title: The PediaSat continuous central SvO2 monitoring system does not reliably indicate state or course of central venous oxygenation.
abstract: OBJECTIVE
  The present study compares the accuracy of a new continuous venous oxygenation monitoring system (PediaSat Oximetry Catheter) with laboratory blood oximetry in paediatric surgical patients.
  
  
  METHODS
  Children and adolescents undergoing cardiac, orthopaedic or craniofacial surgery with major blood loss were included. A 4.5 Fr two-lumen or 5.5 Fr three-lumen central venous oximetry catheter (SPediaSatcvO2) was inserted preoperatively into the superior vena cava. After in-vivo calibration of the PediaSat system, repeated blood samples were obtained from the distal port of the venous catheter and oximetrically analysed for haemoglobin and central venous oxygen saturation (SCO-OXcvO2). Central venous oxygen saturation values measured by the PediaSat (SPediaSatcvO2) were compared with co-oximetry (SCO-OXcvO2) values from the simultaneously taken blood samples by Bland-Altman and simple regression analyses.
  
  
  RESULTS
  Overall, 142 data pairs from 27 patients, aged from 0.6 to 19.0 years (median 5.3 years) were analysed. SPediaSatcvO2 and SCO-OXcvO2 values ranged from 57 to 98% and from 57.1 to 95.8%, respectively. Correlation between SPediaSatcvO2 and SCO-OXcvO2 was poor with r equal to 0.28 (P < 0.0001). SPediaSatcvO2 overestimated SCO-OXcvO2 (mean bias +2.6%), but limits of agreement (+/-2 SD of bias) were unacceptably high (-14.4/+19.6%). Sensitivity and specificity of SPediaSatcvO2 to indicate a fall or rise of SCO-OXcvO2 between two subsequent measurements were only 0.42 and 0.24, respectively.
  
  
  CONCLUSIONS
  In paediatric and adolescent patients undergoing major surgery, the PediaSat system did not reliably reflect SCO-OXcvO2 values and cannot replace repeated invasive ScvO2 assessments in the clinically relevant range of ScvO2.
authors.affiliation: Department of Anaesthesia, University Children's Hospital, Switzerland. werner.baulig@usz.ch
authors.forename: Werner
authors.initials: W
authors.lastname: Baulig
authors.forename: Dominique
authors.initials: D
authors.lastname: Béttex
authors.forename: Christoph
authors.initials: C
authors.lastname: Bürki
authors.forename: Achim
authors.initials: A
authors.lastname: Schmitz
authors.forename: Nelly
authors.initials: N
authors.lastname: Spielmann
authors.forename: Katja
authors.initials: K
authors.lastname: Woitzek
authors.forename: Markus
authors.initials: M
authors.lastname: Weiss
mesh_terms: D000293:Adolescent; D002405:Catheterization, Central Venous / Q000295:instrumentation / Q000379:methods / Q000592:standards*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005336:Fiber Optic Technology / Q000295:instrumentation / Q000379:methods / Q000592:standards*; D006801:Humans; D007223:Infant; D008297:Male; D016343:Monitoring, Intraoperative / Q000295:instrumentation / Q000379:methods / Q000592:standards*; D010092:Oximetry / Q000295:instrumentation / Q000379:methods / Q000592:standards*; D010101:Oxygen Consumption; D015203:Reproducibility of Results; D055815:Young Adult