Pathology staff will ring through all critically abnormal results to an authorised individual at the location of the patient.

Pathology staff will ring through all significantly abnormal results to location of the patient.

The action limits for the most common analytes are listed below.


  • All Blood Gas results (except for those coming from ED, ICU)
  • Urgent requests specifying that the results be phoned through
  • Samples that can’t be analysed due to Haemolysis, Insufficient sample or lab accident.
  • Any Authorised or interimed results that have been amended.
  • All CSF Xanthochromia results and samples not meeting assay criteria.
  • Critical Results that are significantly outside of the normal range exceed critical values (see below) and have been double checked:

Samples that exceed critical values

TestLower LimitUpper LimitUnits
Na+< 120> 150mmol/l
K+< 3.0> 6.0mmol/l
HCO3< 13> 40mmol/l
Glucose< 3.0> 20.0mmol/l
Ca++< 1.5> 2.80mmol/l
Mg++< 0.4> 2.0mmol/l
PO4< 0.35> 3.00mmol/l
Dig--> 3.00nmol/L
Trig--> 12.0mmol/L
Para > 200umol/L
Cort< 100--nmol/L

Electrolytes will be done immediately on blood accompanying glucose specimens >20.0 mmol/l. Results will be rung out as soon as possible.


TestLower LimitUpper LimitUnits
Haemoglogin< 70> 200g/L
Platelets< 50> 1000x109/L
Leucocyte count< 1.1 x109/L
Neutrophil count< 1.0 x109/L
INR > 4.5
INR (Pre Op) > 1.5
APTT (Pre Op) > 40seconds
APTT (On Heparin) > 100seconds
Fibrinogen< 1.0 g/L

A patient result that differs significantly from that obtained on a previous sample, within a short time frame, must also be telephoned to the requesting doctor or ward.

Problems phoning urgent / abnormal results

If pathology are unable to get through to the ward, or no one answers a pager for urgent results, the covering resident will be paged via switch as a last resort. If there is still no response, a comment will be entered in the pathology system.

Result advice

Contact us our expert pathologists for specialist advice.

The Royal College of Pathologists (RCPA) also provides comprehensive information on pathology tests, reference intervals and interpretation.