Tension Pneumocephalus in a Tracheostomized, Chronically Ventilated, Duchenne’s Muscular Dystrophy Patient Without Prior Head Trauma

Abstract

Tension pneumocephalus is a rare condition that can be a life-threatening neurosurgical emergency. It usually results from head trauma, but there have been case reports of iatrogenic causes including on non-invasive mechanical ventilation. We report a case of pneumocephalus resulting from high mechanical ventilation pressures in a patient without prior head trauma.A 37-year-old male with Duchenne’s muscular dystrophy who had been ventilator-dependent through tracheostomy was admitted for shortness of breath and intermittent fevers. The patient was found to have pneumonia, with left-lower lobe consolidation, and was started on linezolid given known Methicillin-resistant Staphylococcus aureus from previous sputum culture; he was later switched to vancomycin and piperacillin-tazobactam given persistent fevers to cover for hospital-acquired pneumonia. The patient went into septic shock requiring multiple pressors as well as stress steroids for persistent shock, with eventual improvement in hemodynamics. He developed further respiratory acidosis on his usual ventilator settings, and peak inspiratory pressures (PIPs) progressively increased to as high as 45-70 cm H2O during his hospital course. PIPs did not improve with suctioning or after bronchoscopy. On the 17th day of the patient’s stay, he had acutely altered mental status with non-reactive fixed and dilated pupils and disconjugate gaze of the right eye on neurologic examination. CT of the head at that time revealed extensive pneumocephalus along the bifrontal convexities, suprasellar cisterns, and posterior fossa, with a possible fracture of the frontal skull base near the ethmoid roof. Mount Fuji sign was present on CT scan, indicative of “tension pneumocephalus”. Neurosurgical consultation was obtained but the family declined intervention given his overall debilitated stated. Comfort measures were instituted, and the patient expired the following day.Pneumocephalus is the accumulation of air entry into the cranial cavity, generally from head trauma, inflammation, or surgery. Patients may have underlying base skull defects or microfractures that permit air to enter the intracranial cavity. Increased sphenoid sinus pressure from mechanical ventilation may enter the subperiosteal space, allowing air to enter the intracranial cavity. It is important to consider pneumocephalus in a patient with new neurological findings after mechanical ventilation.