Clinical Study On The Evaluation Of Simple Parameters For Shock Diagnosis, The Effective Fluid Replacement And Prognosis In Burn Patients During Shock Stage

Objective1. To explore the value and numerical scope of urinary output, haematocrit, baseexcess, lactic acid for evaluating the resuscitation effect of patients with extremely severeburn during shock stage.2. To evaluate the fluid resuscitation formula established by the third Military MedicalUniversity for patients with extremely severe burn.3. To establish a mathematical model and evaluate its efficacy for early prediction forinternal organ complications in patients with severe burn.Methods1. Clinical study on urinary output as a simple predictor for evaluating theresuscitation effect of patients with extremely severe burn during shock stageA review was made on190patients with extremely severe burn (total burn area≥50%TBSA or full-thickness burn area≥20%TBSA) admitted to the Institute of Burn Research,Southwest Hospital (IBRSH) from2000to2011. Urinary output (UO) during shock stageand complications were recorded. Average UO during shock stage were distributed from0ml/h and130ml/h. The patients were divided into six groups: group A (UO0～20ml/h),group B (UO21～40ml/h), group C (UO41～60ml/h), group D (UO61～80ml/h), groupE (UO81～100ml/h) and group F (UO101～130ml/h) based on the average UO duringshock stage. Incidences of complications of the six groups were calculated. Dates wereprocessed with one-way analysis of variance, chi-square test and Kruskal-Wallis H test.2. Clinical study on hematocrit as a simple predictor for evaluating the resuscitationeffect of patients with extremely severe burn during shock stageA review was made on131patients with extremely severe burn (total burn area≥50%TBSA or full-thickness burn area≥20%TBSA) admitted to IBRSH from2000to2011. The patients were divided into group A (≤0.50) and group B (>0.50) based on thehematocrit levels at the end of the first24hours postburn. Hematocrit during shock stage,UO and base excess during the first24hours postburn, incidence of complications andmortality were recorded. Dates were processed with t test, chi-square test and wilcoxonrank sum test.3. Clinical study on base excess as a simple predictor for evaluating the resuscitationeffect of patients with extremely severe burn during shock stageA review was made on190patients with extremely severe burn (total burn area≥50%TBSA or full-thickness burn area≥20%TBSA) admitted to IBRSH from2000to2011.The patients were divided into group A and group B according to the complications afterinjury. The patients in group A had excellent results without any complications while thepatients in group B all developed complications after injury. Heart rate, mean arterypressure, UO per hour, potential of hydrogen, base excess and shock index during shockstage were recorded. Dates were processed with t test, chi-square test and wilcoxon ranksum test.4. Clinical study on Lactic acid as a simple predictor for evaluating the resuscitationeffect of patients with extremely severe burn during shock stageA review was made on86patients with extremely severe burn (total burn area≥50%TBSA or full-thickness burn area≥20%TBSA) admitted to IBRSH from2007to2011.The patients were divided into group A and group B according to the complications afterinjury. The patients in group A had excellent results without any complications while thepatients in group B all developed complications after injury. Heart rate, mean arterypressure, potential of hydrogen, lactic acid, base excess and shock index during shock stagewere recorded. Dates were processed with t test, chi-square test and wilcoxon rank sumtest.5. Clinical study on evaluation of the fluid resuscitation formula for patients withextremely severe burnA review was made on131patients with extremely severe burn (total burn area≥50%TBSA or full-thickness burn area≥20%TBSA) admitted to IBRSH from2000to2011.The patients were divided into group A and group B according to the complications afterinjury. The patients in group A had excellent results without any complications while the patients in group B all developed complications after injury. Heart rate, mean arterypressure, potential of hydrogen, base excess and shock index during shock stage wererecorded. Resuscitation coefficient during the first and second24hours post injury werecalculated. Dates were processed with t test, chi-square test and wilcoxon rank sum test.6. Establishment of a mathematical model and evaluation of its efficacy for earlyprediction for internal organ complications in patients with severe burnsA review was made of205severe burn patients (total burn area≥30%TBSA) admittedto IBRSH from2007to2011. Age, gender, body weight, mechanism of injury, total andfull-thickness body surface area burned, presence of inhalation, escharotomy sites, lacticacid and base excess during shock stage, internal organ failure and the final outcome wererecorded. Logistic regression analysis was used to select the internal organ failure relatedrisk factors. The two predictive equations about adult and all patients including childrenwere derived respectively through logistic regression analysis. The efficiency of the modelswas evaluated with ROC method.Results and conclusion1. Urinary output during shock stage seriously influences prognosis of burn patients.Maintaining UO roughly around61～80ml/h, patients with extremely severe burn havelower incidence of complications and favourable prognosis. Considering the limited healthresources at wartime or peacetime when serious sudden burn calamity occurs, we proposethat UO in adult should be hold at a level of70ml/h.2. Hematocrit promises to serve as an indirect predictor of resuscitation effect at shockstate. Controlling hematocrit at a range of0.50-0.45of patients with extremely severe burnduring the first24hours post injury can alleviate acid-base imbalance, and reduce theincidence of complications and mortality rate, which suggests more effective fluidresuscitation.3. Base excess can reflect the tissue perfusion and oxygen metabolism in cells moreaccurately than blood pressure. It can be used as a sensitive indicator in the fluidresuscitation of burn patients.4. Lactic acid of patients with extremely severe burn should fall below3mmol/L at theend of the first24hours post injury, for the circulatory system tends to be stable, theacid-base imbalance is light, resuscitation is more effective and patient has a better prognosis.5. When resuscitation coefficient of the first24hours post injury raise to1.9ml·Kg-1·%TBSA-1and that of the second24hours post injury raise to1.3ml·Kg-1·%TBSA-1,patients with extremely severe burn tide over the shock stage smoothly and have a betterprognosis, which suggests the fluid infusion volume is more appropriate.6. Predictive model is established for early prediction internal of organ complicationsin patients with severe burn based on age, total body surface area, lactic acid. Predictivemodel Logit(p)=0.065×age+0.086×TBSA+0.319×lactic acid-11.729is suitable for allpatients including adult and children. The best cut-off value of the model predictingprobability is0.242(Sen86.1%, Spe88.8%).