Editing Anesthesia (section)

=== Acute pain management ===
[[File:PCA-01.JPG|thumb|180px|right|A patient-controlled analgesia [[infusion pump]], configured for [[epidural]] administration of [[fentanyl]] and [[bupivacaine]] for postoperative [[analgesia]]]]
[[Nociception]] (pain sensation) is not hard-wired into the body.  Instead, it is a dynamic process wherein persistent painful stimuli can sensitize the system and either make pain management difficult or promote the development of chronic pain. For this reason, preemptive acute pain management may reduce both acute and chronic pain and is tailored to the surgery, the environment in which it is given (in-patient/out-patient) and the individual.<ref name="Miller 2010" />{{rp|2757}}

Pain management is classified into either pre-emptive or on-demand.  On-demand pain medications typically include either [[opioid]] or [[non-steroidal anti-inflammatory drugs]] but can also make use of novel approaches such as inhaled [[nitrous oxide]]<ref name="Klomp">{{cite journal | vauthors = Klomp T, van Poppel M, Jones L, Lazet J, Di Nisio M, Lagro-Janssen AL | title = Inhaled analgesia for pain management in labour | journal = The Cochrane Database of Systematic Reviews | volume = 12 | issue = 9 | pages = CD009351 | date = September 2012 | pmid = 22972140 | doi = 10.1002/14651858.CD009351.pub2 | hdl-access = free | hdl = 1871/48559 }}</ref> or [[ketamine]].<ref>{{cite journal | vauthors = Radvansky BM, Shah K, Parikh A, Sifonios AN, Le V, Eloy JD | title = Role of ketamine in acute postoperative pain management: a narrative review | journal = BioMed Research International | volume = 2015 | pages = 749837 | date = 2015-10-01 | pmid = 26495312 | pmc = 4606413 | doi = 10.1155/2015/749837 | doi-access = free }}</ref> On demand drugs can be administered by a clinician ("as needed drug orders") or by the patient using [[patient-controlled analgesia]] (PCA).  PCA has been shown to provide slightly better pain control and increased patient satisfaction when compared with conventional methods.<ref name="Hudcova">{{cite journal | vauthors = McNicol ED, Ferguson MC, Hudcova J | title = Patient controlled opioid analgesia versus non-patient controlled opioid analgesia for postoperative pain | journal = The Cochrane Database of Systematic Reviews | issue = 6 | pages = CD003348 | date = June 2015 | volume = 2020 | pmid = 26035341 | pmc = 7387354 | doi = 10.1002/14651858.CD003348.pub3 }}</ref> Common preemptive approaches include epidural neuraxial blockade<ref name="Jones">{{cite journal | vauthors = Jones L, Othman M, Dowswell T, Alfirevic Z, Gates S, Newburn M, Jordan S, Lavender T, Neilson JP | display-authors = 6 | title = Pain management for women in labour: an overview of systematic reviews | journal = The Cochrane Database of Systematic Reviews | volume = 3 | issue = 3 | pages = CD009234 | date = March 2012 | pmid = 22419342 | pmc = 7132546 | doi = 10.1002/14651858.CD009234.pub2 }}</ref> or nerve blocks.<ref name="Klomp"/> One review which looked at pain control after [[Aortic aneurysm|abdominal aortic surgery]] found that epidural blockade provides better pain relief (especially during movement) in the period up to three postoperative days. It reduces the duration of postoperative [[tracheal intubation]] by roughly half. The occurrence of prolonged postoperative [[mechanical ventilation]] and [[myocardial infarction]] is also reduced by epidural analgesia.<ref name="pmid26731032">{{cite journal | vauthors = Guay J, Kopp S | title = Epidural pain relief versus systemic opioid-based pain relief for abdominal aortic surgery | journal = The Cochrane Database of Systematic Reviews | issue = 1 | pages = CD005059 | date = January 2016 | volume = 2017 | pmid = 26731032 | pmc = 6464571 | doi = 10.1002/14651858.CD005059.pub4 }}</ref>