Use of dexmedetomidine for pain control

For many years, clonidine, an α2-adrenergic receptor (α2-AR) agonist, has been widely used as an analgesic adjuvant in perioperative conditions and pain therapy. Dexmedetomidine (DMET) is currently the most potent α2-AR agonist available and was first approved as a sedative agent for use in the intensive care unit. However, DMET has recently been investigated for its analgesic effects and has the potential to become an alternative to clonidine

Enhanced neuroinflammation and pain hypersensitivity after peripheral nerve injury in rats expressing mutated superoxide dismutase 1

<p>Abstract</p> <p>Background</p> <p>Neuroinflammation and nitroxidative stress are implicated in the pathophysiology of neuropathic pain. In view of both processes, microglial and astroglial activation in the spinal dorsal horn play a predominant role. The present study investigated the severity of neuropathic pain and the degree of glial activation in an inflammatory- and nitroxidative-prone animal model.</p> <p>Methods</p> <p>Transgenic rats expressing mutated superoxide dismutase 1 (hSOD1^G93A) are classically used as a model for amyotrophic lateral sclerosis (ALS). Because of the associated inflammatory- and nitroxidative-prone properties, this model was used to study thermal and mechanical hypersensitivity following partial sciatic nerve ligation (PSNL). Next to pain hypersensitivity assessment, microglial and astroglial activation states were moreover characterized, as well as inflammatory marker gene expression and the glutamate clearance system.</p> <p>Results</p> <p>PSNL induced thermal and mechanical hypersensitivity in both wild-type (WT) and transgenic rats. However, the degree of thermal hypersensitivity was found to be exacerbated in transgenic rats while mechanical hypersensitivity was only slightly and not significantly increased. Microglial Iba1 expression was found to be increased in the ipsilateral dorsal horn of the lumbar spinal cord after PSNL but such Iba1 up-regulation was enhanced in transgenic rats as compared WT rats, both at 3 days and at 21 days after injury. Moreover, mRNA levels of Nox2, a key enzyme in microglial activation, but also of pro-inflammatory markers (IL-1β and TLR4) were not modified in WT ligated rats at 21 days after PSNL as compared to WT sham group while transgenic ligated rats showed up-regulated gene expression of these 3 targets. On the other hand, the PSNL-induced increase in GFAP immunoreactivity spreading that was evidenced in WT rats was unexpectedly found to be attenuated in transgenic ligated rats. Finally, GLT-1 gene expression and uptake activity were shown to be similar between WT sham and WT ligated rats at 21 days after injury, while both parameters were significantly increased in the ipsilateral dorsal region of the lumbar spinal cord of hSOD1^G93Arats.</p> <p>Conclusions</p> <p>Taken together, our findings show that exacerbated microglial activation and subsequent inflammatory and nitroxidative processes are associated with the severity of neuropathic pain symptoms.</p

Pain management after elective craniotomy: A systematic review with procedure-specific postoperative pain management (PROSPECT) recommendations.

BACKGROUND Pain after craniotomy can be intense and its management is often suboptimal. OBJECTIVES We aimed to evaluate the available literature and develop recommendations for optimal pain management after craniotomy. DESIGN A systematic review using procedure-specific postoperative pain management (PROSPECT) methodology was undertaken. DATA SOURCES Randomised controlled trials and systematic reviews published in English from 1 January 2010 to 30 June 2021 assessing pain after craniotomy using analgesic, anaesthetic or surgical interventions were identified from MEDLINE, Embase and Cochrane Databases. ELIGIBILITY CRITERIA Each randomised controlled trial (RCT) and systematic review was critically evaluated and included only if met the PROSPECT requirements. Included studies were evaluated for clinically relevant differences in pain scores, use of nonopioid analgesics, such as paracetamol and NSAIDs, and current clinical relevance. RESULTS Out of 126 eligible studies identified, 53 RCTs and seven systematic review or meta-analyses met the inclusion criteria. Pre-operative and intra-operative interventions that improved postoperative pain were paracetamol, NSAIDs, intravenous dexmedetomidine infusion, regional analgesia techniques, including incision-site infiltration, scalp nerve block and acupuncture. Limited evidence was found for flupirtine, intra-operative magnesium sulphate infusion, intra-operative lidocaine infusion, infiltration adjuvants (hyaluronidase, dexamethasone and α-adrenergic agonist added to local anaesthetic solution). No evidence was found for metamizole, postoperative subcutaneous sumatriptan, pre-operative oral vitamin D, bilateral maxillary block or superficial cervical plexus block. CONCLUSIONS The analgesic regimen for craniotomy should include paracetamol, NSAIDs, intravenous dexmedetomidine infusion and a regional analgesic technique (either incision-site infiltration or scalp nerve block), with opioids as rescue analgesics. Further RCTs are required to confirm the influence of the recommended analgesic regimen on postoperative pain relief

'Why me?' The problem of chronic pain after surgery.

Chronic postsurgical pain (CPSP) has become a health priority and is scheduled to be included in the upcoming version of the International Classification of Diseases, 11th Revision (ICD-11). Recent studies on CPSP show unchanged prevalence despite progress made in fundamental research about underlying pathophysiological mechanisms. Nevertheless, clinical research has allowed better understanding of some CPSP aspects such as the development of neuropathic CPSP. Actually, some improvements are ongoing such as a refined definition and the assessment of CPSP in vulnerable populations, for example, paediatric patients. Pain after surgery, its resolution or its transition to CPSP is a dynamic process that reinforces the necessity of longitudinal assessment and management. In other words, CPSP can be called 'perioperative medicine'

Postpartum chronic pain.

Postpartum chronic pain is a clinical reality which affects 6.1% to 11.5% of women after delivery and affects their recovery. The large range of incidence observed in the literature relies on criteria used to define chronic postpartum pain. The features depend on the type of delivery. Cesarean delivery which rate is increasing worldwide seems currently associated with lower risk of chronic postpartum pain, specifically chronic pelvic pain. Further chronic scar pain which often involves a neuropathic component is often of mild intensity. In opposite, after vaginal delivery, chronic pelvic pain and perineal pain have an important negative impact on women's mood and quality of life. As for any chronic pain, individual risk factors account more than degree of tissue trauma. From actual reports in the field, better pain education of both women and health care providers might help to reduce the problem

Postcesarean analgesia: effective strategies and association with chronic pain.

PURPOSE OF REVIEW: The management of postoperative pain after cesarean section slightly differs from that of the general surgical population, specifically women need to recover quickly to take care of their newborn baby. Optimal pain management is imperative for the success of immediate-term and long-term rehabilitation and this principle applies to obstetric patients. There is growing evidence that perioperative pain management has consequences extending well beyond the immediate recovery period. Unrelieved postoperative pain is a striking risk factor for the development of residual pain. RECENT FINDINGS: A recent study has highlighted that chronic pain may be a significant clinical problem after cesarean section. Among the risk factors, recalls of severe acute postoperative pain led to the reconsideration of postoperative pain management after cesarean delivery. Current published data agree that drug combinations, that is, multimodal or balanced analgesia, are mandatory to achieve satisfactory and effective pain relief with reduced side effects. SUMMARY: The use of balanced analgesia has significantly improved acute pain management after cesarean section. Future studies should extend their investigations beyond the first 48 h and consider the long-term effects of different analgesic regimens, that is, those that alter the development of residual pain

Chronic pain after childbirth

PURPOSE OF REVIEW: Although childbirth is considered a natural event, some deliveries may necessitate instrumentation or surgical intervention. In contrast with trauma or surgery, persistent pain after delivery has received little attention until recently, despite the large number of individuals potentially at risk. RECENT FINDINGS: Excluding pre-existing pain or pain that developed during pregnancy, prospective studies show a surprisingly low prevalence of persistent pain after childbirth, much lower than the prevalence reported in retrospective studies and that of persistent postsurgical pain in a general population for similar procedures. The nature of persistent pain itself remains poorly characterized; the chronic pain following caesarean delivery appears to be predominantly neuropathic, but the intensity is generally lower than usually reported for other types of chronic neuropathic pain. Finally, the type of delivery and the degree of tissue trauma do not seem to impact the risk of developing persistent pain. It is unclear whether individual factors place specific women at a risk for persistent pain. Experimental study suggests that protective mechanisms against the development of neuropathic pain may be active during the puerperium, but whether these mechanisms exist following human childbirth remains unknown. SUMMARY: Some recent findings on the development of persistent pain after childbirth are intriguing and might open the way to interesting perspectives for the treatment of persistent pain caused by trauma or surgery. © 2013 Wolters Kluwer Health | Lippincott Williams &amp; Wilkins

Chronic pain after surgery and trauma: current situation and future directions

Chronic post-surgical pain (CPSP) stands as a major health issue. The unchanged incidence over the last two decades underlines both the failure of predictive models developed until now and the lack of efficacy of common “preventive” strategies (pharmacotherapy and regional analgesic techniques) applied in current clinical practice. The recognition of CPSP as a disease and the release of a common definition of the condition is an important progress in the field. CPSP predictive scores exist but none has presently demonstrated an impact on patient care. New clinical directions based on the resolution of postoperative pain, a complex and highly dynamic process supported by individual pain trajectories, argue for predictive models and preventive strategies extended to the subacute pain period i.e. after hospital discharge. © 2022 Authors. All rights reserved