A retrospective analysis of outcomes in low- and intermediate-high-risk pulmonary embolism patients managed on an ambulatory medical unit in the UK

Pulmonary embolism (PE) is common and guidelines recommend outpatient care only for PE patients with low predicted mortality. Outcomes for patients with intermediate-to-high predicted mortality managed as outpatients are unknown. 

Electronic records were analysed for adults with PE managed on our ambulatory care unit over 2 years. Patients were stratified into low or intermediate-to-high mortality risk groups using the Pulmonary Embolism Severity Index (PESI). Primary outcomes were the proportion of patients ambulated, 30-day all-cause mortality, 30-day PE-specific mortality and 30-day re-admission rate. 

Of 199 PE patients, 74% were ambulated and at 30 days, all-cause mortality was 2% (four out of 199) and PE-specific mortality was 1% (two out of 199). Ambulated patients had lower PESI scores, better vital signs and lower troponin levels (morning attendance favoured ambulation). Over a third of ambulated patients had an intermediate-to-high risk PESI score but their all-cause mortality rate was low at 1.9% (one out of 52). In patients with intermediate-to-high risk, oxygen saturation was higher and pulse rate lower in those who were ambulated. Re-admission rate did not differ between ambulated and admitted patients. 

Two-thirds of patients with intermediate-to-high risk PE were ambulated and their mortality rate remained low. It is possible for selected patients with intermediate-to-high risk PESI scores to be safely ambulated.