The Blood Loss From Laboratory Testing In Critically Ill Preterm Infants And Its Correlation Between Anemia

Objective The blood loss from laboratory testing of premature infants have a greatdeal of concealment, irregular blood draw is one of the risk factors contributing toanemia.The paper gathering critical premature’s Laboratory phlebotomy lossinformation to quantify blood loss for laboratory diagnostic, describes the function ofblood loss distribution, explore the cause of diagnostic blood loss from phlebotomyand to assess the relationship between anemia and blood loss, also to lay thetheoretical foundation of standardize the blood sampling technique and promotingmicro-sampling.Methods All critically ill premature infants discharged from the Chenzhou firstpeople’s hospital’s Neonatal intensive care unit which affiliated to The South ChinaUniversity from April2012to April2013, admitted within24hours after birth andhospital stay over7days. Recorded the blood loss for each test during hospital days,quantitative analysis the laboratory phlebotomy loss, and descried the features ofphlebotomy blood loss in different age,different weight,different time within4weeks.By classified the blood of application according to test,described the distribution ofblood loss function; The blood volume demanded in theory is determined by theformula B=5(∑s+0.1), Combined to the actual blood volume draw, Calculated thephlebotomy overdraw; collected the first24hours of admission,1th week,2nd week,3rd week, and4th week’s venous blood, when hemoglobin of vein as judge standardof premature anemia, the infants were classified into anemic group, no anemiagroup,exclusion the factors of transfusion and assessed the correlation between bloodloss from laboratory testing and anemia within the first four weeks.Results1、The total blood loss of critically ill premature infants during hospitalization was7972.51ml, and the median was25.57ml(4.60ml~119.20ml). the blood loss concentrated in the first two weeks, for64.40%of the total amount,and two weekswith the1th week of prominent,72.84%in its two-week total of blood loss, part3,4weeks significantly less than the first two weeks. The Blood loss of one person perday was significantly comparing to the first week with four weeks, the first week’swere higher than the second week’s,the difference was statistically significant, the3thand4th week showed no significant difference.2、The smaller gestational age and the lower birth weight, the more daily percapita blood loss in first two weeks,a statistically significant difference (P<0.05), thethird and fourth week showed no statistically significant differences (P>0.05).3、The largest proportion of the blood samples was used for clinical chemicaltests(31.49%), followed by blood gas analysis (19.03%), immunoassays (12.69%),blood cultures (12.63%), Hematology (12.28%). Biochemical and blood gas analysiswere the most common tests items in critically ill preterm infants and the greatestconcentration of blood loss,which amounted to50.52%. Blood gas analysis,Hematology were the most frequent laboratory tests in management and monitoringof critically ill premature infants that amounted to67.43%.4、The total practical blood loss was about twice times of blood volume demandedfor tests in theory, the median total of blood loss was25.57ml,which was7.8timesto a total theoretical median blood loss (3.26ml).5、The blood overdraw was more concentrated in the first two weeks, comparewith different gestational age and birth weight, the difference of blood volume wasstatistically significant (P <0.05).the smaller gestational age and lower weight, themore significant of overdraw.6、According to blood collection items,the phlebotomy overdraw followed byblood culture, biochemical, other, blood gas analysis, the percentage was64%,76%,and41%, respectively.7、The time of anemia concentrated in the first two weeks after admission, theproportion of anemia was up to88.30%,smaller the gestational age, Lower the weight,anemia occurs sooner and the higher of proportion. 8、Phlebotomy was highly associated with changes in hemoglobin,blood loss andanemia were significantly correlated within in first two weeks, but in the third andfourth week they were not obviously related.9、Univariate analysis showed that blood loss, gestational age, birth weight,lengthof hospital stay, admission hemoglobin values were associated with the occurrence ofanemia Within two weeks after admission.10、Multiple factor logistic regression analysis showed that the blood loss fromlaboratory testing in first two weeks and Hospitalization entered the risk factors ofanemia of prematurity,the risk factors of blood volume>15ml/kg was3.57times than7.5ml/kg~15ml/kg in two weeks.Conclusion The blood loss for laboratory test and the phenomenon of bloodwaste was serious in Critically ill preterm infants which closely related withgestational age and weight, the smaller the gestational age and the lower the weight,the amount of blood loss more significantly. Biochemical and blood gas analysis wasthe main items subject to blood loss. Anemia of prematurity was correlated withincreased laboratory blood loss,excessive blood draw were likely exacerbates theanemia of prematurity. The total blood volume>7.5ml/kg in first two weeks was riskfactors to anemia, the more blood volume loss, the greater the probability of anemiaand more severe the degree of anemia. Accordingly, reducing laboratory phlebotomyloss may be beneficial to infants with anemia of prematurity.