Sepsis is a life-threatening organ dysfunction caused by the host's uncontrolled response to infection .Its essence is that infection leads to an imbalance of the body's inflammatory response, the release of a large number of cytokines, which stimulates the body's oxidative stress and the imbalance of the blood coagulation system, thereby causing damage to body tissues and organs , and with the deepening of sepsis research, sepsis The mechanism of disease has gradually involved cell function, metabolism, genes, and microcirculation [18–19].Although the pathogenesis of sepsis is complex and diverse, infection and organ dysfunction are still an important part of its occurrence and development.
According to estimates by the World Health Organization, about 1 million (approximately 10%) of the deaths of children under the age of 5 are caused by sepsis every year.Therefore, how to identify sepsis early and assess the severity and prognosis of sepsis has always been the focus of research by scholars at home and abroad.
Pediatric Clinical Illness Score (PCIS), Pediatric Logistic Organ Dysfunction Sore 2 (PELOD2), Pediatric Multiple Organ Dysfunction Score (P-MODS) scoring methods are commonly used in the past to predict the prognosis of critically ill children. It is of great significance in the evaluation of the prognosis of severe cases[16, 21–22].However, these critically ill scoring methods have various and complex scoring indicators, which are not conducive to timely clinical records.
In recent years, the Sequential Organ Failure Assessment (SOFA) score has been widely used in the prognosis assessment of adult sepsis due to its simple and effective scoring method.
However, the evaluation index reference data comes from adults, so it is not applicable to children[23–24].Scholars such as Matics refer to adult SOFA, children’s PELOD2 and other scoring indicators, and combine the physiological characteristics of children of different ages to develop a new standard for the diagnosis of sepsis in children, that is, the pSOFA score.
Moreover, studies have proved that pSOFA score is of great significance in the prognostic evaluation of PICU patients ;Scholars such as Zhong Mianling verified the role of pSOFA score in the prognostic evaluation of PICU children with sepsis and found that the significance of pSOFA score is better than other scoring systems, and its AUC is as high as 0.937 .Therefore, the pSOFA score is recommended for the diagnosis and prognostic evaluation of sepsis in children. This study once again verified that the pSOFA score is of great significance in the prognosis assessment of children with sepsis, and its AUC is 0.947 (95%CI: 0.914–0.970);
However, the lack of infection indicators in the pSOFA score may cause clinicians to ignore infection as a prerequisite when using the pSOFA score to assess pediatric sepsis, which will lead to overdiagnosis and treatment of sepsis .
Studies have shown that bacterial infections are the most common cause of sepsis in children .As traditional infection indicators, CRP and PCT are still widely used clinically.A large amount of literature shows that the levels of CRP and PCT in peripheral blood can predict infection and sepsis, and are of great significance for the diagnosis, severity assessment and prognosis of sepsis [26–27].This study found that the AUC of CRP and PCT for predicting the death of children with PICU sepsis were 0.547 (95%CI: 0.488–0.606) and 0.667 (95%CI: 0.609–0.721). Obviously, CRP or PCT alone Factors are poor in predicting the death of children with PICU sepsis, but PCT has a stronger predictive ability than CRP;This may suggest that infection is not the direct cause of death in children with sepsis, but is only the initiating factor for the occurrence and development of sepsis.However, a series of inflammatory immune response imbalances caused by infection, resulting in organ dysfunction is the direct cause of death in children with sepsis.Organ dysfunction is closely related to the prognosis of sepsis in children.This is consistent with the reason why the Third International Sepsis Conference emphasized organ dysfunction as the main indicator for evaluating the prognosis of sepsis .
The AUC of the predictive ability of CRP, PCT combined with pSOFA score on the death of children with PICU sepsis is 0.947 (95%CI: 0.914–0.970).It can be seen that CRP and PCT combined with pSOFA score have a strong predictive ability for the death of children with PICU sepsis.However, there was no difference in predicting the death of children with PICU sepsis using the pSOFA score alone (P > 0.05).At the same time, the analysis of the ability to predict the severity of sepsis in children in the survival group showed that: pSOFA score and pSOFA + CRP, pSOFA + PCT are more valuable in predicting the severity of sepsis in children than CRP, PCT and other infection indicators;However, there was no statistically significant difference between the pSOFA score and the AUC between pSOFA + CRP and pSOFA + PCT (P > 0.05).
The final conclusion of the study showed that adding CRP and PCT infection-related indicators to the pSOFA score could not effectively improve the mortality prediction ability of children with PICU sepsis compared with the pSOFA score alone.The reasons for this result may be:(1) Infection is the initiating factor of sepsis, and the direct cause of death of children with sepsis is the multiple organ dysfunction caused by the inflammatory storm of the body's imbalance;(2) Severe sepsis and septic shock cause tissue and organ dysfunction, causing cell damage that releases CRP and PCT, which reduces the concentration of CRP and PCT in the serum, and thus cannot assist in diagnosis and treatment;(3) Early active and effective anti-infective treatment and delayed body fluid examination resulted in CRP and PCT serum examination results inconsistent with clinical results;(4) The sensitivity of laboratory testing instruments and kits is insufficient, causing testing errors;(5) This study is a single-center, retrospective study, with short research time and small sample size, and there may be selective deviations;(6) In this study, data collection and critical illness scores were conducted based on the worst value of the children in the first 24 hours after admission to the PICU.There was no dynamic monitoring, and there was insufficient assessment of the severity of sepsis, which may affect the experimental results.
The innovation of this research: On the basis of sepsis research, the CRP and PCT infection indicators are combined with the sepsis organ dysfunction score (pSOFA score),It lays the foundation for the development of a more complete early diagnosis and prognostic evaluation method of childhood sepsis.
The shortcomings of this study:(1) This study is a retrospective cross-sectional study, which cannot strongly explain the cause and effect relationship;(2) This study is a single-center, retrospective study, with short research time and small sample size, and there may be selective deviations;(3) In this study, the worst value in the first 24 hours after admission to the PICU was used for data collection and critical illness score. There was no dynamic monitoring, and there was insufficient assessment of the severity of sepsis;(4) The sample size of this study is too small, and there is a large amount of data loss, and it is impossible to carry out the hierarchical analysis of indicators such as CRP and PCT, which reduces the reliability of the experimental results.