Background: In trauma patients, acute respiratory distress syndrome (ARDS) is associated with high morbidity and mortality. Changes in diagnostics, management, and treatment may have influenced the incidence of ARDS. Therefore, the purpose of this article is to evaluate whether there is a difference in the incidence of posttraumatic ARDS (1) over time, (2) attributable to geographic distribution, and 3) related to admitting surgical subspecialities.
Methods: A comprehensive search of articles published in English and German language was conducted using PubMed, MEDLINE, and the ISI Web of Science. Search terms included ARDS, acute respiratory distress syndrome, multiple trauma, polytrauma, and surgery. A meta-regression was performed to analyze differences between several decades of patient recruitment (decade 1, 1981-1990; decade 2, 1991-2000; decade 3, 2001-2010), geographic location (North America and Europe), and the type of admitting surgical service (general vs. orthopedic trauma), respectively. Statistical analyses were performed with R (version 3.1.2, metafor package).
Results: The search included studies between January 1, 1980, and December 31, 2015 and revealed 43 trials from 40 publications (117,951 patients, 7,816 with posttraumatic ARDS). The median incidences over the last three decades were similar between decade 1 (10.4%), decade 2 (7.7%), and decade 3 (8.0%) (p = 0.8322). Geographical observations comparing central Europe and North America revealed no statistically significant difference (Europe 13.0%) and North America (6.9%), (p = 0.0696). The ARDS incidence in patients published based on a general surgery service (9.8%) was comparable to those published by orthopedic trauma surgeons (7.0%) (p = 0.3436).
Conclusion: The results of this meta-analysis discard the assumption that the following factors have influenced the incidence of posttraumatic ARDS: There was neither a change in the incidence over the last decades, nor a geographical difference within western societies, nor associated with the admitting surgical subspeciality.
Level of evidence: Systematic review, level III.