Techniques in regional anesthesia & pain management最新文献

Abdominal field blocks are commonly used for postoperative analgesia in major abdominal surgeries. The original transversus abdominis plane (TAP) block is limited in its dermatomal coverage to T10-L1. However, modifications made to the classic TAP block technique can enhance the spread of local anesthetic and provide more effective analgesia. In this article, we describe 2 of such modifications of the classic TAP block, namely quadratus lumborum and subcostal TAP blocks.

The prevalence of chronic pain, including but not limited to back, leg, and pelvic pain, is substantial during the peripartum period. Such pain may affect maternal and fetal outcomes. Therefore, obstetric anesthesiologists should be familiar with the analgesia provided to patients with chronic pain as well as any history of opioid dependence or substance abuse. We systematically searched PubMed and the Cochrane databases for all reports published on perioperative management of parturients with chronic pain. Abrupt cessation of opioid maintenance treatment or the use of partial opioid agonists-antagonists (commonly prescribed to parturients) is likely to cause acute withdrawal and uncontrolled pain that could lead to preterm labor, fetal abnormalities, or even fetal demise. Parturients receiving opioid maintenance therapy typically require higher doses of opioids for pain relief because they have a lower pain threshold. However, complying with such requests for higher doses may further compromise patient, fetus, and neonate safety. Opioid agonist-antagonist drugs, except buprenorphine, should be avoided in patients receiving maintenance opioid therapy. Drugs such as nalbuphine, butorphanol, pentazocine, and tramadol may incite severe withdrawal. Similarly, buprenorphine should not be offered for acute pain management to a parturient who is receiving methadone maintenance. Individualized plans of prenatal and neonatal care as well as breastfeeding are important during hospital admission of those dependent on opioids. Parturients who have implanted pain management devices such as spinal cord stimulators (SCSs) or intrathecal pumps (ITPs) should receive particular attention from anesthesiologists. Localizing the SCS lead or the ITP catheter positions is essential for safe administration of axial analgesia. Fluoroscopic images of the SCS leads and ITP catheters obtained during implantation are routinely available and should be acquired to avoid damage to these leads. Ultrasonography may be used for mapping the lead or catheter if fluoroscopic images cannot be obtained. The substantial prevalence of chronic pain in the obstetric population suggests the need for further research. Investigations should focus on gaining a better understanding of chronic pain during pregnancy, labor, and delivery so as to develop effective anesthetic and analgesic strategies.

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.