The effect of preexisting respiratory co-morbidities on burn outcomes

Abstract

Introduction Burns cause physiologic changes in multiple organ systems in the body. Burn mortality is usually attributable to pulmonary complications, which can occur in up to 41% of patients admitted to the hospital after burn. Patients with preexisting comorbidities such as chronic lung diseases may be more susceptible. We therefore sought to examine the impact of preexisting respiratory disease on burn outcomes. Methods A retrospective analysis of patients admitted to a regional burn center from 2002–2012. Independent variables analyzed included basic demographics, burn mechanism, presence of inhalation injury, TBSA, pre-existing comorbidities, smoker status, length of hospital stay, and days of mechanical ventilation. Bivariate analysis was performed and Cox regression modeling using significant variables was utilized to estimate hazard of progression to mechanical ventilation and mortality. Results There were a total of 7640 patients over the study period. Overall survival rate was 96%. 8% (n=672) had a preexisting respiratory disease. Chronic lung disease patients had a higher mortality rate (7%) compared to those without lung disease (4%, p<0.01). The adjusted Cox regression model to estimate the hazard of progression to mechanical ventilation in patients with respiratory disease was 21% higher compared to those without respiratory disease (HR=1.21, 95% CI=1.01–1.44). The hazard of progression to mortality is 56% higher (HR=1.56, 95% CI=1.10–2.19) for patients with pre-existing respiratory disease compared to those without respiratory disease after controlling for patient demographics and injury characteristics. Conclusion Preexisting chronic respiratory disease significantly increases the hazard of progression to mechanical ventilation and mortality in patients following burn. Given the increasing number of Americans with chronic respiratory diseases, there will likely be a greater number of individuals at risk for worse outcomes following burn.

Re-evaluation of the Effect of Age on In-hospital Burn Mortality in a Resource-Limited Setting

“…26 Several studies show the effect of comorbidities, such as renal insufficiency, respiratory diseases, and diabetes mellitus, on the increased risk of hospitalacquired infections and mortality. [27][28][29] The relative protection of older children and young adults is likely explained by an absence of the factors previously discussed for young children while also avoiding the comorbidities of older age. Older children and young adults have the advantage of having more developed immune systems, predictable responses to resuscitation, and robust compensatory mechanisms during stress.…”

Sex‐Based Differences in Inpatient Burn Mortality

“…Our initial hypothesis was that comorbid conditions and burn characteristics would explain any sex-based disparities in mortality. For example, in prior analyses we found that preexisting pulmonary disease, cardiovascular disease, and diabetes increased mortality in adult burn patients [15,17,19]. We have also shown that the Charlson Comorbidity Index score is predictive of inpatient mortality, even after adjusting for patient age, TBSA, and inhalational injury [18,19].…”

“…Inhalation injury was diagnosed by bronchoscopy. Variables for the IPTW models were chosen by identifying potential confounders and causes of mortality using directed-acyclic graphs (DAGs) and previous research in this cohort [15][16][17][18]. Weights were stabilized using the marginal probability of being female (probability of being female/probability of being female, given their covariates [i.e., PS]).…”

Epidemiology and outcome of acute burn patients at a new dedicated burn centre in Nepal

“…28 Knowlin et al noted higher progression to mechanical ventilation and increased mortality risk in burn patients with COPD. 29 Hypertensive (17% increased risk), diabetic (26% increased risk) as well as patients with psychiatric diagnosis (42% increased risk) or valvular disease (32% increased risk) were more likely to stay longer in the hospital. Thombs et al also found that preexisting cardiovascular admission and mortality in burn patients.…”