Pro-Con Debate: Air or Saline for Loss-of-Resistance Technique of Interlaminar Epidural Access with Fluoroscopy-Guided Pain Medicine Procedures

In this Pro-Con commentary article, the Pro side advocates that using the loss of resistance (LOR) to air technique for interlaminar epidural access is safe as the risk of pneumocephalus is exceptionally low. They note that case reports detailing complications typically utilize at least 1 mL of air, frequently exceeding this amount. Even a 1-mL dosage surpasses the requirement, particularly when fluoroscopy is applied in the context of chronic pain management. The proponents also suggest a modified technique, where a syringe containing a drop of saline or contrast acts as a visual cue, minimizing air injection into the epidural space to a negligible quantity. Moreover, they emphasize that air facilitates the identification of any fluid as an indicator of unintended intrathecal access. The Con perspective argues against the utilization of air for epidural access and advocates for the use of LOR with saline instead. This stance is supported by evidence pointing to a greater occurrence of adverse events, such as postdural puncture headache (PDPH) and pneumocephalus, associated with LOR to air compared to LOR with saline. They also argue that saline's physical properties enhance tactile feedback, potentially contributing to its increased safety. Both saline and air have been used for many years for epidural access via the interlaminar approach. Although both are generally accepted in practice, neither has been formally established as the standard of care. It would benefit the medical community to further delineate the pros and cons of each medium, enabling practitioners to make more informed decisions. This Pro-Con debate will provide 2 perspectives ( Table ) on the evidence and rationales for the use of air or saline for the LOR technique in interlaminar epidural access with fluoroscopy.