Date Published: January 31, 2018
Publisher: John Wiley and Sons Inc.
Author(s): Yasuyuki Okabe.
Blunt chest trauma is common and is associated with morbidity and mortality in patients with multiple injuries, frequently requiring invasive mechanical ventilation. The aim of this study was to elucidate risk factors for prolonged mechanical ventilation (PMV).
Consecutive adult patients with multiple severe injuries and blunt chest trauma who treated in Chiba Emergency Medical Center (Chiba, Japan) between January 2008 and December 2015 were enrolled in this retrospective chart‐review study. According to ventilatory time, the patients were divided into PMV (≥7 days) and shortened mechanical ventilation (SMV; <7 days) groups. Thoracic Trauma Severity Score (TTSS) was calculated. To identify risk factors for PMV, univariate and multivariate logistic analyses and receiver operating characteristic analysis were carried out. Eighty‐four and 49 patients were assigned to PMV and SMV groups, respectively. Compared with the SMV group, the PMV group had a significantly larger number of fractured ribs (P < 0.01), higher rate of severe Glasgow Coma Scale (GCS ≤8) (P < 0.05) and flail chest (P < 0.001), higher TTSS (P < 0.001), or longer intensive care unit and hospital stay (both P < 0.001). Logistic analysis showed that severe GCS (odds ratio [OR] = 4.6, P < 0.01), flail chest (OR = 3.0, P < 0.05), and TTSS (OR = 1.2; P < 0.01) were independent significant risk factors. Receiver operating characteristic analyses showed that the area under the curves for TTSS, flail chest, and severe GCS were 0.74, 0.70, and 0.58, respectively. When the three factors were combined, the area under the curve increased to 0.8. Severe GCS (≤8), flail chest, or TTSS may be independent risk factors. Combining the three risk factors could provide high predictive performance for PMV.
Blunt chest trauma was defined as blunt chest wall injury resulting in rib fractures, lung contusion, hemothorax, pneumothorax, and others with or without life‐threatening lung injury.1 According to the Japan Trauma Data Bank Report 2016, blunt chest trauma is the third most common injury; injuries to the head and lower extremities are the most common.2
During the study period, a total of 4,317 injured patients were admitted to our hospital. According to the exclusion criteria, 4,184 patients were excluded; 3,626 patients did not have any rib fractures, 485 patients did not need mechanical ventilation, 31 patients died within 48 hours, 8 patients had ISS <16, 5 patients were transferred within 5 days, and 29 patients were intubated for reasons other than respiratory failure. No patients had fewer than two injury lesions (Fig. 1). Of the remaining 133 patients, 84 patients were assigned to the PMV group and 49 patients were assigned to the SMV group. Medical records and radiological data were obtained from all 133 patients. Emergency surgery was carried out on 50/133 patients. All patients received invasive mechanical ventilatory support under sedation range (−2 to 1) of the Richmond Agitation Sedation Scale by a continuous infusion of dexmedetomidine or propofol with or without fentanyl. As adjunctive analgesics, loxoprofen and/or acetaminophen were given through a gastric tube at the ICU physician's discretion. Epidural analgesia was not provided for any patient. In the present study of patients with severe multiple injuries and blunt chest trauma, TTSS, severe GCS (≤8), and flail chest were determined to be independent risk factors for PMV. In addition, when the three factors were combined, the receiver operating characteristic analysis showed a high predictive performance for PMV (AUC = 0.8). Severe GCS (≤8), flail chest, or TTSS might be independent risk factors for PMV, and combining the three risk factors could provide high predictive performance. Approval of the research protocol: The present study was approved by the institutional ethical committee. Source: http://doi.org/10.1002/ams2.331