Bilimeter (Minolta transcutaneous bilirubinometer)

Warning

Important: 

All bilimeter readings must be documented in the infant's casenotes

The Minolta bilimeter is not accurate enough to be used as a diagnostic tool to replace measuring SBR. It should only be used to help decide which infants need an SBR performed.

When to use and when not to use

The bilimeter can be used in infants of

  • gestational age 35 weeks to term (note new lower gestation limit)
  • postnatal age 2 to 14 days (jaundice in the first 24 hours should always be investigated)
  • any skin colour -the Minolta bilimeter is reliable in babies with dark skin
  • The Bilirubinometer should not be used to assess need for Prolonged Jaundice referral

Avoid using the bilimeter

  • when an infant has been under phototherapy
  • when an infant has had an exchange transfusion
  • on forehead sites with bruising, birthmarks, haematomas or excessive hairiness
  • on sites other than the forehead

Thresholds for performing SBR

Note that the thresholds differ according to gestational age at birth (i.e. not corrected).

 

Bilimeter Reading

24 to 48 hours

> 48 hours

35+0 - 36+6 weeks

120 µmol/L

200 µmol/L

37+0 weeks and older

170 µmol/L

270 µmol/L

N.B. If the Bilimeter shows the dashed display shown below, it is likely that the estimated bilirubin value is high (above 340), and a lab bilirubin measurement must be carried out.

 

Preparation

  • Remove from charger
  • Clean probe with alcohol swab
  • Switch on -ready lamp should illuminate -if light blinks, charge battery
  • Ensure reading is set to µmol/L (if not, switch off and then switch on again while holding down "reset" button -hold down "reset" for 15 seconds until unit changes)
  • Hold down "reset" until n-3 shows (3 readings will be averaged -note this is different from 5 readings used previously)

Taking a reading

  • Place probe vertically on forehead (avoid obvious bruises or discoloured areas)
  • Apply gentle pressure until probe clicks -the number of remaining measurements is displayed (the value is not displayed until all 3 measurements are done)
  • Repeat until all 3 measurements are done -the average of the measured values is displayed

Editorial Information

Last reviewed: 17/08/2023

Next review date: 17/08/2033

Author(s): David Quine.