There are no specific clinical signs or physical exam findings that can suggest lung torsion as the diagnosis. Non-specific clinical signs range from fever, chest pain, shortness of breath, and cough. Most of these symptoms appear 4 to 14 days after having a thoracic procedure or trauma or any other triggering effect. Some patients were even asymptomatic and showed no clinical signs.

Physical exam findings will reveal hypoxia, dyspnea, productive cough, and hemoptysis. Respiratory discomfort and tachypnea can also be seen. Lung torsion is diagnosed with radiological imaging.[13][16][21][18][10]

Initial laboratory work can show leukocytosis, but it's not always present. Arterial blood gas may appear normal and not reflect the hypoxia; therefore, the diagnosis is made through radiologic imaging.[1]

An X-ray can show worsening consolidation, and sometimes abruption of the pulmonary artery may be seen. Anatomic abnormalities and pulmonary opacities can also be seen in X-ray imaging. Serial X-rays can show consolidation progression, especially if pneumonia is superimposing on lung torsion.[16][22][23]

Bronchoscopy can also reveal findings indicating lung torsion. In previous case studies, bronchoscopy revealed obstruction where the bronchoscope could not advance into the bronchus due to the narrowing of the passageway. The bronchial stenosis and a "fish mouth" orifice could be seen through bronchoscopy. Bronchoscopy does not always reveal narrowing or diagnose lung torsion; therefore, a computed tomography (CT) scan is required to confirm the diagnosis.[16][18][24]

CT scan can show obstruction of bronchial arteries, lobar opacification, or atelectasis and lobular collapse. Vascular and bronchial structures can appear to be stenosed, blocked, or inverted on imaging and may be seen as the "antler sign". Obstruction in the airway can reveal tracheobronchial tree narrowing of the affected bronchus. Rotation of the lung can occur at a variety of angles; however, one case series has shown that in most cases, the lobe was rotated about 180 degrees. Follow up CT scans can show a change in the position of the lesions as the lung torsion progresses.

CT angiography can show abrupt truncation and pulmonary artery obstruction. These images have also revealed interlobular septal thickening in the displaced lobe along with venous congestion. Sometimes abnormal lobe displacement can reveal a fissure. If the lung tissue has already become necrotic, imaging will reveal the loss of parenchymal and pulmonary vascular sites.[16][24][18][25]

Patients that are treated early on before necrosis occurs can have viable tissue saved. Case studies show that patients who underwent detorsion of the rotated lung were able to have full function returned with the lung re-expanding. Once the lungs go through detorsion, they have to then be fixed in place between the involved lung and the surrounding tissue with sutures or staples.

If it is not possible for the lung to go through detorsion or if detorsion fails, then lobectomy must occur. To save viable lung, detorsion must be performed within the first few hours of diagnosis. Any longer, the lung may already have irreversible ischemic damage, where it may be safer to perform a resection without detorsion. This would prevent the inflammatory markers that build up during the torsion from leaking out into the rest of the body and causing multiorgan failure. For the damaged tissue, it is best to keep the lung rotated until the pulmonary veins have been clamped to prevent the systemic release of the inflammatory markers. Once safely clamped, a clinical decision can be made whether the lung can go through detorsion or if resection should occur. 

Delayed treatment can also cause a clot to form, resulting in pulmonary embolism or stroke. Heparin drip can be used as prophylactic measures to prevent this complication. Conservative management was found to have recurrent pneumonia, eventually leading to death. Very few cases had complications of pneumonia, air leaks, or emphysema after fixation. Most procedures occurred without any complications intra-operatively and post-operatively.[18][26][27][28]

Studies have found that misdiagnosis occurred 18.3% of the time in patients with lung torsion. Most of the differentials can be excluded by CT scan, CT angiography, or bronchoscopy from the abnormal lobular placement. Diagnosis is confirmed with the vascular obstruction and airway obstruction seen on the CT scan. Differential diagnosis of lung torsion includes the following:[13][14][16][29][30]

• Hemothorax
• Hemorrhage
• Pneumonia (infectious versus aspiration)
• Contusion (after sub-lobar resection - can appear like airspace consolidation that resolves after a few days)
• Lung gangrene
• Parenchymal infection
• Atelectasis
• Tumor
• Loculated effusion
• Emphysema
• Inadvertent ligation of the hilum
• Diaphragmatic herniation
• Leakage of the anastomosis site 

Prognosis is poor if lung torsion management is delayed or the patient becomes septic resulting in ischemia of the lung tissue. The mortality rate was found to be as high as 8.3%. Higher mortality rates were associated with whole lung torsion as compared to lobar torsion. Studies have found similar survival rates among reposition and direct reposition. Indirection resection had higher mortality. Mortality from lung torsion was found to be highest in trauma patients at 22.2%, followed by thoracic surgery at 8.8%, and spontaneous lung torsion at 3.1%.[16][31]

Correction of lung torsion is an emergent surgical procedure, with a multitude of associated complications. These include:[13][32][33][34][35][36]

• Pneumonia
• Cerebrovascular accident
• Necrosis of the lung tissue
• Hemorrhage
• Vocal cord injury
• Bronchopleural fistulae
• Pulmonary embolism
• Post-thoracic surgery non-cardiogenic pulmonary edema
• Atelectasis
• Bronchospasm
• Respiratory Failure
• Air leak - pneumothorax, pneumomediastinum, pneumopericardium
• Emphysema 

Patients should be advised to avoid any blunt trauma to the thoracic or abdominal cavity after having a thoracic procedure to minimize the risk of post-operative lung torsion.

Lung torsion is a diagnosis that can be made from chest X-ray, CT scan, or bronchoscopy. It is confirmed with a CT scan. It is a life-threatening pathology. It causes bronchovascular and airway compromise. If not treated in a timely fashion, then necrosis of the lung can occur. It is treated through detorsion of the lung or lobectomy.

If a thoracic procedure occurs, pneumopexy of the lung lobe should be completed to prevent lung torsion. After lobectomy or segmentectomy, the remaining lobe should be stabled or sutured, so it stays fixed; this, however, is not commonly practiced as prophylactic treatment. Post-care followup would require monitoring for air leaks. Practitioners should consider heparin drip for prophylactic prevention of pulmonary embolism.

If a thoracic procedure, such as VATS or lobectomy was done, then stapling the lung or pneumopexy of the lobe should be considered to prevent lung torsion. Lung torsion is a diagnosis that must be made in a timely manner, classically done through radiologic imaging. Once a diagnosis is made, it is imperative to contact the thoracic surgical team to salvage the lung. Coordination and rapid, effective communication between interprofessional care team members is essential to ensure a timely diagnosis and correction of this potentially fatal disease.