[Analyses of preanalytical issues on samplings and samples].

Laboratory data accuracy depends on preanalytical, analytical, and postanalytical processes. Preanalytical issues remain a challenge due to limited visibility outside laboratory settings. Established knowledge shows that improper sample handling affects test outcomes. Prior research has shown that factors like sample storage, thawing, and collection methods influence results. However, the exact mechanisms behind these effects remain unclear. This gap motivated an investigation into how specific preanalytical variables impact laboratory data. No prior work had resolved the full range of variables affecting sample integrity. The study aimed to clarify these effects to improve diagnostic reliability. Understanding these factors is crucial for minimizing errors in clinical testing.

This study aimed to analyze preanalytical factors that influence laboratory data accuracy. The specific problem addressed is the lack of standardized protocols for sample handling. The motivation stems from the need to reduce diagnostic errors caused by improper sample collection and storage. The researchers propose that identifying these variables can improve diagnostic precision. The study focused on five key areas affecting test outcomes. These include detergent effects on fecal tests, potassium release from blood, thawing of frozen serum, blood collection methods, and temperature effects on serum. Each issue was examined to determine its impact on test results. The goal was to inform both laboratory and clinical staff about best practices.

The study analyzed five preanalytical issues using experimental and comparative approaches. For fecal occult blood tests, various sanitizers and detergents were tested for their effects on immunological methods. Blood storage effects were studied by adding drugs in vitro and observing potassium release. Cold storage impacts were evaluated using a newly developed method to measure erythrocyte K flux activity. Thawed serum samples were analyzed for concentration differences across layers. Blood collection methods were compared using two syringes to assess APTT, PT, and TT. Heat-inactivation and cold storage effects on serum were tested by measuring enzyme and complement levels. All findings were compared to standard protocols to assess deviations.

Detergents significantly affected fecal occult blood test results, with sanitizers causing moderate to marked interference. Blood storage with added drugs induced potassium release from erythrocytes, though mechanisms remain unclear. Cold storage elevated potassium levels, and a new method revealed reduced erythrocyte K flux in chronic renal insufficiency and aging. Thawed serum showed concentration differences, with upper layers having half and bottom layers twice the original concentration. T3 and FT4 showed smaller differences, but their significance is unknown. Two syringe methods showed minimal differences in APTT and PT, but TT levels increased in the first half of 0.5 ml samples. Physical pretreatment elevated tissue factor levels, though routine use of two syringes is unnecessary. Heat-inactivation reduced enzyme and complement levels, and cold storage affected HCV-Ab positive sera by lowering CH50 levels.

The authors suggest that preanalytical factors significantly influence laboratory data accuracy. They propose that detergent exposure, improper blood storage, and thawing methods can alter test results. The findings indicate that temperature management is essential for preserving serum integrity. The study highlights the need for standardized protocols in sample handling. The authors emphasize that informing both laboratory and clinical staff is necessary to ensure accurate diagnostics. They suggest that physical pretreatment during blood collection may elevate tissue factor levels. The study also shows that heat-inactivation affects enzyme and complement levels, requiring careful temperature control. These conclusions aim to improve diagnostic reliability by addressing preanalytical variables.