Clinical Study On Influencing Factors Of Fluid Requirements During Shock Period In Severe Burns

BACKGROUDBurn shock is a systemic complex pathophysiologic process and clinicalsyndrome which takes place in the early period of postburn and influences the wholedevelopment and prognosis. It may happen when burn size is more than 20ï¼…TBSA inadults and 10ï¼…TBSA in children. It is generally accepted that burn shock is causedby plasma-volum loss. At present there are no effective clinical methods to block thepermeability of microvessels in burn shock, so the traditional fluid therapy is still thechief way to prevent shock in patients with severe burns. Commonly, the fluidrequirements are estimated by resuscitation formulas. The basis of the various burnresuscitation formulas is the fact that the rate of plasma-volume loss is a function ofburn size and body weight. There are many different formulas for different conditions.During the long period of clinic practices, evidences show that the actual fluidrequirements often greatly differed from the estimate-values calculated by thetraditional formulas. The purpose of this study is to explore the influencing factors offluid requirements during the shock period by review our fluid resuscitation practicefor severe burns.OBJECTIVETo explore the influencing factors of fluid requirements during the shock periodby review our fluid resuscitation practice for severe burns. METHODBetween January 2000 and December 2005, 253 patients with burned affectingmore than 50ï¼…of their total body surface area (TBSA) admitted to the Department ofBurns in Nanfang Hopital and Zhujiang Hospital. 117 records met inclusion criteriawere completed. The general data (age, sex, caused of burns, burned area, burneddepth, et al), details of fluid resuscitation, laboratory results and treatments duringshock period were collected.SPSS 13.0 statistical package was used for statistical analysis. Measurement datawere recorded by mean±standard deviation (x±s). One-sample t test was used tocompare the actual fluid volume and formula prediction one. Multiple linearregression was chosen to describe the relationship between mean resuscitationvolume and successive-type variables. Independent-samples t test was used tocompare measurement data between two groups. Paired-samples t test was used tocompare the clinic index before and after fluid therapy. One-way ANOVA waschosen when the number of groups was more than two. The test of homogeneity ofvariance or normality was completed before ANOVA or t test.RESULTS1. Each part of the mean resuscitation volume including colloid, crystal fluid orglucose water was higher than that calculated by the Third Military MedicalUniversity (TMMU) formulas. The values between them had very significantdifference (P＜0.01).2. Total burn size (ï¼…TBSA, x₁), full-thickness burn size (ï¼…TBSA, x₂) andweight (kg, x₄) were significant influenced the mean resuscitation volume(ml/kg/ï¼…TBSA, y) (r²=0.804, P=0.000). The regression equation was: y=5.577-0.015x₁+0.021x₂-0.017x₄. had statistical significance (F=154.138, P=0.000).3. The effect of inhalation injury to resuscitation fluid volume: 117 cases weredivided into four groups: burns without inhalation injury group (n=54), burns withslight inhalation injury group (n=24), burns with medium inhalation injury group (n=24) and burns with serious inhalation injury group (n=15). Mean crystal volume(ml/kg/ï¼…TBSA) during the first 24 hours postburn (F=8.108, P=0.000), meancolloid volume (ml/kg/ï¼…TBSA) during the first 24 hours postburn (F=4.306, P=0.006) and mean colloid volume (ml/kg/ï¼…TBSA) during the second 24 hourspostburn (F=3.712, P=0.014) of four groups had significant differences. Nosignificant differences were found in the other indexes (P＞0.05)4. The effect of tracheotomy to resuscitation fluid volume: 117 cases wereassigned to tracheotomy group (n=41) and group without tracheotomy (n=76). Meancrystal volume (ml/kg/ï¼…TBSA) during the first 24 hours postburn (T=3.822, P=0.000) and mean colloid volume (ml/kg/ï¼…TBSA) during the first 24 hours postburn(T=2.317, P=0.022) of two groups had significant differences. No significantdifferences were found in the other indexes (P＞0.05).5. The effect of treatment during shock period to resuscitation fluid volume:117 cases were assigned to exposed treatment group (n=49) and wrapping treatmentgroup (n=68). Mean crystal volume (ml/kg/ï¼…TBSA) during the first 24 hourspostburn(T=3.522, P=0.001) and mean crystal volume (ml/kg/ï¼…TBSA) during thesecond 24 hours postburn(T=2.122, P=0.036) between two groups had significantdifferences. No significant differences were found in the other indexes (P＞0.05).CONCLUSION1. Resuscitation fluid volume in practical ought to be higher than thatcalculated by the current formula.2. Mean resuscitation fluid volume during shock period was positivecorrelation with full-thickness burn size and negative correlation with body weightand burn size.3. Severe burns with inhalation injury should adequately increase colloidvolume and should not intentionally confine resuscitation fluid volume.4. Patients with exposed treatment during shock period should adequately increase fluid volume and should pay attention to the monitoring and adjusting ofelectrolytes.