Impact of an air bubble within the syringe on test results obtained with a modern blood gas analyzer

Air bubbles in blood gas syringe

  • Giuseppe Lippi
  • Dr. Laura Pighi Section of Clinical Biochemistry and School of Medicine, University of Verona, Verona, Italy
  • Prof. Gian Luca Salvagno Section of Clinical Biochemistry and School of Medicine, University of Verona, Verona, Italy
  • Dr. Roberta Ferraro Section of Clinical Biochemistry and School of Medicine, University of Verona, Verona, Italy
  • Dr. Giovanni Celegon Section of Clinical Biochemistry and School of Medicine, University of Verona, Verona, Italy
  • Dr. Brandon M. Henry Clinical Laboratory, Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
DOI: https://doi.org/10.5937/jomb0-49870
Keywords: Blood gas analysis; Errors; Syringe; Bubble; Air

Abstract


Background. Minimizing air aspiration by carefully filling blood gas syringes is crucial to prevent air contamination from causing undesirable variations in gasses and other molecules. While some previous studies investigated this aspect, these are now outdated and only analyzed a limited number of blood gas parameters. Thus, we investigated the effects air contamination in the syringe using a modern blood gas analyzer.

Methods. We sampled venous blood from 17 laboratory workers (mean age: 46±11 years; 10 women), filling two consecutive blood gas syringes. The first was filled exactly to its nominal volume (i.e., 1.0 mL), while the second was filled with 0.8 mL of blood and 0.2 mL of ambient air. Blood gas analysis was performed in each syringe using an identical analyzer.

Results. In the syringe with the air bubble, we found statistically significant increase in pH (0.1%), pO2 (10.8%), SO2 (11.2%), total hemoglobin (3.0%), and hematocrit (2.7%), while values of pCO2 (-4.8%), sodium (-0.5%), and ionized calcium (-1.3%) were significantly reduced. With exception of pH, all these changes exceeded the performance specifications. Potassium, chloride, glucose, lactate, COHb and MetHb values remained unchanged.

Conclusion. These findings confirm that air bubbles must be removed as soon as possible after sampling from blood gas syringes to prevent artifactual test results and misleading clinical judgment and inappropriate treatment. When blood gas syringes are received in the laboratory with air bubbles inside, the most vulnerable parameters (i.e., pO2, SO2, pCO2, sodium, ionized calcium, hematocrit and hemoglobin) should be suppressed.

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Published
2024/05/21
Issue
Ahead of print
Section
Original paper

Copyright (c) 2024 Giuseppe Lippi, Laura Pighi, Gian Luca Salvagno, Roberta Ferraro, Giovanni Celegon, Brandon M. Henry

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