Point of care estimation of haemoglobin in neonates

Abstract

Objective: To evaluate whether measurement of haemoglobin concentration in neonates using point of care testing agrees with laboratory measurement. Design: 127 paired blood samples taken from babies on a neonatal intensive care unit for full blood count and blood gas analysis by point of care testing were reviewed according to current practice. A comparison was made between the laboratory and blood gas analyser haemoglobin measurements to assess limits of agreement and look for any systematic difference. Setting: Neonatal Unit, Jessop Wing, Royal Hallamshire Hospital, Sheffield, UK Patients: Babies staying on the neonatal unit, who currently have contemporaneous blood samples taken for full blood count and blood gas analysis by point of care testing. Intervention: Results from blood samples were reviewed. Main outcome measure: Comparison between laboratory and point of care testing haemoglobin concentrations. Results: The mean laboratory haemoglobin concentration was 155 g/l (range 30-226 g/l); the mean point of care testing haemoglobin concentration was 157 g/l (range 30-228 g/l). The mean (SD) difference between paired samples was 2 (11) g/l; 95% CI 24.0 to 0.1 g/l; and limits of agreement 223 to 19 g/l. Conclusions: The blood gas analyser on the neonatal unit at Royal Hallamshire Hospital, Sheffield, gives a useful estimation of haemoglobin concentration compared with laboratory measurement, with smaller sample volume. Although this does not replace a full blood count, it is a useful adjunct to neonatal care monitoring. P oint of care testing can be defined as the testing of patient samples at the place where care is delivered. 1 Its advantages include the need for small volumes of blood, reducing the risk of iatrogenic anaemia, 2 and the timely availability of results, diminishing the interval between receipt of a result and therapeutic intervention. Babies requiring neonatal intensive care are susceptible to iatrogenic blood loss from frequent blood sampling, 3-7 which can hasten the onset or exacerbate the severity of anaemia. 5Occasionally babies receiving neonatal care may decompensate from occult blood loss-for example, large periventricular or intraventricular haemorrhage-necessitating prompt action on the basis of clinical assessment and timely results. The turnaround time of laboratory tests can be considerable, which may affect clinical decisions. 2Many neonatal units have blood gas analysers located on site, which are used exclusively for neonatal samples. Thus point of care testing is a routine part of neonatal practice. Many modern blood gas analysers can now estimate haemoglobin, glucose and electrolytes on every blood gas sample, without the need for increased sample volume. It has been suggested that the weekly full blood count (requiring 500 ml of blood) carried out for convalescing neonates, solely to identify anaemia, could be replaced by point of care testing (requiring 95 ml of blood).We therefore evaluated the performance of our blood gas analyser for this potential change in our service...

Point-of-care estimation of haemoglobin concentration in all age groups in clinical practice

“…18 Several research groups have demonstrated the advantages of having a simple and reliable POCT for the diagnosis of anaemia without having to perform venepuncture. [7][8][9][10][11] The introduction of POCT has improved patient care and accessibility in these settings.…”

“…[7][8][9][10][11] These include improved turnaround time, a small sample volume required for testing, and long-term cost savings. 5 The volume required for analysis is very small (10 µl), making this device particularly suitable for paediatric and neonatal Hb measurements, as blood sampling in this age group is often technically difficult and distressing.…”

Comparison between transcutaneous bilirubinometry and total serum bilirubin measurements in preterm infants <35 weeks gestation

“…The phototherapy protocol includes reassessment of bilirubin at least every 12 h: it has been demonstrated that many cases of anaemia on NNU are iatrogenic. 17,18 Therefore, the only remaining safety consideration is whether the small increase in phototherapy treatment that would result is likely to cause injury to any infants, or would increase workload on the NNU to unacceptable levels. Phototherapy is safe and effective 19 and therefore does not constitute any risk to the infant.…”

Rationalising the use of "growing bloods" in stable preterm infants

“…There are few data, however, to support this practice, with much evidence of increased transfusion requirements in this vulnerable population secondary to phlebotomy losses 1. Recently, point-of-care analysers have been validated to decrease phlebotomy losses and minimise the need for transfusion in this population 2. We hypothesised that the results of weekly blood investigations in stable growing preterm infants do not significantly alter clinical management.…”