Hemolysis and blood gas analysis: it's time for a change!

Area of Science:

• Clinical Chemistry
• Laboratory Medicine
• Critical Care Diagnostics

Background:

• Blood gas analysis is vital for critically ill patients, including those with COVID-19.
• Hemolysis, lipemia, and icterus can cause significant clinical misinterpretation of laboratory tests.
• Current blood gas analyzers lack the ability to detect these common sample interferences.

Purpose of the Study:

• To evaluate the influence of hemolysis on blood gas sample analysis.
• To identify factors affecting blood gas parameters and assess the prevalence of sample interferences.

Main Methods:

• Analyzed 1244 blood gas specimens for hemolysis, lipemia, and icterus using Cobas C6000 CE.
• Assessed the impact of sample storage, transport (pneumatic tube system), and size on results.
• Determined the analytical bias introduced by hemolysis on various blood gas parameters.

Main Results:

• Prevalence rates: 5% hemolysis, 12% lipemia, 14% icterus.
• Room temperature storage, pneumatic tube transport, and small sample size significantly affected results (p < .01).
• Hemolysis caused increased bias in pH, pO2, and potassium, and decreased bias in pCO2, HCO3-, sodium, and Ca2+ (p < .01).

Conclusions:

• Hemolysis significantly alters blood gas parameters, potentially leading to misdiagnosis.
• Rapid centrifugation and serum index assessment are crucial for identifying unsuitable samples, but not feasible in emergency departments.
• Automated, built-in serum index detection systems in blood gas analyzers are recommended for manufacturers.