Thrombolysis during cardiopulmonary resuscitation should be addressed in guidelines for pulmonary embolism

Return of spontaneous circulation in patients with out-of-hospital cardiac arrest caused by pulmonary embolism using early point-of-care ultrasound and timely thrombolytic agent application: Two case reports

Introduction:

Acute pulmonary embolism is a confirmed cause of up to 5% of out-of-hospital cardiac arrest and 5%–13% of unexplained cardiac arrest in patients. However, the true incidence may be much higher, as pulmonary embolism is often clinically underdiagnosed. Thrombolytic therapy is a recognized therapy for pulmonary embolism–associated cardiac arrest but is not routinely recommended during cardiopulmonary resuscitation. Therefore, clinicians should attempt to identify patients with suspected pulmonary embolism. Many point-of care ultrasound protocols suggest diagnosis of pulmonary embolism for cardiac arrest patients.

Case presentation:

We describe two male patients (60 years and 66 years, respectively) who presented to the emergency department with cardiac arrest within a period of 1 week. With administration of point-of care ultrasound during the ongoing cardiopulmonary resuscitation in both patients, fibrinolytic therapy was initiated under suspicion of cardiac arrest caused by pulmonary embolism. Both patients had return of spontaneous circulation; however, only the second patient, who received fibrinolytic therapy relatively early, was discharged with a good outcome. In this report, we discussed how to diagnose and manage patients with cardiac arrest–associated pulmonary embolism with the help of point-of care ultrasound. We also discuss the different clinical outcomes of the two patients based on the experience of the clinicians and the timing of thrombolytic agent application.

Conclusions:

If acute pulmonary embolism is suspected in patients with out-of-hospital cardiac arrest, we recommend prompt point-of care ultrasound examination. Point-of care ultrasound may help identify patients with pulmonary embolism during cardiopulmonary resuscitation, leading to immediate treatment, although the clinical outcomes may vary.

Double Bolus Thrombolysis for Suspected Massive Pulmonary Embolism during Cardiac Arrest

More than 70% of cardiac arrest cases are caused by acute myocardial infarction (AMI) or pulmonary embolism (PE). Although thrombolytic therapy is a recognised therapy for both AMI and PE, its indiscriminate use is not routinely recommended during cardiopulmonary resuscitation (CPR). We present a case describing the successful use of double dose thrombolysis during cardiac arrest caused by pulmonary embolism. Notwithstanding the relative lack of high-level evidence, this case suggests a scenario in which recombinant tissue Plasminogen Activator (rtPA) may be beneficial in cardiac arrest. In addition to the strong clinical suspicion of pulmonary embolism as the causative agent of the patient's cardiac arrest, the extremely low end-tidal CO2 suggested a massive PE. The absence of dilatation of the right heart on subxiphoid ultrasound argued against the diagnosis of PE, but not conclusively so. In the context of the circulatory collapse induced by cardiac arrest, this aspect was relegated in terms of importance. The second dose of rtPA utilised in this case resulted in return of spontaneous circulation (ROSC) and did not result in haemorrhage or an adverse effect.

Impact of rescue-thrombolysis during cardiopulmonary resuscitation in patients with pulmonary embolism

Background

Cardiac arrest in patients with pulmonary embolism (PE) is associated with high morbidity and mortality. Thrombolysis is expected to improve the outcome in these patients. However studies evaluating rescue-thrombolysis in patients with PE are missing, mainly due to the difficulties of clinical diagnosis of PE. We aimed to determine the success influencing factors of thrombolysis during resuscitation in patients with PE.

Methodology/Principal Findings

We analyzed retrospectively the outcome of 104 consecutive patients with confirmed (n = 63) or highly suspected (n = 41) PE and monitored cardiac arrest. In all patients rtPA was administrated for thrombolysis during cardiopulmonary resuscitation. In 40 of the 104 patients (38.5%) a return of spontaneous circulation (ROSC) could be achieved successfully. Patients with ROSC received thrombolysis significantly earlier after CPR onset compared to patients without ROSC (13.6±1.2 min versus 24.6±0.8 min; p<0.001). 19 patients (47.5%) out of the 40 patients with initially successful resuscitation survived to hospital discharge. In patients with hospital discharge thrombolysis therapy was begun with a significantly shorter delay after cardiac arrest compared to all other patients (11.0±1.3 vs. 22.5±0.9 min; p<0.001).

Conclusion

Rescue-thrombolysis should be considered and started in patients with PE and cardiac arrest, as soon as possible after cardiac arrest onset.