Ultrasound‐Guided Continuous Superficial Peroneal Nerve Block below the Knee for the Treatment of Nerve Injury

(CRPS) describes a constellation of symptoms including pain, trophic changes, hyperesthesia, allodynia, and dysregulation of local blood flow often following trauma. It is often confined to the extremities. Treatment of this disorder consists of a variety of modalities including systemic pharmacotherapy, local anesthetic injections or infusions, psychological nonpharmacotherapy, physical rehabilitation, and surgical intervention. Chronic pain not related to CRPS can also be treated with similar interventions. Despite the array of available therapies, it can still be difficult to manage. We report a case of a 19‐year‐old patient diagnosed by her surgeon as having CRPS Type II, secondary to foot trauma, which was treated with a continuous infusion of local anesthetic at the superficial peroneal nerve (SPN). While placement of peripheral nerve block catheters to augment chronic pain therapy is not novel, the application of a perineural catheter at the SPN has not been previously described.     

16. Complex Regional Pain Syndrome

Complex regional pain syndrome (CRPS), formerly known as reflex sympathetic dystrophy is a pain syndrome with an unclear pathophysiology and unpredictable clinical course. The disease is often therapy resistant, the natural course not always favorable. The diagnosis of CRPS is based on signs and symptoms derived from medical history and physical examination. Pharmacological pain management and physical rehabilitation of limb function are the main pillars of therapy and should be started as early as possible. If, however, there is no improvement of limb function and persistent severe pain, interventional pain management techniques may be considered. Intravenous regional blocks with guanethidine did not prove superior to placebo but frequent side effects occurred.Therefore this technique receives a negative recommendation (2 A–). Sympathetic block is the interventional treatment of first choice and has a 2 B+ rating. Ganglion stellatum (stellate ganglion) block with repeated local anesthetic injections or by radiofrequency denervation after positive diagnostic block is documented in prospective and retrospective trials in patients suffering from upper limb CRPS. Lumbar sympathetic blocks can be performed with repeated local anesthetic injections. For a more prolonged lumbar sympathetic block radiofrequency treatment is preferred over phenol neurolysis because effects are comparable whereas the risk for side effects is lower (2 B+). For patients suffering from CRPS refractory to conventional treatment and sympathetic blocks, plexus brachialis block or continuous epidural infusion analgesia coupled with exercise therapy may be tried (2 C+). Spinal cord stimulation is recommended if other treatments fail to improve pain and dysfunction (2 B+). Alternatively peripheral nerve stimulation can be considered, preferentially in study conditions (2 C+).     

Complications of regional anesthesia

Perioperative nerve injuries have long been recognized as a complication of regional anesthesia. Although severe or disabling neurologic complications are rare, recent epidemiologic series suggest the frequency of some serious complications is increasing. Risk factors contributing to neurologic deficit after regional anesthesia includes neural ischemia (hypothesized to be related to the use of vasoconstrictors or prolonged hypotension), traumatic injury to the nerves during needle or catheter placement, infection, and choice of local anesthetic solution. In addition, postoperative neurologic injury due to pressure from improper patient positioning or from tightly applied casts or surgical dressings, as well as surgical trauma are often attributed to the regional anesthetic. Patient factors such as body habitus and pre-existing neurologic dysfunction may also contribute. The safe conduct of regional anesthesia involves knowledge of the laboratory studies, large patient series as well as individual case reports of neurologic deficits following regional anesthetic techniques. Prevention of complications, along with early diagnosis and treatment are important in the management of regional anesthetic risks.     

Complex regional pain syndromes

Complex regional pain syndromes (CRPS) (formerly reflex sympathetic dystrophy and causalgia) are neuropathic pain conditions that are initiated by an extremity trauma or peripheral nerve lesion. Clinical definition and scientific understanding of CRPS are still evolving; however, both the clinical picture and therapeutic options are significantly influenced by a dysfunction of the sympathetic nervous system. Recent investigations suggest functional central abnormalities and a peripheral inflammatory component in the pathophysiology of CRPS. Interdisciplinary treatment includes physical, pharmacologic, and invasive interventional therapy, as well as stimulation techniques.     

Anesthesia (3)

Complex regional pain syndrome (CRPS) with resistance to local anesthetic block: a case report. (State University of New York at Stony Brook, Stony Brook, NY) J Clin Anesth 2000;12:67–71.
A case of complex regional pain syndrome (CRPS) Type 1 in a 12-year-old girl is presented. The patient did not respond to the usual therapeutic modalities used to treat CRPS including physical therapy, lumbar sympathetic block, epidural local anesthetic block, intravenous lidocaine infusion, or other oral medications. Of note is the fact that during epidural block the patient demonstrated a resistance to local anesthetic neural blockade in the area of the body involved with the pain problem. The mechanism of this resistance could be related to the changes in the dorsal horn cells of the spinal cord, secondary to activation of N-methyl-D-aspartate receptors, which may play a role in the pathophysiology of this pain syndrome.     

Continuous peripheral nerve blocks

A continuous peripheral nerve block—also termed “perineural local anesthetic infusion”—involves the percutaneous insertion of a catheter adjacent to a peripheral nerve, followed by local anesthetic administration via the catheter, providing anesthesia/analgesia for a prolonged period of time. The most-common indication for continuous peripheral nerve blocks is analgesia following painful surgical procedures; but, they are also used for inducing a sympathectomy and vasodilation following digit transfer/replantation, a vascular accident, limb salvage, or peripheral embolism; treating intractable hiccups; alleviating the vasospasm of Raynaud’s disease; and treating chronic pain such as phantom limb pain, cancer-induced pain, complex regional pain syndrome, and trigeminal neuralgia. Continuous peripheral nerve blocks may also provide pain control during medical transport, or awaiting surgical correction. The most common catheter insertion techniques include electrical stimulation and ultrasound-guidance. Long-acting local anesthetic is usually the sole infusate, and is optimally delivered with a continuous basal infusion with available patient-controlled bolus doses. Benefits are dependent upon analgesia improvement, and include decreasing pain, supplemental analgesic consumption, opioid-related side effects, sleep disturbances, patient dissatisfaction, time until discharge readiness, and actual hospitalization duration. Additional possible benefits include improvements in ambulation/functioning and an accelerated resumption of passive joint range-of-motion. Most benefits occur during the infusion itself, but a few studies suggest prolonged benefits following catheter removal in some cases. Minor complications occur at approximately the incidence as for single-injection peripheral nerve blocks; but, major risks including nerve injury are extraordinary uncommon.     

Complex regional pain syndrome

Complex regional pain syndrome (CRPS), formerly known as reflex sympathetic dystrophy, is a regional, posttraumatic, neuropathic pain problem that most often affects 1 or more limbs. Like most medical conditions, early diagnosis and treatment increase the likelihood of a successful outcome. Accordingly, patients with clinical signs and symptoms of CRPS after an injury should be referred immediately to a physician with expertise in evaluating and treating this condition. Physical therapy is the cornerstone and first-line treatment for CRPS. Mild cases respond to physical therapy and physical modalities. Mild to moderate cases may require adjuvant analgesics, such as anticonvulsants and/or antidepressants. An opioid should be added to the treatment regimen if these medications do not provide sufficient analgesia to allow the patient to participate in physical therapy. Patients with moderate to severe pain and/or sympathetic dysfunction require regional anesthetic blockade to participate in physical therapy. A small percentage of patients develop refractory, chronic pain and require long-term multidisciplinary treatment, including physical therapy, psychological support, and pain-relieving measures. Pain-relieving measures include medications, sympathetic/somatic blockade, spinal cord stimulation, and spinal analgesia.     

Complete Recovery From Intractable Complex Regional Pain Syndrome, CRPS-Type I, Following Anesthetic Ketamine and Midazolam

Objective: To describe the treatment of an intractable complex regional pain syndrome I (CRPS-I) patient with anesthetic doses of ketamine supplemented with midazolam.
Methods: A patient presented with a rapidly progressing contiguous spread of CRPS from a severe ligamentous wrist injury. Standard pharmacological and interventional therapy successively failed to halt the spread of CRPS from the wrist to the entire right arm. Her pain was unmanageable with all standard therapy. As a last treatment option, the patient was transferred to the intensive care unit and treated on a compassionate care basis with anesthetic doses of ketamine in gradually increasing (3–5 mg/kg/h) doses in conjunction with midazolam over a period of 5 days.
Results: On the second day of the ketamine and midazolam infusion, edema, and discoloration began to resolve and increased spontaneous movement was noted. On day 6, symptoms completely resolved and infusions were tapered. The patient emerged from anesthesia completely free of pain and associated CRPS signs and symptoms. The patient has maintained this complete remission from CRPS for 8 years now.
Conclusions: In a patient with severe spreading and refractory CRPS, a complete and long-term remission from CRPS has been obtained utilizing ketamine and midazolam in anesthetic doses. This intensive care procedure has very serious risks but no severe complications occurred. The psychiatric side effects of ketamine were successfully managed with the concomitant use of midazolam and resolved within 1 month of treatment.
This case report illustrates the effectiveness and safety of high-dose ketamine in a patient with generalized, refractory CRPS.     

Defining the therapeutic role of local anesthetic sympathetic blockade in complex regional pain syndrome: a narrative and systematic review

OBJECTIVE: There is growing controversy on the value of blocking the sympathetic nervous system for the treatment of complex regional pain syndromes (CRPS). The authors sought to evaluate the efficacy of sympathetic blockade with local anesthetic in these syndromes. In addition, they performed a comprehensive review of the pathophysiology and other treatments for CRPS. DESIGN: Systematic review of the literature was performed. MEDLINE was searched from 1966 through 1999. The authors identified only three randomized controlled trials (RCTs) that evaluated sympathetic blockade with local anesthetic, but because of differences in study design they were unable to pool the study data. The authors therefore included nonrandomized studies and case series. INTERVENTIONS: Studies were included if local anesthetic sympathetic blockade was used in at least 10 patients. Studies were excluded if continuous infusion techniques, somatic nerve blocks, or combined sympatholytic therapies were evaluated. OUTCOME MEASURES: Pain relief was classified as full, partial, or absent. The lack of a comparison group in the studies allowed only the calculation of distribution of the response categories, and the sum of the pooled rates does not equal 100%. RESULTS: Twenty-nine studies were included that evaluated 1,144 patients. Nineteen studies were retrospective, 5 prospective case series, 3 RCTs, and 2 nonrandomized controlled studies. The quality of the publications was generally poor. Twenty-nine percent of patients had full response, 41% had partial response, and 32% had absent response. It was not possible to estimate the duration of pain relief. CONCLUSIONS: This review raises questions as to the efficacy of local anesthetic sympathetic blockade as treatment of CRPS. Its efficacy is based mainly on case series. Less than one third of patients obtained full pain relief. The absence of control groups in case series leads to an overestimation of the treatment response that can explain the findings.     

A comparison of superficial versus combined (superficial and deep) cervical plexus block for carotid endarterectomy: a prospective, randomized study. (University of Michigan Medical Center, Ann Arbor, MI) Anesth Analg 2000;91:781–786.

Carotid endarterectomy may be preformed by using cervical plexus blockade with local anesthetic supplementation by the surgeon during surgery. Most practitioners use either a superficial cervical plexus block or a combined (superficial and deep) block, but it is unclear which offers the best operative conditions or greatest patient satisfaction. This study compared the 2 techniques in 40 patients undergoing carotid endarterectomy. The patient randomly received either a superficial or a combined cervical plexus block. Bupivacaine 0.375% to a total dose of 1.4 mg/kg was used. The main outcome measure was the amount of supplemental lidocaine 1% used by the surgeon. Subsidiary outcome measures were postoperative pain score, sedative and analgesic requirements before and during surgery, and postoperative analgesic requirements. Median supplemental lidocaine requirements were 100 mg in the superficial block group and 115 mg in the combined block group. These differences were not statistically significant. There was no significant difference in the number of patients needing postoperative analgesia between the groups in the 24 h after surgery. The median time to first analgesia in the superficial block group was 150 min. more than in the combined block group, but this difference, although large, was not statistically significant. No significant differences were found between the anesthetic techniques studied. Comment by Alan Kaye, M.D. Carotid endarterectomy surgery can be performed with regional or general anesthesia. It is probable that a substantial majority of CEAs performed in North America are performed under general anesthesia. Debate over choice of regional versus general anesthesia persists because of various studies of risks and benefits. Each type of anesthesia has its own advantages and disadvantages, which must be considered when choosing the optimal anesthetic for patients. Regional anesthetic techniques available include local infiltration, superficial and deep cervical plexus block, a combination of these with or without contralateral superficial plexus, and cervical epidural anesthesia. This prospective, randomized, double‐blinded study compared superficial versus combined (superficial and deep) cervical plexus block in 40 patients. Outcomes were measured by supplemental local anesthetic used by the surgeon, postoperative pain scores, and sedative and analgesic requirements before, during, and postoperatively. The results showed no significant difference in either study group. Therefore, this small study suggests that superficial block should be preferred in as much that it is relatively easy to do and the potential side‐effects are far less than deep cervical block. Larger studies are warranted in this difficult population of patients.     

Complex regional pain syndrome as a complication of a chemical burn to the foot

Complex regional pain syndrome (CRPS) is an unusual complication after burns; however, it is important to recognize so that appropriate treatment can be administered. A 60-year-old man suffered an alkali burn to the right foot. Subsequently, the patient developed CRPS with severe pain and vasomotor changes. Multimodal treatment included the early use of ropivacaine and fentanyl via epidural catheter. Oral extended-release morphine, gabapentin, and amitriptyline also were administered. Once pain was controlled, early aggressive physical therapy was instituted, and attention was turned toward wound coverage. One year after discharge, the patient was ambulating well and has returned to work. His pain was managed with a single morning dose of gabapentin and a nonsteroidal anti-inflammatory agent. Current examination of the foot revealed mild forefoot swelling without residual erythema. Ambiguities exist in the mainstay of treatment for CRPS, but this multimodal method of controlling CRPS after burn injury allowed for control of the patient's pain, early mobilization, and eventual return to work.     

Regional anesthesia for office procedures: part I. Head and neck surgeries

Although local anesthesia usually is used in surgical procedures, field or nerve blocks can provide more effective anesthesia in some situations. In a field block, local anesthetic is infiltrated around the border of the surgical field, leaving the operative area undisturbed. In field blocks, epinephrine may be added to the anesthetic to enhance vasoconstriction and prolong the duration of anesthesia. In a nerve block, anesthetic is injected directly adjacent to the nerve supplying the surgical field. A review of regional anatomy and the location of nerves and other important structures is essential before administering the injection. Systemic toxicity is rare with regional anesthesia and can be prevented by using the smallest dose possible and aspirating before the injection. Supraorbital, supratrochlear, infraorbital, and mental nerve blocks can provide adequate anesthesia in procedures on parts of the face. Field block also may be considered when operating on the ear or lips.     

MULTIDISCIPLINARY PAIN ABSTRACTS: 34

Because recent studies emphasized the role of peripherally distributed N-methyl-D-aspartate (NMDA) receptors in processing the nociceptive information, the authors investigated whether peripheral application of the ointment containing ketoconazole (KET) is able to attenuate the symptoms of local neuropathic pain. They applied ointment containing KET (0.25%–1.5%) to the affected area on limbs in five patients with complex regional pain syndrome type I (CRPS I) and in two patients with type II (CRPS II). One to 2 weeks later, they observed improvement of the report of pain intensity, measured by the visual analog scale, in four patients with acute early dystrophic stage of CRPS I. Swelling of the affected limbs subsided as well. No apparent changes were noticed in one patient with chronic atrophic stage of CRPS I and in both patients with CRPS II. The authors concluded that topical application of KET appears to be beneficial for the patients with acute early dystrophic stage of CRPS I because of either its local anesthetic effect or NMDA receptor antagonist action. Patients with chronic atrophic stage of CRPS I and CRPS II patients do not appear to respond to this treatment.     

Tibial Nerve Block Using an Ultrasound‐Guided Inframalleolar Medial Plantar Nerve Perineural Injection: A Technical Note

Sonographic‐guided tibial nerve block allows for rapid anesthetization of the heel and plantar regions of the foot. We describe a variant technique for tibial nerve regional anesthesia utilizing perineural injection of the medial plantar nerve proximal to the sustentaculum tali where the nerve is superficial and readily accessed, with resultant retrograde flow of local anesthetic proximally. Perineural injection of the medial plantar nerve at the inframalleolar level provides a simple, safe, and effective alternative method to achieve tibial nerve block for regional anesthesia in a variety of procedures. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45 :134–137, 2017     

Computed tomography guided lumbar sympathetic block for complex regional pain syndrome in a child: a case report and review.

The aim of this paper is to describe the first reported use of computed tomography (CT) guided lumbar sympathetic block as treatment of a case of complex regional pain syndrome (CRPS) in a child. The potential aetiology of CRPS is discussed in relation to the mechanism of action of local anaesthetics used in the block. Based on the successful treatment of this child and the documented success of its use in adults, we conclude that despite the minimal dose of radiation given, CT guided lumbar sympathetic block is an important treatment option in CRPS in children.     

Nurse Practitioner-Administered Chloroprocaine in Children with Postoperative Pain

Background: Pain is a complex physical and emotional experience. Therefore, assessment of acute pain requires self-report when possible, observations of emotional and behavioral responses and changes in vital signs. Peripheral nerve and epidural catheters often provide postoperative analgesia in children. Administration of chloroprocaine (a short acting local anesthetic) via a peripheral nerve or epidural catheter allows for a comparison of pain scores, observations of emotional and behavioral responses and changes in vital signs to determine catheter function. Aims: The aims of this study are to describe the use chloroprocaine injections for testing catheters; patient response; and how changes to pain management are guided by the patient response. Methods: This study describes the use of chloroprocaine injections to manage pain and assess the function of peripheral nerve or epidural catheters in a pediatric population. We examined 128 surgical patients, (0-25 years old), who received chloroprocaine injections for testing peripheral nerve or epidural catheters. Patient outcomes included: blood pressure, respiratory rate, heart rate and pain intensity scores. Results: There were no significant adverse events. The injection guided intervention by determining the function of regional analgesia in the majority (98.5%) of patients. Discussion: Chloroprocaine injections appear to be useful to evaluate functionality of peripheral nerve and epidural catheters after surgery in a pediatric population.     

Clinical Utility of Low‐Volume Ultrasound‐Guided Interscalene Blockade

Objective. The purpose of this series is to describe cases in which ultrasound guidance was used to allow patients to receive the benefits of regional anesthesia while safely circumventing traditional contraindications to interscalene blockade (ISB). Methods. Targeted low‐volume ISB was performed in 3 patients in whom this procedure would typically be contraindicated because of phrenic nerve blockade or risk of local anesthetic toxicity. A patient with severe respiratory dysfunction, a patient undergoing bilateral shoulder surgery, and a patient requiring awake fiberoptic intubation underwent low‐volume ultrasound‐guided ISB. The ultrasound technique involved the use a low local anesthetic volume, anatomic identification of the brachial plexus trunk, needle placement opposite the phrenic nerve position, and control over local anesthetic spread. Results. In both patients in whom diaphragmatic paralysis was a concern, postoperative respiratory parameters indicated successful regional analgesia without evidence of phrenic nerve blockade. In the patient requiring an additional regional anesthetic procedure, ISB was performed with a local anesthetic volume low enough to avoid exceeding toxic safety thresholds. Conclusions. Although further studies are warranted, we report on 3 cases in which ultrasound guidance was used to allow patients to receive the benefits of regional anesthesia while safely avoiding standard contraindications to ISB. Ultrasound technology may allow providers to perform low‐volume brachial plexus blockade while avoiding issues related to phrenic nerve blockade and systemic local anesthetic toxicity.     

Chronic regional pain syndrome, type 1: Part II

Chronic regional pain syndrome, type 1 (CRPS1) is a complex neurologic disease characterized by chronic, severe, burning pain; hyperesthesia; soft tissue swelling; dystrophy; hyperhidrosis; vasomotor and sudomotor instability; joint stiffness; and patchy osteoporosis. Five to six million people in the United States alone suffer from CRPS1. To date, CRPS1 is poorly understood and often is not recognized clinically. This syndrome requires early detection, pain control, and treatment in tandem with physical therapy to the affected area. Part I (published in September) discussed background information on CRPS1 and sympathetic nerve blocks. Part II focuses on the remaining treatment modalities (e.g., sympathectomy, physical therapy, stimulators, trigger point injections, acupuncture, tourniquet effects, placebo effects, amputation).     

Chronic Cancer-Related Pain: Continuous Perineural Infusion of Local Anesthetics as Alternative to Systemic Analgesic Drugs

Pain is a major concern for patients suffering from cancer. Although opioid drugs remain the gold standard for treatment of pain, little is known about the interest of continuous analgesia techniques as alternative. The aim of the present article is to detail the feasibility and to present the diversity of continuous perineural infusion of local anesthetic. A series of five patients suffering from different cancer-related pain is presented. A continuous perineural block was proposed to patients presenting with unbearable pain in an area innervated by a plexus or a nerve despite parenteral analgesic pharmacotherapy. All blocks were performed in a surgical theatre under sterile conditions. An initial bolus dose with 3.75 mg/mL ropivacaine was injected followed by a continuous infusion of 2 mg/mL of ropivacaine. Patient-controlled perineural analgesia was started at home by a nursing network. The technique, the efficacy, and the side effects were reported. Complete pain relief was noted 15 minutes after local anesthetic injection in the five cases, and efficacy was maintained during the following days at home, with no other analgesic treatment required. One patient restarted working a few weeks after catheter insertion. The catheter duration lasted for 12 to 110 days. One catheter was removed because of local anesthetic leak at the puncture point. Some paresthesia was noted in one patient. No other side effect was noted. No infection was reported. In selected patients, continuous perineural infusion of local anesthetics appears to be an attractive alternative to parenteral opioids for cancer-related pain. Further investigation is warranted to better define the place of these techniques in the armamentarium of cancer-related pain treatment.