The Pattern and Outcome of Chest Injuries in South West Nigeria
Author: Ogunrombi A.B. 1 FWACS, MSc(Med)CTS, Onakpoya1 U.U. FWACS, Ekrikpo U.2 MBBS, MSc(Med), Adesunkanmi
A.K. 1 FWACS, FICS, Adejare I.E. 1 MBBS Affiliations: 1 - Department of Surgery, College of Health Sciences, Obafemi Awolowo University, Ile-Ife 2- Department of Medicine, University of Uyo Teaching Hospital, Uyo, Nigeria Correspondence: Akinwumi B. Ogunrombi Department of Surgery, College of Health Sciences, Obafemi Awolowo University, Ile-Ife, 220005, Nigeria. +2348062279218 Email-
Objective: The pattern and management outcome of chest injuries presenting to our tertiary university hospital located in a semi-urban population in the South West of Nigeria, has not been documented previously. We therefore sought to identify factors that may contribute to mortality.
Method: We analyzed 114 patients presenting to the Accident and Emergency Unit with chest trauma, prospectively entered into a data base over a two year period.
Results: Chest trauma accounted for 6% of all trauma admissions with a male preponderance (M:F = 3.6:1). Rib fractures were the most common injury (46.3%) while limb fractures were the most common associated injury (35.8%). Associated head injury accounted for most deaths (56%) in those with severe ISS. Majority of patients (51.8%) required only analgesics, while additional closed tube thoracostomy drainage was necessary (41.8%) in the others who suffered blunt trauma. Thoracotomy was indicated for only 5 (4.5%) penetrating injuries. There is a rising trend towards penetrating gunshot injuries, with mortality increasing with age (p=0.03) and severity of associated injuries (ISS) (p=0.003).
Conclusion: Majority of the patients required only minimal interven-tion with chest drainage or analgesics, with low mortality. Increasing age and severity of injury contributed significantly to mortality. Initia-tion of care for chest trauma victims is still delayed in our centre.
Trauma is a leading cause of morbidity and death in de-veloping countries with thoracic trauma contributing sig-nificantly to these figures especially where infrastructure and personnel are ill equipped to cater for these critically ill patients. It is estimated that death from unintentional trauma is on the increase in developing countries though not as significantly as that from infectious diseases like diarrhoea and malaria, while it is on the decrease in in-dustrialized countries (1). Previous reports on incidence of blunt versus penetrating injury from Nigeria have been conflicting depending on the urbanisation of the region as well as prevailing circumstances of peace or regional armed violence which occur sporadically (2-3).
We have examined the spectrum of these civilian chest in-juries during times of peace to determine the incidences of blunt and penetrating injuries and the outcomes of our management strategies, evaluating the emergency room initiation of care for these critically ill patients to determine factors that may contribute to mortality and ascertain whether our current setup is achieving results comparable with other trauma centers.
Patients and Methods
The Obafemi Awolowo University Teaching Hospital, Ile-Ife, (OAUTH), is a major trauma referral center in South Western Nigeria with compliment of specialists in all ma-jor surgical and other disciplines. The Accident and Emer-gency Unit of the hospital is a 15- bedded ward staffed by trauma doctors and nurses overseen by a trauma con-sultant, while a 6-bedded Intensive Care Unit caters for the critically ill. The hospital is strategically positioned in a network of highways linking major cities in the South West and other parts of Nigeria.
All patients with blunt or penetrating chest trauma presenting to the Accident and Emergency Unit of the OAUTH, Ile-Ife and having had appropriate chest radio-graphs, were prospectively entered into a database which was collected over a period of two years (May 2008 – April 2010). All patients who did not require chest radio-graphs after careful physical examination were excluded from the analyses.
The demographics, mechanism of injury, time to presen-tation, vital signs on admission, injury sustained, Injury Severity Score (ISS) as well as management instituted were evaluated.
Continuous variables were summarized using means and standard deviations or medians and inter-quartile ranges (IQR) for the highly skewed variables and analyzed us-ing two-sample t-test or Wilcoxon rank-sum test. Discrete variables were summarized as counts and percentages and compared using Chi-square test or Fisher’s exact test as appropriate. A multivariate logistic regression model was used to identify factors that are independently associ-ated with mortality. P-values less than 0.05 were consid-ered statistically significant. The data was analyzed using Stata version 10. Statacorp, Texas, USA.
This study was approved by the Hospitals’ Ethical Com-mittee.
Out of a total of 1847 patients admitted to the Accident and Emergency Unit following trauma during the study period, 114 (6.2%) patients had chest injuries. There were 89 (78.1%) males and 25 (21.9%) females (ratio 3.6:1) with mean age of 40.4 ±15.8 years. The mean age for the female patients was 38.6±14.3 years while that of the males was 40.9±16.2 years. Twenty six (22.8%) of the patients were traders; 26 (22.8%) were office workers, 21 (18.4%) were artisans, 15 (13.2%) university students, 11 (9.7%) were drivers and 9 (7.9%) were farmers. There were 2 children (1.8%).
Blunt trauma accounted for 99 (86.8%) patients while penetrating injuries were 15 (13.6%). Automobile accidents caused the majority of blunt trauma (79.1%), with 68.2% in- volving passengers while 10.9% were pedestrians. The ve- hicular types and their frequencies are shown in Figure 1. Other causes of blunt trauma include crushing by objects 5 (4.6%), falls from heights 2(1.8%) and electrocution 1(0.9%).
Gunshot wounds accounted for 8% of chest injuries and was the commonest cause (9/15; 60%) of penetrating chest injury. Other penetrating injuries were from stabs (5/15; 33.3%) and fall unto a sharp object (1/15; 6.7%). The median time to presentation was 120 minutes (inter-quartile range 40 – 540 minutes). The front seat passen-gers of cars (35.5%) and passengers in the second row of buses (35%) were the most likely to suffer chest trauma while the driver of a car was more likely to suffer chest injury than the driver of a bus (p=0.02). Seat belt usage was low at 8.3% with only 36% of drivers using seat belts at the time of the accident.
The most common injury were rib fractures (46.3%) while 49 (44.6%) had hemothorax and 34 (30.9%) presented with pneumothorax both necessitating chest drainage. The most common extrathoracic injuries were limb frac-tures in 29 (35.8%) and head injury in 24 (29.6%) pa-tients. Abdominal injuries were seen in 8 (9.9%) patients. The median ISS score was 9 (interquartile range 4 – 18). Figure 2 shows the proportion of individuals with ISS score less than 16, 16 – 24 and greater than 24. Our study showed a median ISS of 27 (IQR 23.5-36) in those who died and a median ISS of 9 (IQR 4-16) in those who sur-vived.
Fifty three (48.1%) had closed tube thoracostomy drain-age (CTTD) as part of their treatment with 26.4% in-serted on the right, 14.6% on the left and 6.4% bilateral. 91.67% of those that died had a CTTD performed on them (p= 0.002). Insertion of CTTD, based on positive thoracocentesis alone without prior chest radiography occurred in only 3 (2.7%) patients. Supportive chest ra-diographs were available in the others (97.3%) before chest drainage.
Thoracotomy was necessary in only 5 (4.5%) patients, 3 of whom were gunshot victims. The mean hospital stay was 7.1 ± 7.7 (0 - 26) days.
Factors affecting mortality
The overall mortality was 12 (11%) patients. At univariate level, the factors that were found to be associated with mortality included increasing age, respiratory rate, mean arterial blood pressure and ISS score. Table 1 shows the multivariate logistic regression model showing the inde-pendent predictors of mortality in the patients with chest injury in our centre.
For every one year increase in age, there was an 8% in-creased risk of mortality after adjusting for the effect of differences in gender, type of vehicle, mean arterial blood pressure at presentation, time to presentation, respira-tory rate and pulse rate at presentation. The higher the ISS score, the greater the risk of mortality in this cohort of patients. For every unit increase in the ISS, the odds ratio for mortality was 1.27 (95% CI 1.09 – 1.49), p = 0.003.