zarontin)	500–1500 mg/day PO divided (q12h typical).	Hepatic & renal clearance: caution/monitor in impairment.	Few DDIs; GI upset common; first-line absence seizures.
Zonisamide (Zonegran)	200–400 mg/day PO (once daily or divided); max 600 mg/day.	Avoid severe renal (CrCl <50) or severe hepatic impairment.	Sulfonamide; CA inhibition → stones, metabolic acidosis; oligohidrosis/heat risk.
Gabapentin (Neurontin)	900–3600 mg/day PO divided TID (titrate by response).	Renal: dose by CrCl; no hepatic adj.	Minimal DDIs; sedation/ataxia; absorption saturable—TID dosing.
Pregabalin (Lyrica)	150–600 mg/day PO divided BID/TID.	Renal: dose by CrCl; no hepatic adj.	Edema/weight gain; euphoria/misuse potential; minimal DDIs.

GABAergic Agents

Drug (Brand)	Typical Adult Dose Range	Renal/Hepatic Adjustments	Key Interactions / Notes
Benzodiazepines (e.g., Clobazam)	Clobazam 10–40 mg/day (divided). (Diazepam/lorazepam/midazolam: per acute/status protocols.)	Hepatic dysfunction: ↓ dose; elderly: ↓ dose.	Additive CNS depression (opioids, alcohol); tolerance/dependence; CYP2C19 interactions (clobazam).
Phenobarbital / Primidone	Phenobarbital 60–200 mg/day (qHS common); primidone 750–1500 mg/day divided.	Hepatic impairment: avoid/severe caution; renal: adjust (PB is renally cleared partly).	Strong enzyme inducer; sedation/cognitive effects; bone health issues.
Tiagabine (Gabitril)	16–56 mg/day divided (BID–QID), titrate slowly.	Hepatic impairment: ↓ dose; no renal adj.	Enzyme inducers may ↓ levels; risk of non-epileptic seizures in nonepileptics.
Vigabatrin (Sabril)	1000–3000 mg/day divided BID.	Renal: ↓ dose; no hepatic adj.	Irreversible GABA-T inhibitor; permanent visual field loss risk (REMS).

Glutamate Receptor Antagonists / Modulators

Drug (Brand)	Typical Adult Dose Range	Renal/Hepatic Adjustments	Key Interactions / Notes
Perampanel (Fycompa)	4–12 mg PO nightly (titrate by 2 mg weekly).	Mod hepatic: max 8 mg; avoid severe hepatic; avoid severe renal.	Enzyme inducers ↓ levels; behavioral AEs (aggression, irritability).
Felbamate (Felbatol)	1200–3600 mg/day divided TID–QID.	Avoid in hepatic dysfunction; monitor LFTs; adjust in renal impairment.	Aplastic anemia/hepatotoxicity risk; CYP interactions (↑ phenytoin/VPA; ↓ CBZ).
Topiramate (Topamax)	100–400 mg/day divided BID (or once-daily ER).	CrCl <70: ↓ dose/slow titration; hepatic impairment: caution.	↓ OCPs ≥200 mg/day; CA inhibition → stones, metabolic acidosis; weight loss/cognitive effects.

Synaptic Vesicle Protein 2A (SV2A) Ligands

Drug (Brand)	Typical Adult Dose Range	Renal/Hepatic Adjustments	Key Interactions / Notes
Levetiracetam (Keppra)	1000–3000 mg/day divided BID (XR once daily).	Renal: dose by CrCl; no hepatic adj. typically.	Minimal DDIs; behavioral changes in some (irritability).
Brivaracetam (Briviact)	50–200 mg/day divided BID (or once-daily XR).	Severe hepatic impairment: ↓ dose; no renal adj. (non-dialyzable largely).	Fewer behavioral AEs vs LEV; minor CYP2C19 interactions.

Carbonic Anhydrase Inhibitors

Drug (Brand)	Typical Adult Dose Range	Renal/Hepatic Adjustments	Key Interactions / Notes
Acetazolamide (Diamox)	250–1000 mg/day divided BID–QID (intermittent use typical for epilepsy).	Renal: ↓ dose/avoid severe; hepatic disease: avoid (risk of encephalopathy).	Metabolic acidosis, hypokalemia; caution with salicylates; sulfonamide cross-reactivity.
Topiramate (Topamax)	See above (100–400 mg/day; ER once daily possible).	CrCl <70: ↓ dose; hepatic: caution.	↓ OCPs ≥200 mg/day; stones, acidosis; cognitive effects, weight loss.
Zonisamide (Zonegran)	See above (200–400 mg/day; max 600 mg/day).	Avoid severe renal/hepatic impairment.	Stones, acidosis; oligohidrosis/heat; sulfonamide allergy caution.

Broad / Mixed Mechanisms

Drug (Brand)	Typical Adult Dose Range	Renal/Hepatic Adjustments	Key Interactions / Notes
Valproate / Divalproex (Depakote)	500–3000 mg/day divided BID/TID or ER daily; target by levels/response.	Hepatic disease: contraindicated/severe caution; thrombocytopenia risk; renal: no routine adj.	↑ lamotrigine levels (halve/quarter LTG); teratogenic; weight gain, tremor; UGT inhibitor.
Topiramate (Topamax)	100–400 mg/day (see above).	CrCl <70 ↓; hepatic caution.	↓ OCPs; CA inhibition; migraine prevention dual use.
Zonisamide (Zonegran)	200–400 mg/day (see above).	Avoid severe renal/hepatic impairment.	Mixed mechanism; heat/stones/acidosis cautions.
Lamotrigine (Lamictal)	100–400 mg/day (see above; titration crucial).	↓ dose w/ hepatic impairment; consider ↓ in renal failure.	DDI with VPA (↑), inducers (↓); rash risk—educate patient.
Cenobamate (Xcopri)	Maintenance 200 mg/day (100–400 mg/day range) after very slow titration.	Hepatic impairment: ↓ dose; renal impairment: caution/↓ dose.	↑ GABAA, ↓ persistent Na+ current; DRESS—slow titration; induces CYP3A4, inhibits CYP2C19 (↑ phenytoin/phenobarb).

Other / Unique Mechanisms

Drug (Brand)	Typical Adult Dose Range	Renal/Hepatic Adjustments	Key Interactions / Notes
Cannabidiol (Epidiolex)	Up to 10–20 mg/kg/day divided BID (FDA-labeled syndromes).	Hepatic impairment: ↓ dose; monitor LFTs.	↑ by CYP2C19/3A inhibitors; ↑ clobazam metabolite (sedation); monitor transaminases esp. w/ VPA.
Everolimus (Afinitor)	TSC-associated seizures: 5–10 mg/m²/day (target trough 5–15 ng/mL).	Hepatic impairment: ↓ dose; renal: none typically.	CYP3A4/P-gp substrate—many DDIs (azoles/macrolides); stomatitis, hyperlipidemia, immunosuppression.

Quick ID: Eslicarbazepine = Na⁺ blocker (slow inactivation). Zonisamide = mixed (Na⁺ + T-type Ca²⁺ + carbonic anhydrase inhibition).
Always consider formulation (IR vs ER), titration speed, age, comorbidities, pregnancy, enzyme-inducer status, and seizure type.

Hypotension during Hemodialysis

Intradialytic Hypotension and Reactions – Crash Card (Adult HD)

P1: Rapid actions and differentiation | P2: Algorithms | P3: Expanded dosing

Immediate Steps (seconds to 1 minute)

• - Set ultrafiltration (UF) rate to 0 mL/hr; keep dialysis running to prevent circuit clotting.
• - Lay supine/Trendelenburg; apply O2; give 100 to 200 mL IV normal saline; reassess and repeat as needed.
• - Check rhythm, symptoms, access and lines, machine alarms.
• - If still unstable after one small bolus: begin vasopressor (norepinephrine infusion).

How To Tell What Is Happening (chairside cues)

Anaphylaxis (dialyzer or drug)

• - Onset: within first 5 to 20 minutes of run or immediately after exposure.
• - Skin/airway: pruritus, hives, flushing, angioedema, wheeze or stridor, hypotension.
• - Action: STOP dialysis; DO NOT return blood; treat with IM epinephrine.

Hemolysis (machine, water, or line problem)

• - Symptoms: back, chest, or abdominal pain; nausea; dyspnea; headache.
• - May see "port-wine" blood in venous line or pink plasma; hyperkalemia risk.
• - Action: STOP dialysis; CLAMP; DO NOT return blood; check K+, LDH, plasma-free Hgb; manage hyperkalemia.

Typical IDH (volume or UF related)

• - Lightheadedness, cramps, nausea without allergic features; improves with UF off plus small saline bolus.
• - Action: Continue dialysis with UF off; lengthen session; consider cool dialysate (35 to 36 C).

When To Terminate The Run

• - Persistently unstable despite UF off plus fluids with or without pressor.
• - Suspected anaphylaxis, hemolysis, major blood leak, air embolus, or dialyzer reaction.
• - If stopping: RINSE-BACK blood unless reaction, hemolysis, or contamination is suspected; in those cases DO NOT return blood.

Pressor Quick Reference (for crash hypotension)

• - Norepinephrine infusion (first-line): start about 0.05 to 0.1 mcg/kg/min (or 5 to 15 mcg/min) and titrate to MAP 65 or higher.
• - Phenylephrine push-dose bridge while starting norepi: 50 to 200 mcg IV bolus; may repeat every 1 to 3 minutes as needed.
• - Avoid push-dose epinephrine unless experienced and protocols allow; prefer norepinephrine infusion for vasodilatory shock.

Suspected Anaphylaxis On Dialysis - Action Plan

1. Stop dialysis immediately. DO NOT return circuit blood. Call for help.
2. Position supine; high-flow O2; large-bore IV or IO; continuous monitor.
3. EPINEPHRINE (first-line): IM 0.3 to 0.5 mg (1 mg/mL) into lateral thigh; repeat every 5 to 10 minutes if needed. If refractory or impending collapse: start IV epinephrine infusion 0.05 to 0.1 mcg/kg/min and titrate (typical range 0.05 to 0.5 mcg/kg/min).
4. Rapid IV fluids: 1 to 2 liters normal saline as tolerated.
5. Adjuncts (after epinephrine): diphenhydramine 25 to 50 mg IV; famotidine 20 mg IV; methylprednisolone 125 mg IV; albuterol nebulizer for wheeze.
6. If on beta-blocker and poor response: glucagon 1 to 5 mg IV over 5 minutes, then 5 to 15 mcg/min infusion.
7. Investigate trigger (dialyzer membrane or sterilant, medication). Document and switch to alternative membrane next session; consider premedication per nephrology or allergy.

Suspected Hemolysis - Action Plan

1. Stop dialysis; CLAMP lines. DO NOT return circuit blood.
2. Draw STAT labs: K+, hemoglobin/hematocrit, LDH, plasma-free hemoglobin, haptoglobin, bilirubin; type and screen.
3. ECG and treat hyperkalemia per protocol (for example: calcium, insulin with dextrose, beta-agonist) and support ABCs.
4. Notify biomedical and water treatment immediately; check dialysate temperature or mixture, chloramine or copper, tubing kinks, blood leak.
5. Stabilize, then arrange monitored re-dialysis when safe; replace implicated components.

Default IDH Pathway (no reaction or hemolysis)

• - UF off -> 100 to 200 mL NS -> reassess.
• - Keep dialysis running (lower blood flow if needed); consider cool dialysate (35 to 36 C).
• - Resume at lower UF or extend time once stable; review antihypertensive timing and interdialytic weight gain.

Bradycardia Plus Hypotension (add-on)

• - If symptomatic bradycardia with hypotension: give ATROPINE 1 mg IV push; repeat every 3 to 5 minutes to a maximum total dose of 3 mg.
• - If atropine ineffective or high-degree AV block: begin transcutaneous pacing without delay.
• - Consider EPINEPHRINE infusion 2 to 10 mcg/min or DOPAMINE infusion 5 to 20 mcg/kg/min while arranging pacing and treating the cause.
• - Phenylephrine may worsen bradycardia; prefer norepinephrine or epinephrine when vasopressor support is needed in bradycardic patients.

Notes

• - DO NOT return blood if anaphylaxis, hemolysis, major leak, or contamination is suspected.
• - Document the event; flag the chart; arrange allergy and nephrology follow-up; change dialyzer or membrane as advised.
• - Units: keep premixed norepinephrine available; standardize phenylephrine push-dose concentration; educate on recognition signs.

Medication Dosing - Expanded (Adults)

Epinephrine (anaphylaxis)

• - IM: 0.3 to 0.5 mg (1 mg/mL) into lateral thigh; repeat every 5 to 10 minutes as needed.
• - IV infusion for refractory anaphylaxis: start 0.05 to 0.1 mcg/kg/min; usual range 0.05 to 0.5 mcg/kg/min; titrate to perfusion.
• - Avoid IV push in anaphylaxis unless in cardiac arrest.

Norepinephrine (first-line for vasodilatory shock)

• - Start 0.05 to 0.1 mcg/kg/min or 5 to 15 mcg/min; titrate to MAP 65 or higher.
• - Peripheral start is acceptable if needed; monitor for extravasation.

Phenylephrine

• - Push-dose: 50 to 200 mcg IV bolus; may repeat every 1 to 3 minutes as needed.
• - Infusion: 0.5 to 2 mcg/kg/min; avoid as sole agent in bradycardia.

Atropine (symptomatic bradycardia)

• - 1 mg IV push; repeat every 3 to 5 minutes to a maximum total dose of 3 mg.

Epinephrine (bradycardic hypotension when pacing not yet available)

• - IV infusion 2 to 10 mcg/min; titrate to perfusion.

Dopamine (alternative for bradycardia with hypotension)

• - 5 to 20 mcg/kg/min IV infusion; titrate; avoid in tachyarrhythmias.

Glucagon (beta-blocker associated anaphylaxis)

• - 1 to 5 mg IV over 5 minutes, then 5 to 15 mcg/min infusion; titrate to effect.

Anaphylaxis adjuncts

• - Diphenhydramine 25 to 50 mg IV.
• - Famotidine 20 mg IV.
• - Methylprednisolone 125 mg IV.
• - Albuterol nebulizer 2.5 to 5 mg; may repeat.

Hyperkalemia rescue (if hemolysis suspected)

• - Calcium gluconate 1 g IV over 5 to 10 minutes (may repeat). If central access, calcium chloride 1 g IV.
• - Insulin regular 10 units IV + dextrose 25 g IV; monitor glucose.
• - Nebulized albuterol 10 to 20 mg (for K+ shift); consider sodium bicarbonate 50 mEq IV if acidotic.
• - Re-dialysis urgently once stabilized.

This content is for trained clinicians and does not replace local protocols or clinical judgment.

PHTN2

Pulmonary Hypertension by Echo - ASE 2025 + ESC/ERS 2022

Screening (ASE 2025): TRV >= 2.9 m/s suggests PH; or TRV >= 2.8 m/s with at least 2 adjunctive echo signs suggests PH. Adjunctive signs include RV enlargement, abnormal LV eccentricity index (>1.1), mid-systolic notching or short AccT, PR end-diastolic velocity >2.2 m/s, and signs of elevated RAP (IVC >2.1 cm or RA area >18 cm2). When TR jet is adequate, RVSP = 4*TRV^2 + RAP.

Required inputs

TR jet adequate for RVSP reporting? Yes No or poor signal

Peak TR velocity (m/s)

RAP estimate (mmHg) (3, 8, or 15 typical)

Adjunctive signs (check all present)

RV enlargement (Category A) LV eccentricity index > 1.1 (Category A) Mid-systolic notching or short AccT (Category B) PR end-diastolic velocity > 2.2 m/s (Category B) Elevated RAP sign: IVC > 2.1 cm or RA area > 18 cm2 (Category C)

ESC/ERS 2022 probability uses categories A/B/C. Signs from at least 2 categories are needed to modify probability.

Optional advanced inputs (AccT, RVOT VTI, mPAP and PVR)

RVOT Acceleration Time (ms)

RVOT VTI (cm)

Early PR velocity (m/s) (optional mPAP)

v1.1 Updated 2025-08-21 - Now includes ESC/ERS 2022 echo probability. ASCII-only text to avoid HTML entities.

Status Epilepticus -2 ( dosing /contraindications)

IV Antiepileptic Drugs – Status Epilepticus (ICU Reference)

Lorazepam

• Bolus: 0.1 mg/kg IV (max 4 mg/dose); may repeat once in 10–15 min
• Maintenance: Not used for continuous infusion in SE
• Contraindications: Severe respiratory depression, hypotension, caution elderly
• Notes: Preferred benzodiazepine for SE

Diazepam

• Bolus: 0.15–0.2 mg/kg IV (max 10 mg/dose); may repeat once
• Maintenance: Not ideal; bridge to longer AED
• Contraindications: Respiratory depression, hepatic impairment

Midazolam (⚠ sedation differs)

• Bolus (SE): 0.2 mg/kg IV over 2 min (max 10 mg)
• Maintenance (SE): 0.05–2 mg/kg/hr continuous infusion
• Sedation (ICU): 0.02–0.2 mg/kg/hr (much lower)
• Contraindications: Hypotension, respiratory depression

Propofol (⚠ sedation differs)

• Bolus (SE): 1–2 mg/kg IV
• Maintenance (SE): 2–10 mg/kg/hr continuous infusion
• Sedation (ICU): 0.3–5 mg/kg/hr (5–80 mcg/kg/min)
• Contraindications: Hemodynamic instability, egg/soy allergy, PRIS risk >4 mg/kg/hr >48h

Ketamine (⚠ sedation differs)

• Bolus (SE/RSE): 0.5–2 mg/kg IV (may repeat to a total of ~3 mg/kg as needed)
• Maintenance (SE/RSE): 1–5 mg/kg/hr continuous infusion; titrate to seizure control/EEG goals
• Sedation/Analgesia (ICU ⚠): 0.05–0.4 mg/kg/hr (≈0.8–6.7 mcg/kg/min); optional small bolus 0.1–0.5 mg/kg for breakthrough discomfort
• Contraindications/Cautions: Uncontrolled hypertension; tachyarrhythmias; decompensated CAD or aortic disease; severe hepatic dysfunction; history of psychosis; elevated intracranial/intraocular pressure (relative/controversial); pregnancy (relative). Can ↑ BP/HR (in catecholamine-depleted shock may cause hypotension).
• Notes: NMDA antagonist useful in refractory SE; bronchodilatory; tends to preserve respiratory drive.

Pentobarbital

• Bolus: 5–15 mg/kg IV over 1 hr
• Maintenance: 0.5–5 mg/kg/hr (EEG guided)
• Contraindications: Hypotension, respiratory depression, porphyria

Thiopental

• Bolus: 3–5 mg/kg IV
• Maintenance: 3–5 mg/kg/hr
• Contraindications: Same as pentobarbital

Valproic Acid

• Bolus: 20–40 mg/kg IV over 5–10 min (max 3 g)
• Maintenance: 1–6 mg/kg/hr infusion or 15–60 mg/kg/day divided
• Contraindications: Hepatic failure, POLG mutation, pregnancy (relative)

Levetiracetam

• Bolus: 60 mg/kg IV over 15 min (max 4.5 g)
• Maintenance: 20–30 mg/kg IV q12h (max 1.5 g q12h)
• Contraindications: Renal failure (dose adjust)

Lacosamide

• Bolus: 200–400 mg IV over 15 min
• Maintenance: 200–400 mg/day divided q12h
• Contraindications: AV block, PR prolongation

Phenytoin / Fosphenytoin

• Bolus: 15–20 mg PE/kg IV (max rate phenytoin ≤50 mg/min, fosphenytoin ≤150 mg PE/min)
• Supplemental: 5–10 mg/kg if needed
• Maintenance: 4–6 mg/kg/day divided q12h
• Contraindications: Bradycardia, AV block, hypotension, arrhythmias

Phenobarbital

• Bolus: 15–20 mg/kg IV at ≤100 mg/min
• Maintenance: 1–3 mg/kg/day divided BID
• Contraindications: Respiratory depression, porphyria, hepatic failure

Management Altered Mental Status

Altered Mental Status (AMS) – Differential, Workup, and Empiric Therapy

Use this as a quick reference. Scoped styles ensure your blog’s theme stays intact.

• Airway/Breathing: O₂ to keep SpO₂ 92–96%; consider early intubation for GCS ≤8, loss of airway reflexes, or refractory hypoventilation.
• Circulation: Cardiac monitor, IV access ×2, treat hypotension (balanced crystalloids; vasopressors if needed).
• Check glucose immediately; if <70 mg/dL → D50W 25 g IV (or D10W infusion). Give thiamine 100 mg IV first if malnourished/alcohol use.
• Consider naloxone for suspected opioid toxicity: 0.04–0.4 mg IV q2 min, titrate up to 2 mg (repeat/infuse for long-acting opioids).
• Temperature control: treat hyper/hypothermia.
• 12-lead ECG; treat dysrhythmias promptly.

Dextrose Thiamine Naloxone Airway Fluids/Pressors

Toxicologic / Iatrogenic

• Opioids, benzodiazepines, alcohols, stimulants, gabapentinoids
• Polypharmacy, sedative overdose, anticholinergics, TCAs
• Withdrawal (benzos, alcohol, opioids)

Infectious

• Sepsis, meningitis, encephalitis
• Pneumonia, UTI/pyelo, skin/soft tissue infection

Endocrine/Metabolic

• Hypo/hyperglycemia, HHS/DKA
• Electrolytes (Na, Ca, Mg), uremia, hepatic failure/hyperammonemia
• Thyroid/adrenal crisis

Neurologic

• Stroke/ICH/SAH, seizure/post-ictal, NCSE
• Traumatic brain injury
• Brain tumor, hydrocephalus

Respiratory/Circulatory

• Hypercapnia/hypoxemia, CO poisoning
• Shock (septic, cardiogenic, hypovolemic, distributive)

Environmental/Psych

• Heat/cold exposure
• Primary psychiatric (diagnosis of exclusion)

Bedside / Initial

• POC glucose; vitals incl. temp
• ABG/VBG (ventilation/CO₂, oxygenation)
• Focused neuro exam; pupillary response

Core Labs

• CBC, CMP, Mg/Phos, LFTs
• Lactate, CK, troponin (if indicated)
• Ammonia (encephalopathy), TSH ± free T4
• Pregnancy test (β-hCG) in women of childbearing age
• UA/urine culture; blood cultures if infection suspected

Toxicology

• Serum acetaminophen & salicylate levels
• Ethanol level
• UDS (screen); consider serum osmol gap for toxic alcohols
• Carboxyhemoglobin if CO exposure possible

Imaging

• Non-contrast CT head (rapid screen for ICH/large stroke)
• CXR (aspiration, pneumonia, edema; ETT confirmation if intubated)
• MRI brain if encephalitis/early stroke suspected after CT

When to Perform Lumbar Puncture

• Suspected meningitis/encephalitis: LP for cell count, protein, glucose, Gram stain/culture, HSV PCR.
• Head CT before LP if focal deficits, papilledema, immunocompromised, new seizures, or concern for mass effect.

Scenario	Key Actions & Empirics
Suspected Opioid Toxicity	Airway/ventilation support; Naloxone 0.04–0.4 mg IV, titrate up to 2 mg; repeat or start infusion for long-acting opioids. Avoid deep sedation unless necessary.
Benzodiazepine Overdose	Supportive care, airway protection as needed. Avoid flumazenil unless known isolated benzo ingestion with no seizure risk or co-ingestants.
Unknown/Poly-Overdose (early)	Consider activated charcoal 1 g/kg (max 50 g) within 1–2 h if protected airway. Obtain tox levels (APAP/salicylate). Poison control/toxicology consult.
Acetaminophen Ingestion	Start N-acetylcysteine (IV 3-bag: 150 mg/kg → 50 mg/kg → 100 mg/kg) while clarifying timeline; adjust per nomogram/levels.
Tricyclic / Na⁺ Channel Blocker	If wide QRS, hypotension, or arrhythmias → Sodium bicarbonate 1–2 mEq/kg IV bolus; repeat/titrate; consider infusion.
Possible Meningitis (Adult)	Draw blood cultures → Dexamethasone 10 mg IV → Ceftriaxone 2 g IV q12h + Vancomycin; add Ampicillin 2 g IV q4h if age >50 or immunocompromised; add Acyclovir 10 mg/kg IV q8h if encephalitis suspected. Do not delay antibiotics for imaging/LP if unstable.
Sepsis (no clear source)	Sepsis bundle: fluids (30 mL/kg balanced crystalloids if hypotensive or lactate ≥4), norepinephrine to MAP ≥65 if needed, cultures before antibiotics when feasible, lactate now & recheck. Empiric: Piperacillin-tazobactam or Cefepime ± metronidazole; add Vancomycin for MRSA risk. Tailor to local antibiogram.
HSV Encephalitis Suspected	Start Acyclovir 10 mg/kg IV q8h promptly (renal dose adjust), obtain HSV PCR on CSF.
Hyperammonemia / Hepatic Encephalopathy	Lactulose titrated to 2–3 soft BMs/day; consider Rifaximin; search for precipitant (GI bleed, infection, meds).
Alcohol Withdrawal / Wernicke Risk	Thiamine 100 mg IV before glucose; symptom-triggered benzodiazepines (CIWA-Ar); consider phenobarbital adjunct per protocol.

Doses are typical adult starting points and require renal/hepatic adjustment and local protocol alignment.

• Sepsis: Suspected/documented infection plus acute ↑ in SOFA ≥2.
• Septic shock: Sepsis + vasopressors to keep MAP ≥65 and lactate >2 mmol/L despite fluids.
• qSOFA (screen): RR ≥22, SBP ≤100, altered mentation (≥2 → high risk).

• Initial vent: Vt 6–8 mL/kg PBW, RR to target pH 7.30–7.45, PEEP 5–10 cmH₂O, FiO₂ to SpO₂ 92–96%.
• ETT: Confirm with waveform capnography; CXR: tip ~3–5 cm above carina; depth ~21 cm (women) / 23 cm (men) at teeth.
• Sedation: Analgesia-first; propofol or dexmedetomidine preferred; avoid deep benzodiazepine sedation unless indicated. Daily SAT/SBT.

• Airway threat, hypoventilation, refractory hypoxemia
• Focal neuro deficits, thunderclap headache, meningismus
• Severe hypotension/shock, fever with neck stiffness/photophobia
• Wide-QRS dysrhythmias, seizures/status epilepticus, NCSE concern

RVSP/Pulmonary Hypertension Workup – Quick Reference

RVSP / PH Workup – Quick Reference

Enter what you have (TR Vmax and RAP, or RVSP and RAP). The tool will solve the missing value, classify PH likelihood, and suggest next steps.

Inputs

TR Vmax

m/s

RAP

mmHg

RVSP

mmHg

Assume no RVOT/PR obstruction (PASP ≈ RVSP)

Formula: RVSP = 4 × (TR Vmax)² + RAP

Supportive Echo Signs (check what’s present)

Category A – RV/RA

RV basal diameter > 41 mm
RA area > 18 cm²
TAPSE < 17 mm
S′ (TDI) < 9.5 cm/s
RV FAC < 35%

Category B – Septum/LV

Septal flattening (D-shaped LV)
LV eccentricity index > 1.1

Category C – PA/IVC

PA diameter > 25 mm
IVC > 21 mm with poor collapse
PAAT < 105 ms (if available)

Symptoms / Context (optional)

Unexplained dyspnea
Syncope/presyncope
Signs of right-sided congestion

Risk for CTEPH (prior PE/DVT)
Connective tissue disease, portal HTN, HIV, drugs/toxins
Chronic lung/OSA/ILD

Results

Enter values and click Calculate.

Suggested Next Step

Action — will populate after calculation —

Reference cutoffs & logic (tap to view)

• TR Vmax ≤ 2.8 m/s (RVSP ≲ 36 mmHg with RAP 3–5): PH unlikely.
• TR Vmax 2.9–3.4 m/s (RVSP ~ 37–50 mmHg): PH possible.
• TR Vmax > 3.4 m/s (RVSP > 50 mmHg): PH likely.
• Upgrade suspicion if ≥2 supportive signs across ≥2 categories (A/B/C).
• Assume PASP ≈ RVSP only if no RVOT obstruction or significant PR.

Ketamine

Ketamine in the ICU – quick reference

Adult dosing; light background for readability. Use with your fentanyl ± dexmedetomidine plan; avoid large rapid boluses if hypertension is a concern.

Indications (ICU and ED)

• Analgesia Sub-dissociative opioid-sparing pain control in trauma, burns, post-op abdominal pain, opioid tolerance/hyperalgesia, neuropathic pain.
• Sickle crisis Vaso-occlusive crisis pain when opioid-sparing is needed or allodynia limits opioid escalation.
• Procedural sedation Short painful procedures, dressing changes, reductions.
• RSI/induction Especially in hypotensive trauma or with bronchospasm.
• ICU sedation Analgosedation adjunct or alternative to propofol/benzodiazepines.
• Status asthmaticus Bronchodilation and improved ventilation.
• Refractory status epilepticus NMDA antagonism for seizure control.
• Severe agitation Excited delirium rescue with airway-ready monitoring.
• Status migrainosus Rescue in selected protocols.
• Alcohol withdrawal Refractory cases as adjunct to standard care.
• Psychiatry Treatment-resistant depression (protocolized settings).

Dosing cheat sheet

• Analgesia (sub-dissociative): bolus 0.1–0.3 mg/kg IV given slowly; infusion 0.1–0.3 mg/kg/hr (≈1.7–5 mcg/kg/min). Titrate by 0.05–0.1 mg/kg/hr q15–30 min.
• Sickle cell VOC pain: same sub-dissociative dosing; avoid large/rapid boluses if BP/HR sensitive.
• Procedural sedation: 0.5–1 mg/kg IV over 1–2 min, then 0.25–0.5 mg/kg IV q5–10 min PRN. IM 3–5 mg/kg if no IV.
• RSI/induction: 1–2 mg/kg IV once (lower end if shocked/on pressors).
• ICU maintenance sedation: 0.3–1 mg/kg/hr; short-term up to 2 mg/kg/hr with close monitoring.
• Status asthmaticus: 0.5–1 mg/kg IV once, then 0.5–1 mg/kg/hr.
• Refractory status epilepticus: load 1–2 mg/kg IV, then 1–5 mg/kg/hr (protocols up to 10 mg/kg/hr to EEG target).
• Severe agitation/excited delirium: 4–5 mg/kg IM or 1–2 mg/kg IV with airway-ready monitoring.
• Status migrainosus: 0.2–0.3 mg/kg IV once or infusion 0.1–0.3 mg/kg/hr for 3–6 hr.
• Refractory alcohol withdrawal: 0.3 mg/kg IV then 0.3–0.5 mg/kg/hr as adjunct to standard therapy.

Units crosswalk: 0.1 mg/kg/hr ≈ 1.7 mcg/kg/min. Use kg weight and round to practical infusion rates.

Practical pearls and safety

• Hemodynamics: mild–moderate ↑BP/↑HR, most after bolus; prefer slow small boluses or start a low infusion if hypertension is a concern.
• Catecholamine depletion: late sepsis/critical illness can unmask myocardial depression → BP may fall; start low and be ready to support.
• Airway/secretions: hypersalivation common → suction first; consider glycopyrrolate 0.2 mg IV PRN.
• CNS: dysphoria/emergence reactions are dose/rate-related; avoid rapid pushes; tiny GABAergic rescue if needed.
• Gut: generally motility-neutral—useful when ileus risk makes anticholinergics undesirable.
• Combinations: plays well with opioids; dexmedetomidine offsets tachy/HTN and improves sleep continuity.
• Titration: adjust q15–30 min to pain/RASS/BP/HR; continuous ECG/SpO₂; capnography preferred with opioids.
• Renal/hepatic: no renal adjustment; go slow in hepatic impairment/cirrhosis.

Contraindications and cautions

• Absolute: known ketamine or formulation allergy.
• Strong cautions: uncontrolled HTN; acute aortic dissection; active ischemia/severe CAD; tachyarrhythmias; severe pulmonary HTN; ICH/SAH where BP surges are hazardous.
• Neuropsychiatric: severe psychosis/mania—use only if benefits outweigh risks with close monitoring.
• Endocrine: pheochromocytoma or untreated thyrotoxicosis → exaggerated sympathetic response.
• Pregnancy: use only when benefits outweigh risks and after OB consult.
• Peri-MI/HOCM: avoid large boluses; prefer slow titration.

If severe hypertension, chest pain, ischemic ECG changes, or distressing dysphoria occurs, pause and treat; resume at a lower rate or consider an alternative.

Monitoring and hold parameters

• Continuous ECG and pulse oximetry; use capnography when combined with opioids.
• Check BP/HR every 5 min during bolus and every 15 min during titration.
• Hold or reduce for: new chest pain/ischemic ECG, severe uncontrolled HTN, sustained HR above target, intolerable dysphoria, or SpO₂ < 92% despite support.