Predictors of mortality of pediatric burn injury in the Douala General Hospital, Cameroon

Introduction Burn injuries are a major cause of hospitalization and are associated with significant morbidity and mortality, particularly in children aged four years or below. In Cameroon, the mortality rate of pediatric severe burns was estimated at 41.2%. There is need to determine the predictors of such mortality in order to guide appropriate management. Methods This study is aimed at assessing the predictors of mortality of pediatric patients who sustained a burn injury over a period of 11 years (between 1st of January 2006 and 31st of December 2016) in Douala General Hospital (DGH). The data for this study was entered in an electronic questionnaire and analyzed using Epi info version 7. All variables thought to be associated with mortality were entered in a multiple binary logistic regression model. The magnitude or risk was measured by odds ratio, and the 95% confidence interval was estimated. Results A total of 125 cases of pediatric burns were recorded over the study period. A total of 69 (55.65%) were males, giving a male to female ratio of 1.25:1. The median age was 4 years. Most pediatric burns resulted from accidents. Most patient 78 (69%) came before 8 hours following injury. Scalding was the predominant mechanism of injury in 56 (45.5%) of patients. Most patients had partial thickness burn and most burns involved 1-9.9% body surface areas (BSA). The mean length of hospital stay in this study was 7 days, more than half of the patients had no complications during admission. Among those that developed complications, 19 (35%) developed sepsis. Conclusion Mortality rate of pediatric burns obtained in this study was 29%, mostly due to cardiac arrest. Flame burns (p=0.03) and BSA >25% (p=0.001) were statistically significant predictors of mortality.


Introduction
Burn injuries are a major cause of hospitalization and are associated with significant morbidity and mortality, particularly in children aged four years or below [1][2][3]. Childhood burns place enormous socio-economic burden on individuals, their families and health services [2]. Burns are the fourth commonest type of trauma worldwide, after traffic injuries, falls and interpersonal violence [4].
Nearly one quarter of all burn injuries occur in children under the age of 16 [5], of whom the majority are aged five years and below [5,6].
Flames, scalds, and contact burns are the top three mechanisms of severe burns in most studies [6][7][8][9]. In pediatric populations, scalds represent the most frequent mechanism, accounting for 60% to 75% of all hospitalized burn patients, followed by flame and contact burns [7]. Most patients do not receive pre hospital care, and among patients who receive pre hospital interventions only 17.3% of them receive interventions which are considered to be appropriate (water irrigation) [10]. The main complications noted during the course of admission are wound infections and anaemia [9]. The lack of standardized burn care protocols has a huge impact on African burn care. Some African countries use standard protocols inclusive of the assessment of wound severity [11], administration of analgesia, airway management, intravenous fluids administration, surgery and nutritional support [12]. Other countries have to make do with the expertise and experience of their health care providers. Resuscitation practices follow standard regimes with regard to burn size, resuscitation fluids, monitoring practices, and early feeding [12]. The use of early excision and skin grafting allows initial acute coverage of burns and also reduces necrotic and infected tissue [13]. In addition, early excision and skin grafting leads to decreased lengths of hospital stay, a reduced cost of hospital care, and a significant reduction in mortality [14].
In Cameroon, the mortality rate of pediatric severe burns was estimated at 41.2% [6]. Gender, age, burn size, presence of inhalation injury, presence of comorbidity, and co-existing injury are considered predictors of outcome of burn patients [15][16][17]. Variations between adult and pediatric patients do exist. Three main reasons for burn mortality common among pediatric patients are identified; burn shock during the first few hours after injury, respiratory failure in the following days, and septic complications and organ failures during the subsequent weeks [18]. Children younger than 48 months with burns involving more than 30% of the body surface have a higher rate of mortality than adults with identical injuries. This is because Children aged less than 48months do not tolerate large thermal injuries as well as adults [19,20]. The mortality doubles with the development of sepsis along with respiratory failure regardless of total body surface area involved [21]. Acute lung injury and respiratory distress syndrome (ARDS) account for 40-50% of all deaths. Multi-drug resistant organisms also increase death rates in patients with burn-related sepsis from 42% to 86% [22]. Delay of resuscitation is another very important predictor of death, [22] which has been measured as length of time to intravenous access. Patients receiving resuscitation within the first hour have significantly higher chances of survival [23], total body surface area (TBSA) >36% is found to be associated with the highest mortality [24]. This study aimed at identifying the predictors of outcome of pediatric burns in the DGH.
This study will provide surgeons, clinicians and other health practitioner's information on factors to consider in the management of burns in children.

Methods
Study design: this study was a retrospective cross-sectional observational study with review of files over a period of 11 years Data management: the data that was collected and the paper checklist was entered into an electronic questionnaire created in Epi info by the researcher. The electronic data was saved in a folder in a computer that was accessible only to the researcher and the hard paper questions were locked in a cupboard that was also accessible only to the researcher.

Results
The number of admitted pediatric cases (0-16 years) within the study period was 125 (28.03%), with a male predominance of 69 (55.65%) giving a male to female ratio of about 1.25:1. The sociodemographic/burn correlates of patients' death in relation to burns managed at the DGH. In the bivariable analysis, the factors that appeared to be associated with patients' death resulting from burns included complications of burns, initial treatment given to a patient with burns, burn depth, burn size and mechanism of burns (Table 1). However, after adjusting for potential confounding by each of the socio-demographic/burn factors that appeared to have an association with death from burns in the bivariate analysis, only having burn sizes greater than 25% and having burns resulting from electrical and flame mechanisms remained significant predictors of death from burns. Actually, the odds of death from burns in participants with burn sizes greater than 25% was 30.1 times (95%CI: 6.54, 80.96) that in participants with burn sizes of 25% or less. Finally, the odds of death from burns comparing participants with flame mechanisms of burns to participants with scalds, chemical, electrical and other mechanisms of burns was 7.26 times (95%CI: 1.95, 27.04) ( Table 2).

Discussion
The proportion of pediatric burns (0-16 years) hospitalized in the Douala General Hospital during this study was 125 (28.03%). There was a male predominance of 69 (55.65%) similar to results in a study conducted in Yaoundé (Cameroon) [6]. Flames, scalds, and electrical burns were the top three mechanisms of severe burns in this study.

This was similar to other studies carried out in Yaoundé Central
Hospital, Europe, Bordeaux, Nigeria, Ghana, South Africa and India. [6-9, 15, 17]. Overall in this study, most of the burns (45.5%) resulted from scalds.
In Cameroon, Amengle et al. estimated the mortality rate of pediatric severe burns at 41.2% [6]. In this study, 32 patients died in the course of treatment giving a mortality rate of 29%. Most (60.5%) of pediatric burns patients received in the DGH were treated and discharged. the mortality rate obtained in this study was lower than that obtained by Amengle et al. but similar to the results obtained in Ghana by Agbenorku et al. [24] and India by Mukerji et al. [21].
In most of the patients (41.7%), the cause of death was not recorded.
Gender, age, burn size, delay of resuscitation, presence of inhalation injury, presence of complications in the course of treatment, presence of comorbidity, and co-existing injury are considered predictors of outcome of burn patients [15][16][17]. In this study, after adjusting for potential confounding by each of the socio-demographic/burn factors that appeared to have an association with death from burns in the bivariate analysis, only having burn sizes greater than 25% (p=0.001) and having burns resulting from flame mechanisms (p=0.03) remained significant predictors of death from burns. The odds of death from burns in participants with burn sizes greater than 25% was 30.1 times (95%CI: 6.54, 80.96) that in participants with burn sizes of 25% or less.
Finally, the odds of death from burns comparing participants with flame mechanisms of burns to participants with scalds, electrical, chemical and other mechanisms of burns was 7.26 times (95%CI: 1.95, 27.04). In this study, gender, age, burn depth, prehospital interventions, delay of resuscitation proved not to be predictors of mortality in pediatric burns. These results were different from those obtained in Ghana by Agbenorku et al. [24]. In the study conducted

Conclusion
This study was aimed at analyzing the epidemiological profile, mechanisms and predictors of outcome of pediatric burns so as to reduce incidence, morbidity and mortality. Most burn injuries were partial thickness and burn size was 0-9.9%. The most affected body regions were the lower limbs, trunk and upper limbs respectively. The mortality rate was 29% mostly from cardiac arrest. Predictors of outcome in this study were burn size >25%, flame burns.
What is known about this topic  In other countries, the odds of death starts increasing when the burn size is >36%. Study done in Ghana [15];  In Cameroon, the mortality rate of pediatric severe burns was estimated at 41.2% [6];  Gender, age, burn size, presence of inhalation injury, presence of comorbidity, and co-existing injury are considered predictors of outcome of burn patients [15][16][17].

What this study adds
 This is the first study to the best of our knowledge and literature search done in Cameroon to assess predictors of dead of pediatric burns in Cameroon;  In our setting, the odds of death starts increasing when the burn size is as low as 25% (23 times risk of dead). People die more in Cameroon from burns with lower body surface area affected than in other developing countries;  Mortality rate of pediatric burns was lower in this study (29%) compared to another study done in Cameroon