A diversity of blood smear examination system of Thai public hospital

Abstract

A good laboratory practice is the heart of clinical laboratory quality. One must establish a standard system in order to achieve the quality. However, standard system is not only the technical but also a state of the art. The socioeconomic and culture are the influence factors. At present, technique of reporting the blood smear examination is still a nation controversy. We surveyed the blood smear examination reporting system of the public hospital in Thailand. There were 77 hospitals participated in this study. A questionnaire comprised of 23 questions was distributed to 105 clinical laboratory staffs of the public health hospitals. Results showed that there was a diversity of blood smear examination reporting system. Generally, there were 2 ways of blood smear review. Every smeared slide and only abnormal slides were re-examined by the conventional technique. When an abnormal white blood cell blood picture was observed. The presence of either blast cell or atypical lymphocyte has clinical significance. A majority of laboratory would report in form "counting number of abnormal cell within 100% of the differential count". For other abnormalities of white blood cell; i.e. the neutrophils with toxic granules, most of laboratory reported as "presence". Interestingly, the red blood cell reporting system varied from laboratory to laboratory. There was a total of nine reporting patterns. Results indicated that pattern 4 (few or some, l+,2+,3+,4+ are 5-10%, 11-25%, 26-50%, 51-75% and 51-100% cell/oil field, respectively) was the most popular one in reporting anisocytosis and poikilocytosis. However, the reporting pattern on red blood cell staining was difference. Pattern 4 and pattern 7 (grading by the size of central pallor) obtained a same popularity on the consideration of hypochromia. But the pattern 9 (few or some, l+,2+,3+ are 0-1, 1-3, 4-6 and >6 cell/oil field, respectively) was the most frequently used in reporting of polychromasia. Fortunately we found that the reporting system for platelet was not complicated. A majority of laboratory chose the qualitative pattern (reporting as adequate, increased and decreased). Our study indicated that Thai clinical laboratory encounter a diversity of blood smear reporting system. Every clinical laboratory should pay a great attention to this circumstance. Since a good laboratory practice is a knot of the knot-bolt system of healthcare service, therefore, a nation standard system must be established in the near future.