Editing Epidural administration (section)

=== Insertion ===
[[File:Epidural needle insertion between the spinous processes of the lumbar vertebrae.jpg|thumb|Simulation of the insertion of an epidural needle between the spinous processes of the lumbar vertebrae. A syringe is connected to the epidural needle and the epidural space is identified by a technique to assess loss of resistance.]]
Epidural administration is a procedure which requires the person performing the insertion to be technically proficient in order to avoid complications. Proficiency may be trained using bananas or other fruits as a model.<ref name="Raj2013">{{cite journal|vauthors=Raj D, Williamson RM, Young D, Russell D|year=2013|title=A simple epidural simulator: a blinded study assessing the 'feel' of loss of resistance in four fruits.|journal=Eur J Anaesthesiol|volume=30|issue=7|pages=405–8|doi=10.1097/EJA.0b013e328361409c|pmid=23749185|s2cid=2647529|doi-access=free}}</ref><ref name="Leighton1989">{{cite journal|author=Leighton BL|year=1989|title=A greengrocer's model of the epidural space.|journal=Anesthesiology|volume=70|issue=2|pages=368–9|doi=10.1097/00000542-198902000-00038|pmid=2913877|doi-access=free}}</ref>

The person receiving the epidural may be seated, or lying on their side or stomach.<ref name="episteroid" /> The level of the spine at which the catheter is placed depends mainly on the site of intended operation – based on the location of the pain. The [[iliac crest]] is a commonly used anatomical landmark for lumbar epidural injections, as this level roughly corresponds with the fourth lumbar vertebra, which is usually well below the [[conus medullaris|termination of the spinal cord]].<ref name="episteroid" /> The [[Tuohy needle]], designed with a 90-degree curved tip and side hole to redirect the inserted catheter vertically along the axis of the spine, may be inserted in the midline, between the [[spinous process]]es. When using a paramedian approach, the tip of the needle passes along a shelf of vertebral bone called the [[Lamina of the vertebral arch|lamina]] until just before reaching the [[Ligamenta flava|ligamentum flavum]] and the epidural space.<ref name="tuohy">{{cite journal |last1=Nagel |first1=Sean J. |last2=Reddy |first2=Chandan G. |last3=Frizon |first3=Leonardo A. |last4=Holland |first4=Marshall T. |last5=Machado |first5=Andre G. |last6=Gillies |first6=George T. |last7=Howard |first7=Matthew A. |title=Intrathecal Therapeutics: Device Design, Access Methods, and Complication Mitigation: INTRATHECAL THERAPEUTICS REVIEW |journal=Neuromodulation: Technology at the Neural Interface |date=October 2018 |volume=21 |issue=7 |pages=625–640 |doi=10.1111/ner.12693|pmid=28961351 |s2cid=25494914 }}</ref>

Along with a sudden loss of resistance to pressure on the plunger of the syringe, a slight clicking sensation may be felt by the operator as the tip of the needle breaches the ligamentum flavum and enters the epidural space. [[saline (medicine)|Saline]] or air may be used to identify placement in the epidural space. A systematic review from 2014 showed no difference in terms of safety or efficacy between the use of saline and air for this purpose.<ref>{{cite journal|last1=Antibas|first1=Pedro L|last2=do Nascimento Junior|first2=Paulo|last3=Braz|first3=Leandro G|last4=Vitor Pereira Doles|first4=João|last5=Módolo|first5=Norma SP|last6=El Dib|first6=Regina|date=2014-07-17|title=Air versus saline in the loss of resistance technique for identification of the epidural space|journal=Cochrane Database of Systematic Reviews| volume=2015 |issue=7|pages=CD008938|doi=10.1002/14651858.cd008938.pub2|pmid=25033878|pmc=7167505|issn=1465-1858}}</ref> In addition to the loss of resistance technique, direct imaging of the placement may be used. This may be conducted with a [[portable ultrasound]] scanner or [[fluoroscopy]] (moving X-ray pictures).<ref name="Rapp2005">{{cite journal |vauthors=Rapp HJ, Folger A, Grau T | s2cid = 17614330 | title = Ultrasound-guided epidural catheter insertion in children | journal =  Anesthesia & Analgesia| volume = 101 | issue = 2 | pages = 333–9, table of contents | year = 2005 | pmid = 16037140 | doi = 10.1213/01.ANE.0000156579.11254.D1 | doi-access = free }}</ref> After placement of the tip of the needle, a catheter or small tube is threaded through the needle into the epidural space. The needle is then withdrawn over the catheter. The catheter is generally inserted 4–6&nbsp;cm into the epidural space, and is typically secured to the skin with adhesive tape, similar to an [[Intravenous therapy|intravenous line]].<ref name="Beilin1995">{{cite journal |vauthors=Beilin Y, Bernstein HH, Zucker-Pinchoff B | title = The optimal distance that a multiorifice epidural catheter should be threaded into the epidural space | journal = Anesth Analg | volume = 81 | issue = 2 | pages = 301–4 | year = 1995 | pmid = 7618719 | doi = 10.1097/00000539-199508000-00016 | s2cid = 26405808 | doi-access = free }}</ref>