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HSL RRLs: Request procedures


HSL is contracted to provide results on an urgent and routine basis. There are contractually-defined lists of urgent tests and their target turnaround times (TATs) for each RRL, and these are monitored on a daily basis by laboratory staff and reported on formally at the HSL Board, at Laboratory Operations Committees, Clinical Pathology Advisory Committees and Operational Management Group meetings every month.


Urgent requests

The laboratory defines urgent samples as those where the results are required for immediate patient management. For each individual contract there is a defined list of locations from which samples are always treated as urgent; procedures for requesting urgent testing from other locations differ slightly depending on the Trust.

Barnet / Chase Farm

  • A&E/AAU
  • CC North and South
  • Mulberry Ward
  • Victoria Ward
  • Maternity Delivery Room
  • Starlight Ward (Paediatric and Transitional Care)
  • Paediatrics Special Care Unit
  • OPAU
  • Pre-chemo samples


North Middlesex Hospital

  • A&E
  • Critical Care
  • Ambulatory Care
  • Neonatal ICU
  • Labour Ward

Royal Free Hospital

  • A&E / 2NA / Urgent Care
  • MAAU
  • IRCU
  • Lyndhurst Rooms
  • ICU
  • Clinic 6 (Haematology only)
  • 11 South (Haematology only)
  • Oncology (only if patient awaiting chemotherapy)
  • Pre-chemo samples in a bag labelled ‘pre-chemo priority’
  • SCBU/NNU (BUT not routine paediatric samples)


UCL Hospitals

  • A&E
  • AAU
  • ITU
  • Haematology Wards
  • Oncology (only if patient awaiting chemotherapy)
  • Pre-chemo samples
  • SCBU/NNU (BUT not routine paediatric samples)

Royal Free London

Other urgent samples:

  • Samples phoned to extension 38851 help desk option 2 (Hampstead) and requested as urgent prior to sending sample to the laboratory.
  • Samples delivered by clinicians directly to laboratory staff and identified to laboratory staff as urgent
  • Any requests for blood gases, ammonia, lactate, CSF protein, CSF glucose.

Barnet/Chase Farm

  • Samples phoned to 65037 (Barnet), 51786 (Chase Farm) and requested as urgent prior to sending sample to the laboratory

Please note: Samples requested as urgent on Cerner or on the specimen bag (unless specifically requested to do so by the laboratory) will not be treated as such.

Urgent results are usually communicated by telephone, therefore in order to effectively communicate abnormal urgent results the bleep number/telephone number of the clinician requesting the test is required.

If a clinician is offsite outpatient/ward/GP setting and require urgent Contact RFH switchboard and ask them to contact extension 38851 help desk option 2 (Hampstead) or phone 65037 (Barnet).

Provide the laboratory with the details of the patient whose sample you wish to be processed urgently and what tests you would like to request.

Make the request in the usual way ensuring that you have provided a telephone number or bleep number by which the lab can contact you should the results be abnormal. Please note results will be available within 1 hour of the samples receipt by the laboratory.

Package the sample which requires urgent processing separately and make it clear on the packaging that the sample is urgent. Arrange transport of the sample to the laboratory.

North Middlesex University Hospital

Samples from certain locations, such as A/E, will be automatically processed urgently.

For other locations, order comms requests should only be marked as urgent where they are required for the immediate management of the patient. Urgent samples from other locations must be sent in red bags.

It is essential to telephone a Microbiology Consultant before sending an urgent request. To prevent delay, it is good practice to telephone Blood Transfusion for all urgent requests.


Requesting additional tests (‘add-on’ requests)

Under certain circumstances, it is possible to add tests on to samples that are already in the laboratory, but this will depend on sample stability, tube type and, for some tests, there will be timing restrictions. There may not be sufficient specimen to perform the additional tests. Investigations are best performed on fresh primary specimens and where possible, any non-urgent investigations should be deferred until a further phlebotomy episode is being performed.

The availability of a sample for further analysis cannot be guaranteed owing to limits imposed by refrigerated storage space, even if the analyte required is stable for weeks at a time.

It will not always be possible to add on a test if the analyte requested is sufficiently unstable that any result provided would be inaccurate (eg Troponin 24h), or if the quality of the sample is such (haemolysed, lipaemic, icteric) that the result would be inaccurate.

Please note that standard sample retention time will differ according to the nature of the original request. The laboratory will be able to advise if a sample is still in storage and appropriate to the test required to be added retrospectively. Where the laboratory receives a request for an add-on that cannot be fulfilled the user will be advised through the standard laboratory report.

Blood Transfusion accepts additional test and blood component requests over the telephone depending on the sample validity of 72 hours (7-day sample validity is also applicable at UCLH). Blood component requests made by telephone must be made by medical staff, qualified midwives or trained and authorised practitioners.

All requests for urgent add-on tests [only tests that will change management immediately and in our urgent test repertoire] should be requested by contacting the Laboratory. All requests should include the following information; Name of Patient, DOB, Hospital Number, Name of test to be added, Date and time of sample, Contact number/bleep of requestor.

Add on tests requested urgently should be available within 2 hours (if appropriate) of the time the telephone request is received. For non-urgent add on tests requested during working hours, results should be available within 24 hours of the time the email request is received. Requests for add on tests that must be sent to a referral laboratory, or be processed by our specialist sections may take longer.

Chemistry/Haematology samples are not suitable for use when requesting additional testing for virology/serology due to the potential for cross-contamination of samples during the original analysis.

At Royal Free there is an add-on email address for routine requests. This will be monitored Monday to Friday
09:00 – 17:00. rf.biochemhaemaddon@nhs.net

At North Middlesex there is an add-on email address for routine requests. This will be monitored 24/7. nmhpathology.addonrequests@nhs.net

At Barnet there is an add-on email address for routine requests. This will be monitored Monday to Friday
09:00 – 17:00. rf-tr.barnetlab.helpdesk@nhs.net

At UCLH, there is an email for routine add-on requests, monitored Monday – Friday 09:00-17:00 uclh.enquiry.biochemhelpdesk@nhs.net