[CG] Outpatient investigation of venous thromboembolism (VTE) in pregnant women attending PRM (COVID-19)


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Woman presents to MAU / antenatal clinic with symptoms of DVT or PE

Assessment by member of obstetric team– follow GGC Obstetric VTE guideline re Hx, examination, CXR/ECG, bloods.

VTE suspected

Prescribe and administer treatment dose enoxaparin (1.5mg/kg OD) sc, as soon as possible, and within 1 hour of assessment if suspect PE or within 4 hours if suspect DVT

Book urgent outpatient scan (V/Q or Leg Doppler USS as applicable): investigation required within 72 hours of clinical suspicion. Remember to state patient pregnant (in clinical details box). Phone relevant department (radiology 29384 ; nuclear medicine 24762) to state a request has just been submitted for a pregnant patient, if in daytime hours. Include obstetric on-call contact numbers (Reg: 10055, Cons: 10056)

  • Obstetric Registrar can make decision regarding need for Doppler USS
  • Discuss with Consultant before proceeding with request for V/Q scan *

If scan appointment unavailable on the same day that patient presents, then patient may go home with therapeutic enoxaparin as long as all the following parameters are met;

  • Clinically stable (BP>90/60 Pulse <100bpm, RR<21, O2sats>96% in air)
  • able to self-administer enoxaparin
  • understands instructions, including parameters as to when should represent to hospital if symptoms worsen
  • can provide a reliable contact telephone number (NHS outgoing calls “0800” number)
  • has transport enabling easy return to hospital
  • Not known to have a major placenta praevia
  • Considered reliable to return for scan

Only provide patient with sufficient number of clexane injections to last until scan performed. Remember sharps box.

If patient does not meet all of these criteria or an outpatient scan cannot be obtained within 72 hours of presentation, then admission is necessary until investigation performed.

If a patient is discharged prior to the scan, then this decision must be discussed with obstetric consultant (ST6/7 if consultant unavailable) prior to discharge

List of patients under outpatient investigation for possible DVT/PE should be kept in Maternity Assessment to ensure;

  • scan appointment booked with the date and time of scan (if not booked, specify who will chase the scan appt the following day)
  • repeat scan appointment booked with the date and time of scan (if applicable)
  • Patient lost to follow up can be chased e.g. women post scan doesn’t return to MAU
  • Women only scored off once investigations and management has been completed

Patients should have an allocated scan appointment before they go home. If this is not possible e.g. presents out of hours, MAU must call radiology the following day to obtain an appointment and contact patient with this information and tell patient to attend daycare / MAU following scan.

Patient attends GRI radiology department directly for leg Doppler or nuclear medicine department  for V/Q scan

Following scan patient reports to daycare (09:00-16:45) or Maternity Assessment (level 2 PRM) out of hours to await result and plan further management.

Medical staff review result –

 If positive scan (proven DVT or PE) continue therapeutic enoxaparin as per GGC VTE guidelines. Refer patient to Haematology antenatal clinic for follow-up.

If negative scan

  1. Stop enoxaparin & discharge home
  2. If significant clinical suspicion of DVT remains despite negative Doppler: stop enoxaparin & arrange outpatient repeat leg Doppler in 5-7 days. Process as above. Medical staff who review the patient on presentation should document in patient record if a repeat Doppler should be performed in the event of the initial Doppler being negative (i.e. they have significant clinical suspicion). This note will aid colleagues in the event of having to review a scan result remotely to patient.

*Women with suspected / confirmed COVID19 should not undergo V/Q scan.

Test symptomatic women [Strict criteria for testing: new, continuous cough means coughing for longer than an hour, or three or more coughing episodes in 24 hours (if you usually have a cough, it may be worse than usual)  and/or a fever].  If she does have either, or particularly both, of those symptoms then she probably doesn’t have a PE.

If patient well she may be home on therapeutic clexane to self-isolate while awaiting COVID19 result & subsequent scan.

  1. If COVID19 result negative: V/Q scan.
  2. If COVID19 result positive: CTPA if clinically indicated. Consultant decision. Inform X-ray COVID19 positive.

Key features

Ensure robust system for scans being appointed & patients receiving details – with fail safe to check

Ensure robust system for medical review of scan results & ensure patients receive correct management thereafter.

If delays in receiving results then will need to develop system allowing patients to go home after scan & be phoned with result once available. This would need to be robust. This may be less problematic for leg Doppler results but may be necessary for V/Q scans if these are only reported at end of afternoon – don’t want patient sitting in daycare all day waiting for result. For negative results this is less of an issue as patients will be discontinuing clexane treatment although small number of patients will require repeat scan booking. For positive results: patients will be required to return to hospital in order to receive on-going treatment.


Last reviewed: 30 March 2020

Next review: 31 March 2021

Author(s): Dr Vicki Brace, Consultant Obstetrician PRM