Techniques in regional anesthesia & pain management最新文献

The objective of this study was to measureand record trainee performance during an ultrasound-guided femoral nerve block (FNB) with a novel high fidelity feedback based simulator device. The method decribes a novel phantom simulator that was built, capable of objectively recording trainee performance and providing visual and audio feedback on the completion of a successful FNB. Overall, 33 subjects were comprised of medical students and residents performed 2 separate ultrasound simulation sessions, and were placed in 1 of 3 groups: light emitting diode and piezoelectric buzzer feedback (LED and PBZ), voice feedback alone, or no feedback. This phantom simulator measured 2 separate performance parameters including; the time (in seconds) to carry out a FNB and the number of needle passes. Each trainee was then evaluated with a global rating scale. Trainee confidence in ultrasound-guided procedures was also recorded.

All trainees improved their performance in the simulated block time (p < 0.005) and gained significant confidence in ultrasound-guided procedures (p < 0.0005). The LED and PBZ group improved the most in block time performance (p < 0.0001). Only the LED and PBZ group improved in visualizing the simulated nerve and advancing needle (p < 0.05), as well as simultaneously visualizing the needle reach the simulated nerve target (p < 0.005). For all groups there was robust correlation (−0.72, p < 0.0001) between the time to carry out a FNB and correct visualization of the needle during a successful FNB.

The high fidelity ultrasound phantom simulator used in this study, recorded and improved performance, and confidence in ultrasound guided procedures carried out by novice trainees.

The analgesic properties of cold therapy have been well known for many centuries. Cryoneurolysis of sensory peripheral nerves, in which the epineurium and perineurium resist freeze damage, allowing the structural scaffold to remain intact for normal axonal regeneration and remyelination to occur, has been used to treat pain for many decades. Chronic knee pain due to osteoarthritis is a common condition associated with significant disability among the elderly. Because no single treatment modality has been shown to be effective for treatment of knee pain secondary to osteoarthritis, treatment usually involves a combination of nonpharmacologic (including total knee arthroscopy) and pharmacologic therapies. Given the paucity of effective nonsurgical options for the treatment of knee pain, cryoneurolysis of the sensory nerves surrounding the knee may be a novel effective treatment strategy. Because cutaneous innervation of the knee is highly variable and complex, additional research is needed to understand which sensory nerves should be targeted for cryoneurolysis to maximize effectiveness. Recent advances in cryoneurolysis technology have allowed for the creation of more precise cold zones using smaller gauge needles that cause less pain when puncturing the skin. Emerging evidence suggests that this technology has clinical utility when used as part of a multimodal pain regimen for total knee arthroplasty. In addition to its potential to treat chronic knee pain, cryoneurolysis of sensory nerves has shown efficacy for the temporary relief of pain caused by numerous conditions.

Ultrasound-guided interventions are rapidly growing area in pain medicine. We developed a novel “underhand” technique aimed to improve upon the “freehand technique”. With the operator's hand stabilization, precise movements of the transducer are easier to perform that can improve visualization of the needle and targeted anatomical structures. Similar to the classical technique hydrolocalization can be used incrementally during the needle advancement to the target structure. Both the wrist up and the wrist down underhand approaches are described and provide the patient and physician comfort with superior needle visualization that can improve injection accuracy. This novel underhand out-of-plane technique may serve as a convenient and precise method to carry out ultrasound-guided interventions when the classical freehand technique may be challenging to perform.

Digital ischemia secondary to Raynaud’s phenomenon (RP) presents a significant challenge to clinicians because its symptoms are progressive, painful, and often unresponsive to medical management or conservative measures. The associated symptoms (pallor, cyanosis, and pain) can profoundly affect quality of life and are associated with significant morbidity, including ulceration, infection, and gangrene. Given the limitations of medical management and conservative therapies, a number of interventional and surgical techniques may be considered for treatment of pain and ischemic symptoms: peripheral nerve blockade of the brachial plexus, botulinum toxin injections, stellate ganglion blockade, spinal cord stimulation, and surgical sympathectomy. Data regarding RP are currently limited to case reports, case series, and retrospective reviews. To this date none of these interventional and surgical techniques have been evaluated individually or head to head in prospective clinical trials. This article reviews the current surgical and interventional treatment options for digital ischemia secondary to RP to allow clinicians to familiarize themselves with the available alternatives for patients whose symptoms are severe or unresponsive to medical management. Further research is needed to determine the optimal interventional treatment options for patients suffering from this debilitating disorder.

Postamputation residual limb pain is often a disabling chronic pain condition. Oftentimes, patients are left with a chronic stump pain that is refractory to current pain management modalities, such as medications, peripheral nerve blocks or denervation techniques, nerve or spinal cord stimulation, or surgical revision. Using high-frequency alternating current via a peripheral nerve cuff electrode creates a complete depolarizing nerve block, which blocks painful or unwanted nerve transmission of pain signals; the cuff is placed proximal to the neuroma at the end of the severed nerve. This article demonstrates the technique of placing a peripheral nerve cuff surgically around the peripheral nerves of patients who suffer from debilitating stump pain with lower extremity amputations. In total, 10 patients were implanted with the nerve cuff with 9 patients receiving in-clinic testing and 7 patients progressing onto long-term home-use. The average numerical rating scale pain scale for tested patients decreased from 5.7-1.4 (out of 10) after high-frequency alternating current electrical nerve block therapy with 85% of all testing sessions yielding a >50% pain reduction. Additionally, patients noted improved ability to maintain activity of daily living, as well as noted improvement of quality of life scores, and a reduction in overall pain medication use. Although the study’s initial endpoint was 90 days, we have continued to follow our implanted patients who have now reached 36 months.

Using drugs that follow anatomical pathways and act on receptors to treat acute pain and prevent its transformation into chronic pain is an appealing idea. The challenge consists of providing personalized treatment based on risk factors, pain and surgery type, and the type of rehabilitation program to minimize complications and optimize the pain treatment to prevent chronic pain. Clinical practice has started to understand the pathophysiological mechanisms and various neurochemical receptors involved in the transformation of acute pain into chronic pain. Unfortunately, the clinical reality differs greatly from the theory and no studies based on medical evidence show that using drugs to prevent chronic pain is a real possibility, nor what kinds of pain can actually be prevented with the use of preventive drugs. This article examines what kinds of pain are most commonly referred to chronic pain centers, looks at which drugs can be used to prevent chronic pain, and aims to establish a preventive treatment algorithm based on the type of postoperative pain. There is growing interest in providing therapeutic patient education, which consists of health professionals transferring knowledge to patients. In the model proposed in this article, therapeutic patient education acts as a connecting thread to different factors and enables patients to become more responsible for and proactive in the healing process. Prevention should be comprehensive, and not just pharmacologic.

It has been well known for years that there is considerable interindividual variability in the sensitivity to and tolerance of experimental pain stimuli, in the propensity to develop painful pathologies, and in the response to analgesic therapies; however, this does not mean that such differences are because of genetic factors alone, as pain is a complex phonemenon in which psychological and environmental factors, for example, as well as those inherent to physiological mechanisms, play an important role. Several different methods are used in genetic pain research. Although the identification of mutations can explain some very infrequent pathologies that follow Mendelian patterns of inheritance, the research method used in most cases is the genetic association study, which tests the correlation between a certain phenoytpe (pain) and a polymorphism or single-nucleotide polymorphism. At present there is evidence suggesting that genetic factors may be at least partially responsible for the greater pain experienced by certain individuals following an acute injury, such as a surgical intervention; however, studies analyzing the influence of genetics on chronic postsurgical pain have been scarce.

The existence of opioid-induced hyperalgesia (OIH), ie, nociceptive sensitization, caused by exposure to opioids remains difficult to appraise in perioperative setting because objective assessment is rare, evidence mostly relying on subjective measures like pain scores and postoperative analgesics use. Basic diagnostic criteria of OIH are still needed. Experimental studies have highlighted the pronociceptive effects of intraoperative high doses of opioids in term of latent hypersensitivity and long-term vulnerability to pain. The real question in daily clinical practice is then whether OIH prevention matters and which patients might be concerned. Until recently, OIH has been associated to intraoperative administration of high doses of opioids, mainly remifentanil, which increases acute postoperative pain and perhaps might cause the persistence of postsurgical pain. Recently, the existence of preoperative OIH has been demonstrated in chronic pain patients under chronic opioids intake and its exacerbation by the administration of intraoperative opioids has been suggested. Finally, the effect of long-term postoperative opioids intake on pain persistence after surgery or trauma certainly deserves to be questioned. Thereby, the prevention of perioperative OIH should extend up to several weeks after surgery and should include chronic postsurgical pain. The later point argues for the development of dedicated chronic postsurgical pain services.