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Pathology Phone Limits

Pathology Phone Limits

By Department

Clinical Chemistry

Phoning and Critical Limits

Analyte

Phone results below or equal to:

Phone results above or equal to:

Units

Notes

Sodium

120

150

mmol/L

 

Potassium

2.5

6.5

mmol/L

 

Urea

-

Adults: 30

Paediatrics: 10

mmol/L

 

Creatinine

-

Paediatrics: 200

umol/L

Except those on renal wards or under renal consultants.

eGFR

Adults: 15

-

ml/min

AKI

-

3

 

Not CKD patients

Glucose

2.5

25

mmol/L

 

Calcium adjusted

1.8

3.5

mmol/L

 

Magnesium

0.4

-

mmol/L

 

Phosphate

0.3

-

mmol/L

 

AST

-

600

U/L

 

ALT

-

600

U/L

 

Total CK

-

5000

U/L

 

Amylase

-

500

U/L

 

Digoxin

-

2.5

ng/mL

 

Theophylline

-

25

mg/L

 

Phenytoin

-

25

mg/L

 

Lithium

-

1.5

mmol/L

 

Troponin I

-

16 (female or unknown)

34 (male)

ng/L

GP only

Ammonia

-

100

umol/L

 

Ethanol

-

Paediatrics only: any detectable

mg/L

Paediatrics only

Paracetamol

-

10

mg/L

Not ED patients

Salicylate

-

300

mg/L

Not ED patients

Conj bilirubin (DBIL)

-

Paediatrics only:

25

umol/L

Paediatrics only

Total bilirubin

-

Paediatrics only: 225

umol/L

Paediatrics only

Carbamazepine

-

25

ug /mL

 

Iron

-

ED only: 70

umol/L

ED only

Phenobarbitone

-

70

mg/L

 

CSF Gluc

3.3

-

mmol/L

 

CSF Prot

-

0.45

g/L

 

Lactate

-

2.3

 mmol/L  

CRP

-

300

 mg/L  GP only

Total bile acids

-

20

 umol/L  Antenatal only
Urine protein:creatinine ratio   30 mg/mmol Antenatal only, first raised result only

Methotrexate

Phone all

umol/L

 

Haematology

HaemoglobinWhite Blood Cell Count
<8.0 g/dl normochromic and normocytic Low result – neutropenia <0.5 x 10 9/L
<7.0 g/dl microcytic and hypochromic   High result – White cell count >40 x 10 9/L
<7.0 g/dl macrocytic  or Lymph count > 20 x 10 9/L
<5.0 g/dl renal patients Any presence of blast cells

PlateletsClotting Studies
Lower limit - <70 x 10 9/L   INR - >5.0
Upper limit - >1000 x 10 9/L   PTT - >180 seconds
  Fibrinogen < 1.0g/l
  • All Positive Malaria Screens
  • All Anti FXa results >1.20 iu/ml
  • If the patient is known to the department and has had a similar result within the previous 7 days then the urgent contact is not necessary.

Immunology

  • CD4 count <200 cells/cumm or <10% on new patients (paediatric levels are different, but agreed with Paed consultants)
  • Lymphocyte subsets in infants <2yo: Any T cell subset below age-related normal range, any other abnormality suggesting SCID (e.g. MHC class II deficiency). (Note this is not exclusive: any abnormality may be discussed with requesting clinician)
  • New positive GBM antibodiest
  • New positive MPO antibodies
  • New positive PR3 antibodies
  • New paraprotein IgG , A or M  > 20g/L
    • IgD or IgE (any size)
    • serum monoclonal free light chains (any size, whether or not with intact paraprotein)

HPA Microbiology

Bacteriology

  • Gram stain results of positive blood culture on Day 1
  • Positive CSF results
  • Positive sterile site results
  • Significant in-patient results from enteric bench
  • Multi resistant gram negative and gram positive isolates including mupirocin resistant MRSA
  • Group B streptococcal isolates from neonates
  • Group A in patient isolates
  • Positive Legionella urinary antigen and Pneumococcal urine antigen results
  • Smear and culture positive Mycobacteria
  • Antibiotic assay results outside normal ranges
  • Any other significant results at the discretion of Medical Microbiologists

Virology

  • Serological evidence of acute infection with Hep A, Hep B and in pregnant patients CMV, Parvovirus and Rubella
  • New diagnoses of HIV
  • VZV IgG negative from exposed patients at risk of severe VZV infection
  • New diagnosis of Hep B, Hep C and HIV in haemodialysis patients
  • Evidence of Hep B/Hep C and HIV in needle stick injury source patients
  • Clinically important positive respiratory PCR results i.e.: influenza, RSV in immunocompromised patients
  • Positive PCR results in outbreaks
  • Positive blood PCR for CMV and Adenovirus
  • Negative blood results for CMV PCR
  • Significant blood PCR results for EBV and Polyomavirus
  • All positive PCR results on CSF specimens
  • All positive Chlamydia PCR results on eye swabs
  • All positive PCR results from neonatal unit
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