Login to South West London Pathology Services

If you have any queries about pathology consumables – you need a new account or you have a query about your order, please telephone 020 8266 6827. Forgotten your password

Grossly abnormal results

At SWLP, each discipline handles how grossly abnormal results are communicated to GPs in a different way, depending on the nature of the test.

Below is information about how each discipline makes decisions about when to contact GPs urgently with results.

Chemistry

Results outside the limits in the table below will be telephoned to GP practices during normal working hours.

From 6pm to 10pm weekdays, and 8am to 10pm weekends and bank holidays, results will be reviewed by a clinical scientist/chemical pathologist, and telephoned to the out-of-hours service if required. Values marked in red are a change from the current telephone limits. These limits do not preclude telephoning of any significantly changed results.

AnalyteLower limitUpper limitUnitsNotes
Sodium≤ 120
≤ 130 if age
under 16 y
≥ 160mmol/L
Potassium≤ 2.5≥ 6.5mmol/L
Glucose≥ 25
≥ 15 if age
under 16 y
mmol/L
Creatinine≥ 350
≥ 200 if
age
under 16 y
mmol/LResults won’t be
telephoned if
dialysis
patient or
known
CKD unless
creatinine
has increased by
≥ 100 umol/L
from
previous result
CRP≥ 300mg/L
Calcium≤ 1.8≥ 3.5mmol/L
Bilirubin
(Paediatric)
≥ 250umol/L
ALT≥ 750IU/L
Cortisol≤50nmol/LUnless post
dexamethasone
CK≥ 5000U/L
Digoxin≥ 2.5umol/LSample should be
6h post dose
Lipase≥300U/L
Lithium≥ 1.5mmol/L
Magnesium≤ 0.4mmol/L
ParacetamolAll
detectable
levels
Phosphate≤ 0.3mmol/L
Phenytoin≥ 25mg/L
Salicylate≥ 300mg/L
Theophylline≥ 25mg/L
Troponin T≥ 50mg/L
Urea≥30
≥ 10 if age
under 16 y
mmol/LResults won’t be
telephoned if
dialysis patient
or
known CKD
unless
urea increases
by ≥ 10 mmol/L

Results outside the critical limits stated below will be telephoned to the GP out-of-hours (111) service during the overnight period (10pm to 8am). As well as reviewing renal function, samples with high potassium levels will be checked for haemolysis, age of sample, and possible contamination prior to telephoning.

AnalyteLower limitUpper limitUnitsNotes
Sodium≤ 115≥ 160mmol/L
Potassium≤ 2.0mmol/L
≥ 6.5
Potassium levels
≥ 6.5 will not be
telephoned
overnight
if the creatinine is
within normal
limits
Glucose≥ 30
≥ 15 if
patient
under 16
years old
mmol/L
Creatinine≥ 350
≥ 200 if
patient
under 16
years old
mmol/LResults won’t be
telephoned if
dialysis patient or
known CKD unless
creatinine has
increased by
≥ 100 umol/L
from previous
result
CRP≥ 300mg/L
Calcium≤ 1.5≥ 3.5mmol/L
Bilirubin
(paediatric)
≥ 250umol/L

Haematology

If an abnormal result which meets the criteria set out below is detected within office hours a biomedical scientist will contact the patient’s clinical team (consultant or GP).

If the result is detected out of hours a biomedical scientist will call the clinical team for an in-patient or 111 if the request came from a GP. In this case, clinical queries should do through the on-call registrar.

HB≤70 g/l if new anaemia or fall of 40 g/l in 24 hours
Neutrophils≤ 0.5 x 10⁹/L unless patient known to be receiving chemotherapy
Lymphocytes≥ 50 x 10⁹/L unless known CLL
Platelets≤ 30 x 10⁹/L

Immunology

Any clinically significant results warranting urgent action are telephoned to the requestor at the discretion of a consultant clinical scientist

Microbiology

In microbiology, there are no reference ranges per se. Significant urgent results are telephoned or communicated by other means on the judgement of the clinical microbiologists.

Latest news

June 24, 2022

HIV service at Croydon Hospital wins ‘Top Global Winner’ at the UNIVANTS awards

This week, it was announced that work to improve HIV outcomes at Croydon Hospital was awarded ‘Top Global Winner’ at the UNIVANTS 2021 awards. The work focused on the introduction of ‘opt-out’ HIV testing in the Emergency Department at Croydon Hospital, with a sustained rate of 97% over 18 months, setting an international gold standard. […]

Read more
June 20, 2022

Immunology services across south west London to be centralised at the Immunology Laboratory at St George’s Hospital

All Immunology services and tests are moving to the South West London Pathology (SWLP) Immunology Laboratory and Protein Reference Unit at St George’s Hospital, which will become the hub for immunology across south west London. Already one of the largest immunology services in the country, the team will be expanded further when immunology services and […]

Read more
May 16, 2022

Point of Care Testing (POCT) at St George’s gets first UKAS accreditation

Last month, the SWLP POCT team received the exciting news that after two years of hard work, the blood gas and glucose meter service at St George’s was given full UKAS accreditation. It is the largest and most complex POCT service in the country to receive full accreditation, which proved challenging for both the POCT […]

Read more
May 4, 2022

SWLP Point of Care Testing Team runs first community diagnostic outreach clinic

South West London CCG ran their first diagnostic outreach clinic in the community supported by our Point of Care Testing (POCT) team testing at-risk groups for diabetes. The clinic was run at a Shree Ghanapathy Temple in Wandsworth where 34 members of the community were tested. Of that 34, 32 had abnormal results and two […]

Read more