Traumatic shock is the most common cause of serious adverse outcomes in patients with severe traumatic diseases such as fractures, and some studies here have shown that the main cause of death from traumatic shock is the impairment of organ function that occurs after shock. In this study, we explored the role of serum kidney injury molecule-1 (KIM-1), neutrophil gelatin-related lipid transporter protein (NGAL), and N-acetyl-β-D-glucosidase (NAG) levels in evaluating and diagnosing the condition of patients with fracture traumatic shock based on the goal of contributing to the clinical diagnosis of the patient’s condition as soon as possible and taking measures to alleviate its progress. 96 patients with fracture traumatic shock were included in the study as the observation group and 58 healthy examiners as the control group, and the observation group was divided into 69 cases in the mild-moderate group and 27 cases in the severe group according to the Acute Physiology and Chronic Health Status Scale (APACHE-II). In this study, we detected and analyzed the differences in serum KIM-1, NGAL, and NAG levels between the observation group and the control group and the observation group with different disease levels. We found that the observation group was significantly higher than the control group, and the severe patients were higher than the mild to moderate patients, and we observed that serum KIM-1, NGAL, and NAG are significantly correlated with the condition of patients with fracture traumatic shock after further analysis using the Pearson model. In addition, the diagnostic value of receiver operating characteristic curve analysis showed that the AUC of serum KIM-1 for the diagnosis of fracture traumatic shock was 0.755, the AUC of serum NGAL was 0.750, the AUC of serum NAG was 0.772, and the AUC of the combination of the three indicators was 0.915. The results of this study thus suggest the possibility of serum KIM-1, NGAL, and NAG as clinical indicators for evaluating the condition of patients with fracture traumatic shock and the possibility of a combined test of serum KIM-1, NGAL, and NAG for diagnosing the condition.
1. Introduction
Currently, the risk of fractures from outdoor injuries is increasing due to the modern infrastructure and the development of transport and construction. In addition to the symptoms of local fracture, severe limb fractures and multiple fractures are usually accompanied by systemic reactions such as massive blood loss and severe pain resulting in traumatic shock which is the main cause of death in fracture patients [1]. Studies [2, 3] have shown that the main cause of death in patients with traumatic shock is the activation of the renin-angiotensin system (RAS) and the upregulation of related cytokine activity, leading to multiple organ damage, among which most commonly kidney damage. Therefore, the goal of improving the prognosis of patients with traumatic shock and reducing their mortality can be achieved by timely and accurate judgment of the patient’s condition and taking corresponding measures to alleviate the progress of the condition [4].
Kidney injury molecule-1 (KIM-1) is a transmembrane protein that is not expressed when the kidney is functioning normally. However, the expression of KIM-1 will be significantly upregulated when the kidney shows ischemia, drug poisoning, and other conditions [5, 6]. Neutrophil gelatin-related lipid transporter protein (NGAL) is a secretory protein expressed by neutrophils and renal tubular epithelial cells [7]. Serum N-acetyl-β-D-glucosidase (NAG) is an intracellular lysosomal enzyme with high relative molecular weight and widely distributed in various tissues, with the highest content in the proximal tubules of the kidney [7]. The imbalance of KIM-1, NGAL, and NAG levels is an important pathophysiological alteration in animal models of renal injury due to traumatic shock, but there are no reports about the role of serum KIM-1, NGAL, and NAG levels in the evaluation and diagnosis of patients with fracture traumatic shock [8].
In this study, the relevant information of serum KIM-1, NGAL, and NAG levels between fracture trauma shock patients and healthy people was collected and compared. The differences of serum KIM-1, NGAL, and NAG levels in patients with different injuries and their correlation with the disease were statistically analyzed, and the diagnostic value of the single index and combined index for fracture traumatic shock was analyzed by using the receiver operating curve. The results of the study suggest that serum KIM-1, NGAL, and NAG levels were significantly elevated in patients with fracture trauma and were closely related to the severity of the disease, and the combination of serum KIM-1, NGAL, and NAG is of great value in the diagnosis of fracture trauma patients.
2. Materials and Methods
2.1. General Materials
96 patients with fractures combined with traumatic shock admitted to our hospital during September 2016 to December 2019 were selected as the observation group. Among them, 52 males and 44 females were aged from 20 to 73 years, and the average age was 44.12 ± 8.26 years. Patients were grouped according to the Acute Physiology and Chronic Health Status Scale (APACHE-II) upon admission, with 69 patients scoring less than 15 in the mild-moderate group and 27 patients scoring greater than or equal to 15 in the severe group. Another 58 healthy physical examiners were selected as the control group during the same period. Among them, 32 males and 26 females were aged from 21 to 75 years, and the average age was 45.84 ± 7.63 years. Our study was approved by the hospital ethics committee, and the patients and their families were informed about the study and had signed an informed consent form.
2.2. Inclusion Criteria
The inclusion criteria were as follows: (i) patients with a history of more severe fractures and confirmed by CT, X-ray, and other imaging studies; (ii) patients exhibit signs of shock such as pale skin, cold sweats, apathy, weak pulse, and shortness of breath; (iii) the patient had systolic blood pressure < 13.3 kPa, pulse pressure < 4 kPa, urine output < 25 ml/h, central venous pressure < 5 cm H2O, and altered metabolic acidosis seen on blood gas analysis.
2.3. Exclusion Criteria
The exclusion criteria were as follows: (i) patients with severe failure of the heart, liver, spleen, and other organs; (ii) patients with malignant tumors; (iii) patients who have used hormone therapy in the past month; (iv) patients with incomplete clinical data.
2.4. Experiment Equipment
The equipment used in the experiment was as follows: serum KIM-1 ELISA kit, serum NGAL ELISA kit, serum NAG ELISA kit (Beijing Dingguo Changsheng Biotechnology Co., Ltd.), and microplate reader (Bio-Rad Company, United States; model: 450).
2.5. Methods
In the control group, 1 to 2 ml of venous blood was collected at the time of physical examination using EDTA anticoagulation tubes. Patients in the observation group were collected immediately after the diagnosis of traumatic shock. Blood specimens were naturally solidified at room temperature for 10∼20 min. After solidification, the serum was centrifuged at a speed of 2000 r/min for 20 min, and then the supernatant was collected and stored at −20°C for cryopreservation. Serum KIM-1, NGAL, and NAG were detected by the enzyme-linked immunosorbent assay, and all experimental steps were strictly performed in accordance with the instructions. The results were read at an absorbance value of 450 nm using the assay zymography, and the concentration corresponding to the sample to be measured was calculated from the standard curve.
2.6. Statistical Methods
All data were processed with SPSS 22.0 statistical software, and GraphPad Prism 8 was used to make statistical graphs. Measurement data were expressed as mean ± standard deviation (), independent sample t-test was used for comparison between groups, count data were expressed as (n (%)), and chi-square (χ²) test was performed. Pearson correlation analysis was used for correlation analysis. The diagnostic value of the ROC curve was evaluated to determine the diagnostic threshold, sensitivity, and specificity, and the area under the curve (AUC) ≥0.700 indicated a high diagnostic value. The difference is statistically significant when .
3. Results
3.1. Comparison of Serum KIM-1, NGAL, and NAG Levels between the Observation Group and Control Group
In the control group, the mean serum KIM-1, NGAL, and NAG levels were (34.32 ± 10.86) pg/ml, (76.15 ± 8.61) ng/ml, and (23.59 ± 3.15) U/g-Cr, respectively. In the observation group, the mean serum KIM-1, NGAL, and NAG levels were (53.15 ± 4.95) pg/ml, (147.68 ± 23.13) ng/ml, and (45.25 ± 6.34) U/g-Cr, respectively. Statistical analysis showed that serum KIM-1, NGAL, and NAG levels in the observation group were significantly higher than those in the control group (, Figure 1). Significant changes in serum KIM-1, NGAL, and NAG levels were seen in patients with fracture trauma shock.
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