====== Postoperative pain ======

Studying the characteristics of postoperative pain at such an early stage allows for improved management. It helps to predict, according to the type of surgery and the anaesthesia used, those patients in which higher VAS values may be seen and to better adapt analgesic therapy
((Cabedo N, Valero R, Alcón A, Gomar C. Prevalence and characterization of
postoperative pain in the Postanaesthesia Care Unit. Rev Esp Anestesiol Reanim.
2017 Mar 28. pii: S0034-9356(16)30211-0. doi: 10.1016/j.redar.2016.11.006. [Epub 
ahead of print] English, Spanish. PubMed PMID: 28363327.
)).

Despite advances in surgical and anesthesiology techniques, many patients continue to experience postoperative pain after lumbar disc operations

The administration of tramadol with paracetamol was more effective than tramadol alone for early acute postoperative pain therapy following lumbar discectomy. Therefore while adding paracetamol in early pain management is recommended, continuing paracetamol for the late postoperative period is not advised
((Uztüre N, Türe H, Keskin Ö, Atalay B, Köner Ö. Comparison of Tramadol versus
Tramadol with Paracetamol for efficacy of postoperative pain management in lumbar
discectomy: a randomized controlled study. Int J Clin Pract. 2019 Sep 11. doi:
10.1111/ijcp.13414. [Epub ahead of print] PubMed PMID: 31508863.
)).

===== Etiology =====

[[Epidural fibrosis]] and [[epidural]] adhesion after [[laminectomy]] are developed from adjacent dense [[scar]] tissue, which is a natural [[wound healing]] process
((Alkalay RN, Kim DH, Urry DW, Xu J, Parker TM, Glazer PA. Prevention of postlaminectomy epidural fibrosis using bioelastic materials. Spine (Phila Pa 1976) 2003;28:1659–1665.))
((Hsu CJ, Chou WY, Teng HP, Chang WN, Chou YJ. Coralline hydroxyapatite and laminectomy-derived bone as adjuvant graft material for lumbar posterolateral fusion. J Neurosurg Spine. 2005;3:271–275.))
((Temel SG, Ozturk C, Temiz A, Ersozlu S, Aydinli U. A new material for prevention of epidural fibrosis after laminectomy: oxidized regenerated cellulose (interceed), an absorbable barrier. J Spinal Disord Tech. 2006;19:270–275.))
((Yu CH, Lee JH, Baek HR, Nam H. The effectiveness of poloxamer 407-based new anti-adhesive material in a laminectomy model in rats. Eur Spine J. 2012;21:971–979.))
, 
and ranked as the major contributor for [[postoperative pain]] recurrence after laminectomy or discectomy.

see [[Failed back surgery syndrome]]
----
[[Postcraniotomy acute pain]].

===== Diagnosis =====
[[Pain intensity]] evaluation by self-report is difficult and biased in non-communicating people, which may contribute to inappropriate [[pain treatment]]. The use of [[artificial intelligence]] (AI) to evaluate pain intensity based on automated facial expression analysis has not been evaluated in clinical conditions.

Fontaine et al. trained and externally validated a deep-learning system (ResNet-18 convolutional neural network) to identify and classify 2810 facial expressions of 1189 patients, captured before and after surgery, according to their self-reported pain intensity using a numeric rating scale (NRS, 0-10). AI performances were evaluated by accuracy (concordance between AI prediction and patient-reported pain intensity), sensitivity, and specificity to diagnose pain ≥4/10 and ≥7/10. We then confronted AI performances with those of 33 nurses to evaluate pain intensity from facial expressions in the same situation.

Results: In the external testing set (120 face images), the deep learning system was able to predict exactly the pain intensity among the 11 possible scores (0-10) in 53% of the cases with a mean error of 2.4 points. Its sensitivities to detect pain ≥4/10 and ≥7/10 were 89.7% and 77.5%, respectively. Nurses estimated the right NRS pain intensity with a mean accuracy of 14.9% and identified pain ≥4/10 and ≥7/10 with sensitivities of 44.9% and 17.0%.

Subject to further improvement of AI performances through further training, these results suggest that AI using facial expression analysis could be used to assist physicians to evaluate pain and detecting severe pain, especially in people not able to report appropriately their pain by themselves.

Significance: These original findings represent a major step in the development of a fully automated, rapid, standardized, and objective method based on facial expression analysis to measure pain and detect severe pain
((Fontaine D, Vielzeuf V, Genestier P, Limeux P, Santucci-Sivilotto S, Mory E, Darmon N, Lanteri-Minet M, Mokhtar M, Laine M, Vistoli D; DEFI study group. Artificial intelligence to evaluate postoperative pain based on facial expression recognition. Eur J Pain. 2022 Mar 30. doi: 10.1002/ejp.1948. Epub ahead of print. PMID: 35352426.)).

===== Prevention =====
[[Intradiscal surgical procedures]] are among the most controversial [[procedure]]s for [[lumbar spine surgery]]. The theoretical [[advantage]] is that an epidural [[scar]]ring is avoided and that a smaller [[incision]] or even just a [[puncture]] site is used. 
This is also purported to reduce [[postoperative pain]] and [[hospital stay]] (often performed as an outpatient procedure).

===== Treatment =====

[[Postoperative pain treatment]]



===== References =====