Thoracic Injuries in earthquake-related versus non-earthquake-related trauma patients: differentiation via Multi-detector Computed Tomography

PURPOSE:

Massive earthquakes are harmful to humankind. This study of a historical cohort aimed to investigate the difference between earthquake-related crush thoracic traumas and thoracic traumas unrelated to earthquakes using a multi-detector Computed Tomography (CT).

METHODS:

We retrospectively compared an earthquake-exposed cohort of 215 thoracic trauma crush victims of the Sichuan earthquake to a cohort of 215 non-earthquake-related thoracic trauma patients, focusing on the lesions and coexisting injuries to the thoracic cage and the pulmonary parenchyma and pleura using a multi-detector CT.

RESULTS:

The incidence of rib fracture was elevated in the earthquake-exposed cohort (143 vs. 66 patients in the non-earthquake-exposed cohort, Risk Ratio (RR) = 2.2; p<0.001). Among these patients, those with more than 3 fractured ribs (106/143 vs. 41/66 patients, RR = 1.2; p<0.05) or flail chest (45/143 vs. 11/66 patients, RR = 1.9; p<0.05) were more frequently seen in the earthquake cohort. Earthquake-related crush injuries more frequently resulted in bilateral rib fractures (66/143 vs. 18/66 patients, RR = 1.7; p<0.01). Additionally, the incidence of non-rib fracture was higher in the earthquake cohort (85 vs. 60 patients, RR = 1.4; p<0.01). Pulmonary parenchymal and pleural injuries were more frequently seen in earthquake-related crush injuries (117 vs. 80 patients, RR = 1.5 for parenchymal and 146 vs. 74 patients, RR = 2.0 for pleural injuries; p<0.001). Non-rib fractures, pulmonary parenchymal and pleural injuries had significant positive correlation with rib fractures in these two cohorts.

CONCLUSIONS:

Thoracic crush traumas resulting from the earthquake were life threatening with a high incidence of bony thoracic fractures. The ribs were frequently involved in bilateral and severe types of fractures, which were accompanied by non-rib fractures, pulmonary parenchymal and pleural injuries.     

Suction due to left ventricular assist: implications for device control and management

Left ventricular assist device (LVAD) overpumping is associated with hemolysis, thrombus release, and tissue damage at the pump inlet. However, the impact of LVAD suction on pulmonary circulatory function remains unknown. We investigated LVAD suction as induced by pulmonary artery banding and overpumping in experimental animals and in a computer model. In six sheep, a rotary LVAD was implanted. Before inducing suction, partial support (40-60% of cardiac output) was established and characterized by measuring pressures and flows. In the animals, pulmonary artery occlusion (PAOC) elicited LVAD suction (left ventricular pressure was from -10 to -20 mm Hg) within 5-10 heartbeats. During suction, aortic pressure dropped to 50% and LVAD flow decreased significantly. After releasing the occlusion (20 s), the collapsed state persisted for another 20 s. A similar trend was obtained by simulating PAOC in the computer model. Additional simulations showed that pulmonary vascular resistance (PVR), volume status, and right ventricular (RV) contractility are exponentially related to the persistence of collapse after a suction event. Even modest increases in predisposing factors (elevated PVR, RV dysfunction, hypovolemia) caused sustained hemodynamic collapse lasting in excess of 15 min. Both in selected animals and the computer model, comparable suction-induced collapse was obtained by increasing LVAD speed by about 33%. Attempted compensation by simply decreasing speed was not effective, but temporarily shutting down the LVAD caused rapid reversal of collapse. In conclusion, rotary LVAD suction causes unfavorable conditions for effective unloading. The use of pump interventions appears a promising tool to detect suction and to avoid the associated hemodynamic depression.     

新型冠状病毒肺炎治愈病例的胸部 CT影像学变化与临床表现相关性分析

目的 探讨新型冠状病毒肺炎(COVID-19)发病早期、进展期、转归期的胸部CT影像学动态变化与临床分型及表现的关系.方法 收集重庆大学附属三峡医院2020年1—2月88例治愈出院COVID-19病人的临床与影像学资料,其中出院诊断普通型51例,重型29例,危重型8例.每例病人做了(4±1)CT检查,范围为3～6次,每次检查间隔3～7 d,总共346次胸部CT.回顾性分析每例病人发病早期(1～7 d)、进展期(8～14 d)、转归期(>14 d)胸部CT影像学表现及变化.采用Kruskal-Wallis秩和检验(非正态分布)比较普通型、重型、危重型病人的年龄、发病至影像学好转天数、发病至出院天数差异.结果 COVID-19发病早期CT主要表现为双肺多叶多段(74/88,84％)、斑片状磨玻璃影(82/88,93％),以外带及胸膜下分布为主(374/492,76％);进展期双肺磨玻璃病灶逐渐增多、增大,密度增高,边缘变清晰,其内纹理增多、间质增厚,常出现"铺路石"征(29/88,33％)和"蜘蛛网"征(26/88,30％),斑片状实变影及条索影增多;转归期双肺磨玻璃及实变病灶逐渐吸收、减少,95％(84/88)的病人出院时双肺残留条索影、浅淡磨玻璃影或条网状间质纤维化病灶.普通型、重型、危重型病人的年龄中位数(四分位数间距)分别为47(7)、49(13)、69(20)岁,发病至影像学好转天数分别为13(6)、17(3)、24(9)d,发病至出院天数分别为18(5)、23(4)、29(4)d,三者均P<0.001.结论 胸部CT可以很好地观察COVID-19病人发病早期、进展期、转归期的影像学动态变化,COVID-19病人临床分型的严重程度与病人年龄、影像学及临床好转天数存在相关性.