Role of first day levels and subsequent trends of serum proteins in acute burns

Gupta S, Bhattacharya S, Goyal P. Role of first day levels and subsequent trends of serum proteins in acute burns. J Acute Dis 2018; 7(1):31 35. have been proposed[5]. The protein loss through leaking capillaries during acute burn is compounded by subsequent hyper-catabolism and hepatic dysfunction leading to hypo-proteinemia throughout the clinical course[6-8]. Serum albumin as a marker for prognosis has been studied previously but the results are conflicting[9]. The physiological and metabolic derangements in burns are dynamic over the whole clinical course. Since most of the literatures dwell upon first day of burn serum protein values only, the dynamics of trend of serum proteins levels through the clinical course of burns needed evaluation. 2. Material and methods This prospective observational study was carried out in Department of Burns, Plastic and Maxillofacial Surgery, and Department of Biochemistry from November 2015 to March 2017. A total of 100 patients in the age group of 18-60 years with 20% to 60% TBSA burn injury were included in the study. Relevant approvals had been obtained from the Institutional Review Board and the Ethics Committee [reference number: No. T. P (DM/MCh) (18/2015)/IEC/9633]. Burn admission delayed by more than 24 h, electrical or chemical burn and patients with associated injury were excluded from the study. All patients were treated conservatively with regular dressing till wound healing or delayed skin grafting after eschar separation. The patients were divided into survivors (Group A) and non-survivors (Group B). There were 83 survivors (Group A) who were discharged in stable condition and 17 patients non-survivors (Group B) who expired during the course. Average age of the patients in the survivor group (n=83) was 41 years and in non survivor group (n=17) it was 49 years. The average hospital stay in the non-survivor group was 21 days whereas it was 13 days in survivor group. Average TBSA of burns in the non-survivor group was (50.00±5.59)% and in survivor group it was (34.76±8.76)%. Serum albumin, globulin and total protein were estimated on alternate days starting from day one of admission. For this 4-5 mL of whole blood sample was collected from each patient in serum separator gel tubes. Serum was separated by centrifuging at 3 500 rpm for 10 min and serum proteins estimation was done on Fully Automated Dry Clinical Chemistry Analyzer, Vitros, 5,1 by Ortho Clinical Diagnostics. A drop of patient sample was deposited on the respective slides for estimation of total protein and albumin. Protein in the sample formed a complex with cupric ion and the decrease of the copper–azo dye complex, measured by reflectance spectrophotometry was proportional to the concentration of proteins in the sample. Serum albumin levels were measured by the bromcresol green method. The dye binds to albumin from the sample and the colour complex formed was proportional to the concentration of albumin in the sample. Within lab imprecision for total protein was 4.9% and for albumin was 1.7%. The first day value and the trend of serial values of total protein, albumin and globulin throughout the clinical course were compared in the two groups. The value of each predictor variable in relation to time, in predicting mortality was evaluated by Pearson correlation coefficient for every patient. Trend of variables over time in survivor and non survivor groups was tested by one sample t test of the Pearson correlation with the reference value of zero and difference between survivors and non survivors was tested by Two samples t test. The risk of increasing or decreasing values of variables on survival was assessed with the proportional hazard regression model of Cox. Univariate and Multivariate Logistic regression analysis was used to assess predictability of mortality by different risk factors by considering their day 1 value. Receiver Operating Characteristic Curve was used to find out cut-off point of different risk factors in predicting mortality. The results were considered significant with P value less than 0.05. 3. Results Mean serum values of albumin, globulin, total protein on first day of burns in survivor group was (24.3±3.4) g/L, (25.3±4.1) g/L, (49.6±6.6) g/L, respectively. In the non-survivor group, the average serum albumin, globulin and total protein were (18.5±3.2) g/L, (19.9±3.2) g/L and (38.4±5.5) g/L, respectively. This difference was statistically significant with lower levels of each parameter in non survivor group. Receiver Operating Characteristic Curve was used to deduce the cut-off value of day 1 level of serum albumin, globulin and total protein in predicting mortality (Table 1). Serum albumin levels equal to or less than 21.0 g/L on first day of burns was considered as a poor prognostic factor (P<0.0001)with sensitivity of 88.24 and specificity of 78.31, and area under the ROC curve (AUC) of 0.89. Serum globulin levels equal to or less than 22.0 g/L on first day of burns was considered as a poor prognostic factor (P<0.0001) with sensitivity of 76.47 and specificity of 77.11 Table 1 ROC curve for initial prognostication on first day of burns. Serum level at Day 1 AUC Standard error 95% confidence interval P value Cut off value (g/L) Sensitivity Specificity Albumin 0.89 0.041 0 0.811877 - 0.