RESUMO
Preanalytical errors constitute about 40-65% of laboratory errors, of which 60% are due to hemolysis. This leads to imprecise reporting and misinterpretation of the actual concentration of analytes. Hence the aim of this study was to estimate the extent of different degrees of interference by visible hemolysis. 25 hemolysed samples along with their fresh unhemolysed sample were studied. Hemolyzed serum was mixed with unhemolyzed serum in predefined serial ratios from 100%, 70%, 50%, 30% and 10% to achieve different grades of hemolysis. Each dilution was analysed for BUN, creatinine, uric acid, phosphorus, Na, K, total protein, amylase, lipase, LDH, tacrolimus and methotrexate. Percentage difference of each dilution of the hemolyzed sample as compared to the unhemolyzed sample was calculated and considered acceptable only if less than TEa. It was observed that Percentage difference of BUN, creatinine, amylase and lipase in all dilutions of hemolyzed samples were within TEa while phosphorus, Na, K, total protein and LDH were beyond the acceptance criteria. Hence It was concluded that it may be safe to analyse a hemolysed sample for BUN, creatinine, amylase, lipase, tacrolimus and methotrexate while uric acid may be estimated in a moderately hemolysed sample. Phosphorus, sodium, potassium, total protein and LDH must never be analyzed in any hemolysed sample.