Pathology Phone Limits

Pathology Phone Limits

By Department

Clinical Chemistry

Phoning and Critical Limits

  Below Above Units Sodium 120 150 mmol/L Potassium 3 6.5 mmol/L Urea   30 mmol/L Creatinine   500 umol/L Glucose 2.5 20 mmol/L Calcium adjusted 1.8 3.5 mmol/L Magnesium 0.4   mmol/L Phosphate 0.3   mmol/L AST   700 U/L ALT   400 U/L Total CK   500 U/L Amylase   600 U/L TBA   20 umol/L Iron   70 umol/L Total bilirubin   225 umol/L Carbamazepine   25 ug /mL Digoxin   2.5 ng/mL Theophylline   45 mg/L Phenytoin   20 mg/L Phenobarbitone   70 mg/L Lithium  <0.2 >1.5 mmol/L Valproate   100 mg/L Cyclosporin A   200 ug/L CRP   300 mg/L Salicylate   50 mg/L Paracetamol   10 mg/L Ammonia All phoned     Lactate All phoned    


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.


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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To assess prednisolone metabolism in steroid dependent asthmatics


Small group of asthmatics remain symptomatic despite long term treatment with oral corticosteroids “prednisolone”, with major implication in terms of steroid induced side effects.  The cause of this lack of effect could be due to poor adherence, malabsorption, rapid metabolism or genetically mediated resistance to steroids.  The aim of this test is to assess the cause of the apparent lack of responsiveness to steroids in a patient.


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