Pathology News

1 November: changes to the clinical biochemistry diagnostic service for primary care colleagues

1st November 2019

 

For the attention of all clinical colleagues in Primary care

 

Dear Colleagues,

In line with NHS Improvement and laboratory review processes, please see below for some relevant information which will help to streamline our clinical biochemistry diagnostic service.

 

Requests for biochemistry are collected in brown top tubes.

Requests for serology & virology are collected in white top tubes. Please ensure that sufficient blood is taken because many samples have insufficient serum.

If biochemistry requests are received in white top tubes then TAT is delayed.

 

Add on requests biochemistry

Please only use the email: ADDONS, Biochem (HOMERTON UNIVERSITY HOSPITAL NHS FOUNDATION TRUST) biochem.addons@nhs.net

We do not take phone calls for add on tests.

 

Glucose tolerance tests (GTT)

To diagnose diabetes it is easiest to request HbA1c, because HbA1c does not require the patient to be fasting, nor to undergo the ingestion of 75g glucose.

GTT should be reserved for diagnosis of gestational diabetes & by Diabetologists.

Please send both basal or time 0 min sample together with the 120 min sample together, to the lab on a single request form. (Please see document ‘HbA1c interpretation for diagnosis & monitoring of diabetes’).

 

Lithium

The blood sample for lithium measurement should be taken 12 hours post dose, preferably at the same time of day for each patient. The time of the blood sample and the time of the last dose must be recorded on the request form.                               

 

Zinc

Requests for serum zinc must be collected in a trace metal tube.

 

Vitamin B12 deficiency diagnosis (changes applicable from 15th November 2019):

Serum vitamin B12 < 200 pmol/L is diagnostic of deficiency and does not require further testing for serum holotranscobalamin (active vitamin B12) and methyl malonic acid (MMA).

 

Both holotranscobalamin (active B12- cost £9) & MMA (methylmalonic acid -cost £46) will no longer be available as a request on T-Quest wef 15th November 2019. This follows current practice of harmonizing with standard practices and also a request from the CCG pathology Lead which has been approved by the Haematology Clinical Lead and Clinical Biochemistry Clinical Lead.

 

Patients with serum vitamin B12 level of 200-400 pmol/L will have reflex serum holotranscobalamin (active B12) request added to the sample. MMA testing will only be available on consultant led request in secondary care patients only, however this will require approval by the duty biochemist. A MMA test request without prior approval will be rejected, which can cause delay in diagnosis and patient management.

 

If vitamin B12 < 200 pmol/L and should this patient warrant holotranscobalamin, then you may state the detailed clinical reasoning for this & send an email to ADDONS, Biochem (HOMERTON UNIVERSITY HOSPITAL NHS FOUNDATION TRUST) biochem.addons@nhs.net and if the lab holds a sample (samples are stored in the lab for 4-5 days only, depending on the storage capacity),  it will be considered. MMA testing will be available for high risk bariatric surgery patients in secondary care at HUH, and will require approval by the duty biochemist.

 

Renin & Aldosterone requests

There will be a change in request terminology from ‘plasma renin’, to ‘renin and aldosterone’. Renin, aldosterone will be requested and the ratio calculated.

Requests for aldosterone should be restricted to monitoring adreno-cortical hyperplasia & tumours.

 

FLC – free light chains:

FLC (cost £25) are to be restricted to requests from haematology & Renal

 medicine. When a new paraprotein is observed in serum protein electrophoresis, then serum free light chains will be added & urine for protein electrophoresis requested.  MGUS monitoring by GPs will not receive free light chains. Should a patient warrant FLC, then you may state the detailed clinical reasoning for this & send an email to ADDONS, Biochem (HOMERTON UNIVERSITY HOSPITAL NHS FOUNDATION TRUST) biochem.addons@nhs.net and if the lab holds a sample it will be considered.

 

Serum protein electrophoresis (SPE- Changes applicable from 15th November 2019):

Raised globulins will no longer generate reflex testing for SPE from 15th November. This follows current practice of harmonizing with standard practices and also a request from the CCG pathology lead which has been approved by Haematology Clinical Lead and Clinical Biochemistry Clinical Lead.

 

GP: Hypertension in Pregnancy Diagnosis-NICE guidance:

Tests required: FBC, LFTs, Kidney function CE, if urine spot dipstick check is positive for protein then request urine protein: creatinine ratio & if > 30 mg/mmol, which is the diagnostic threshold.

The manual test request PET profile will be discontinued.

BMJ 2019;366:l5119 doi: 10.1136/bmj.l5

 

Should you wish to discuss these changes, please contact the lab on email address provided above and it will be referred to Duty biochemist of the day.

 

Dr Jeffrey Barron & Dr Manisha Sharma                              Mehwish Khalid (Laboratory Manager & HOD)

(Consultant Chemical Pathologists)                                      Susan Benson (Head of Pathology)

1 November: changes to the clinical biochemistry diagnostic service for seconday care colleagues

1 November 2019

For the attention of all clinical colleagues in secondary care (HUH) including medical, nursing, maternity, sexual health and phlebotomy

In line with NHS Improvement and laboratory review processes, please see below for some relevant information which will help to streamline our clinical biochemistry diagnostic service.

Ammonia
Requests for blood ammonia must be collected in lithium heparin tube. The sample should be immediately put in ice in a plastic bag, together with another unused lithium heparin tube which is used as the blank tube for the assay.

Requests for biochemistry are collected in brown top tubes.

Requests for serology & virology are collected in white top tubes. Please ensure that sufficient blood is taken because many samples have insufficient serum. If biochemistry requests are received in white top tubes then TAT is delayed.

Add on requests biochemistry
Please only use the email: ADDONS, Biochem (HOMERTON UNIVERSITY HOSPITAL NHS FOUNDATION TRUST) biochem.addons@nhs.net
We do not take phone calls for add on tests.

Glucose tolerance tests (GTT)
To diagnose diabetes it is easiest to request HbA1c, because HbA1c does not require the patient to be fasting, nor to undergo the ingestion of 75g glucose. GTT should be reserved for diagnosis of gestational diabetes & by Diabetologists.
Please send both basal or time 0 min sample together with the 120 min sample together, to the lab on a single request form. (See document ‘HbA1c interpretation for diagnosis & monitoring of diabetes’).

Lithium
The blood sample for lithium measurement should be taken twelve hours post dose, preferably at the same time of day for each patient. The time of the blood sample and the time of the last dose must be recorded on the request form.                              

Zinc
Requests for serum zinc must be collected in a trace metal tube

Vitamin B12 deficiency diagnosis:
Serum vitamin B12 < 200 pmol/L is diagnostic of deficiency and does not require further testing for serum holotranscobalamin (active vitamin B12) and methyl malonic acid (MMA).
Both holotranscobalamin (cost £9) & MMA (cost £46) will no longer be available as a request on T-Quest wef 15 November 2019. This follows current practice of harmonizing with standard practices and also a request from the CCG pathology Lead which has been approved by the Haematology Clinical Lead and Clinical Biochemistry Clinical Lead.

Patients with serum vitamin B12 level of 200-400 pmol/L will have reflex serum holotranscobalamin (active B12) request added to the sample. MMA testing will only be available on consultant led request in secondary care patients, however this will require approval by the duty biochemist.A MMA test request without prior approval will be rejected, which can cause delay in diagnosis and patient management.

If vitamin B12 < 200 pmol/L and should this  patient warrant holotranscobalamin, then you may state the detailed clinical reasoning for this & send an email to ADDONS, Biochem (HOMERTON UNIVERSITY HOSPITAL NHS FOUNDATION TRUST) biochem.addons@nhs.net and if the lab holds a sample (samples are stored in the lab for 4-5 days only, depending on the storage capacity), it will be considered.

Renin & Aldosterone requests   
There will be a change in request terminology from ‘plasma renin’, to ‘renin and aldosterone’. Renin, aldosterone will be requested and the ratio calculated. Requests for aldosterone should be restricted to monitoring adreno-cortical hyperplasia & tumours.

FLC – free light chains
FLC (cost £25) are to be restricted to requests from haematology & kidney medicine. When a new paraprotein is observed in serum protein electrophoresis, then serum free light chains will be added & urine for protein electrophoresis requested.  MGUS monitoring by GPs will not receive free light chains. Should a patient warrant FLC, then you may state the detailed clinical reasoning for this & send an email to ADDONS, Biochem (HOMERTON UNIVERSITY HOSPITAL NHS FOUNDATION TRUST) biochem.addons@nhs.net and if the lab holds a sample it will be considered.

Serum protein electrophoresis (SPE)
Raised globulins will no longer generate reflex testing for SPE from 15th November. This follows current practice of harmonizing with standard practices and also a request from the CCG pathology lead which has been approved by Haematology Clinical Lead and Clinical Biochemistry Clinical Lead.

Maternity: Hypertension in Pregnancy Diagnosis-NICE guidance
Tests required: FBC, LFTs, Kidney function UE, if urine spot dipstick check is positive for protein then request urine protein: creatinine ratio & if > 30 mg/mmol, which is the diagnostic threshold.
The manual test request PET profile will be discontinued.
BMJ 2019;366:l5119 doi: 10.1136/bmj.l5119 

Should you wish to discuss these changes, please contact the lab on email address provided above and it will be referred to Duty biochemist of the day.

Dr Jeffrey Barron & Dr Manisha Sharma                              Mehwish Khalid (Laboratory manager & HOD)
(Consultant Chemical Pathologists)                                     Susan Benson (Head of Pathology)