Middle-Lobe Bronchus Transection in Blunt Thoracic Trauma From a High-Speed Motor Vehicle Collision: A Case Report

Introduction

Chest injuries continue to be a major concern in trauma care, accounting for approximately 25% of trauma-related deaths worldwide [1]. While thoracic trauma includes a broad spectrum of injuries, the most severe and rare cases pose the greatest diagnostic and management challenges. Among these, tracheobronchial injuries, particularly complete bronchial transections, are exceptionally uncommon, occurring in less than 1% of blunt chest trauma cases [2]. The rarity of these cases makes each one a valuable learning opportunity for the medical community.

Diagnosing airway injuries is challenging, as clinical manifestations can be subtle and easily missed, ranging from mild dyspnea to severe respiratory failure. Welter and Hoffmann [3] emphasized that the severity and location of the injury significantly influence clinical presentation, making early recognition crucial. However, these injuries are frequently underdiagnosed during initial evaluations, leading to delayed treatment and increased morbidity.

The pathophysiology of bronchial injuries in blunt trauma involves 3 well-documented mechanisms: compression of the chest between the sternum and the spine, sudden and extreme increase in intrathoracic pressure, and deceleration forces causing shearing of the bronchial structures.

Caputo et al [4] provided a comprehensive review of these mechanisms, correlating them with diagnostic approaches in thoracic trauma. Despite advances in imaging and early recognition, bronchial transections due to blunt trauma remain exceptionally rare and often pose significant diagnostic challenges. These injuries require a high index of suspicion, as their mechanism is complex and they do not always present with classic clinical or radiological signs.

The Extended Focused Assessment with Sonography for Trauma (eFAST) is widely used as a rapid bedside tool to assess pneumothorax, hemothorax, and intra-abdominal free fluid in trauma patients [5]. However, while eFAST is highly effective for detecting free fluid and pneumothorax, its sensitivity for identifying tracheobronchial injuries is limited [5].

In cases of suspected airway trauma, computed tomography (CT) remains the criterion standard for diagnosis. Multi-detector CT (MDCT) with 3D reconstruction has proven invaluable in detecting complex airway injuries, providing superior anatomical detail compared to conventional imaging methods [6].

The management of tracheobronchial injuries necessitates a multidisciplinary approach, involving thoracic surgeons, anesthesiologists, and intensive care specialists [7]. Treatment options range from conservative management in stable cases to immediate surgical repair in cases of complete bronchial transection [8].

Bronchial transections due to direct impact are particularly rare and pose significant diagnostic and management challenges. These injuries require a high index of suspicion, as their mechanism is complex and they do not always present classic clinical or radiological signs [9].

This report presents the case of a 52-year-old man who sustained multiple injuries following a high-speed motor vehicle accident, including blunt thoracic trauma, middle-lobe transection, and complete bronchial rupture due to direct impact. This case underscores the importance of early recognition of airway injuries, the role of computed tomography (CT) in diagnosis, and the surgical considerations in the management of bronchial rupture in blunt chest trauma.

Case Report

INITIAL DIAGNOSTIC FINDINGS AND EMERGENCY MANAGEMENT:

Initial laboratory findings showed hemoglobin 11.2 g/dL (reference range: 13.5–17.5 g/dL), hematocrit 33% (reference range: 41–50%), an elevated white blood cell count of 18.5×10⁹/L (reference range: 4.5–11.0×10⁹/L), platelet count 185×10⁹/L (reference range: 150–450×10⁹/L), and lactate level 3.8 mmol/L (reference range: 0.5–1.0 mmol/L). Arterial blood gas analysis revealed a pH of 7.32 (reference range: 7.35–7.45), PaO₂ 68 mmHg (reference range: 75–100 mmHg), PaCO₂ 48 mmHg (reference range: 35–45 mmHg), and bicarbonate (HCO₃^–) 22 mEq/L (reference range: 22–26 mEq/L).

A focused ultrasound (eFAST) suggested intra-abdominal free fluid, prompting further imaging. A subsequent chest CT scan identified a right-sided pneumothorax with a 2.5-cm apical separation, multiple pelvic fractures (including a comminuted fracture of the right iliac wing), bladder and prostate rupture, and injury to the left external iliac vein.

The patient underwent an urgent exploratory laparotomy, which revealed 200 cc of hemoperitoneum, a grade 1 liver injury affecting segments 2 and 4, and a non-bleeding hematoma near the hepatic hilum. After surgery, his hemoglobin dropped to 9.8 g/dL, and hematocrit to 29%, prompting transfusion of 2 units of packed red blood cells.

RESPIRATORY DETERIORATION AND THORACIC INTERVENTION:

Following stabilization, the patient was transferred to the Intensive Care Unit (ICU) for further monitoring. Despite chest tube placement, which initially drained 450 mL of serosanguineous fluid, he continued to experience worsening subcutaneous emphysema and refractory hypoxemia. Arterial blood gas on day 1 after the operation indicated worsening respiratory function with pH 7.28, PaO₂ 62 mmHg, PaCO₂ 52 mmHg, and HCO₃⁻ 20 mEq/L, while on mechanical ventilation with 60% FiO₂.

On day 2, due to the patient’s deteriorating respiratory status, an emergency thoracotomy was performed. Intraoperatively, a complete transection of the middle-lobe bronchus extending to the intermediate bronchus was discovered. Postoperatively, a chest X-ray confirmed successful lung re-expansion and resolution of the pneumothorax.

SEPSIS AND MULTIORGAN FAILURE:

Despite initial improvements, complications arose. On day 7, he developed severe hypotension (blood pressure 85/50 mmHg), requiring vasopressor support. Blood tests showed a high white blood cell count of 22.5×10⁹/L, C-reactive protein 280 mg/L (reference range: <3 mg/L), procalcitonin 2.8 ng/mL (reference range: <0.5 ng/mL), and lactate 4.5 mmol/L. Blood cultures revealed Escherichia coli, for which meropenem was initiated.

A second exploratory laparotomy on day 7 revealed urinous peritonitis caused by a dismantled prostatic urethra. Analysis of the peritoneal fluid showed a white blood cell count of 15 000 cells/mm³, with 85% polymorphonuclear cells, glucose 38 mg/dL, and creatinine 4.2 mg/dL, matching the serum levels.

For the next 2 weeks (days 8–21), the patient remained in the ICU, where he was treated for septic shock. Despite broad-spectrum antibiotics, vasopressors, and meticulous fluid management, his condition worsened. Laboratory results showed a progressive decline in organ function, with creatinine peaking at 3.8 mg/dL, total bilirubin rising to 4.5 mg/dL, and international normalized ratio (INR) increasing to 2.3.

On day 22, despite aggressive medical interventions, he died due to multiple organ failure. Final laboratory values indicated severe metabolic acidosis, renal failure, hepatic dysfunction, and coagulopathy, with pH 7.15, lactate 12 mmol/L, creatinine 4.2 mg/dL, total bilirubin 6.8 mg/dL, and INR 3.1.

FIGURES AND VISUAL REPRESENTATION OF CASE PROGRESSION:

This case report includes several diagnostic images and graphical representations that illustrate the progression and complexity of the patient’s condition:Figure 1 presents a CT image in the lung window, providing a detailed view of the initial pulmonary involvement that led to the patient’s admission.Figures 2A and 2B display 3D tomographic reconstructions, offering a three-dimensional visualization of the patient’s pulmonary anatomy and the extent of disease progression over time.Figure 3 illustrates the median pulmonary lobe thoracotomy performed on day 14, representing a critical surgical intervention in the patient’s treatment course.Figure 4 consists of a horizontal bar chart depicting the time-line of the patient’s case. This comprehensive visual aid tracks the chronological progression of significant clinical events, from initial presentation through various interventions and ultimately to the patient’s decline.

The timeline culminates on day 22, when, despite aggressive medical interventions, the patient died due to multiple organ failure. This comprehensive timeline underscores the critical role of timely and multidisciplinary interventions in managing severe trauma cases.

Discussion

This case report presents a unique instance of thoracic trauma in a polytraumatized patient, featuring a middle-lobe lung rupture and complete bronchial section due to a direct collision.

The significance of this case lies in the unusual mechanism of bronchial rupture, providing critical insights into the diverse presentations of severe chest trauma and broadening our understanding of tracheobronchial injuries [10].

The management of polytrauma, particularly in complex cases such as this one, demands solid clinical expertise and a multi-disciplinary approach. The authors of this report possess extensive experience in managing severely injured patients, including those with complex thoracic injuries, within a multidisciplinary environment at a specialized trauma center. The entire clinical team is certified in Advanced Trauma Life Support (ATLS), ensuring that care aligns with international standards and the most current protocols for critically injured patients [11].

This expertise has been pivotal in identifying and managing a rare and potentially fatal injury, such as the complete bronchial rupture observed in this case, which represents less than 1% of blunt thoracic trauma cases [12].

Furthermore, this case underscores not only the diagnostic challenges involved but also the value of adopting a conservative surgical approach to preserve long-term pulmonary function.

Maintaining a high index of clinical suspicion remains essential in scenarios like this. Bronchial injuries often go unnoticed during the initial evaluation. However, the use of advanced diagnostic imaging techniques, such as high-resolution CT with 3D reconstruction, has proven invaluable in this case, enabling precise delineation of the injury and facilitating meticulous surgical planning [13].

Managing polytrauma is inherently challenging, and this case underscores the potential for complications, such as complete bronchial section. The detailed progression of laboratory values and diagnostic findings highlights the difficulties in treating such severe injuries and their sequelae. These insights highlight practical strategies for immediate and longitudinal management of thoracic injuries

In this case, CT proved superior to conventional radiography for trauma assessment, particularly in detecting thoracic injuries, especially with image reconstruction, and CT is more effective in identifying pulmonary contusions, thoracic aortic injuries, and bony trauma in the cervicothoracic spine. Our experience aligns with the consensus that CT is the criterion standard for comprehensive trauma imaging, as it enabled the identification of complex injuries not evident through initial assessments [14].

Interestingly, the classic “fallen lung sign”, [15], a radiological hallmark of bronchial rupture, was not initially present in our patient. This underscores the importance of maintaining a high index of suspicion for tracheobronchial injuries, even in the absence of classic signs. CT combined with fiberoptic bronchoscopy was pivotal in accurately delineating the bronchial injury and guiding surgical management [16].

The management of bronchial rupture remains a critical challenge in thoracic trauma surgery. While conservative management may be feasible in small, stable injuries, complete bronchial transections typically require urgent surgical intervention. The approach varies depending on the extent of the injury and the patient’s overall stability.

van Roozendaal et al provided an extensive review of surgical strategies for bronchial rupture, highlighting the indications for primary repair, segmental resection, and lobectomy based on the extent of the injury and the patient’s hemodynamic status. Their findings underscore the importance of early intervention and a tailored surgical approach to minimize complications and optimize pulmonary function recovery [17].

In our case, the presence of complete middle-lobe bronchial transection necessitated a surgical approach to restore airway continuity and preserve pulmonary function. According to van Roozendaal et al, the choice of bronchial repair, segmental resection, or lobectomy is determined by the extent of tissue damage, the presence of ischemia, and associated lung contusion [18]. In our patient, a middle lobectomy was performed to remove the devitalized tissue while preserving maximal pulmonary function.

Additionally, intraoperative ventilation strategies, such as one-lung ventilation, play a key role in the success of surgical repair, reducing complications and optimizing exposure for anastomosis

To contextualize our findings, we compare this case with previous reports of tracheobronchial injuries due to blunt trauma:

Aliev et al [2] presented a case series on tracheobronchial injuries after blunt trauma, emphasizing the critical role of CT and bronchoscopy in early diagnosis. Their findings align with our case in terms of diagnostic challenges and surgical indications, reinforcing the necessity of a multidisciplinary approach for these complex injuries.

Rieth et al discussed contemporary management strategies for blunt tracheobronchial injuries, including both surgical and non-surgical approaches. Our case further contributes to this discussion by demonstrating that, in cases of complete bronchial transection with devitalized tissue, immediate surgical intervention remains the optimal approach [19].

By incorporating these references, we have strengthened our Discussion section with evidence-based insights, ensuring a comprehensive comparison with previous literature on diagnostic and therapeutic strategies for bronchial rupture in blunt chest trauma.

Thoracic trauma is generally associated with 4 primary mechanisms:Direct impactCompression between rigid structuresRapid acceleration or deceleration forcesBlast shock waves [4].

In this case, the bronchial rupture resulted from a direct collision, which is a less common cause of severe intrathoracic injury than impalement or deceleration forces. This unusual mechanism highlights the complexity and variability of trauma presentations [9].

The presence of pericardial effusion, which necessitated a pericardial window procedure, was likely the result of the impact on fixed anatomical structures such as the chest wall or spine.

The successful management of this case exemplifies the importance of rapid hemodynamic stabilization and timely surgical intervention in severe thoracic trauma. Hypovolemic shock and tension pneumothorax, a potentially fatal condition occurring in up to 50% of blunt chest traumas, required immediate and decisive action [20].

Our management approach, which involved providing initial stabilization followed by prompt transfer to a specialized trauma center for definitive care, is consistent with best practices in trauma care. This is particularly important for facilities with limited resources, where early transfer can be lifesaving.

The complete bronchial section observed in this patient, extending from the middle lobe to the intermediate bronchus, is an exceedingly rare finding. We suggest that a combination of direct trauma, pericardial effusion, and compression between the lung and chest wall may have contributed to this unusual injury pattern.

While this case provides valuable insights, systematic reviews and multicentric studies are needed to establish standardized treatment protocols for bronchial injuries in blunt trauma. Additionally, long-term follow-up studies are needed to evaluate pulmonary function recovery and quality of life in patients who undergo surgical repair for bronchial transection [21].

Conclusions

This case underscores the necessity of maintaining a high index of suspicion for tracheobronchial injuries in patients with blunt chest trauma, even when the mechanism of injury is atypical. Successful management of such complex cases hinges on rapid recognition, comprehensive imaging, and a collaborative, multidisciplinary approach involving emergency medicine, radiology, thoracic surgery, and critical care.