title: Blood cell counting in neonates: a comparison between a low volume micromethod and the standard laboratory method.
abstract: BACKGROUND
  Iatrogenic anaemia caused by repeated blood sampling to monitor laboratory parameters can contribute, particularly in neonates, to the need for transfusion. "Point of care" laboratory equipment uses smaller amounts of blood for analytic determinations and could, therefore, help to prevent secondary anaemia. In this study we compared the results of haematological parameters measured using a standard laboratory method and using a "point of care" micromethod, with the aim of validating the use of this latter method in clinical practice in neonatology.
  
  
  METHODS
  One hundred and fifty venous or capillary blood samples were taken from full-term or premature neonates 2-4 hours or 48 hours after birth. Each sample was processed by a standard haematology analyser and another micromethod instrument. Bland-Altman plots were constructed for each parameter and intra-class coefficients of correlation were calculated in order to evaluate the concordance between the two analysers.
  
  
  RESULTS
  The concordance between the data obtained with the two analysers, expressed as the intra-class correlation, was 0.98 for white blood cell count, 0.97 for haemoglobin concentration, 0.96 for haematocrit, 0.95 for mean red cell volume and 0.98 for platelet count. The micromethod produced overestimated mean values for the leucocyte count (+1.27; p<0.001), haematocrit (+1.80; p<0.001) and platelet count (+13.55; p<0.001).
  
  
  CONCLUSIONS
  Overall, the concordance between the values obtained with the two analysers was high for each of the parameters taken into consideration. In the case of haemoglobin and leucocytes, give the high intra-class correlation and lack of systematic overestimation of one method over another, the micromethod guarantees a correct evaluation; however, despite the high intra-class correlations for platelet counts, the systemic error seems to suggest that the micromethod cannot guarantee an appropriate evaluation of this parameter.
authors.affiliation: Clinical Pathology Unit, San Giovanni Calibita, Fatebenefratelli Hospital, Rome.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Papa
authors.forename: Mauro
authors.initials: M
authors.lastname: Rongioletti
authors.forename: Marco Della
authors.initials: MD
authors.lastname: Ventura
authors.forename: Francesco
authors.initials: F
authors.lastname: Di Turi
authors.forename: Maurizio
authors.initials: M
authors.lastname: Cortesi
authors.forename: Patrizio
authors.initials: P
authors.lastname: Pasqualetti
authors.forename: Maria Bernardetta
authors.initials: MB
authors.lastname: Majolini
authors.forename: Valeria
authors.initials: V
authors.lastname: Collegiani
authors.forename: Marika
authors.initials: M
authors.lastname: Cicchese
authors.forename: Maria Letizia
authors.initials: ML
authors.lastname: Notarmuzi
authors.forename: Rocco
authors.initials: R
authors.lastname: Agostino
authors.forename: Giancarlo Maria
authors.initials: GM
authors.lastname: Liumbruno
mesh_terms: D001772:Blood Cell Count / Q000379:methods*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D019095:Point-of-Care Systems / Q000592:standards*