Research On Key Technologies Of Precise Fluid Administration For Severe Burn Patients

The World Health Organization(WHO)estimated that 265,000 people died each year from burns,most of them in low-and middle-income countries,and about 58% of burn death occurred within 72 hours of burns,36% of which died of burn shock.Severe burn means that total burn size approaches 30% total body surface area(TBSA),or burn size of ? degree approaches 10%TBSA,or burn size of ? degree and ? degree less than the above percentage,but happens with hypovolemic shock and other complications,respiratory burns or severe compound injuries.Severe burns could cause inflammation and lead to hypovolemic shock,peripheral edema,multiple organ failure and death.The goal of fluid resuscitation is to prevent hypovolemic shock by maintaining adequate end-organ perfusion,which is important treatment for severe burn patients.Fluid resuscitation not timely,over-and under-resuscitation will increase the incidence of complications and mortality.There were many fluid resuscitation formulas nowadays,but all of them merely provided the initial amount of fluid required by patients,the amount of fluid during fluid resuscitation needed to be adjusted hourly according to the state of the patients.Clinically,doctors calculate the fluid required by patients based on experience and the amount of urine,infusion and other information recorded by nurse,but patients with excess fluid are still common.To achieve precise fluid resuscitation for severe burn patients,some key problems still need to be solved:1.During the fluid resuscitation for severe burn patients,nurses with many other important duties,could not always read the amount of urine from urine bag accurately and on time,which would result in the error of patient urine record.Clinically,fluid required by patients was supplied by infusion pump through disposable blood transfusion sets,but the material of transfusion sets were different,which would have an impact the accuracy of infusion pump.2.The amount of fluid and urine needed to be recorded during fluid resuscitation,but fluid required by patients could not adjust accurately only rely on the information provided by the two parameters,and other relevant physiological parameters monitoring devices were complex and difficult to be integrated into the fluid resuscitation management system for severe burn patients.3.Fluid resuscitation formulas merely provided the initial amount of fluid required by patients,the amount of fluid supplement during fluid resuscitation needed to be adjusted hourly according to the state of the patient,the workload of clinical staff is heavy,and needing experienced doctors,and was difficult to carry out in small medical centers and during transit,the automatic adjustment algorithm for fluid required by patients remains to be further studied.To solve the above problems,we constructed fluid resuscitation management system for severe burn patients to study the factors affecting precise fluid resuscitation and computer-aided automatic algorithms for the adjustment of fluid.The major contributions of this study were presented in the following points.1.constructed a fluid resuscitation management system for severe burn patients based on infusion pump,urine meter,photoplethysmography(PPG)signal detection circuit and software which was developed base on.NET platform and running on laptop computer.Achieved the control of two infusion pump,and acquisition,processing,display and record of infusion,urine and PPG signal.The system also prompted and processed the communication exceptions of the software and achieved a log system to record system exceptions and user operation information.2.Tested the accuracy of urine meter,and compared the urine record difference between urine meter and manual.Result showed that the urine meter recorded urine accurately and manual recorded urine was 5% more than urine meter at least.3.Studied the influence of disposable blood transfusion sets on the accuracy of the infusion pump.Result showed that elasticity of the transfusion sets was the main factor affecting the accuracy of the infusion pump.The best choice of transfusion sets was the supporting transfusion sets of the infusion pump or soft and good elasticity transfusion sets,and infusion pump needed regular quality control.4.Studied the relationship between blood pressure(BP),(Shock Index)SI and the characteristics of PPG during fluid resuscitation for severe burn patients.Result showed that the characteristics extracted from PPG signal significantly correlated with systolic blood pressure,mean arterial blood pressure,pulse pressure,diastolic blood pressure and shock index.5.Studied the automatic adjustment algorithm of fluid required by patients based on linear fitting model and decision table algorithm.The computer simulation test result showed that the change trend of fluid calculated by this algorithm was similar with the actual,there was no significant difference between the total amount of fluid calculated by this algorithm and the actual,and the standard deviation of the fluid calculated by this algorithm was smaller than the actual.These results indicated that the fluid resuscitation management system for severe burn patients can accurately monitor,process and record the amount of urine,infusion and PPG signal of severe burn patients.PPG signal characteristics were well correlated with the blood pressure and shock index during fluid resuscitation,could be regarded as a indicator of blood volume during fluid resuscitation,the automatic adjustment algorithm well adjusted the fluid required by patients in computer simulation test,all of which laid the foundation of achieving precise fluid resuscitation for severe burn patients.