Abstract
Background and objectives: Blood gas analysis is one of the main diagnostic tools for acid – base imbalances. By considering the invasive nature of arterial blood gas analysis out its problem hazards such as arterial spasm, there is an increasing trend toward non-invasive methods such as venous blood gas analysis.
This study was aimed to survey the validity and clinical agreement of venous blood gases in main ten diseases occurring in intensive care unit to determine whether they can substitute the arterial blood gases.
Material and methods: In a cross sectional – analytical study 10 disease which consist the most burden of admission in intensive care unit was surveyed. Duration of study was one year (Oct 2004- Oct 2005).
In this study the venous blood was simultaneously sampled with arterial blood and their different parameters such as pH, PCo2, Hco3, and PO2 were analyzed. The results were assessed with different statistical methods such as validity and clinical agreement or kappa test.
Results: findings indicate that in respiratory distress syndrome, sepsis, pneumonia, renal failure, diabetic Ketoacidosis, and status epilepticus, there is a good validity and fair to good clinical agreements (>40%) between arterial and venous blood gas analyses.
But in other disease such neural seizure, shock, congestive heart failure and congenital heart disease there is a low validity and negligible kappa test (<20%).
Conclusion: based on the findings, at least in 6 of 10 diseases, venous blood gas analysis can be substitute those of arterial blood. The result can be used to develop guide lines for intensive care unit.