"Outpatient Management" of Pulmonary Embolism Defined in the Primary Literature: A Narrative Review

The evidence for the effectiveness of outpatient treatment of low-risk patients with acute pulmonary embolism (PE) continues to mount. However, lack of definitional clarity may hinder understanding of this emerging management strategy and impede translation into clinical practice. We describe the range of definitions provided in the primary outpatient PE literature. We undertook a narrative review of the English-language medical literature indexed in PubMed and Embase through the end of 2019. We identified studies of outpatient treatment of patients with acute PE. Fifty-one studies met our criteria. All studies provided some degree of definition of "outpatient," even if implicit or broad. Forty-six studies (90%) reported 1 or 2 sites of patient discharge (or departure) to home: emergency department (ED)/ambulatory care unit (n = 31), inpatient ward (n = 13), and secondary care clinic (n = 8). Of the 31 ED-based studies, 9 (29%) delimited duration of care (from < 24 to < 48 hours). All inpatient studies placed an outer boundary on the time to discharge within their definition of outpatient care. Definitions of outpatient care in the PE literature vary considerably. The sites, duration, and intensity of care involved in outpatient PE management prior to home discharge range from comprehensive specialty clinic care to an ED evaluation, sometimes coupled with 1 to 5 days of additional inpatient care. Research on the outpatient management of acute PE would benefit from greater definitional clarity as clinicians, departments, and health systems seek to translate this research into real-world clinical practice.