Critical Care, Critical Care Alert

Critical Care Alert: Venoarterial Extracorporeal Membrane Oxygenation in Massive Pulmonary Embolism-Related Cardiac Arrest: A Systematic Overview

Critical Care Alert

Article
Scott JH, Gordon M, Vender R, et al. Venoarterial Extracorporeal Membrane Oxygenation in Massive Pulmonary Embolism-Related Cardiac Arrest: A Systematic Review. Crit Care Med. 2021 Feb 15. doi: 10.1097/CCM.0000000000004828. PMID: 33590996.

OBJECTIVE
The authors performed a systematic review assessing both survival and predictors of mortality when using venoarterial extracorporeal membranous oxygenation (VA-ECMO) to treat patients who suffered massive pulmonary embolism (PE) related cardiac arrest.

BACKGROUND
Pulmonary embolism is a common and at times fatal presentation in the emergency department, ranging in severity from low-risk to massive PE. A massive PE is defined as an acute PE with sustained hypotension (systolic blood pressure <90 mmHg or systolic drop >40 mmHg for more than 15 minutes, or requiring vasopressors or inotropes).1-2 Among the contributors to hemodynamic instability with massive PE is subsequent cardiac arrest, which carries an increased risk for mortality compared to massive PE alone.

When there is high suspicion for PE or when the diagnosis is established, mainstay treatment includes prompt anticoagulation followed by systemic thrombolysis or thrombectomy if necessary. For patients who sustain massive PE-related cardiac arrest or obstructive shock, VA-ECMO has emerged as an intriguing treatment modality as it offers relief of preload to the right ventricle while perfusing critical organs and tissues. The utility of VA-ECMO in massive PE with cardiac arrest is relatively unknown, especially in patients who had already received thrombolysis. The authors of this systematic review aimed to further evaluate the role of VA-ECMO in the treatment of patients with massive PE-related cardiac arrest.

DESIGN
Systematic review

Study Selection and Inclusion Criteria

  • Article must describe a very specific clinical scenario of massive PE-related cardiac arrest managed with VA-ECMO.
  • Article must have reported whether patients survived to discharge.

 

OUTCOMES
Primary

  • Patient survival to discharge

Secondary

  • The impact of the following on patient survival:
    • Patient age
    • Patient gender
    • Use of systemic thrombolytics prior to ECMO
    • ECMO cannulation during CPR or after return of spontaneous circulation (ROSC)
    • PE as primary reason for admission
    • Location in the hospital in which ECMO cannulation occurred
  • Major bleeding occurrence
  • Neurologic outcome determined by cerebral performance category (CPC) score

KEY RESULTS
Primary Outcomes

  • A total of 301 patients from 77 articles met inclusion criteria. 183 (61%) of these patients survived to discharge.

Secondary Outcomes

  • Statistically significant increase in the risk of death in two secondary outcomes:
    • Age greater than 65 years old (OR, 3.56, 95% CI, 1.29-9.87; p = 0.02).
    • Patients who were cannulated during CPR (OR, 6.84, 95% CI, 1.53-30.58; p = 0.01).
  • No significant difference in risk of death for the following:
    • Use of thrombolytics prior to ECMO (OR, 0.78, 95% CI, 0.39-1.54; p = 0.48).
    • PE as primary reason for admission (OR, 1.62, 95% CI, 0.60-4.40; p = 0.35).
    • Cannulation occurring in the emergency department versus all other sites in hospital (OR, 2.52, 95% CI, 0.69-9.26; p = 0.16).
    • Patient gender (OR, 0.59, 95% CI, 0.22-1.56, p = 0.29)
  • All six patients who received thrombolysis which sustained a major bleeding event survived.
  • 88% of patients (n = 53 of 60) were neurologically intact at discharge or follow up with CPC score of 1.

STRENGTHS

  • Systematic review with large sample size of patients all presenting with a very specific diagnosis and treatment.
  • Examined if VA-ECMO can be used as complementary treatment to thrombolysis.
  • Assessed risk of death when VA-ECMO was initiated in the emergency department versus other sites within the hospital, allowing results to be directly translated to Emergency Department decision making.

LIMITATIONS

  • Of the 77 studies reviewed, 37 were deemed moderate risk for bias and 6 were high risk.
  • Articles used did not report survival beyond discharge.
  • Variable reporting among the articles regarding several variables, including neurological status at discharge, presence or absence of significant bleed, cannulation during or after CPR, and duration of CPR.
  • No report on long-term outcomes including need for dialysis, chronic ventilator use, discharge to home or nursing facility, percutaneous endoscopic gastrostomy, readmission rate, and artificial feeding.

EM TAKE-AWAYS
This systematic review revealed a survival rate of 61% in patients who suffered massive PE-related cardiac arrest when treated with VA-ECMO. The mortality rate of such diagnosis has been demonstrated to possibly exceed 90%, indicating prompt consideration of VA-ECMO in the therapeutic strategy after initial assessment and stabilization of patients in the ED.3 Consideration of VA-ECMO in the emergency department is further supported by the finding of no increased risk for mortality when VA-ECMO was initiated there compared to any other location within the hospital.

Systemic thrombolysis is a standard component in treating massive PE, which tends to complicate other care due to the risk of major bleeding. This review provided evidence that the use of VA-ECMO following systemic thrombolysis did not increase the risk of death, giving assurance both treatments may be used in a complementary manner when used in a proper patient population.

There were two important subgroups that had a statistically significant increase in mortality when treated with VA-ECMO. This included patients who were over the age of 65 and when VA-ECMO cannulation occurred during CPR; therefore, physicians should abstain from incorporating VA-ECMO when treating massive PE with cardiac arrest in older patient populations and prior to the establishment of ROSC.


References

  1. Sekhri V, Mehta N, Rawat N, Lehrman SG, Aronow WS. Management of massive and nonmassive pulmonary embolism. Arch Med Sci. 2012;8(6):957-969. doi:10.5114/aoms.2012.32402
  2. Konstantinides SV, Meyer G, Becattini C, Bueno H, Geersing GJ, Harjola VP, Huisman MV, Humbert M, Jennings CS, Jiménez D, Kucher N, Lang IM, Lankeit M, Lorusso R, Mazzolai L, Meneveau N, Ní Áinle F, Prandoni P, Pruszczyk P, Righini M, Torbicki A, Van Belle E, Zamorano JL; ESC Scientific Document Group. 2019 ESC Guidelines for the diagnosis and management of acute pulmonary embolism developed in collaboration with the European Respiratory Society (ERS). Eur Heart J. 2020 Jan 21;41(4):543-603. doi: 10.1093/eurheartj/ehz405. PMID: 31504429.
  3. Mata R, McDermott G, Diaz L. Massive Pulmonary Embolism as a Cause of Cardiac Arrest: Navigating Unknowns in Life After Death. Cureus. 2020;12(5):e8361. Published 2020 May 30. doi:10.7759/cureus.8361

Related Articles

Controversies Surrounding Ultrasound Guided Regional Anesthesia in the ED

Controversies Surrounding Ultrasound Guided Regional Anesthesia in the ED Ultrasound guided regional anesthesia was first introduced in 1994, and it has since become a powerful tool for achieving ade

Letter from the Editor

Letter from the Editor One of my first editions as Editor-in-Chief of EM Resident featured a story about the fascinating history of space medicine. I loved this article not only because it introduced