Neutrophil-to-lymphocyte ratio in relation to trauma severity as prognosis factors in patients with multiple injuries complicated by multiple organ dysfunction syndrome：A Retrospective Analysis. (Preprint)
Authors: Liu Xing , He Yongming , Zhong Siyi , Fu Qiuhong 
Published: December 2022

BACKGROUND

Multiple injuries refer to serious injuries to more than two sites and organs caused by one causative factor . Multiple injuries are severe and complicated, and are prone to secondary infection. Within the first 12 hours after trauma, the expression of some genes is up regulated in inflammatory cells and lymphocytes, leading to overexpression of some inflammatory factors . If effective interventions were not provided in time after trauma, once uncontrolled inflammatory reaction occurs, a chain waterfall reaction process of "systemic inflammatory response syndrome sepsis (SIRSS) multiple organ dysfunction syndrome (MODS) multiple organ failure" might be gradually developed, eventually, the patient even died. The incidence of MODS after multiple injuries has been reported to be 8.3% - 28%.
MODS is a reversible dysfunction syndrome of two or more organs suffered from severe trauma, infection, or other damages. The essence of MODS is the over-activation of systemic inflammation, which is one of the major causes of death in critically ill patients. However, due to the reversibility of its process, early detection and attention to MODS and interruption of its progression by removing the cause and modulating inflammatory responses might be the key to treating MODS.
Neutrophil lymphocyte ratio (NLR) is an emerging composite inflammatory biomarker in recent years, which is more and more recognized as a rapid reflection of a patient's immune and inflammatory status . Compared to other inflammatory markers such as C-reactive protein, NLR has its own characteristics. NLR integrates two distinct but complementary immune pathways, reflecting the degree of the body's stress response through lymphocyte counts. In addition, it reflects the degree of deterioration of systemic inflammatory response through neutrophil counts. A lower ratio of the two indicates a higher level of the body stress .
Currently, research and application of NLR in multiple injury is still rare. Therefore, here we retrospectively reviewed the clinical data of patients with multiple injury treated in our hospital from January 2018 to December 2021. Risk factors for MODS patients with multiple injuries were systematically analyzed. Notably, the possibility of using NLR to predict MODS occurrence in multiple injury patients was also explored in detail.

OBJECTIVE

The aim of this study was to explore potential risk factors for the occurrence of multiple organ dysfunction syndrome (MODS) in patients with multiple injuries, by evaluating neutrophil-to-lymphocyte ratio (NLR)-associated trauma severity.

METHODS

A retrospective case-control study was performed on 95 patients with multiple injuries admitted to our hospital (from Jan. 2018 to Dec. 2020). Clinical data including gender, age, underlying disease, number of injury sites (NIS), injury severity score (ISS), hemoglobin level within 24 h of admission (HL-24h), neutrophil count (NC), white blood cell count (WBCC), platelet count (PC), NLR, D-dimer level, activated partial thromboplastin time (APTT), complicated shock within 24h of admission (CS-24h), length of stay, as well as prognostic outcome was systematically analyzed. According to MODS occurrence, patients were divided into MODS group (n = 27) and non-MODS group (n = 68), respectively. Risk factors affecting patients with multiple injuries complicated by MODS were identified using univariate and multivariate logistic regression analysis. The candidate risk factors were further analyzed with receiver operating characteristic (ROC) curves.

RESULTS

According to univariate analysis, significant difference was observed between MODS and non-MODA groups in NIS, ISS, HL-24h, platelet count, APTT, D-dimer level, CS-24h, NLR, NC, prognostic outcome and other indicators (P < 0.05). Multivariate logistic regression analysis results showed that D-dimer levels within 24 h of admission, ISS, NLR, and CS-24h were more significantly associated with multiple injuries complicated by MODS. Compared to the non-MODS controls, NLR in MODS groups showed a much higher level and up-regulated tendency with the increase of ISS score, indicating a significant inter-group difference (P < 0.05). ROC curve analysis results suggested that NLR had good sensitivity and specificity for prognosis predictions of MODS patients with multiple injuries.

CONCLUSIONS

Collectively, D-dimer levels, ISS, NLR, and CS-24h are all important risk factors for MODS patients with multiple injuries. Notably, NLR expression level might be a good indicator of the injury severity and a good predictor of the occurrence of MODS in patients with multiple injuries. Therefore, assessment of injury severity and coagulation function, active resuscitation, as well as prevention of infection should be emphasized during treatment of multiple injuries, to reduce and prevent the risk of MODS in patients with multiple injuries.