title: Lactate study using umbilical cord blood: agreement between Lactate Pro hand-held devices with blood gas analyser and evaluation of lactate stability over time.
abstract: BACKGROUND
  Lactate measurements have become increasingly preferred over pH analysis in the evaluation of fetal acidaemia in labour. In a busy labour ward, often the umbilical cord may be sampled late and as a result yield unreliable lactate values.
  
  
  OBJECTIVE
  To investigate the agreement of hand-held device Lactate Pro with a reference method blood gas analyser and evaluate the stability of umbilical cord lactate values over time.
  
  
  METHODS
  Prospective study carried out at elective caesarean section. Sixteen umbilical cords were double clamped immediately after delivery with paired arterial and venous blood samples collected by an independent researcher, at varying time intervals, and processed by two Lactate Pro devices and a reference method blood gas analyser.
  
  
  RESULTS
  A significant difference of -0.41 to 0.10 mmol/L was found when different groups of Lactate Pro devices were compared with blood gas analyser at lactate values up to 5.70 mmol/L, with average lactate value of 2.45 mmol/L. Over time, there is progressive rise in lactate samples obtained from the umbilical cord.
  
  
  CONCLUSIONS
  Lactate Pro devices have a significant difference, but when used in clinical practice on cord blood after delivery, this is unlikely to be meaningful. In intrapartum fetal surveillance, a systematic overestimation might lead to unnecessary intervention. It is possible to retrospectively predict the likely level of lactate at birth in delayed cord samples.
authors.affiliation: Obstetrics and Gynaecology, Westmead Hospital, Sydney, New South Wales, Australia. drtinasu@gmail.com
authors.forename: Tina Y
authors.initials: TY
authors.lastname: Su
authors.forename: Mifanwy
authors.initials: M
authors.lastname: Reece
authors.forename: Seng C
authors.initials: SC
authors.lastname: Chua
mesh_terms: D001322:Autoanalysis / Q000295:instrumentation; D001784:Blood Gas Analysis / Q000295:instrumentation* / Q000379:methods; D002585:Cesarean Section; D005260:Female; D005312:Fetal Blood / Q000737:chemistry*; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D011247:Pregnancy; D011446:Prospective Studies; D012015:Reference Standards
chemical_list: D019344:Lactic Acid
keywords: agreement; blood gas analyser; comparison; lactate; umbilical cord blood