Pneumothorax, Pneumomediastinum, and Pneumorrhachis: A Rare Presentation in a Neurological Patient
Occurrence of pneumothorax with associated presence of air in the mediastinum, pericardium, and spinal canal is a rare entity seen in neuroanesthetic and neurocritical care practice. We describe a neurological patient with these clinical manifestations and discuss the possible factors contributing to this uncommon complication.
An 18-year-old male patient presented with history of headache and vomiting. A computed tomography of the brain showed a hyperdense lesion in the brainstem. Magnetic resonance imaging revealed a partially thrombosed venous sac in the fourth ventricle. (Fig. 1A) A cerebral angiogram demonstrated a posterior fossa arteriovenous fistula (Fig. 1B), and he was scheduled for endovascular management. His hospital course was complicated by a lower respiratory tract infection for which he was treated with antibiotics for 3 days. On the morning of the neuroradiologic intervention, he developed sudden respiratory distress. Chest radiography showed subcutaneous emphysema, lung opacities, and pneumomediastinum (Fig. 1C). An urgent computed tomography scan of the thorax demonstrated pneumothorax on the right side, pneumomediastinum, pneumopericardium, and pneumorrhachis (Fig. 1D). Bilateral large-segment consolidation of the lungs was also seen. Arterial blood-gas analysis and imaging findings pointed to the diagnosis of acute respiratory distress syndrome (ARDS). He was immediately intubated and received an intercostal drain in the intensive care unit. Antibiotics and mechanical ventilation with lung protective strategy was instituted to manage ARDS. However, over the next 48 hours, his clinical condition rapidly deteriorated with development of multiorgan failure and resulted in death. Bacterial culture of the tracheal secretions revealed coagulase-negative staphylococcus.
Previous reports describing similar clinical and radiologic presentation are few and have been described following common flu, thoracic trauma, acute exacerbation of asthma, and even spontaneously.1–4 Isolated “pneumo” presentation is rare and air in one compartment is most commonly associated with spread to the other adjacent cavities and compartments. In our patient, vigorous coughing due to respiratory condition could have resulted in increased intra-alveolar pressure leading to alveolar rupture, air leak in the peribronchovascular space causing subcutaneous emphysema, pneumothorax, pneumomediastinum, pneumopericardium, and pneumorrhachis (4Ps). Air under pressure could have resulted in breach in the compartmental boundaries and facilitated the entry of air through the path of least resistance to different cavities across various fascial planes. Air could have traversed from posterior mediastinum to epidural space through the neural foramen resulting in pneumorrhachis. Pneumorrhachis, though most often self-limiting, can lead to compression of the spinal cord and its consequences. Other manifestations are generally self-limiting without significant morbidity and mortality. But the rapid spread of air in various compartments in association with development of severe ARDS contributed to the adverse clinical outcome in our patient.
To conclude, severe manifestation leading to adverse clinical outcome can result from occurrence of 4Ps in presence of ARDS. Early detection and prompt management of the primary cause might prevent manifestation of a “difficult to treat” concurrent complications.