Full of Hot Air: A Systematic Review of Pneumocephalus and Pneumorrhachis as a Complication of Spinal Procedures

Introduction: Pneumocephalus and pneumorrhachis have rarely been described as complications of spinal procedures, requiring unique strategies for symptom management and treatment. These conditions are often caused by trauma and present as neurosurgical emergencies when entrapped air causes increased pressure in the central nervous system.

Methods: A systematic review was performed using PRISMA guidelines to interrogate PubMed/MEDLINE for cases of pneumocephalus and/or pneumorrachis that present following spinal procedures. Symptom presentation and improvement, radiologic persistence of the pneumocephalus, ICU stay, and mortality were extracted as primary outcomes.

Results: A total of 106 cases of pneumocephalus and/or pneumorrachis presenting as complications of spinal procedures were identified. The most common procedures investigated were epidural injections (38.7%) and decompression surgeries (17.0%). Overall symptom improvement rate was 86%, and mortality rate was 5%. Tension pneumocephalus was reported in 17 cases and conveyed no increased risk of mortality (p=0.59), ICU admission (p=0.76), or persistent symptoms (p=0.71). Patients receiving surgical treatment were significantly more likely to have ICU stay during their hospital course (p=0.005) but had no difference in symptom improvement (p=0.35), radiologic resolution (p=0.34), and mortality (0.62) compared to non-surgically managed patients. Patients who had additional neurologic sequelae beyond the pneumocephalus were also more likely to receive surgery (p < 0.001). Patients who presented with headache were significantly less likely to experience persistent symptoms (p=0.008), persistent imaging findings (p=0.01), ICU care (p < 0.001), and mortality (p=0.04), while altered mental status was associated with significantly greater risk of symptom persistence (p=0.04), ICU stay (p < 0.001), and mortality (p=0.049).

Conclusion : The overall prognosis for pneumocephalus as a complication of spinal procedures is favorable. Presentation with headaches is associated with a greater likelihood of recovery, and presentation with altered mental status is associated with a worse likelihood of recovery. Tension pneumocephalus and pneumorrachis showed no association with worse symptomatic or radiologic outcomes.