Guideline Summary for Intra‑Arrest Thrombolysis in High‑Risk Pulmonary Embolism

Indications and Contraindications

Systemic thrombolysis should be administered immediately during cardiopulmonary resuscitation (CPR) for patients with high‑risk pulmonary embolism (PE) causing cardiac arrest, provided no absolute contraindications exist; the recommended agents are recombinant tissue‑type plasminogen activator (rtPA) 50 mg IV bolus or the full accelerated regimen of 100 mg infused over 2 h. 1, 2
Thrombolysis is the first‑line therapy for high‑risk PE presenting with cardiogenic shock and/or persistent hypotension, and only a few absolute contraindications apply. 1, 2
In the setting of imminent or established cardiac arrest, contraindications that are normally absolute (e.g., recent major surgery, recent gastrointestinal bleeding) become relative because the immediate threat to life outweighs the bleeding risk. 1, 2
Absolute contraindications that remain even during cardiac arrest: intracerebral hemorrhage or stroke of unknown origin at any time; central‑nervous‑system injury or active malignancy; known bleeding diathesis. 1, 2
Relative contraindications in the arrest setting: ischemic stroke within the previous 6 months; major trauma, surgery, or cranial injury within the prior 3 weeks; gastrointestinal bleeding within the past month; traumatic resuscitation. 1, 2

Preferred rtPA regimen during CPR: 50 mg administered as an IV bolus (maximum dose when using 0.6 mg/kg). 1, 2
Alternative rtPA regimen: 100 mg infused continuously over 2 h. 1, 2
If rtPA is unavailable:
- Streptokinase accelerated protocol – 1.5 million international units given over 2 h. 1, 2
- Urokinase accelerated protocol – 3 million international units given over 2 h. 1, 2

Unfractionated heparin should be started immediately, without waiting for complete diagnostic confirmation, in high‑risk PE. 3
Target activated partial thromboplastin time (aPTT) to 1.5–2.5 × the normal value. 3
Anticoagulation must be continued throughout thrombolysis and after its completion. 5
Vasopressors (norepinephrine and/or dobutamine) are recommended for persistent hypotension during CPR. 3
Aggressive fluid boluses should be avoided because they increase right‑ventricular afterload and worsen right‑ventricular failure. 3
Supplemental oxygen should be provided to treat hypoxemia. 4

Surgical embolectomy is the recommended therapeutic alternative for high‑risk PE when thrombolysis is absolutely contraindicated or has failed; it is traditionally reserved for patients requiring CPR and can be performed with normothermic cardiopulmonary bypass without cardiac arrest. 3
Catheter‑directed thrombectomy may be considered as an alternative to surgery in similar high‑risk patients; however, its level of evidence is lower than that of surgical embolectomy. 3

Monitor for signs of hemodynamic deterioration: persistent hypotension, new requirement for vasopressors, worsening hypoxemia, altered mental status, and rising lactate levels. 4
Perform serial assessments of right‑ventricular function using echocardiography and cardiac biomarkers. 4

Thrombolysis should not be used in low‑risk PE, even if right‑ventricular dysfunction is present without hemodynamic instability, because the bleeding risk outweighs any benefit. 3, 2
In intermediate‑risk, hemodynamically stable PE, thrombolysis is reserved as a rescue therapy only if the patient deteriorates despite adequate anticoagulation. 4