The blood parameters and liver function changed inconsistently among children between burns and traumatic injuries

Introduction

Epidemiologic analysis has long identified that children have a high risk of injury. Burns are the third to fifth leading cause of unintentional injury in children, and traumatic injury is the second most common cause of unintentional injury (Nie et al., 2017; Ogilvie et al., 2014; Shi et al., 2016; Shi et al., 2014; Sminkey, 2009). Both injury types are sudden attacks by external forces that damage the body. Burns refer to skin or other tissue damage caused by flames, hot liquid, electricity, or chemicals. Traumatic injury is a body wound or shock produced by sudden physical collision or movement. Once injured, the body undergoes an acute response, which can encompass a wide range of endocrinological, immunological and haematological effects (Krepska, Hastings & Roodenburg, 2017).

The acute phase response (APR) is a complex systemic early-defense mechanism activated by trauma, thermal injury, infection, stress, or drug exposure (Ceron, Eckersall & Martýnezsubiela, 2010). APR local reactions, initiated via neural signals, create proinflammatory cytokine (IL-1, IL6, TNF-α, and Neutrophil activation), and activate liver hepatocytes, modulating protein synthesis. APR induces leukocytosis, complement activation, protease inhibition and clotting, which serve to prevent infection, clear potential pathogens, initiate inflammatory processes, and contribute to the healing process (Borek, 1987; Carolyn, Julia & Altman, 2009; Ceron, Eckersall & Martýnezsubiela, 2010). During APR, immune system components are redistributed in order to adapt to the defensive state of the body. Studies have shown that during APR, the body’s defense system quickly mobilizes, exciting the sympathetic-adrenal medulla system. By mobilizing the action of catecholamines, glucocorticoids, and cytokines, blood cells in bone marrow reservoirs or blood edge pools mobilize to enter blood circulation, thereby increasing peripheral RBC, WBC and PLT counts (Chiu, Carlson & Lilly, 2007; Korkmaz et al., 2017; Lord et al., 2014; Pepe & Barba, 1999). As the detection of changes in blood biochemical indicators is relatively simple in clinical practice, and quantitative values can be obtained directly to reflect the physiological changes of injured patients. According to the change in blood biochemical indices, doctors can judge the injury characteristics of patients, give symptomatic treatment, and achieve the goal of wound healing. Thus blood biochemical indices of injured patients are of great significance.

In this study, we aim to test whether there are differences in blood parameters and liver enzyme levels between burned and traumatically injured children.

Participants and Methods

Results

Discussion

Blood routine analyses showed that the levels of HB and RBC were higher in burned children than traumatically injured children, while TP and ALB levels were lower. In the early stage of burn wounds, the permeability of microvessels can be significantly increased, resulting in massive fluids and protein extravasation, which causes a decrease in blood volume (Arlati et al., 2007; Haberal, Abali & Karakayali, 2010), thus the concentration of RBC and HB increases. Moreover, the super metabolism decomposition and weakening synthesis of protein in wounds leads to a further decrease in permeation pressure and total blood volume. It causes the protein in plasma to decrease, resulting in a significant reduction in the levels of ALB and TP, which in turn can cause the occurrence of hypoproteinemia (Cochran et al., 2007). In addition, most of the enrolled children were at a young age in our study. Their glomerular and renal tubular functions have not been well developed yet, thus their ability to maintain body fluid balances is poor, so they are more likely to lose fluid in certain conditions. It is worth noting that in our study, the mean age of the burn group is lower than the traumatic injury group (3.23 vs. 6.60). Although we have taken age as an adjusted factor in our analysis, our results would benefit from further evaluation.

Additionally, the level of WBC was higher in burned children. Leukocytes are the body’s main line of defense to defend against pathogens and other invading foreign bodies (Chertov et al., 2010; Friedl & Weigelin, 2008), thus an increased number of WBC is a typical response to acute inflammatory/traumatic stress. It seems that both burns and traumatic injuries can induce APR, however the acute response to burns is markedly greater. It has been observed that burn patients have a greater and more sustained immune-inflammatory response than traumatically injured patients (Mace et al., 2012; Valvis et al., 2015). This study’s results support the above observation, showing that WBC levels increased more in burned children.

It is well known that the serum enzymes ALT, AST, ALP and GGT contribute to the function of liver cells. When the hepatocyte membrane is damaged or the cells undergo necrosis, these enzymes enter the serum and as a result their concentration increases (Pimentel et al., 2018; Puranik et al., 2002; Solovyeva et al., 2013). In contrast, serum CHE is synthesized by the liver, thus a decrease in this enzyme often reflects liver damage (Ogunkeye & Roluga, 2006). The multivariate analysis of variance of our results showed liver enzymes were significantly different in burn and traumatic injury groups. AST was significantly higher in burned children and CHE was lower, which suggests that the liver damages were often concomitant in burned children. This might relate to the decreased hemagglutination in the early stage of burn wounds, causing hepatocyte ischemia and hypoxia.

The generalized linear model showed that the level of WBC and HB is higher in boys than girls, which is consistent with the fact that male blood cell counts are generally higher than female. In contrast, this study showed levels of AST in males to be lower than females, which might indicate that injury has a greater effect on liver damage in males than in females. We found age to be positively correlated with the concentrations of HB, AST and TP, but negatively correlated with WBC. Older children, with a more complete kidney function to maintain fluid and protein balances, had lower WBC and higher HB levels, however the influence of age on AST is not yet clear.

We suggest the negative correlation between BMI and WBC, HB, AST and TP is due to children with a lower BMI inducing a particular APR to trauma. On the other hand, ISS is well established in trauma patients to measure the severity of an injury (Citerio, 2012; Copes et al., 1988). Results showed that ISS was positively correlated with WBC and HB, but negatively correlated with AST and TP. It is reasonable to suggest that a severe injury would induce an immune response and a fluid imbalance disorder, causing the levels of WBC, HB and TP to change. However, the negative correlation between ISS and AST levels indicates that a severe injury may not cause liver damage.

Interestingly, we found that children burned by hot oil had the highest levels of WBC, followed by hot food and hot water or soup. We suggest this is because oil is more likely to adhere to the skin and the residual heat can be transmitted deep into the tissue. However food contains a variety of spices and other substances, and it is difficult to explain their role in the etiology of WBC in burned children.

Conclusion

It is noteworthy that in our study the ISS in the traumatic injury group was higher than in the burn injury group, but the blood parameters and liver enzyme levels indicated that there was a greater APR and more severe liver damage in burn patients. It has been found that ISS is an independent risk factor for mortality in patients with a combination of burns and traumatic injuries; however, ISS is limited to predict outcomes of burn patients. Despite the limitation of the ISS, we concluded that burns play a more important role in APR and liver damage than traumatic injury. Subsequent research could explore the relationship of blood parameters and liver enzymes to other injury data, such as duration of hospital stay, presence of multiple organ dysfunction syndrome, mortality, etc., and further clarify the prognosis of burned and traumatically injured patients.

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