Although fluid overload may also play a role [3], we did not find significantly higher infusion volumes in consolidation patients, and all five patients who received more than four liters of infusions had Mlung values within the reference interval (Table (Table3).3). The association of severe head injury with increased AP24534 Mlung further underlines the fact that multiple factors, such as neurogenic pulmonary edema, may be involved in the development of posttraumatic lung dysfunction [41]. Even if the precise etiology of posttraumatic lung dysfunction remains unclear in some patients, information on preexisting lung damage could help clinicians to judge the individual patient’s tolerance for further aggressive shock resuscitation and definitive surgical repair [20,24].

It could also guide clinicians in choosing treatment concepts such as lung-protective mechanical ventilation or damage control surgery, which are focused on the prevention of “second hits” to lungs which have already been primed by shock and pulmonary or systemic injuries. Among such “second hits” are surgical trauma, ongoing intraoperative blood loss and transfusion, fat embolism following intramedullary nailing or injurious mechanical ventilation [3,17-20,51].Parameters such as ISS or PaO2/FiO2, which have previously been used for the prediction and further characterization of posttraumatic ALI, failed to distinguish atelectasis from consolidation patients [3,52,53]. In contrast, age as well as LIS, GCS and qCT results differed statistically significantly between these groups.

Interestingly, atelectasis patients spent fewer days on mechanical ventilation and in the ICU than consolidation patients (Table (Table3).3). However, given the fact that all patients fulfilling the ALI criteria early after trauma have been managed according to the damage control concept in our institution, the latter differences should be considered hypothesis-generating rather than hypothesis-confirming. The variable reliability of clinical parameters and scores for characterizing posttraumatic ALI supports the potential clinical usefulness of qCT, which is the only available in vivo method to directly and reliably quantify Mlung and the amount of nonaerated lung tissue, which both characterize the severity of lung injury [10-12,52].Some aspects of our methodology warrant discussion.

(1) We studied ALI patients within 24 hours after trauma (Table (Table1)1) because it was our aim to study the etiology of early posttraumatic respiratory failure, which may differ significantly from respiratory problems developing later [3,4,49,54]. Anacetrapib (2) All whole-body CT scans performed in our emergency trauma patients routinely involved the clinically indicated application of contrast material [21,31]. A possible effect of contrast material on the normal Mlung was the reason why we included a reference group and did not refer only to existing data [10,11,40,55].