survival after occurrence of a burn injury has dramatically increased over the past decades . however , burn is still causing a considerable morbidity and mortality for its victims . several predicting models have been developed to estimate the risk of mortality in these patients among which baux score points to the important relationship of total burned surface area ( tbsa ) and age with the overall probability of death . however , with increasing incidence of inhalation injuries among victims of burn , the concerns has been raised about the necessity of including such critical determinant in these models ; hence , the revised baux score ( r - baux score ) has been developed to resolve the mentioned issue . in fact , the purpose of developing such scoring model was the need to recalibrate the original baux score after introduction of newer treatment options for burn patients . therefore the outcome of modern burn care could be predicted while the primary simplicity of the formula is maintained . despite universally acceptance of modified baux score ( r - baux score ) in prediction of burn mortality it seems that in this group of patients , based on r - baux score , mortality rate raises as the age increases . however , the probability of death may be greater in younger children especially neonates as is seen in critical circumstances . hence , we aimed to investigate the applicability of this scoring model discretely in children with burn injuries to determine how p ( pediatric)-baux score can predict prognosis in this population . we enrolled pediatric cases of burn injuries which were admitted to emergency department of motahari burn hospital in tehran ( the most great referral center in iran ) during 2005 to 2009 . patients were evaluated physically to determine the extent and severity of burn injuries , general conditions , and vital signs . then they were stabilized and admitted to the pediatric ward of the hospital for further management . inclusion criteria were age of less than 15 years and need to be admitted due to the severity of their burn injuries . the following data was recorded for each patient : demographics , epidemiologic characteristics , clinical features of their injuries , mechanism of injury and cause of burn , total body surface area ( tbsa by the lund and browder method calculated by two independent physicians on admission ) , presence of inhalation injury ( defined on the basis of exposure to smoke , burn injury in a closed space , presence of carbonaceous sputum , signs of airway obstruction , deterioration of po2 in serial arterial blood gas ( abg ) tests and/or positive findings in bronchoscopy ) . according to tbsa , patients were divided into 4 categories : 0 - 10% , 10 - 20% , 20 - 40% , and > 40% . also , children were categorized into five age groups of infants ( 0 - 1 year ) , toddlers ( 1 - 2 years ) , early childhood ( 2 - 6 years ) , primary school ( 6 - 10 years ) , and secondary school ( 10 - 15 years ) . r - baux score to predict the probability of death after burn injury was calculated for each patient by following formula : r - baux score = ( tbsa + age + [ 17r ] ) . { r = 1 if patient has inhalation injury and r = 0 if not}. the measurement of this score in our patients revealed that in contrast to adults , increasing age in children may have inverse relationship with the score bearing a positive prognostic value . in addition , presence of inhalation injuries seems to add an additional 18 to the score leading to more probability of death according to our analysis . hence , p - baux score for the 95% probability of death in our population was calculated as follows : p ( pediatric)-baux score = ( tbsa - age + [ 18r ] ) . { r = 1 if patient has inhalation injury and r = 0 if not}. patients were then categorized based on the calculated p - baux score to reveal the relationship between percentages of death occurrence with calculated score . data were analyzed by statistical package for social sciences ( spss version 16 , washington , inc . ) . the logistic regression model was performed to reveal the effects of age , tbsa , and inhalation injury on mortality . we then developed a modified revised baux score ( as pediatric baux score ) by a second logistic regression model to estimate the probability of death . we enrolled pediatric cases of burn injuries which were admitted to emergency department of motahari burn hospital in tehran ( the most great referral center in iran ) during 2005 to 2009 . patients were evaluated physically to determine the extent and severity of burn injuries , general conditions , and vital signs . then they were stabilized and admitted to the pediatric ward of the hospital for further management . inclusion criteria were age of less than 15 years and need to be admitted due to the severity of their burn injuries . the following data was recorded for each patient : demographics , epidemiologic characteristics , clinical features of their injuries , mechanism of injury and cause of burn , total body surface area ( tbsa by the lund and browder method calculated by two independent physicians on admission ) , presence of inhalation injury ( defined on the basis of exposure to smoke , burn injury in a closed space , presence of carbonaceous sputum , signs of airway obstruction , deterioration of po2 in serial arterial blood gas ( abg ) tests and/or positive findings in bronchoscopy ) . according to tbsa , patients were divided into 4 categories : 0 - 10% , 10 - 20% , 20 - 40% , and > 40% . also , children were categorized into five age groups of infants ( 0 - 1 year ) , toddlers ( 1 - 2 years ) , early childhood ( 2 - 6 years ) , primary school ( 6 - 10 years ) , and secondary school ( 10 - 15 years ) . r - baux score to predict the probability of death after burn injury was calculated for each patient by following formula : r - baux score = ( tbsa + age + [ 17r ] ) . { r = 1 if patient has inhalation injury and r = 0 if not}. the measurement of this score in our patients revealed that in contrast to adults , increasing age in children may have inverse relationship with the score bearing a positive prognostic value . in addition , presence of inhalation injuries seems to add an additional 18 to the score leading to more probability of death according to our analysis . hence , p - baux score for the 95% probability of death in our population was calculated as follows : p ( pediatric)-baux score = ( tbsa - age + [ 18r ] ) . { r = 1 if patient has inhalation injury and r = 0 if not}. patients were then categorized based on the calculated p - baux score to reveal the relationship between percentages of death occurrence with calculated score . data were analyzed by statistical package for social sciences ( spss version 16 , washington , inc . ) . the logistic regression model was performed to reveal the effects of age , tbsa , and inhalation injury on mortality . we then developed a modified revised baux score ( as pediatric baux score ) by a second logistic regression model to estimate the probability of death . age , tbsa , number of patients with inhalation injury , and number of deaths are presented in table 1 . 10.6% of patients died and 9.5% of the patients ( 82 cases ) had complications requiring icu admission . 31 cases of inhalation injuries were due to gas explosion . among patients who had inhalation injury , 18 ( 33.3% ) patients died ; however , in patients without inhalation injury ( 810 cases ) , 71 ( 8.7% ) patients died with a statistically significant difference ( p<0.01 ) . demographics , tbsa , and outcomes of the patients with burn injuries tbsa : total body surface area comparison of sex in different age groups in pediatric burn injuries among inhalation injury cases ( total = 60 ) , 49 ( 81.7% ) patients were in a closed space during the accident compared to 11 ( 18.3% ) patients in an open space . flame related burn injuries accounted for 57% of the deaths and 43% were due to scalds . 8 cases of death were due to multiple organ failure compared to 7 deaths due to infection and sepsis ( table 3 ) . fifteen patients ( 25% ) with inhalation injury developed severe respiratory failure and were admitted to intensive care unit ( icu ) for intensive respiratory care . patients diagnosed with sepsis had 11% mortality compared to those without sepsis ( 9.4% ) which did not reveal a statistically significant difference ( p>0.05 ) . comparison of the causes of burns in the different age groups in the four year period of our study , there were 89 ( 10.6% ) in - hospital deaths due to burn of which 64 ( 72% ) cases occurred in patients with a burned area of more than 40% . seventy seven patients ( 8.8% ) aged between 10 and 15 years old . in this group , 14.2% patients died due to severe morbidities which was the highest amount of mortality rate among these five groups . odds ratio ( or ) was 2.74 for female sex , 0.758 for an additional year of age , 1.27 for an additional percent of tbsa . or for inhalation injury among flame burn victims was 255.5 . comparison of age and tbsa tbsa : total body surface area patients were categorized into 12 groups according to r - baux score to compare the percentage of death ( table 5 ) . p - baux score was calculated for each patient and then compared with the occurrence of death ; the probability of death was then calculated by percentages of the patients who died compared to total number of patients which received similar score in a unique category . it is obvious that  p - baux score  has a direct relationship with mortality rate of patients and had a relatively higher predictive value ( r=0.57 ) . 1 shows the direct and sigmoid relationship of  p - baux  to patients death . scores less than 50 were associated with no probable mortality while the likelihood of death increased from the score of 50 to 100 and stayed at a 100% probability from 100 to the highest score which was 130 ( table 5 ) . relationship of  r - baux  with patients death percentage of death calculated by r - baux formula in patients with inhalation injury a limited number of risk factors have been certainly linked to increased probability of death after burn injuries ; these include age greater than 60 years , tbsa more than 40% , and the presence of inhalation injury and also burn depth . osler et al had noted in their study to calibrate the baux score to the r - baux score , the calibrated features of their models , so it could not easily be applied to all of the burn care centers . baux score ( which is calculated as : age + tbsa ) is no more used for mortality prediction of burn patients . according to the previous data , there are three important factors predicting the mortality of burned patients with a rather simple pattern as the following : 
 r - baux score : ( tbsa + age+[17r ] ) { r = 1 if patient has inhalation injury and r = 0 if not } we calculated the original baux score in our patients and then by employing a logistic regression analysis , an additional 18 was added to revise the predicting model to the p - baux score . in fact , as we used such a score in children , we found that an additional 18 in case of inhalation injuries would predict burn related mortalities with more probability . although there are statements on the young age as risk factors of burn - related mortality , a few studies have expressed that age does not interfere with mortality in children . the controversy indeed stands as a result of the differences in treatment options , type , severity , and extent of burns in the studied groups of pediatric patients . however , mortality due to burn injuries has been shown to be lower in children and it has been stated that pediatric cases survive even severe incidents of burn . children younger than 4 years have been shown to experience shallower burns , smaller tbsa , and lower incidence of inhalation injuries ; so these conventional risk factors of mortality need to be considered before interpreting any results . as it has been shown in previous studies , greater tbsa and larger extent and severity of burns and presence of wound infections and inhalation injuries have all been related with more probability of death . this is considerably higher than in other similar studies which have included children in their investigations . however , we should notice that this rate is reflective of the overall factors which influence mortality including age , type and severity of burn , well care providing , and psychosocial supports . these factors absolutely differ between different studies which have been carried out in various settings and on varying populations . p - baux score was directly related to the probability of death except for the 90 - 100 score which is related to decreased mortality ( fig . they have proposed r - baux score and have used it to predict the probability of mortality after burn injuries . however , they have not paid sufficient attention to explicit children from other age groups of patients . our study indeed went the same way as they did , but in children aging less than 15 years rather than inclusion of all age population . such model although gives a rough estimation of the death probability , but it is obvious that many other factors may impact on end outcomes ; these include but are not limited to the external supports , sufficient resuscitation , complications after burn such as acute respiratory distress syndrome , ventilator associated pneumonia , wound infection , sepsis , and multi organ failure syndrome . but , these complications are predictable by the extent and severity of injuries which is remarked by tbsa in the formula ; in addition , the mentioned complications are late onset and the aim of the current model is to predict mortality prediction in the early hours of burn injuries . p - baux score is easy to use and simply calculated and hence would award easy benchmarking in emergent settings . in addition , other models of prediction for burn related mortality employ the proved risk factors of death due to burn which are unique among different systems and they are age , tbsa , and the presence or absence of inhalation injury . but despite these facts , validation and previous experience in application of these models are essential before recommending them as a routine method in estimation of death probability . in our model , probability of death was 0% when the score was assumed to be less than 50 , while mortality tended to increase when the score rose up and got constant at 100% for scores greater than 100 ( table 5 ; fig . this simple calculation of mortality prediction has been shown to outweigh the rough estimation of the mentioned percentage . there were limitations to this study which need to be taken into account before certain interpretation of our study results . the most important issue is the number of patients ; we should expand the sample size of our study to be able to improve the validity of our model . using a data set available from burn care centers has been shown to be much beneficial in this regard ; however , before using such sources , precautions must be taken into account in terms of accuracy and validity of the extracted data and if not assured , a new data registry should be established . another consideration for this study is the need to the close collaboration of different burn care centers to reveal the unique differences of participants which may remain hidden between such a wide spectrums of patients . p - baux score can be useful for predicting the probability of survival in pediatric burn injuries . our study showed that p - baux score is directly correlated with probability of death after burn injuries in pediatric patients .
objectiver - baux score has obtained an acceptable validity and accuracy in predicting burn - related mortality . however , its usage and efficacy among pediatric burn patients has not been well documented . 
 the aim of this study was to employ pediatrics - baux ( p - buax ) score as modified version of r - baux score in these patients to determine how it could be applicable in this population.methodsthrough a prospective study , 870 pediatric burn patients were enrolled . 
 p - baux and r - baux scores were calculated for each patient and they were categorized to different groups according to these scores . 
 mortality and further death probability were measured for each subject and then analyzed by logistic regression model to reveal how they change in relation with age in pediatric burn patients.findingsr-baux score for 95% probability of death revealed a mean of 73 among patients of this study . also p - baux score was measured in these patients with inhalation injury which showed to be 55 for 95% probability of death . 
 results showed that age had a positive prognostic value in contrast to the negative prognostic value of total body surface area ( tbsa ) and inhalation injury.conclusionour analysis showed that in children under the age of 15 years , age has a positive prognostic value while tbsa and inhalation injuries had negative prognostic values in relation to mortality . 
 hence , in contrast to the adult population , burn injury related mortality may be predicted by modified r - baux score as ( tbsa - age + [ 18r ] ) which could be named as p - baux score .