Pharmetheus · Emergency Pharmacotherapy · 2025 Update

Emergency Drugs — Essentials

A comprehensive clinical reference synthesising AHA 2025, ILCOR 2025, Surviving Sepsis Campaign, and CuratED EMPHARM-NET evidence across all major emergency categories.

AHA 2025 CPR & ECC Guidelines ILCOR 2025 Surviving Sepsis Campaign Am J Emerg Med 2025 Neurocritical Care Society 2024
10
Emergency Categories
60+
Key Drugs
11
RCTs Referenced
2025
Guidelines
Quick Reference Summary
First-line drugs & critical doses at a glance
12 Emergencies
Emergency First-Line Drug(s) Critical Dose Guideline
Septic ShockNorepinephrine0.01–0.1 μg/kg/min IV; titrateSSC 2021 / AJEM 2025
Cardiac Arrest (VF/pVT)Epinephrine + AmiodaroneEpi 1 mg q3–5 min; Amio 300 mg IVAHA 2025 / ILCOR 2025
AnaphylaxisEpinephrine 1:1000 IM0.3–0.5 mg IM anterolateral thighAHA 2025 Special Circ
Status EpilepticusLorazepam IV → Levetiracetam0.1 mg/kg IV; then 60 mg/kg IVNeurocritical Care / ESETT
AF with RVRMetoprolol ± MagnesiumMetoprolol 2.5–5 mg IV; MgSO₄ 2 gAF Guidelines 2024
Hypertensive EmergencyLabetalol or Nicardipine IVLabetalol 20 mg IV; titrateACC/AHA HTN Guidelines
Opioid OverdoseNaloxone0.4–2 mg IV/IM/IN; repeat q2–3 minAHA 2024 First Aid; ACMT
TCA ToxicitySodium Bicarbonate1–2 mEq/kg IV; target pH 7.45–7.55AHA 2023/2025 Toxicology
Digoxin ToxicityDigoxin-specific FabWeight/level-based dosingAHA 2025 (Class I)
Cyanide PoisoningHydroxocobalamin5 g IV over 15 minAHA 2025 (Class I)
Acute Pulmonary EdemaGTN + FurosemideGTN 0.4 mg SL; Furosemide 40–80 mg IVESC Heart Failure Guidelines
Trauma HaemorrhageTranexamic Acid (TXA)1 g IV over 10 min (within 3 hrs)CRASH-2 Trial
CCB OverdoseCalcium + High-dose Insulin + LipidCaCl 1–3 g; Insulin 1 U/kg/hrAHA 2025 Toxicology
Massive PEAlteplase (tPA)100 mg IV over 2 hrsESC/AHA PE Guidelines
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Sepsis & Septic Shock
Vasopressors · Fluids · Corticosteroids · Antimicrobials
SSC 2021 · AJEM 2025
Vasopressors
DrugDose & RouteMechanismClinical RoleKey Evidence
Norepinephrine0.01–3 μg/kg/min IVα1 >> β1 agonistFirst-line vasopressor; peripheral admin ≥20G safeSSC 2021; AJEM 2025
Vasopressin0.03 units/min IVV1 receptor agonist (vasoconstriction)Add-on when NE >0.25 μg/kg/min; catecholamine-sparingVASST trial; OVISS/JAMA 2025
Epinephrine0.01–0.5 μg/kg/min IVα1, α2, β1, β2 agonistThird-line or adjunct for refractory shockSSC 2021
Angiotensin II20 ng/kg/min IV; titrateAT1 receptor agonistRefractory vasodilatory shockATHOS-3 RCT (NEJM)
Dopamine5–20 μg/kg/min IVD1, β1, α1 (dose-dependent)⚠ Avoid in septic shock — higher arrhythmia riskDe Backer NEJM 2010
Corticosteroids

Indication: Septic shock refractory to vasopressors (norepinephrine ≥0.25 μg/kg/min for ≥4–6 hours).

Regimen: Hydrocortisone 200 mg/day IV (continuous infusion or 50 mg q6h) plus Fludrocortisone 50 μg/day via nasogastric tube. Evidence: APROCCHSS trial — improved 90-day survival.

Antimicrobials

Initiate broad-spectrum antibiotics within 1 hour of recognising septic shock (within 3 hours for sepsis without shock). Each hour of delay significantly increases mortality.

For nosocomial or immunosuppressed: anti-pseudomonal coverage (piperacillin-tazobactam or cefepime) + MRSA coverage (vancomycin). Source control is paramount.

🔄 2025 Key Update

The OVISS reinforcement learning study (JAMA 2025) derived and validated optimal timing rules for vasopressin addition to norepinephrine. Peripheral administration of vasopressors through a ≥20-gauge IV line is now confirmed safe, allowing earlier initiation without waiting for central access (AJEM 2025).

The CLOVERS trial (NEJM 2023) showed no mortality difference between restrictive (early vasopressors) and liberal (30 mL/kg crystalloid) fluid strategies — early vasopressors are equally valid when fluids alone fail to restore MAP.

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Cardiac Arrest
VF · pVT · PEA · Asystole
AHA 2025 / ILCOR 2025
DrugIndicationDoseRoute2025 Update
Epinephrine (Adrenaline)VF, pVT, PEA, Asystole1 mg every 3–5 minIV / IOStandard dose preferred; early admin for non-shockable rhythms; no high-dose benefit
AmiodaroneShock-refractory VF/pVT300 mg IV bolus, then 150 mgIV / IOPreferred first antiarrhythmic for shock-refractory VF
LidocaineShock-refractory VF/pVT1–1.5 mg/kg IV bolusIV / IOAlternative to amiodarone; similar outcomes (ALPS trial)
Magnesium SulfateTorsades de pointes (TdP)1–2 g IV over 5–20 minIV / IO⚠ NOT for routine VF — reserve for TdP only
AdenosineStable SVT6 mg IV rapid, then 12 mgIV rapid pushFirst-line for regular narrow-complex SVT
Sodium BicarbonateHyperkalemia, TCA OD, metabolic acidosis1 mEq/kg IVIV⚠ NOT for routine cardiac arrest use
Calcium (CaCl / Gluconate)Hyperkalemia, CCB toxicity500–1000 mg IV slowIVKey antidote for calcium channel blocker OD
AtropineSymptomatic bradycardia0.5–1 mg IV q3–5 min (max 3 mg)IV⚠ Not used in PEA / Asystole in ALS protocols
🔄 AHA 2025 Key Updates

Vasopressin no longer recommended as a substitute for epinephrine in cardiac arrest (updated 2023). Intraosseous (IO) access is now an earlier option when IV fails — not a last resort. Double sequential external defibrillation may be considered for shock-refractory VF (DOSE VF trial). ECMO-CPR is indicated in select etiologies including poisoning-related cardiac arrest.

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Anaphylaxis
Epinephrine must never be delayed
AHA 2025 Special Circ
DrugDoseRouteMechanism / Role
Epinephrine 1:10000.3–0.5 mg adult; 0.01 mg/kg childIM — anterolateral thigh (preferred)FIRST-LINE. α1: vasoconstriction ↑BP; β1: ↑HR ↑CO; β2: bronchodilation; inhibits mast cell degranulation
Epinephrine 1:10,0000.1 mg/kg slow IVIV / IO (cardiac arrest only)For anaphylactic cardiac arrest. AHA 2025: higher IM dose (5 mg) under investigation
Diphenhydramine (H1)25–50 mgIV / IM / oralH1 blocker — relieves urticaria/pruritus. ⚠ NOT life-saving — adjunct only
Ranitidine / Famotidine (H2)50 mg / 20 mg IVIVH2 blocker — adjunct for cutaneous features
Hydrocortisone / Methylprednisolone200 mg IV / 1 mg/kg IVIVPrevents biphasic anaphylaxis; delayed onset
Salbutamol (Albuterol)2.5–5 mg nebulisedInhaledβ2 agonist — for bronchospasm not responding to epinephrine
Glucagon1–2 mg IV over 5 minIVβ-blocker–refractory anaphylaxis; bypasses β-receptor blockade
⚡ Clinical Pearl — AHA 2025

For cardiac arrest due to anaphylaxis, standard ACLS protocols apply. The 2025 AHA Special Circumstances Guidelines raise the question of whether a higher-dose IM epinephrine (5 mg) may confer additional benefit in anaphylactic arrest — active investigation. ECMO should be considered for refractory anaphylactic arrest.

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Seizures & Status Epilepticus
Stepwise pharmacologic management
Neurocritical Care 2024
StageDrugDose & RouteTimingEvidence
First-line (0–5 min)Lorazepam IV0.1 mg/kg IV (max 4 mg)ImmediatelyClass I; best evidence
First-line (no IV)Midazolam IM10 mg IM (>40 kg adult)ImmediatelyRAMPART trial; non-inferior to lorazepam IV
First-line (no IV)Diazepam PR0.2 mg/kg rectallyImmediatelyPrehospital use
Second-line (5–20 min)Levetiracetam IV60 mg/kg IV (max 4500 mg) over 10 minAfter BZD failureESETT: non-inferior to valproate; fewer ADRs
Second-lineValproate IV40 mg/kg IV over 10 min (max 3000 mg)After BZD failureESETT trial (NEJM 2019)
Second-lineFosphenytoin IV20 mg PE/kg IV ≤150 mg PE/minAfter BZD failureESETT trial; CV monitoring required
Third-line (RSE)Propofol1–2 mg/kg IV bolus; 20–200 μg/kg/minICU settingContinuous EEG monitoring required
Third-line (RSE)Midazolam infusion0.2 mg/kg bolus; 0.05–2 mg/kg/hrICU settingMonitoring essential
Third-line (RSE)Ketamine1.5–4.5 mg/kg IV bolus; 1.2–7.5 mg/kg/hrEmerging useNMDA antagonist; growing evidence
🔄 2024 Update — TBI Seizure Prophylaxis

Neurocritical Care Society 2024: For moderate-to-severe TBI with acute radiographic abnormalities, routine prophylactic anti-seizure medication may or may not be initiated — evidence shows no significant reduction in long-term epilepsy development. If prophylaxis is used, prefer Levetiracetam or Phenytoin/Fosphenytoin, limited to the first 7 days post-injury.

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ACS & Arrhythmias
Acute Coronary Syndromes · Atrial Fibrillation
AHA / CuratED 2024
Acute Coronary Syndrome Pharmacotherapy
Drug ClassAgent(s)DoseIndicationNotes
AntiplateletAspirin300 mg oral loadingAll ACSImmediate, before reperfusion
P2Y12 InhibitorTicagrelor180 mg loading; 90 mg BDNSTEMI / STEMIPreferred over clopidogrel; PLATO trial
P2Y12 InhibitorPrasugrel60 mg loading; 10 mg ODSTEMI (PCI)Avoid: prior stroke/TIA, age >75, wt <60 kg
P2Y12 InhibitorClopidogrel300–600 mg loadingACS (alternative)When ticagrelor/prasugrel unavailable; more drug interactions
AnticoagulantEnoxaparin1 mg/kg SC BDNSTEMI/STEMI (non-PCI)Fondaparinux for NSTEMI if no PCI planned
AnticoagulantUFH60–70 units/kg IV bolus (max 5000 U)STEMI (primary PCI)Weight-based; activated clotting time monitoring
NitrateGTN (Nitroglycerin)0.4 mg SL q5 min × 3; infusion prnAngina, acute pulmonary oedema⚠ Avoid if RV infarction; SBP <90; PDE5 use
Beta-blockerMetoprolol25–50 mg oral or 5 mg IV × 3Rate control; anti-ischaemicAvoid in acute decompensated HF, severe bradycardia
AF with Rapid Ventricular Response
DrugDoseNotes
Metoprolol IV2.5–5 mg IV over 2 min; max 3 dosesFirst-line rate control; avoid in decompensated HF
Diltiazem IV0.25 mg/kg IV over 2 min; infusion 5–15 mg/hrEffective rate control; avoid in pre-excitation AF
Digoxin IV0.25–0.5 mg IV loadingSlower onset; useful when beta-blockers contraindicated
Amiodarone IV150 mg IV over 10 min, then infusionRate/rhythm control; useful in haemodynamically unstable
Magnesium Sulfate2 g IV over 15 min (adjunct)New 2024 update: adjunct to standard rate control of AF-RVR (COR 2a, LOE A)
Electrical Cardioversion120–200 J biphasic synchronizedIf haemodynamically unstable or refractory to drugs
🔄 2024 Update — IV Magnesium in AF-RVR

The 2024 AF Guidelines (CuratED EMPHARM-NET, Am J Emerg Med 2025) recommend that IV magnesium sulfate as an adjunct to standard rate-control agents is reasonable to achieve and maintain rate control (Class 2a, Level of Evidence A). A meta-analysis supports its use; no specific dose was mandated.

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Hypertensive Emergency
SBP >180 or DBP >120 + end-organ damage
ACC/AHA HTN Guidelines
DrugDose / RouteBest IndicationTarget / Notes
Labetalol IV20 mg IV bolus; infusion 0.5–2 mg/minMost hypertensive emergencies; aortic dissection10–20% BP reduction in first hour
Nicardipine IV5–15 mg/hr infusion, titratedHypertensive encephalopathy; post-stroke; eclampsia10–15% reduction in first hour
Sodium Nitroprusside IV0.25–10 μg/kg/min infusionAcute LVF; aortic dissection (with beta-blocker)Rapid; careful titration; ⚠ cyanide risk if prolonged
GTN (Nitroglycerin) IV5–200 μg/min infusionACS + hypertension; acute pulmonary oedemaVenous > arterial dilator at low doses
Hydralazine IV10–20 mg slow IVEclampsia / hypertension in pregnancyAvoid in aortic dissection
Magnesium Sulfate IV4–6 g loading; 1–2 g/hr maintenanceEclampsia (seizure prevention + BP)Gold standard for pre-eclampsia/eclampsia
Esmolol IV500 μg/kg bolus; 50–300 μg/kg/min infusionAortic dissection; peri-operative hypertensionRapid onset and offset; ideal for fine titration
Phentolamine IV2–5 mg IV bolusCatecholamine excess (phaeochromocytoma, MAOI, cocaine)Alpha-blocker; short-acting
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Poisoning & Toxicological Emergencies
Antidotes · Reversal Agents · Specific Toxidromes
AHA 2023/2025 Toxicology
Poison / ToxidromeAntidote / DrugDoseMechanism / Notes
Opioid overdoseNaloxone0.4–2 mg IV/IM/IN; repeat q2–3 min prnμ-opioid antagonist; titrate to adequate respiration (not full reversal)
Opioid OD (alternative)Nalmefene0.5 mg/70 kg IVLonger-acting; ⚠ risk of prolonged withdrawal; major toxicology orgs caution against routine use (CuratED 2024)
Benzodiazepine ODFlumazenil0.2 mg IV; repeat up to 1 mgGABA-A antagonist; ⚠ limited use — risk of seizures in chronic BZD users
Beta-blocker ODGlucagon + High-dose InsulinGlucagon 3–10 mg IV; Insulin 1 unit/kg/hrGlucagon bypasses β-receptor; insulin improves myocardial glucose use
Calcium channel blocker ODCalcium + High-dose Insulin + Lipid emulsionCaCl 1–3 g IV; Insulin 1 unit/kg/hr; Lipid 1.5 mL/kg bolusLipid emulsion traps lipophilic drugs; ECMO if refractory
Digoxin / cardiac glycosideDigoxin-specific Fab (DigiFab)Based on serum level or tablets ingestedAntibody fragments; Class I recommendation (AHA 2025)
Organophosphate / CarbamateAtropine + Pralidoxime (2-PAM)Atropine 2–4 mg IV (double q5 min until secretions dry); 2-PAM 1–2 g IV over 15–30 minAtropine blocks muscarinic effects; 2-PAM regenerates cholinesterase (give early)
TCA overdoseSodium Bicarbonate1–2 mEq/kg IV; target arterial pH 7.45–7.55Reverses sodium channel blockade; Class I recommendation (AHA)
Cyanide poisoningHydroxocobalamin5 g IV over 15 minCombines with cyanide → cyanocobalamin; Class I (AHA 2025)
MethemoglobinaemiaMethylene blue1–2 mg/kg IV over 5 minElectron donor; reduces met-Hb back to Hb; Class I (AHA 2025)
Local anaesthetic toxicity (LAST)20% Lipid emulsion1.5 mL/kg IV bolus; 0.25 mL/kg/minLipid sink mechanism; Class 1 for LAST (AHA 2025)
Warfarin OD / bleedingVitamin K + 4-factor PCCVit K 5–10 mg IV; 4F-PCC 25–50 units/kgPCC for immediate reversal; Vit K for sustained effect
Dabigatran reversalIdarucizumab5 g IV (2 × 2.5 g)Humanised antibody fragment; complete and immediate reversal
Anti-Xa reversal (rivaroxaban, apixaban)Andexanet alfa400–800 mg IV bolus + infusionRecombinant Xa decoy; specific reversal agent
🔄 2024 Update — Nalmefene vs Naloxone

The push for nalmefene over naloxone is largely driven by manufacturer-sponsored data. Major toxicology organisations — including the American College of Medical Toxicology — caution against routine use of long-acting reversal agents due to prolonged withdrawal risk. Naloxone remains the standard of care (CuratED 2024).

ECMO for toxicologic cardiac arrest (CCB, β-blocker, TCA) is now a class recommendation in the AHA 2025 Special Circumstances Guidelines.

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Acute Pulmonary & Respiratory Emergencies
Cardiogenic oedema · Asthma · COPD · Massive PE
ESC / AHA Guidelines
EmergencyDrug(s)DoseNotes
Cardiogenic Pulm OedemaGTN (Nitroglycerin)0.4 mg SL; IV 10–200 μg/minReduces preload and afterload; first-line if not hypotensive
Cardiogenic Pulm OedemaFurosemide IV40–80 mg IV (1–2 mg/kg)Venodilation + diuresis; caution in cardiorenal syndrome
Cardiogenic Pulm OedemaMorphine2–4 mg IV (controversial)Venodilation + anxiolysis; ⚠ newer evidence questions routine use
Acute Asthma / BronchospasmSalbutamol (Albuterol)2.5 mg neb q20 min × 3; or MDI 4–8 puffsShort-acting β2 agonist; first-line bronchodilator
Acute AsthmaIpratropium bromide0.5 mg neb q20 min × 3 (with salbutamol)Anticholinergic; adds to bronchodilation in severe asthma
Acute AsthmaMagnesium Sulfate IV2 g IV over 20 minBronchodilation via Ca²⁺ channel antagonism; for severe/refractory asthma
Acute AsthmaCorticosteroidsHydrocortisone 200 mg IV or Prednisolone 40–50 mg oralReduces airway inflammation; early use critical
COPD ExacerbationSalbutamol + IpratropiumAs above (combined neb)Combined nebulisation preferred in acute COPD
Massive PEAlteplase (tPA)100 mg IV over 2 hr (systemic) or catheter-directedSystemic thrombolysis for massive PE with haemodynamic instability
Submassive PE / All PEUFH80 units/kg bolus; 18 units/kg/hr infusionIV UFH preferred in massive PE before/after thrombolysis
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Trauma Pharmacotherapy
Haemorrhage · Resuscitation · RSI · Seizure Prophylaxis
CRASH-2 · NAEMSP 2024
Drug / InterventionIndicationDoseKey Evidence / Update
Tranexamic Acid (TXA)Major haemorrhage within 3 hrs of injury1 g IV over 10 min, then 1 g over 8 hrsCRASH-2 trial; reduces haemorrhagic death; ⚠ not recommended after 3 hrs
Isotonic CrystalloidsPrehospital trauma resuscitationTitrated to permissive hypotension (SBP 80–90 mmHg)NAEMSP 2024: isotonic crystalloids preferred prehospitally
Packed RBCs + FFP + PlateletsHaemorrhagic shock1:1:1 ratio (balanced resuscitation)Damage-control resuscitation approach
NorepinephrineVasodilatory shock in trauma0.01–3 μg/kg/minPeripheral administration acceptable (NAEMSP 2024)
Ketamine (RSI)Rapid sequence intubation in trauma1.5–2 mg/kg IVHaemodynamically safe; analgesic; bronchodilator
Succinylcholine (RSI)Neuromuscular blockade1.5 mg/kg IVRapid onset/offset; ⚠ caution in hyperkalemia, crush injury >24 hrs
Rocuronium (RSI)If succinylcholine contraindicated1.2 mg/kg IVReversed by sugammadex 16 mg/kg
Levetiracetam / PhenytoinSeizure prophylaxis in moderate-severe TBILev 500–1000 mg BD or PhenytoinNeurocritical Care 2024: limit to 7 days; no long-term epilepsy reduction
🔄 2024 Update — Damage Control Resuscitation

NAEMSP 2024 position statement reflects evolving shift toward damage-control resuscitation and permissive hypotension (SBP 80–90 mmHg) in trauma. Isotonic crystalloids are preferred prehospitally; early vasopressor use (norepinephrine) is acceptable via peripheral access. Avoid over-resuscitation with crystalloids — dilutional coagulopathy worsens outcomes.

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Special Situations
Pregnancy · Paediatrics · LVAD · Hyperkalemia
AHA 2025 Special Circ
SituationDrug(s)Key Point
Eclampsia / Pre-eclampsiaMgSO₄ + Labetalol / NicardipineMgSO₄ 4–6 g loading; maintain uterine blood flow; MgSO₄ prevents eclamptic seizures — gold standard
Maternal cardiac arrestStandard ACLS drugs + perimortem C-sectionEpinephrine dosing unchanged; consider early delivery within 5 min of arrest if no ROSC
Paediatric cardiac arrestEpinephrine0.01 mg/kg IV/IO (max 1 mg) every 3–5 min
Paediatric anaphylaxisEpinephrine 1:10000.01 mg/kg IM anterolateral thigh (max 0.5 mg)
Hyperkalaemia (cardiac arrest)Calcium + Bicarbonate + Insulin/Glucose ± SalbutamolCalcium is membrane-stabilising; insulin-glucose drives K⁺ intracellularly; salbutamol neb as adjunct; dialysis if refractory
LVAD failureEpinephrine infusion + ECMOStandard CPR may be ineffective in LVAD patients; ECMO is the primary rescue strategy per AHA 2025
References & Evidence Base
  • Feldman R, Faine B, Rech MA, et al. CuratED: The emergency medicine pharmacotherapy literature of 2024. Am J Emerg Med. 2025;93:146–153.
  • Panchal AR, Bartos JA, et al. Part 9: Adult Advanced Life Support: 2025 AHA Guidelines for CPR and ECC. Circulation. 2025;152(suppl 2).
  • Lavonas EJ, et al. Part 10: Adult & Paediatric Special Circumstances: 2025 AHA Guidelines for CPR and ECC. Circulation. 2025.
  • Evans L, Rhodes A, Alhazzani W, et al. Surviving Sepsis Campaign: International Guidelines for Management of Sepsis and Septic Shock 2021. Crit Care Med. 2021;49(11):e1063–e1143.
  • Kalimouttou A, et al. Optimal Vasopressin Initiation in Septic Shock (OVISS). JAMA. 2025;333(19):1688–1698.
  • Shapiro NI, Douglas IS, et al. CLOVERS Trial: Early Restrictive or Liberal Fluid Management for Sepsis-Induced Hypotension. N Engl J Med. 2023;388:499–510.
  • Greif R, et al. ILCOR 2025 Advanced Life Support Consensus on Science with Treatment Recommendations. Resuscitation. 2025.
  • American Heart Association / American Red Cross. 2024 Guidelines for First Aid. Circulation. 2024.
  • Lavonas EJ, et al. 2023 AHA Focused Update: Cardiac Arrest or Life-Threatening Toxicity Due to Poisoning. Circulation. 2023;148:e149–e184.
  • Neurocritical Care Society. Pharmacologic Seizure Prophylaxis for Adult Patients with Moderate to Severe TBI. 2024 Guidelines.
  • National Association of EMS Physicians (NAEMSP). Position Statement: Fluid Resuscitation and Vasopressors in Trauma. 2024.
  • CRASH-2 trial collaborators. Effects of tranexamic acid on death, vascular occlusive events, and blood transfusion in trauma patients. Lancet. 2010;376:23–32.
  • Cheskes S, Drennan IR, et al. Defibrillation Strategies for Refractory VF (DOSE VF). N Engl J Med. 2022;387:1947–1956.
  • Mościcki A, et al. ESETT Trial: Established Status Epilepticus Treatment Trial. N Engl J Med. 2019;381:2103–2113.
  • De Backer D, et al. Comparison of Dopamine and Norepinephrine in the Treatment of Shock. N Engl J Med. 2010;362:779–789.