A 25-year-old man was seen in the emergency department (ED) after an assault with a machete. On arrival, he was diaphoretic with a heart rate of 110 beats per minute, respiratory rate 36 breaths per minute, blood pressure 99 mm Hg systolic, and oxygen saturation 85% on room air. On examination, he had lacerations over the left posterior chest wall and left flank. He was given tranexemic acid and supplemental oxygen, and massive transfusion protocol was initiated. Blood investigations revealed metabolic acidosis with pH of 7.19, a hemoglobin level of 160 g/L, and a serum lactate level of 9.7 mmol/L. Extended focused abdominal sonography for trauma showed a small left hemothorax, but there was no hemoperitoneum or hemopericardium. Plain chest radiograph done in the trauma bay showed a small left-sided hemopneumothorax. His vital signs stabilized after treatment initiated in the ED, and hence, decision was made to withhold chest tube insertion in ED. The patient was sent immediately for computed tomography (CT) trauma scan before being taken to the operating room. Computed tomography scan showed penetrating left lower lateral chest wall injury with moderate left-sided hemopneumothorax (Fig. 1).
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Figure 1: Computed tomography (CT) scan of the chest showing moderate left-sided haemo-pneumothorax.
Question:
Given the patient’s mechanism of injury, Figure 2 on CT scan of the chest indicates:
Figure 2: CT axial (A) and coronal (B) images show the discontinuous diaphragm sign with omental herniation (marked by arrow) and the sagittal (C) image shows thickening and curling at the site of rupture suggestive of dangling diaphragm sign (marked by arrow).
- Diaphragmatic injury
- Eventration of diaphragm
- Hiatus hernia
- Tension pneumothorax
Answer:
Penetrating trauma secondary to stab injury causes injury along the trajectory of the weapon. Diaphragmatic injuries are clinically occult, usually small in size, and can be easily missed on the initial CT scan in 12%–63% of the patients.[1] Patients either present immediately after trauma or can have a delayed presentation after months with signs and symptoms of abdominal organ herniation. Some patients are initially asymptomatic, while others may present with abdominal pain, nausea/vomiting secondary to gastrointestinal herniation through the diaphragmatic wound.[2] Diaphragmatic injuries diagnosed on initial presentation had a higher rate of associated liver, spleen, or hollow viscous injuries.[3]
Common signs of diaphragmatic injury on CT include discontinuous and/or dangling diaphragm sign, thickened diaphragm, organ herniation, collar sign, associated rib fracture, and contiguous injury on either side of the diaphragm.[1]Figure 2 axial (A) and coronal (B) CT images show the discontinuous diaphragm sign with omental herniation (marked by arrow), and the sagittal (C) image shows thickening and curling at the site of rupture suggestive of dangling diaphragm sign (marked by arrow). There was also contiguous injury on either side of the diaphragm (associated left hemopneumothorax and left rib fracture in our patient), which also aids the diagnosis of diaphragmatic injury in patients with penetrating trauma. Radiological signs of associated abdominal and thoracic visceral injury along the trajectory of penetrating weapon/object also serve as an indirect evidence of diaphragmatic injury. There is a variation in the detection of these signs based on the mechanism of injury. Patients with penetrating trauma have a higher incidence of discontinuous diaphragm sign on CT compared with blunt trauma, and they also had contiguous injuries on either side of the diaphragm. Collar sign and intrathoracic herniation of abdominal organs were commonly seen in patients with blunt diaphragmatic rupture.[1]
Surgical management of an unstable patient with penetrating trauma and diaphragmatic injury is exploratory laparotomy, which also helps identify other associated injuries. The diaphragmatic wound is closed with interrupted nonabsorbable sutures once the herniated contents have been reduced. Laparoscopy, which has a sensitivity, specificity, and negative predictive value of 100%, 87.5%, and 96.8% for diaphragmatic injuries, is an alternate option in hemodynamically stable patients with penetrating wounds to the thoracoabdominal area.[4] A missed diaphragmatic injury may result in complications including bowel herniation and/or strangulation. Hence, a high level of suspicion is required to avoid missing this occult diagnosis.
Conflict of interest statement
The author declares no conflict of interest.
Author contributions
Pothiawala S conceptualized the manuscript and wrote and reviewed the final draft of the manuscript.
Funding
None.
Ethical approval of studies and informed consent
The ethics committee of Auckland City Hospital guideline states that the publication of case reports is exempt from ethics approval. Written informed consent was obtained from the patient.
Acknowledgments
None.
References
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2. Morgan B, Watcyn-Jones T, Garner J. Traumatic diaphragmatic injury.
J R Army Med Corps. 2010;156(3):139–144. doi:10.1136/jramc-156-03-02
3. Tavakoli H, Rezaei J, Yazdi SAM, Abbasi M. Traumatic right hemi-diaphragmatic injury: delayed diagnosis.
Surg Case Rep. 2019;5(1):92. doi:10.1186/s40792-019-0650-5
4. Tserng TL, Gatmaitan MB. Laparoscopic approach to the management of penetrating traumatic diaphragmatic injury.
Trauma Case Rep. 2017;10:4–11. doi:10.1016/j.tcr.2017.05.010
