Establishment of a prognostic nomogram model for predicting acute renal injury in patients with moderate and severe burns / 中华危重病急救医学

OBJECTIVE@#To establish a prediction model of acute kidney injury (AKI) in moderate and severe burn patients, so as to provide basic research evidence for early identification of burn-related AKI.@*METHODS@#Patients who were admitted to the department of plastic burn surgery of the Affiliated Hospital of Southwest Medical University from November 2018 to January 2021 were selected, and their clinical characteristics, laboratory examinations and other indicators were recorded. Multivariate Logistic regression analysis was used to screen out the risk factors of AKI related to moderate and severe burns, and R software was used to establish the nomogram of moderate and severe burn patients complicated with AKI. The Bootstrap method model was used for internal verification by repeating sample for 1 000 times. Consistency index and calibration curve were used to evaluate the accuracy of the model, and the receiver operator characteristic curve (ROC curve) and the area under the curve (AUC) were used to evaluate the prediction efficiency, decision curve analysis (DCA) was used to evaluate the clinical utility of the model.@*RESULTS@#A total of 186 patients with moderate and severe burn were included, among which 54 patients suffered from AKI, and the incidence rate was 29.03%. Multivariate Logistic regression analysis showed that the total burn surface area [TBSA; odds ratio (OR) = 1.072, 95% confidence interval (95%CI) was 1.031-1.115, P = 0.001], estimated glomerular filtration rate (eGFR; OR = 0.960, 95%CI was 0.931-0.990, P = 0.010), neutrophil (NEU; OR = 1.190, 95%CI was 1.021-1.386, P = 0.026), neutrophil/lymphocyte ratio (NLR; OR = 0.867, 95%CI was 0.770-0.977, P = 0.019), D-dimer (OR = 4.603, 95%CI was 1.792-11.822, P = 0.002) were the risk factors for patients with moderate and severe burn complicated with AKI. Taking the above indexes as predictive factors, a nomogram prediction model was established, the ROC curve was plotted with AUC of 0.998 (95%CI was 0.988-1.000). Optimum threshold of ROC curve was -0.862, the sensitivity was 98.0% and the specificity was 98.2%, and the consistency index was 0.998 (95%CI was 0.988-1.000). The calibration curve showed that the prognostic nomogram model was accurate, DCA showed that most patients can benefit from this model.@*CONCLUSIONS@#The burned patients with higher TBSA, NEU, NLR, D-dimer and lower eGFR tend to suffer from AKI. The nomogram based on the above five risk factors has high accuracy and clinical value, which can be used as a predictive tool to evaluate the risk of AKI in moderate and severe burn patients.

Design and study of nitric oxide portable producing device using continuous discharging arc plasma reaction keeping low energy efficiency for viral pneumonia emergency therapy.

This study investigated the efficiency of a portable nitric oxide (NO) inhalation device through optimizing its design and structure. The portable rescue device could be used in clinical applications in outbreaks of viral pneumonia such as SARS. To reduce energy consumption for battery-powered portable usage, NO micro-channel plasma reactions induced by a continuous discharge arc were employed. A single-use airway tube could be combined with an intubation tube in clinical applications. In the experiment, a switching transistor controlled high frequency DC (12.5 kHz) was used to create a continuous discharge arc between two stainless steel electrodes (1-mm separation) after high-voltage breakthrough. A rotate instrument was employed to change the direction angle between the airflow and discharge arc, tube filled with Calcium hydroxide connected with gas outlet for reducing NO2, gas flow rate and input voltage were evaluated separately with concentration of NO and NO2/NO ratio. Results showed that a 2 L/min air flow direction from the cathode to the anode of electrodes (direction angle was zero) under 4 V input voltages produced 32.5±3.8 ppm NO, and the NO2/NO ratio reduced to less than 10%, stable output of nitric oxide might be convenient and effective for NO inhalation therapy. Modularization of the design produced a portable NO inhalation device that has potential for use in clinical applications as it is low cost, easy to disinfect, consumes low levels of energy and is ready to use.

Effects of platelet-rich plasma on the survival of ultra-long dorsal random flaps in rats / 中华烧伤杂志

Objective@#To observe the effects of platelet-rich plasma (PRP) on the survival of ultra-long dorsal random flaps in rats.@*Methods@#Sixteen male Sprague Dawley rats aged 6 to 8 weeks (the same below) were sacrificed to collect whole blood of 9 to 10 mL from each rat, and PRP was prepared by modified APPLE method. The platelet count of retained whole blood and PRP detected by automated blood cell analyzer showed that PRP was made successfully. The other thirty-two rats were collected and divided into PRP group and control group according to the random number table, with 16 rats in each group. One rectangular ultra-long random flap with area of 8 cm×2 cm was made on the back of each rat and replanted in situ. The equidistant 3 points were designed on both sides of the flap of each rat. Rats in PRP group were injected with 0.1 mL PRP from dermis and subcutaneous tissue of each injection point, while rats in control group were injected with the same volume of normal saline. Eight rats in each group were sacrificed at post operation hour (POH) 24 and on post operation day (POD) 7. On POD 7, survival of flaps of rats in 2 groups was observed, and the survival rates of flaps were calculated. On POD 7, the proximal, middle, and distal flaps of rats in 2 groups were collected, and histological changes of the flaps of rats in 2 groups were observed with hematoxylin-eosin staining. At POH 24 and on POD 7, flaps in 3 to 4 cm to pedicles were taken to detect mRNA expressions of vascular endothelial growth factor (VEGF), platelet-derived growth factor AA (PDGF-AA) and PDGF-BB by real-time fluorescent quantitative reverse transcription polymerase chain reaction, and to determine content of nitric oxide by nitrate reductase method. Data were processed with t test.@*Results@#(1) On POD 7, flaps of rats in PRP group were dry without purulent exudate, and covered with scab, and the pink new skin emerged after scab fell off. On POD 7, flaps of rats in control group were with a large amount of inflammatory exudates, 1/2 to 2/3 of flaps at the distal were with necrosis and covered by scab which was not easy to be stripped. The survival rate of flap of rats in PRP group was (67±6)%, significantly higher than (52±10)% of rats in control group (t=1.94, P<0.05). (2) There were no obvious inflammatory cell infiltration and a number of microvessels, and fibrous tissue arranged neatly in the proximal flaps of rats in PRP group. There were a few of inflammatory cell infiltration and a number of microvessels, and fibrous tissue arranged slightly disorderly in the middle flaps of rats in PRP group. There were many more inflammatory cell infiltration and microvessels, a small amount of vascular embolism, and fibrous tissue arranged disorderly in the distal flaps of rats in PRP group. There were a large number of inflammatory cells infiltration and a few of microvessels, and fibrous tissue arranged disorderly in the proximal, middle, and distal flaps of rats in control group. (3) At POH 24 and on POD 7, mRNA expressions of VEGF, PDGF-AA, and PDGF-BB of rats in PRP group were significantly higher than those of rats in control group (t=6.46, 5.61, 2.88, 10.18, 6.10, 7.67, P<0.001). (4) At POH 24, content of nitric oxide in flap of rats in PRP group was (5.0±0.9) μmol/g, significantly higher than (3.4±0.9) μmol/g of rats in control group (t=19.14, P<0.001). On POD 7, content of nitric oxide in flap of rats in PRP group was (3.3±0.8) μmol/g, which was close to (3.0±0.6) μmol/g of rats in control group (t=2.93, P>0.05).@*Conclusions@#PRP can improve the survival rate of ultra-long dorsal random flap in rats, which may be related to regulation of angiogenesis related factors, increase of nitric oxide content, and inhibition of excessive apoptosis of cells of PRP, so as to alleviate ischemical reperfusion injury and improve microcirculatory disturbance.