title: Validation of a point-of-care (POC) lactate testing device for fetal scalp blood sampling during labor: clinical considerations, practicalities and realities.
abstract: BACKGROUND
  Although fetal blood sampling for pH is well established the use of lactate has not been widely adopted. This study validated the performance and utility of a handheld point-of-care (POC) lactate device in comparison with the lactate and pH values obtained by the ABL 800 blood gas analyzer.
  
  
  METHODS
  The clinical performance and influences on accuracy and decision-making criteria were assessed with freshly taken fetal blood scalp samples (n=57) and umbilical cord samples (n=310). Bland-Altman plot was used for data plotting and analyzing the agreement between the two measurement devices and correlation coefficients (R²) were determined using Passing-Bablok regression analysis.
  
  
  RESULTS
  Sample processing errors were much lower in the testing device (22.8% vs. 0.5%). Following a preclinical assessment and calibration offset alignment (0.5 mmol/L) the test POC device showed good correlation with the reference method for lactate FBS (R²=0.977, p<0.0001, 95% CI 0.9 59-0.988), arterial cord blood (R²=0.976, p<0.0001, 95% CI 0.967-0.983) and venous cord blood (R²=0.977, p<0.0001, 95% CI 0.968-0.984).
  
  
  CONCLUSIONS
  A POC device which allows for a calibration adjustment to be made following preclinical testing can provide results that will correlate closely to an incumbent lactate method such as a blood gas analyzer. The use of a POC lactate device can address the impracticality and reality of pH sample collection and testing failures experienced in day to day clinical practice. For the StatStrip Lactate meter we suggest using a lactate cut-off of 5.1 mmol/L for predicting fetal acidosis (pH<7.20).
authors.forename: Philipp
authors.initials: P
authors.lastname: Reif
authors.forename: Ioanna
authors.initials: I
authors.lastname: Lakovschek
authors.forename: Carmen
authors.initials: C
authors.lastname: Tappauf
authors.forename: Josef
authors.initials: J
authors.lastname: Haas
authors.forename: Uwe
authors.initials: U
authors.lastname: Lang
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schöll
mesh_terms: D001774:Blood Chemical Analysis / Q000295:instrumentation*; D036861:Delivery, Obstetric; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D005323:Fetal Monitoring / Q000295:instrumentation*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000097:blood; D019095:Point-of-Care Systems; D011247:Pregnancy; D012535:Scalp
chemical_list: D019344:Lactic Acid