{'fraction_non_alphanumeric': 0.024680073126142597, 'fraction_numerical': 0.002742230347349177, 'mean_word_length': 5.293103448275862, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Pseudo loss of resistance in epidural space localization: A complication of subcutaneous emphysema or simply a faulty technique

We read with interest the Letter to the Editor, “Pseudo loss of resistance in epidural space localization”.[1] The inference of the authors seems to be simple, but a closer look reveals the omission of many implicating factors that would have contributed to the false loss of resistance (LOR). Therefore, we dispute the conclusions. It appears that the needle was merely inserted into the supraspinous (SS) or interspinous (IS) ligament before the LOR with glass syringe was attempted. Therefore, we strongly believe that the pseudo LOR perceived by the authors could be primarily due to the needle entering the paraspinous muscles with subcutaneous emphysema forming air pockets in the deeper planes may be a secondary factor. We believe that the formation of air pockets within the tough ligamentum flavum (LF) and IS ligaments following subcutaneous emphysema is impossible, though cystic degeneration of these ligaments is well described in the literature.[1,2]