Thoracic injuries caused by blunt trauma are commonly encountered emergencies in veterinary medicine. However, no literature exists comparing radiography to computed tomography (CT) in blunt thoracic trauma caused by motor vehicle accidents in canine patients. The aim of this prospective case series was to estimate the sensitivity (Se) and specificity (Sp) of thoracic radiography relative to CT for detecting lung contusions, pneumothorax, pleural effusion and rib fractures. The study further aimed to establish a severity scoring system for radiography and CT and to compare the findings between the two modalities. The hypothesis was that radiography would be less sensitive than CT at detecting these injuries and that radiography would underestimate the severity of lung contusions compared to CT. Fifty-nine patients met the inclusion criteria. Radiography underestimated the presence of lung contusions (Se = 69%, 95% Confidence interval (CI)) and overestimated the severity of the contusions relative to CT. There was also high interobserver variability in evaluating lung contusion severity (coefficient of variation = 91%). Both the three-view thoracic and horizontal beam radiography had poor sensitivities for the detection of pneumothorax (Se = 19% and 63% respectively) and pleural effusions (Se = 43% and 71% respectively). Similarly, the sensitivity (56%) of three-view thoracic radiographs for the detection of rib fractures was poor relative to CT. To conclude, three-view thoracic radiography had low sensitivity for pathology related to blunt thoracic trauma caused by motor vehicle accidents and CT could be considered as an additional diagnostic imaging modality in these patients. / Dissertation (MMedVet (Diagnostic Imaging))--University of Pretoria, 2019. / Companion Animal Clinical Studies / MMedVet (Diagnostic Imaging) / Unrestricted

Background. There are roughly 300,000 rib fractures treated for in the United States each year. These represent 10-26% of thoracic trauma injuries and have about a 10% mortality rate. There is a common belief that mortality in rib fracture patients can be contributed to the diagnosis of pneumonia, but this study does not support that claim. Purpose. To determine the predictors of morbidity and mortality in rib fracture patients. Methods. Using a level 1 trauma center patient registry, we retrospectively analyzed all patients that were admitted with at least one rib fracture (n=1,344). All predictors were analyzed with linear regressions. Results. The average age of the patients was 55.48 ± 20.29 years old and ranged between 15 and 98. ISS (OR: 1.0508, p<0.001), bilateral fractures (OR: 1.9495, p = 0.009) and pulmonary contusion (OR: 1.7481, p = 0.022) were all significant predictors of pneumonia. The age of the patient (OR: 1.0467, p < 0.001), ISS (OR: 1.0585, p <0.001), having 6 or more fractured ribs (OR: 3.1450, p < 0.001), the presence of hemothorax (OR: 2.5063, p = 0.048), and the use of mechanical ventilation (OR: 13.2125, p < 0.001) were all significant predictors of mortality. Flail segments (OR: 1.9871, p = 0.067), ISS (OR: 1.1267, p < 0.001), pulmonary contusions (OR: 1.5329, p = 0.047), pneumothorax (OR: 1.4372, p =0.073) and pneumonia (OR: 21.4516, p < 0.001) are all predictors of requiring mechanical ventilation. Conclusion. There are many studies that indicate rib fracture patients who are diagnosed with pneumonia have a higher risk or mortality. With this in mind, the logical course of treatment would be to counteract the complications pneumonia brings as to reduce the risk or mortality. To do this, it is recommend the patient be put on mechanical ventilation. While this has been seen to help with pneumonia patients, this study provides evidence that health care professionals should look for ways to reduce the need for mechanical ventilation instead of using it to combat the pneumonia.

The presence of rib fractures in deceased infants is generally considered to be highly specific of non-accidental injury, with some pathologists considering them to be evidence of abuse. Although rib fractures may occur during resuscitative efforts in adults, the general consensus is that such injuries are exceptional in infants owing to inherent plasticity within the thoracic region. The recommendation for cardiopulmonary resuscitation (CPR) of infants since the year 2000 has been for the use of the “two-thumb” technique. However, there has been limited biomechanical investigation to what injuries may occur subsequent to this specific form of CPR. The overall aim of this thesis was to determine if two-thumb CPR can cause similar rib injuries to those seen in abusive squeezing cases. In particular, whether or not this CPR technique allows for over excessive levering of the posterior rib over the transverse process of the spine. To this end, physical experimentation simulating both two-thumb CPR and abusive squeezing was performed on an immature swine model of the infant thorax. The results of these tests did not show any significant difference in the force required to compress the thorax by one third its original anterior-posterior diameter in the two scenarios. One third being the recommended depth for CPR compressions. Fractures resultant from the testing were assessed with radiography and computed tomography, techniques commonly used by post-mortem pathologists. The type and nature of the injuries observed were remarkably similar in both scenarios. Rib injuries were primarily seen in the anterior part of the thoracic cage in both CPR and abusive specimens. The specific site of rib fracture was typically close to or within the costochondral joints. There was however an apparent absence of posterior rib fractures in the abusively tested cohort. This is in part due to the slight difference in profile of the neck and head areas within the ribs of the surrogate model. This acts to reduce the mechanical advantage offered by levering over the transverse processes of the spine. This study has shown anterior fractures of the ribs result from two-thumb CPR, challenging the long held belief that CPR cannot produce rib fractures. X-ray CT offered a significant improvement on the ability to detect costochondral junction injuries. This would offer further support to the routine use of X-ray CT in post-mortem examinations of infants where the cause of death is unknown. This has the potential to offer differential interpretation to the cause of rib injuries, especially in cases of sudden unexpected deaths in infancy, where otherwise child abuse may be diagnosed.