# Prognostic Scores for Mortality in Invasive Mechanically Ventilated Burn Patients

## TL;DR

This study identifies factors affecting mortality in burn patients needing mechanical ventilation and finds that the R-Baux score is the most accurate predictor.

## Contribution

The study evaluates and compares prognostic scores for mortality prediction in mechanically ventilated burn patients.

## Key findings

- Age, ventilation duration, hospitalization length, burn severity, TBSA, and buttock burns are associated with mortality.
- R-Baux score showed the highest accuracy (AUC_ROC of 0.834) in predicting mortality.
- In-hospital mortality was 29.8%, with a 12% death rate at one-year follow-up.

## Abstract

Introduction: Managing burn patients is a challenge requiring a multidisciplinary team with the ability to predict complications and act early to avoid them. There are few studies characterizing the population of critically ill burn patients in need of ventilatory support. This study aimed to describe the population of burn patients in need of invasive mechanical ventilation support and assess in-hospital mortality and the factors associated with it.

Material and methods: A longitudinal retrospective study was conducted, including burn patients admitted to a tertiary hospital burn unit over five consecutive years, who required invasive mechanical ventilation support during their hospitalization. Demographic data, comorbidities, characteristics of the injury scene, etiology, and characteristics of the burn were collected. Length of mechanical ventilation and hospitalization as well as mortality rate were evaluated. The determination of mortality predictors and the prognostic performance of mortality prediction scores were analyzed. A one-year follow-up was performed to evaluate the survival of discharged patients.

Results: A total of 141 patients were included in this study; 68.1% patients were male with a median age of 58 years. The mean percentage of total body surface area (TBSA) burned was 24.5%. Home incidents were the most frequent, and fire was the most common cause of burns (80.9% of patients). The mean Abbreviated Burn Severity Index Score (ABSI) was 7.83, with an area under the curve in receiver operating characteristic curve (ROC) analysis (AUC_ROC) of 0.725; the mean Belgium Outcome of Burn Injury (BOBI) score was 3.45, with AUC_ROC of 0.740 and mean R-Baux of 89.1 and AUC_ROC of 0.834. The mean duration of invasive mechanical ventilation was 16.9±19.3 days. Age (p<0.001), length of mechanical ventilation (p<0.001), length of hospitalization (p<0.001), higher degree of burn (p=0.001), TBSA (p=0.040), and the presence of buttock burn (0.006) were associated with mortality in this sample. In-hospital mortality was 29.8%. The survival group had a 12% death rate at one-year follow-up, mostly in the first three months after discharge.

Conclusion: Age, duration of mechanical ventilation, length of hospitalization, higher degree of burn, TBSA, and the presence of buttock burn were associated with mortality in this sample. R-Baux score was the most accurate test score to predict mortality in this challenging group of patients.