LEUKERGY TEST , A SIMPLE NEW TEST IN THE DIAGNOSIS OF POSTOPERATIVE ORTHOPEDIC WOUND INFECTION

Post operative wound infection is a common problem encountered in many hospitals allover the world. It necessitates the increase in resources loss, the more stay in hospital, the more of economy to spend on to combat. Thus its prevention & monitoring to detect earlier can help to reduce all mentioned resources & efforts. A simple test to predict such an infection besides clinical features & other laboratory tests is recommended. We tried to perform leukergy test on 83 patients, out of 103, who underwent different orthopedic surgical procedures in Basrah General Hospital, along with looking for the existence of postoperative wound infection using clinical manifestations, aided by laboratory tests including complete blood count, estimation of ESR & qualitative determination of CRP. We found that the rate of postoperative wound infection (13.5%) was slightly higher in our study than reported ones. Leukergy test showed a sensitivity of 85.71 % & specificity of 75.36 %, thus positive leukergy test was significantly related to the existence of post operative wound infection & negative result was significantly related to the absence of such an infection.


Introduction
ost-orthopedic operative wound infections are those that can occur after any operation on bone especially after operations on open fractures & after procedures involving the use of foreign implants.The reported rate after orthopedic operation on broad cross-sectional study varies from 0.2-10 % 1 , while after implant surgery, they seem to be in the range of 0.08-13 % despite the vast advances in surgery in the past decades 2 .They can delay recovery & often increase the length of hospital stay and may produce lasting sequels & require extra resources for Correspondence to: Dr. Zuhair A .Al-Barazanchi.Consultant Hematologist, Laboratory Department, Basrah General Hospital, e mail: barazanchi_57@yahoo.com investigation, management & nursing care.Therefore, their prediction & then prevention is relevant to getting higher quality of patient care 3 .The prediction of postoperative wound infections depends on the cardinal symptoms & signs of infection, the existence of purulent discharge from the wound site or the drain, and the aid of laboratory investigations, including a full blood count, estimation of erythrocyte sedimentation rate, tests for acute phase proteins, like C-reactive protein, & by microbiological examination of any discharged material from the wound 4 .Leukergy is "the phenomenon in which white blood cells agglomerate in P Bas J Surg, September, 12, 2006 the peripheral venous blood".This phenomenon was first identified in 1956 by Fleck 5 .It occurs as well in several metabolic disorders like burns & acute pancreatitis with noninfectious inflammatory conditions, ischemic heart disease, polycythemia rubra vera and some rheumatic diseases.Unlike ESR and CRP, the amount of leukergy has been shown to correlate with the level of activity of the disease besides its simplicity to perform, its inexpensiveness & rapidity 6,7 .For this purpose, a prospective study was conducted to evaluate the reliability of leukergy test in the prediction of early postoperative, orthopedic wound infection in Basrah Province.

Materials & methods
During a period of 6 months, 103 patients who underwent many orthopedic operations in Orthopedic Department of Basrah General Hospital, were followed up clinically and by laboratory means (including periodic observations of cardinal symptoms & signs of postoperative wound infections, and by using the available laboratory investigations, including complete blood count, ESR determination, C-reactive protein analysis.From those, 83 patients were subjected to leukergy testing (20 cases were missed for many administrative reasons yet, all showed no feature of postoperative wound infection).The test was performed by using citratedanticoagulated blood samples collected from patients, from which slanted smears were prepared, which were subjected to repeated freezing & thawing( to lyse red cells).After that, they were fixed with methanol for 20 minutes & then stained with eosin stain (in stead of the original fast red used by Fleck, due to the unavailability of the last).For an agglomerate to be significant, at least 3 (or more) white cells in contact to each other were considered.The percentage of those WBC agglomerates was obtained by counting at least 300 cells per each sample.More than 10 % agglomerates were considered positive for the study 6 .Statistical analysis of results was performed by obtaining the frequency (percentage), the mean, the sensitivity & the specificity 8 .

Results
One hundred and three patients were included in the study, the age ranged between 1.5 year to over 80 years with a mean of 32.4 .The age distribution of the patients (Table I III).Of those, only 12 cases (14.4%) did genuinely have postoperative wound infection (using all above criteria) and the rest, 17 were negative for postoperative wound infection.The sensitivity & specificity were calculated according to the following formulas 8 .

Discussion
In this study, the frequency of postoperative wound infection in Basrah General Hospital was 13.5 %, a result slightly higher than that observed by Onche I, 2003 ( 0,08-13 %) (2) .This can be probably attributed to the lower  11 .

Conclusion
From those results we can conclude that postoperative wound infection is common after orthopedic surgical procedures in Basrah, being more common than other localities and leukergy test with its simplicity and easiness to perform is a very useful test to predict & monitor postoperative wound infection.

Recommendations
The policy of expanding the use of leukergy test, beside other laboratory tests, is to be encouraged to predict the emergence of postoperative wound infection.However, a wider scale study of leukergy with comparison of its sensitivity & specificity along with other tests for postoperative wound infection (like ESR, quantitative CRP, and microbiological studies) is to be encouraged as well.