The Evaluation Value Of Procalcitonin Clearance Rate,Interleukin-6 And Platelet Parameters On The Prognosis Of Severe Pneumonia

Background and ObjectiveLung infection is one of the most common infectious diseases in humans.With the substantial increase in the average life expectancy of human beings,the prevalence of various underlying diseases has increased year by year,coupled with the impact of various immune system diseases and immunosuppressive drugs,which has increased the number of immunodeficiency populations,which has led to the increase in the incidence of severe pneumonia year by year.The fatality rate of patients with severe pneumonia is extremely high,which brings a heavy burden to the family and society and consumes medical and health resources greatly.At present,relying on the subjective judgment of clinicians or various clinical scoring systems to assess the patient’s condition shows certain limitations,and no reliable single biological indicator has been found.Therefore,actively exploring new predictive indicators is of great significance for guiding the treatment of severe pneumonia and improving the prognosis.This study detected the levels of procalcitonin,interleukin-6and platelet related parameters in patients with severe pneumonia,explored their changing trends,and analyzed their predictive value for the clinical outcome of severe pneumonia.Materials and MethodsA retrospective study was used to select 85 patients who were hospitalized in the Second Affiliated Hospital of Zhengzhou University from September 2018 to January2021 and met the criteria for severe pneumonia established by IDSA/ATS.All pa-tients were diagnosed with severe pneumonia in a timely manner in accordance with routine detection of infection indicators,chest X-rays,chest CT,combined with clin-ical manifestations,imaging and laboratory examinations,and given anti-infection,expectorant,antispasmodic and antiasthmatic,sedation,oxygen therapy,nutritional support,reduce cytokine storm and other comprehensive treatments.All patients will be reviewed in a timely manner according to the routine inspections,and combined with clinical manifestations to assess their condition in a timely manner,and timely adjustment of treatment according to the patient’s condition.According to the prognosis of patients within 28 days,they are divided into im-proved group and death group,of which 54 cases were in the improved group and 31cases were in the death group.Relevant test indicators of patients were collected,in-cluding PCT,IL-6,platelet count,mean platelet volume,platelet-lager cell ratio,platelet distribution width,etc.,dynamic monitoring of the above indicators was conducted,and the clearance rate of procalcitonin was calculated:PCTc_n=[(PCT₁-PC T_3/5/7/9)/PCT₁]×100%.The differences of the indexes between the two groups of pa-tients were compared,the trends of the indexes of the two groups of patients were recorded.The receiver operating characteristic curve（ROC）to determine the evalua-tion value of each index for the clinical outcome of patients with severe pneumonia was drawn.ResultsConstituting the two groups in age,sex ratio,combining underlying diseases of the basic information,and on the day of diagnosis body temperature,leukocyte count,neutrophil percent,C-reactive protein and oxygenation index and other indicators was not statistically significant（P>0.05）;the proportion of patients in the improvement group who used mechanical ventilation was lower than that in the death group（P<0.05）.There was no significant difference in serum PCT levels between the improvement group and the death group on the 1st and 3rd days（P>0.05）,and the serum PCT level in the improvement group was lower than that of the death group on the 5th,7th and9th day（P<0.05）;with treatment time the PCT level of the prolonged and improved group gradually decreased,the PCT level of the death group was always at a high state,the PCTc of the improved group gradually increased,and the PCTc of the death group was always lower than that of the improved group（P<0.05）.There was no significant difference in serum IL-6 levels between the improvement group and the death group on day 1,3,and 5（P>0.05）,and the serum IL-6 level of the improvement group was lower than that of the death group on days 7and 9（P<0.05）;With the extension of the treatment time,the IL-6 level of the improvement group gradually decreased,the IL-6 level of the death group gradually decreased on the first,third,and fifth days,and showed an upward trend on the seventh and ninth days.There was no statistically significant difference in PLT levels between the improvement group and the death group on day 1,3,and 5（P>0.05）.The PLT level of the improvement group was higher than that of the death group on day 7 and 9（P<0.05）,with the extension of treatment time PLT in the improvement group gradually increased,and PLT in the death group was always maintained at a low level;there was no significant difference in MPV,P-LCR and PDW between the improvement group and the death group on the first and third days（P>0.05）,the levels of MPV,P-LCR and PDW in the improvement group on the 5th,7th and 9th days were lower than those in the death group.With the extension of treatment time,MPV,P-LCR and PDW in the improvement group were always lower,and MPV,P-LCR and PDW in the death group gradually showed an upward trend.With the extension of treatment time,the AUC value of each index showed a gradually increasing trend;the area under the curve for PCT,PCTc,IL-6,PLT,MPV,P-LCR,and PDW on the 9th day of diagnosis to predict the death of severe pneumonia patients were respectively 0.937,0.968,0.882,0.720,0.694,0.704,0.719（P<0.05）.Compared with the detection of separate indicators,the area under the curve is increased for combined detection.Conclusions1.Inflammation index PCT and its derivative index PCTc,IL-6 and platelet related parameters PLT,MPV,P-LCR and PDW can reflect the severity of severe pneumonia;the increase of PCT,IL-6,MPV,P-LCR,PDW,the decrease of PLT and the low level of PCTc suggest that patients with severe pneumonia have a poor prognosis.2.Dynamic monitoring of changes in the levels of PCT,IL-6 and platelet related parameters and joint analysis are more helpful to judge the severity and prognosis of severe pneumonia.