Rib fractures represent a frequent condition associated with thoracic injury. Studies suggest that more than one third of the patients with blunt chest trauma will have rib fractures. These are associated with acute pain and discomfort to the patient. Serious acute complications, such as pneumothorax, hemothorax, lung contusion, and flail chest, may be associated with rib fractures.

           These complications increase with the number of diagnosed rib fractures as does mortality. To identify patients at risk of complications, an early and accurate diagnosis of rib fracture may be helpful.

           CT scan of the thorax is considered as the gold standard to diagnose rib fractures but has many limitations including the need to shift the patient to the CT room, significant radiation exposure as well as higher cost burden to the patients.

           Chest radiograph is commonly used for diagnosis of rib fractures. Chest radiograph has historically been the initial test of choice of diagnosis for rib fractures. However, it has low sensitivity and can miss upto 50% of rib fractures.

           Point of care ultrasound (POCUS) is a quick and non-invasive bedside examination. It is routinely used as a part of trauma assessment in emergency departments. Of late there is growing evidence that POCUS can be used to detect fractures of the ribs in blunt chest trauma. POCUS is repeatable and can be used with minimal to no interference to the normal resuscitation activity in trauma patients.

           While there are large number of studies in published literature on the role of POCUS in blunt trauma thorax, few of them detail the utility of POCUS in the detection of rib fractures. Hence, we propose to conduct this study to assess the utility of POCUS in blunt trauma thorax with a focus of rib fractures.  

Review of the Literature:           

Thoracic trauma constitutes up to 15% of all trauma cases and has been reported to have a mortality rate of up to 25%. Blunt trauma accounts for 70% of thoracic trauma, while penetrating injuries account for the remaining 30%.

Rib fractures are the most common thoracic injury and are seen in 40% of patients with severe non-penetrating trauma. Rib fractures mostly occur as a consequence of blunt injuries to the chest, although firearm injuries, which cause penetrating trauma to the chest, can result in rib fractures as well. Rib fractures usually are seen to affect the 5^th rib through 9^th rib as the lower ribs are relatively more mobile. In a study published by Bekir Nihat Dogrul et.al in 2020 describing the various types of injuries in blunt trauma thorax, rib fractures of 4-9 ribs occur frequently and are commonly associated with pulmonary, pleural and pericardial complications.

Blunt chest trauma is also associated with other injuries such as pneumothorax (28.8%), hemothorax (24%), hemopneumothorax (11%), pericardial effusion (3%), pulmonary contusion (2.4%), pulmonary laceration (2%) as well as diaphragmatic rupture (1.8%).

CT chest has become a common imaging modality in trauma patients with suspected thoracic injury. CT scan is considered as the gold standard in diagnosing rib fractures as well as associated injuries in blunt chest trauma. In patients presenting with isolated blunt trauma to the chest of a minor intensity, CT scans are usually not ordered. This is because CT scans have a radiation dose that is at least seventy times higher than that of plain chest radiographs. CT chest may also impose a substantial economic burden, especially for patients treated at smaller centers of lower- to middle-income countries. CT scan requires patients to be transported out of clinical area which may be risky in patients with compromised hemodynamical stability.

A cross sectional study performed at Aga khan university in 2019 by Muhammed Awais et.al comparing CT scout film and Chest Xray for detection of rib fractures concluded that sensitivity and specificity of chest X-ray in detecting rib fractures is 61.3% and 98.5% respectively. Though chest radiograph is routinely ordered in blunt trauma chest, the diagnostic accuracy is much lower compared to bedside lung Ultrasound examination as well as CT thorax.

POCUS for diagnosing rib fractures was done as a pilot study in 1995 by E.Wischhofer  et.al. Study was conducted in patients with normal chest radiograph but clinically suspected rib fractures. Findings recorded in this study showed that Ultrasound investigation of the rib fractures are more reliable method of diagnosis that chest radiograph.

Mahmoud yousefifard et.al conducted a meta-analysis of comparison of ultrasonography and radiography in 1667 patients in 2016 for detection of thoracic bone fractures concluded that screening performance characteristics of ultrasonography in detection of thoracic bone fractures was higher than radiography.

In a comparison of determination of traumatic thoracic injuries between CT thorax and Ultrasonography in 2019, Nalan Kozaci et.al, concluded that Ultrasonography was highly specific (98) and moderately sensitive (67%) in diagnosing rib fractures.

A systematic review and meta-analysis were performed by James Gilbertson et.al in 2022 who reported that chest ultrasonography had pooled sensitivity of 89.3% and specificity of 98.4% in comparison with CT thorax for diagnosis of any rib fracture.

^{Material and methods}

^{a) Study Design: Cross-sectional study.}

^{b) Study Duration: 18 Months.}

^{c) Sampling technique: consecutive sampling}  

^{Sample size – 106 ;}

^{Sample size is derived considering the sensitivity of the point of care ultrasound in predicting rib fracture in blunt trauma thorax as 89.3%; with prevalence of rib fracture in blunt trauma thorax as 32.1%; absolute precision as 10%; alpha error as 5%}

^{This is single centered, cross sectional analytical study in patients presenting to Emergency Department, JSS Hospital, Mysuru, with blunt trauma chest.}

^{Patients will be included in the study after applying inclusion and exclusion criteria.}

^{Informed consent will be obtained and filed. Usual care for the patient will be continued as per the standard trauma assessment and management.}

^{Bedside point of care ultrasound will be performed by a trained personnel in ED. Chest Radiograph(AP) is obtained as a part of usual care.}

^{Method :}

^{A high frequency linear probe placed vertically over the thorax at the point of maximal bony tenderness. After adequately locating the rib, the probe is  turned ninety degrees and rib cortex which appears as a white, hyperechoic line is followed along its long axis.}

^{Screening of the rib 10 cm before and after the point of maximal tenderness is done to ensure that no fracture is missed . The upper and lower adjacent ribs are also screened. A rib fracture is diagnosed when a discontinuity of the cortical alignment is observed, visualized as a gap through the hyperechoic cortical line of the rib, local hematoma.}

^{Point of care ultrasound will be performed to look for other associated injuries like pneumothorax(absent lung sliding and lung point), hemothorax(free fluid in pleural cavity), and pulmonary contusions.}

^{Chest Xray and CT thorax of the patient are obtained and reported.}

 ^{Study Population and source of data:}

^{Patients presenting to Emergency Department, JSS Hospital, Mysuru, with blunt trauma chest who are willing to enroll in the study.}

^{Subject Eligibility:}

^{a.      Inclusion Criteria}

^{·         Age above 18}

^{·         Clinical suspicion of blunt trauma thorax.}

^{·         Positive chest compression test.}

^{b.      Exclusion Criteria}

^{·         Associated penetrating trauma chest}

^{·         Patients requiring immediate surgery}

^{·         Patients deemed unsuitable because of extent of trauma or hemodynamically too unstable by ED physician.}

^{Study Assessments of endpoints}

^{●       Analytical study of utility of Point of  Care Ultrasound in Blunt trauma chest for detection of rib fractures and associated injuries.}

^{Study Conduct:}

^{·         The study will be conducted in the emergency department of JSS hospital, Mysuru in patients aged above 18 years presenting with history of blunt trauma. Instruments} Required.

^{·         Ultrasound machine}

^{·         Point of care chest radiograph.}

^{·         Computed tomography thorax}