The effect of sodium citrate in arterial catheters on acid-base and electrolyte measurements.

Author(s): Cardinal P, Allan J, Pham B, Hindmarsh T, Jones G, Delisle S

Publication: Crit Care Med, 2000, Vol. 28, Page 1388-92

PubMed ID: 10834683 PubMed Review Paper? No

Purpose of Paper

Conclusion of Paper

Studies

1. Study Purpose

   The purpose of this study was to determine the effects of type of anticoagulant in the catheter used to collect blood specimens on clinical chemistry analytes in sequentially drawn aliquots of blood. Ten 1 mL aliquots of blood were obtained through an arterial catheter containing heparin or sodium citrate and an additional specimen was collected by arterial puncture. All specimens were stored on ice for up to 60 min prior to analysis.

   Summary of Findings:

   Partial pressure oxygen (PO2), lactate, and sodium did not vary between specimens collected through catheters containing heparin or sodium citrate, but calcium, pH, glucose, partial pressure carbon dioxide (pCO2) chloride and potassium levels were affected by anticoagulant in the catheter as well as specimen sequential collection. When blood was collected through a catheter containing sodium citrate, calcium levels were decreased by more than 20% in all aliquots compared to non-anticoagulated arterial blood. However, when blood was collected through a catheter containing heparin, only a 2.2% decrease was found after the first 2 mL of blood were discarded compared to arterial blood collected without anticoagulant. Use of catheters containing sodium citrate led to a more than 5% decrease in pH for all specimens compared to arterial blood collected without anticoagulant, but after discarding the first mL, this difference was eliminated. When blood was collected through catheters containing sodium citrate, glucose levels were more than 6% higher in all aliquots than in arterial blood collected without anticoagulant, but when collected through a catheter containing heparin, there was a slight reduction in glucose in all aliquots compared to arterial blood collected without anticoagulant. Importantly, after the first 3 mL of blood collected through a catheter containing heparin were discarded, glucose levels were in the clinically expected range. Collection of blood through catheters containing sodium citrate led to increased pCO2 compared to arterial blood collected without anticoagulant, but those containing heparin led to decreased pCO2 compared to arterial blood collected without anticoagulant; however, the magnitude of the change was similar between anticoagulants and, after discarding the first 2 mL, was not significant. Chloride and potassium levels were unaffected by anticoagulant in the catheter after the first 2 mL were discarded.

   Biospecimens

   • Bodily Fluid - Blood

   Preservative Types

   • None (Fresh)

   Diagnoses:

   • Not specified

   Platform:

   Analyte	Technology Platform
   Carbohydrate	Clinical chemistry/auto analyzer
   Electrolyte/Metal	Clinical chemistry/auto analyzer
   Gas	Clinical chemistry/auto analyzer
   Small molecule	Clinical chemistry/auto analyzer

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Biospecimen Acquisition	Anticoagulant	Heparin Sodium citrate
   Biospecimen Aliquots and Components	Aliquot sequential collection	1st collection 2nd collection 3rd collection 4th collection 5th collection 6th collection 7th collection 8th collection 9th collection 10th collection

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