Pattern of chest injuries in road traffic incident victims: a six-year retrospective study

Introduction

The young are the most common victims of trauma, and trauma is the leading cause of death in the first four decades of life. Injury accounts for more than 50% of deaths in children and is the third leading cause of death after cancer and atherosclerosis in all age groups. Thoracic trauma is one of the leading causes of death in all age groups and accounts for 25–50% of all traumatic injuries in the world. ¹ It has been estimated in the USA that thoracic trauma accounts for one-quarter of all trauma deaths. In a five-year Canadian study of patients admitted to an urban trauma unit, 96.3% had sustained blunt trauma while the remaining 3.7% were injured with a penetrating mechanism. The causes of blunt injuries were attributed to motor vehicle accidents (70%), suicides (10%), falls (8%), homicides (7%) and others (5%). The incidence of thoracic trauma was 46%. Patients with thoracic injuries had a mortality rate of 15.7%, while those without thoracic injuries had a mortality rate of 12.8%. When patients present to the operating room within 24 hours of admission, the incidence of blunt thoracic trauma has been reported to be as high as 62.5%. ^2–4 The aim of this work is to report on the causes of trauma, indexes of trauma and mortality related to thoracic trauma.

Material and methods

In this retrospective study, fatal cases of thoracic trauma autopsied during the period 1 January 2004 to 31 December 2009 were analysed at the Department of Forensic Medicine & Toxicology, JN Medical College, Belgaum, Karnataka. During this study several epidemiological observations and their results were considered including details about the type, nature and frequency of injuries to various organs of chest regions.

Results

Table 1: In the present study, 67.8% of victims were 40 years old or younger. Women were less involved than men with a ratio of 1:2.2. Table 2: The victims in most of the cases sustained road traffic accidental injuries (139 cases; 61.2%) followed by fall from height (43 cases; 19%). Table 3: Nature of death in most of the cases was accidental (187 cases; 82.4%). Table 4: Overall 26.4% of victims involved in all road traffic accidents were in heavy motor vehicles. Table 5: Most of the victims sustained their injuries on highways (118 cases; 52%). Table 6: In the present study 34.4% of victims had injuries to both the chest and head/neck and 16.7% had only chest injuries. Table 7: The most common cause of death was asphyxia (38.3%), followed by shock and haemorrhage (27.8%). Table 8: The bony involvement of the chest region was the fracture of ribs in 29.5%, clavicle fracture in 25.6% and sternum found fractured in 14.1% of victims. Table 9: Of these victims sustaining intrathoracic injuries, the lungs were injured in 40.1%, the major blood vessels in 25.5% and the heart was injured in 20.3% of cases. Table 10: Haemothorax was found in 38.3% and pneumothorax was seen in 20.7% of cases. Table 11: Survival period of less than one day was seen in 26% of cases.

Discussion

In the present study, 67.8% of victims were 40 years old or younger (Table 1). Van Nooten et al. ⁵ in their study of fatal chest injury mentioned that the average age of the victims was 27 years; around 82.5% of the victims were men and 17.5% were women.

The victims in most of the cases sustained road traffic accidental injuries (139 cases; 61.2%) followed by fall from height (43 cases; 19%) (Table 2). Bickford studied 26 cases of chest injuries at Liverpool in which nine were injured in road traffic accidents, seven were injured by motor bikes, seven were due to bomb blast, two had injuries with automobiles and only one was a stab injury case. In this series only four victims died with fracture of ribs and rupture of heart and lung. ⁶

The nature of death in most of the cases was accidental (187 cases; 82.4%) (Table 3). Arthur et al. ⁷ studied 100 cases of blunt chest trauma, 76 of which were due to auto accidents (76%). Das Ratnakar studied 58 cases of fatal chest injuries. He observed 51.72% of deaths were homicidal in nature, whereas the remaining 48.27% of deaths were accidental in nature. Globally various authors observed the nature of death in fatal chest injuries. More than 50–60% of deaths were accidental in nature in their studies. ⁸

Overall 26.4% of victims involved in all road traffic accidents were in heavy motor vehicles (Table 4). Cameron et al. ⁹ studied 109 cases of non-penetrating chest injuries, which comprised mainly roadside automobile accidents; very few resulted from a fall from height. Edward et al. ¹⁰ worked in Chicago and found that in road traffic accidents crush injuries to the chest were the most common cause of death. Jummbelic reported that motor vehicles accidents were responsible for approximately 42–46,000 deaths per year in the USA. Sevett observed in his study that the pedestrian constituted 50% of total deaths in road traffic accidents. ¹¹

Most of the victims sustained their injuries on highways (118 cases; 52%) (Table 5). Cameron et al. ⁹ studied 109 cases of non-penetrating chest injuries, sustained by accidents mainly on road sides.

In the present study 34.4% of victims had injuries to both the chest and head/neck and 16.7% had only chest injuries (Table 6). Agrawal and Agrawal reported that pedestrians constituted 71.91% of the fatalities in their study. They also noticed that 14% of victims had thoracic injuries alone in causing death. ¹² Sevett specifically mentioned that 45% of victims died due to thoracic injuries alone, whereas 19% of victims died due to thoracic injuries along with abdominal injuries out of 150 victims of fatal road traffic accidents. ¹³

The commonest cause of death was asphyxia (38.3%), followed by shock and haemorrhage (27.8%) (Table 7). Molar ¹⁴ conducted 245 medicolegal autopsies in which 52 cases (21.2%) had penetrating incised wounds of the thorax and it was found that the cause of death was hypovolaemic shock due to intrathoracic haemorrhage.

The bony involvement of the chest region was the fracture of ribs in 29.5%, clavicle fracture in 25.6% and sternum found fractured in 14.1% of victims (Table 8). Dougall et al., from the Department of Surgery, reviewed the records of 353 patients with chest injuries at University and Victoria Hospital in London from 1965 to 1975. It was observed that the most common manifestations of chest trauma in the study were fracture of ribs and their penetration of the lung parenchyma. ¹⁵

A total of 40.1% of these victims were injured, sustaining intrathoracic injuries in the lungs, 25.5% in the major blood vessels and the heart was injured in 20.3% (Table 9). Mattila et al. ¹⁶ observed 571 cases of penetrating chest injuries. The organs most often involved were the lungs (67.42%) and heart (11.03%).

Haemothorax was found in 38.3% and pneumothorax was seen in 20.7% of cases (Table 10). McLatchie et al. described pneumothoraces in a retrospective study of 56 patients who sustained stab wound of chest. A total of 10% developed pneumothorax between 12 hours and three days after injury. ¹⁷ Arthur et al. observed haemothorax in 18% of victims who had blunt chest trauma. ⁷ Dougall et al. observed that 40% of victims had pneumothorax in their series of the study of chest trauma. ¹⁵

A survival period of less than one day was seen in 26% of cases (Table 11). Pathak MK et al., ¹⁸ described the survival period in the retrospective study of 123 cases of fatal chest trauma. In 69.91% of cases, death occurred at the scene. Death occurred in hospital in 18.69% of cases and en route to hospital in 11.38% of cases.

Conclusion

The mechanism and circumstance of a blunt chest injury can be assessed in relation to the number and localization of rib fractures, as well as to the presence of pulmonary contusions and cardiac and major vascular injuries. Many deaths were caused by heavy goods vehicles and most often death occured at the scene. This indicates the seriousness and great life risk involved for the victims of RTA. In chest trauma, if force affects the thoracic organs or the associated abdominal organs, then the same may become fatal because all the visceral or vital organs are richly supplied by blood. Such victims need immediate, prompt, effective and adequate medical help. Further establishment of ‘hi-tech trauma centres’ at each district level is the present need.

Competing interests: The authors declared that they have no competing interests. Both authors have read and approved the final manuscript.