My patient has a pulmonary embolism (PE) – can I still send them home?

The full reference:

Howard LSGE et al.British Thoracic Society Guideline for the initial outpatient management of pulmonary embolism (PE). Thorax 2018; 73: ii 1-29

What does this guideline add?

This new guideline gives specific recommendations on the risk stratification of adults (>16 years) with PE and, of particular importance to Emergency Department (ED) clinicians, which groups can be considered for safe outpatient management. It also gives specific advice on the management of PE in special patient groups e.g. pregnancy, the intravenous drug user and those already on full therapeutic anticoagulation and recommendations on the choice of therapeutic agents.

What isn’t changing?

There is no change to, or new guidance on: the diagnostic process for pulmonary embolism, cancer screening in PE, discussion of which patient groups should or shouldnt be treated (including subsegmental PE), a detailed comparison of anticoagulation drugs, the duration of anticoagulation or thrombophilia investigations.

Why is there a new guideline?

There is an increasing drive to manage conditions in the outpatient setting. This is for a combination of reasons including patient preference, reducing patients length of stay and, in the context of PE, a change in how the disease is treated. The licensing of Direct Oral Anticoagulant Drugs (DOACs) has resulted in a reduced use of Low Molecular Weight Heparins and Vitamin-K antagonists, meaning less monitoring is required following anticoagulation initiation.

The European Society of Cardiology (ESC) and the American College of Chest Physicians have supported outpatient management of low risk PE but detailed practical recommendations have not previously been available. Centres are already establishing outpatient pathways, building on their experience of the outpatient management of Deep Vein Thrombosis (DVT), but there was a need to conduct this using appropriate validated risk assessments which was lacking at the time of this guidelines creation.

How have they created this guideline?

The guideline has been four years in the making and is clearly the product of a huge amount of work. It has been written from the best available evidence following current international criteria on guideline development (AGREE II). A systematic literature review was performed with a subsequent appraisal of the literature, grading and critical appraisal of evidence using the SIGN checklist. The guideline development group has then drafted and finalised the guideline, with extensive stakeholder involvement including our own Dan Horner and Laura Hunter as RCEM representatives.

Practice changing key point:

Many of us are already doing this, but the recommendations are now clear that we should be assessing all patients with PE for suitability for outpatient management. Low risk patients should be offered outpatient treatment within a robust pathway that ensures follow-up and monitoring.

Which patients with confirmed PE can be considered for outpatient management? Guideline recommended risk assessment tools and thresholds

All of the recommended risk assessment tools detailed in the table below can be accessed on MDCalc. In your ED we suggest you use whichever risk assessment strategy is incorporated into your local policy. These patients could be considered for outpatient management.

Pulmonary Embolism Severity Index (PESI) class I or II	PESI predicts 30-day outcome using 11 clinical criteria. Class I denotes very low risk and class II low risk, with 30 day mortality of 0.0 – 1.6% and 1.7 – 3.5% respectively1.
Simplified PESI (sPESI): Score 0	sPESI also predicts 30-day outcome but has fever criteria (6). 0 points denotes the “low” risk group with 1.1% mortality and 1.5% VTE recurrence1.
Hestia Criteria: Score 0	Hestia Criteria identify low-risk PE patients safe for outpatient management. There are 11 criteria. A score of 0 denotes low risk with 0% mortality and 2% VTE recurrence1.

¹Risk statistics are taken from www.mdcalc.com

Which patients shouldn’t be managed as an outpatient? Exclusion criteria for outpatient management even if “low risk”

Some of these criteria will mean that the patient does not score as “low risk” on the recommended risk assessment tool but the presence of one of these in isolation means that outpatient management is not recommended. These patients will need admission from an ED clinician perspective.

Haemodynamic Instability	Heart Rate > 110 bpm. Systolic Blood Pressure < 100 mmHg. Needs inotropes and critical care. Requires thrombolysis or embolectomy
Respiratory demands	Oxygen saturation < 90% on air
Current anticoagulation	On full-dose anticoagulation at the time of the PE
Anticoagulation risks	Active bleeding or risk of major bleeding e.g. Recent GI bleed, surgery, previous intracranial bleeding or uncontrolled hypertension. Heparin-induced thrombocytopaenia (HIT) within the last year where there is no alternative to repeating heparin treatment
Other medical needs	Severe pain (e.g. requiring opiates). Chronic Kidney Disease stages 4 or 5. Severe liver disease. Other medical comorbidity requiring hospital admission*. Unsafe discharge due to social reasons including inadequate care at home, lack of a telephone or concerns over compliance

*Low risk patients do not need specific right ventricular (RV) functional assessment but where RV dilatation has been identified on CT or Echo in patients otherwise suitable for outpatient management, consider measuring BNP, NT-proBNP and hsTnI or hsTnT. Elevated biomarkers should prompt inpatient admission for observation. Incidental elevated troponin requires senior review and consideration of an alternative cause to the elevated troponin.

Can a patient with suspected but yet to be confirmed PE be managed as an outpatient?

Patients that meet the same criteria as confirmed PE can be managed as an outpatient if they undergo investigation the same day or within 24 hours as part of a robust system of follow up investigation and review.

What should suspected or confirmed PE patients be treated with?

1. LMWH and dabigatran
2. LMWH and edoxaban
3. Single drug regimen with either apixaban or rivaroxaban

A single DOAC pathway is now preferred to minimise confusion over dose administration. Patients with suspected but not confirmed PE could be initiated on a single DOAC pathway pending diagnosis as an alternative to LMWH. Depending on your local pathway we could be discharging people from our EDs on DOACs a lot more.

Does guidance change for special patient groups?

Yes. Three special patient groups have been highlighted in the guidance.

Intravenous drug use	These patients need to admitted for further investigation regardless of risk assessment
Pregnancy	Outpatient management can be considered but clinical risk scores derived from non-pregnant populations (PESI/sPESI) should not be used. DOACs and Vitamin K antagonists should not be used. All pregnant or post partum women with suspected or confirmed PE should be reviewed by a consultant and discussed with maternity services prior to discharge
Cancer patients	Can be assessed for outpatient management using the Hestia Criteria. Incidental PEs should be managed in the same way as symptomatic ones. Given the higher risk of 30 day mortality, they should have consultant review prior to discharge.

Safe discharge: What do the guidelines state needs to happen?

For safe discharge from the ED, all of the below need to have been addressed. The one of particular impact is the need for senior review and the existence of an established pathway that should address these other key areas including the assessment and advice for the patient.

Local protocol	Should be in place with guidance on the need to conduct a full cardiorespiratory assessment including history, examination, ECG, chest radiograph and risk assessment.
Senior review	Consultant review of all patients is required prior to discharge on an outpatient PE pathway In the ED, where a consultant is not available, the middle grade senior doctor or designated ANP/ clinical nurse specialist must review prior to discharge.
Discharge information	Verbal and written information on the signs and symptoms of recurrence, major bleeding and additional complications must be provided. A point of contact both in and out of hours also needs to be provided.
Follow up	From an ED perspective the take home is that patients need to be discharged into an established pathway. Patients will need a formal review in the first week post discharge and a follow up consultation by a clinician with a special interest in Venous Thromboembolism (VTE) for consideration of provoking risk factors.

The above summarises the key points from the new BTS ambulatory PE guidelines from an ED perspective. There is further information within the full guideline itself and we would encourage you to look at your local pathways and reflect on your own clinical practise to ensure that it reflects these new guidelines on recommended best practise.