Risk factors for mortality in severe multiply injury patients with acute hypoxemic respiratory failure.

OBJECTIVE

To investigate the risk factors related to mortality in severe polytrauma patients with acute hypoxemic respiratory failure (AHRF).

PATIENTS AND

METHODS

From December 2011 to December 2014, we identified and intubated 524 traumatic AHRF patients in a level 1 trauma centers. Amongst those, we enrolled seventy-six severe traumatic AHRF patients with an injury severity score (ISS) over 16 and need for over 24 hour intra-tracheal mechanical ventilation for our study. Patients were followed daily to collect data about demographics, injury characteristic, diagnostic, treatment, respiratory parameters, major complications, duration of mechanical ventilation, length of stay, prevalence of major complications and 28-days mortality.

RESULTS

Of the 76 patients in our study, 61 patients were male. Patients' ages were from 15 to 78 years old (43±17) and the predominant source of trauma was road traffic accidents. Before ventilation, patients had a mean PaO2/FiO2 ratio of 108±63, pH of 7.1±0.3, PaCO2 of 54±24 mmHg, respectively. The PaO2/FiO22 ratios were significantly improved by ventilation and the average duration of ventilation was 9.63±8.74 days. There were two peak dying times and the 28-days ICU mortality rate was 28.9%. Logistic regression analysis revealed the mortality rate to be significantly higher in patients with higher APACHE II scores (odds ratio: 1.60, p=0.002), shorter intervals between injury and admission (odds ratio: -0.91, p=0.03) and between admission and ventilation (odds ratio: -1.85, p=0.012), and lower pH (odds ratio: -0.692, p=0.044). The receiver operating characteristic (ROC) curves showed that best cut off points for mortality predictors were APACHE II scores greater than 25, time interval between injury and admission less than 2h, time interval between admission and ventilation less than 0.5h, and pH <7.16.

CONCLUSIONS

Traumatic AHRF patients requiring ventilation support show a high rate of early mortality. Greater vigilance for high APACHE II score, short time interval between injury and ventilation, low pH in traumatic AHRF patients is required.