Respiratory failure as an indication for thrombolysis in pulmonary embolism

Introduction: Use of thrombolysis in the management of pulmonary embolism (PE) is currently based on the European Society of Cardiology guidelines which use shock and right ventricular (RV) dysfunction as indications (Konstantinides, S.V. et al . European Heart Journal 2014;35:3033-3080). Thrombolysis in the absence of cardiovascular compromise remains controversial. Aim: To identify whether respiratory failure should be an indication for thrombolysis in PE. Methods: A retrospective single-centre cohort study. PE cases were identified from CT pulmonary angiogram reports over a 12 month period. Thrombolysed cases were identified from medical records. Results: 280 cases of PE were diagnosed between 01/12/2014-30/11/2015. 7 were thrombolysed. At the time of thrombolysis, mean respiratory rate was 28 (data incomplete for 2). 6 had arterial blood gas sampling, revealing type 1 respiratory failure in all. PaO 2 was 100bpm. 86% had CT or echocardiographic evidence of RV dysfunction. Serum troponin was raised in 71%. 3 cases died within 30 days of thrombolysis. The remaining cases survived to discharge and remain alive at the time of reporting (at least 3 months survival). Conclusions: Current guidelines exclusively use cardiovascular parameters to guide thrombolysis in PE. In this study, more than half of the thrombolysed cases were not hypotensive whilst all were hypoxic and tachypnoeic. Our experience suggests that greater emphasis should be placed on markers of respiratory compromise when risk stratifying in PE and that further research is needed to guide clinicians9 use of thrombolysis outside of currently accepted scenarios.