Since you believe drug error (which explains all the symptoms, and resolution after GA was induced) isn't possible, you're left to search for causes of the increased ICP and resulting Cushing's response. If that's the case, only air entry into CS space could possibly explain (and I imagine it'd need to be a lot of air), in which case you're left to consider your CSE technique and whether or not you should be doing CSE. Air would've been seen most likely on the CT. Regardless, I hope you understand by now (since most posters have pointed it out) that CSE isn't needed for your practice. I hate using epidurals for CS (it's inferior to SAB), and I really can't find a reason to do CSE for labor for reasons previous posters have described. I don't see how how dural ectasia explains any of the symptoms described.