Value Of Neutrophil-lymphocyte Ratio Combined With Red Blood Cell Distribution Width In Predicting Severe Acute Pancreatitis

Background:Acute pancreatitis(AP)is a non-specific inflammation of the pancreas which is a common acute abdominal pain.About 20% of patients will have severe complications such as organ failure and severe infection,which will progress to severe acute pancreatitis(SAP).Therefore,early assessment of the condition of AP is essential.Today,these scoring systems such as the acute physiology and chronic health evaluation(APACHE-II)scoring system,the Ranson criteria,and the bedside index for severity in acute pancreatitis(BISAP)are widely used to assess the severity of pancreatitis.However,these includes many indicators,which is very tedious and complicated to use.It is urgent to find indicators which are simple,easy to obtain and can be observed dynamically.In recent years,many studies have shown that neutrophil to lymphocyte ratio(NLR)and red blood cell distribution width(RDW)have significant correlation with AP.But few studies explored the value of the combined application of the two indicators.Objctive:The purpose of this study aims to explore the value of RDW and NLR inevaluating the severity of AP patients independently or in combination.Methods:This subject retrospectively collected 264 patients who were diagnosed with AP in our hospital from July 2017 to June 2019 and met the conditions for enrollment.And 124 patients in common gastrointestinal polyps with no other diseases at the same time were included as controls.The data of the total number of white blood cells(WBC),neutrophil count,lymphocyte count,RDW,blood calcium,Glucose etc.of the patients at 0 hours,36 hours,72 hours after admission included.The patient's gender,age,and condition assessment were also required.264 AP patients were divided into mild AP(MAP)group,moderately severe AP(MSAP)group and SAP group.For the needs of the research,the MSAP group was merged into the SAP group.The indicators of the Receiver operator characteristic(ROC)curve and the area under ROC(AUC),sensitivity and specificity were used to analyze and compare the predictive value of NLR,RDW and combined NLR and RDW on diagnosis of SAP at different times of admission.P value less than 0.05 is statistically significant.Results:There was no significant difference in gender and age of patients between the AP and the control group(P> 0.05).The Glucose,WBC,NLR and RDW of patients in the AP group were higher than those in the control group,while the blood calcium was lower.And the differences were statistically significant(P<0.01).The gender,age,and etiology of patients were no statistically significant between the MAP and the SAP group(P>0.05).The patients in SAP group had higher level of Glucose,WBC,and hospital stays than the MAP group,while the level of blood calcium was lower.And the differences were statistically significant(P<0.01).The middle NLR of patients on admission(NLR0),36 hours after admission(NLR36),and 72 hours after admission(NLR72)in MAP group were significantly lower than those in the SAP group.And the differences were statistically significant(P<0.01).Similarly,the middle RDW of patients on admission(RDW0),36 hours after admission(RDW36),72 hours after admission(RDW72)were also statistically lower than those in the SAP group(P<0.01).The results of the comparison of the AUC predicted SAP by NLR and RDW for each period showed the AUC of NLR0,NLR36,NLR72 were respectively 0.760,0.720 and 0.782.But the difference among the three is not statistically significant(P> 0.05).The AUC of RDW0 diagnosed with SAP was 0.729,while the AUC of RDW36 diagnosed with SAP was 0.720.There were no significant differences between the AUC of the two indicators diagnosed with SAP(Z=0.455,P=0.649).The AUC of RDW72 diagnosed with SAP was 0.648,which was lower than those of RDW0 and RDW36(P<0.05).However,the differences between the AUC of NLR0 and RDW0 for the diagnosis of SAP were not statistically significant(Z=0.581,P=0.561).The AUC of NLR0+RDW0 diagnosed with SAP was 0.819,which was statistically higher than those of NLR0 and RDW0(P <0.05).Its diagnostic sensitivity and the specificity reached respectively 76.56% and 77.5%.The differences between the AUC of NLR36 and RDW36 diagnosed with SAP were also not statistically significant(Z=0.660,P=0.509).But the AUC of NLR36+RDW36 diagnosed with SAP was 0.839,with sensitivity and specificity,respectively 85.94% and 70.5.0%,which was significantly higher than those of NLR36 and RDW36.And the differences were statistically significant(P <0.05).The AUC of NLR72 diagnosed with SAP was greater than that of RDW72,and the differences were statistically significant(Z=2.445,P=0.015).The AUC of NLR72+RDW72 diagnosed with SAP was 0.821,which was higher than those of NLR72 and RDW72(P <0.05).Among them,the sensitivity and specificity of NLR72+RDW72 diagnosed with SAP were respectively 76.5% and 78.12%.There were no significant differences in the AUC of NLR0+RDW0,NLR36+RDW36 and NLR72+RDW72 diagnosed with SAP(P> 0.05).Conclusion:The results of this study confirms that NLR and RDW measured at 0,36,and 72 hours of admission can effectively predict SAP.NLR and RDW are simple,convenient,and dynamically monitored hematological indicators for assessing severity of AP.The predicted value of RDW is lower than NLR 36 hours after admission.Combining the two indicators of NLR and RDW in each period is better than a single indicator which will predict SAP more accurately.