The Polytrauma Objective Scales Prognostic Values Comparison for the Severe Combined Thoracic Trauma

Introduction. According to WHO data near 2 million people die as the result of polytrauma every year. Up to 93% cases of thoracic injuries are recorded in patients with polytrauma in case of traffic accidents. For the correct decision of polytrauma management with the evaluation of indications/contraindications for polytrauma second step surgery, including combined chest trauma, evaluation of the patient state is necessary in early posttraumatic period after primary resuscitation in conditions of damage control strategy. The specific objective of this study was to evaluate prognostic abilities of the common scales used for the polytrauma severity objective rating in case of the severe combined thoracic trauma. Materials and methods. Study was performed on 73 male patients aged from 20 to 68. Patients with the severe blunt combined thoracic trauma with pneumothoraxes and hemothoraxes, lung contusions, heart contusions and multiply (≥3) rib fractures were included in this study. ISS, PTS, ВПХ-МТ scales were used for injury rating. RTS and TRISS – for evaluation of the patient status severity in admission. The cohort was divided into two groups according to outcome - survival (n=42, mean ISS=24,5 (22,73-28,22)) and non-survival (n=31, mean ISS=34 (30,38-38,53), p=0,0006 in comp. with survival group). Mann-Whitney test was used to assess differences between groups. ROC-analysis was used for the parameters' diagnostic value evaluation. A Fisher exact test was performed to consider differences in nominal data. Results. The highest values of AUROC among all injury severity objective methods were got for ВПХ-МТ (0,7569, (0,6448-0,869), р=0,0001913) and for TRISS model (0,8076 (0,701-0,9142), р<0,0001). Cut-off values were established according to Youden coefficient in points of ISS>25,5 (acc=65,75%, odds=5,044 (1,715-14,83), p=0,0034), ВПХ-МТ>13,15 (acc=72,6%, LR=2,71, odds=6,899 (2,433-19,43), p=0,0003), RTS<7,004 (acc=78,08%, odds=12,57 (4,105-38,5), p<0,0001) and TRISS<0,8339 (acc=79,45%, LR=5,69, odds=15,54 (4,681-51,59), p<0,0001). It is possible to calculate probability of mortality according to Bayes theorem with the help of this data considering that apriory probability is 18,47 – 19,37%. So if the severity of polytrauma is greater than 13,15 according to ВПХ-МТ scale in patient with the severe blunt combined thoracic trauma, the probability of mortality becomes 38,03-39,43%. Decrease of TRISS model probability below 0,8339 increases probable mortality up to 56,31-57,75%. Conclusions. This study has shown that it can be possible with statistically significant level to predict outcome in patients with the severe blunt combined thoracic trauma based on objective methods, evaluated in this study. But low prognostic accuracy does not allow recommending for the use of the estimated cut-off values alone for outcome prediction in case of such type wound dystrophy. The objective methods of the patient's status severity in admission give better outcome prediction than scales for rating injury severity. The most accurate is TRISS model as it consists of objective criteria for injury severity, the severity of patient's status on admission and age of the victim. The PTS scale is least suitable for outcome prediction because components of chest injury are not enough represented in it.