Introduction: Spontaneous bacterial peritonitis (SBP) is a prevalent complication in the patients with cirrhosis and ascites, which leads to high intrahospital mortality. Diagnosis is made when ascetic fluid neutrophils is ≥250 cells/mm3. Manual counting of neutrophils is time-consuming, technically difficult, expensive and in many cases individual-dependent. In contrast, automated counting is an easier, faster and much cheaper method, which enables earlier treatment. The objective of this study was comparing the automated vs. manual neutrophil counting in ascetic fluid in the patients suspected to have SBP.
Methods: Fifty two patients, clinically-suspected to SBP, were selected via convenience sampling in two emergency departments of Kerman city during one year. Their ascetic fluid neutrophils counted by conventional manual and automated (by cell counter) methods. Simultaneous ascetic and blood culture and peripheral WBC count were performed. SBP diagnosis was made when neutrophil count was ≥250 cells/mm3. Sensitivity, specificity, positive predictive value and negative predictive value of manual test were measured. Additionally, positive and negative results of these two methods were compared.
Results: Mean value of neutrophil count was 406 and 407 by automated and manual method, respectively; which showed no significant difference (p<0.001). Correlation was detected between two methods based on interpretation of neutrophil count in each patient (Kappa=0.653, Pearson correlation=0.989). Sensitivity, specificity, positive predictive value and negative predictive value of manual test was 84.61%, 80.76%, 81.48% and 84%, respectively.
Conclusion: This study shows that automated neutrophil count can well substitute manual count. Considering the limited studies on this issue, definite judgment necessitates further studies with higher sample volumes, various devices and considering role of humanistic conditions on manual count.
