Guideline summary review: an evidence-based clinical guideline for the diagnosis and treatment of low back pain.

BACKGROUND CONTEXT: The North American Spine Society's (NASS) Evidence Based Clinical Guideline for the Diagnosis and Treatment of Low Back Pain features evidence-based recommendations for diagnosing and treating adult patients with nonspecific low back pain. The guideline is intended to reflect contemporary treatment concepts for nonspecific low back pain as reflected in the highest quality clinical literature available on this subject as of February 2016. PURPOSE: The purpose of the guideline is to provide an evidence-based educational tool to assist spine specialists when making clinical decisions for adult patients with nonspecific low back pain. This article provides a brief summary of the evidence-based guideline recommendations for diagnosing and treating patients with this condition. STUDY DESIGN: This is a guideline summary review. METHODS: This guideline is the product of the Low Back Pain Work Group of NASS' Evidence-Based Clinical Guideline Development Committee. The methods used to develop this guideline are detailed in the complete guideline and technical report available on the NASS website. In brief, a multidisciplinary work group of spine care specialists convened to identify clinical questions to address in the guideline. The literature search strategy was developed in consultation with medical librarians. Upon completion of the systematic literature search, evidence relevant to the clinical questions posed in the guideline was reviewed. Work group members utilized NASS evidentiary table templates to summarize study conclusions, identify study strengths and weaknesses, and assign levels of evidence. Work group members participated in webcasts and in-person recommendation meetings to update and formulate evidence-based recommendations and incorporate expert opinion when necessary. The draft guideline was submitted to an internal and external peer review process and ultimately approved by the NASS Board of Directors. RESULTS: Eighty-two clinical questions were addressed, and the answers are summarized in this article. The respective recommendations were graded according to the levels of evidence of the supporting literature. CONCLUSIONS: The evidence-based clinical guideline has been created using techniques of evidence-based medicine and best available evidence to aid practitioners in the diagnosis and treatment of adult patients with nonspecific low back pain. The entire guideline document, including the evidentiary tables, literature search parameters, literature attrition flowchart, suggestions for future research, and all of the references, is available electronically on the NASS website at https://www.spine.org/ResearchClinicalCare/QualityImprovement/ClinicalGuidelines.aspx.

Efficacy of Lubiprostone for the Treatment of Opioid-Induced Constipation, Analyzed by Opioid Class.

Objectives: To examine the efficacy and safety of lubiprostone for the treatment of opioid-induced constipation (OIC) in patients by opioid class received. Design: Data were pooled from three phase III, randomized, double-blind, placebo-controlled studies. Subjects/Setting: Adults with chronic noncancer pain receiving opioid therapy for 30 or more days and diagnosed with OIC. Methods: Overall mean change from baseline in spontaneous bowel movement (SBM) frequency, overall treatment response (≥1 SBM/week improvement over baseline SBM frequency in all treatment weeks with available data and ≥3 SBMs/week for ≥9 of the 12 weeks of treatment), and OIC-related symptoms were examined in patients taking opioids. Data were pooled and analyzed by opioid group. Results: In patients receiving phenanthrene opioids (e.g., oxycodone; N = 1,159), lubiprostone significantly increased overall mean changes in SBM frequency from baseline (P = 0.0001), increased overall response rate (P = 0.0024), and improved OIC symptoms (P ≤ 0.0229) vs placebo. Patients receiving phenylpiperidine opioids (e.g., fentanyl; N = 137) had significant improvement in SBM frequency (P = 0.0129) and favorable trends in response rates (21.4% vs 9.8%; P = 0.0723) and OIC symptoms vs placebo. Efficacy was not observed in overall analyses of patients receiving diphenylheptane opioids (e.g., methadone), although an increase in SBM frequency was observed in patients who received a morphine-equivalent daily dose of 200 or fewer mg, suggesting a dose-dependent negative interference of this opioid class on lubiprostone effects. For all groups, the lubiprostone adverse event profile was similar; the most common treatment-emergent adverse events were nausea and diarrhea. Conclusions: In patients using commonly prescribed opioids, lubiprostone is effective and generally well tolerated for the treatment of OIC.

Lubiprostone for Opioid-Induced Constipation Does Not Interfere with Opioid Analgesia in Patients with Chronic Noncancer Pain.

OBJECTIVE: To determine whether lubiprostone 24 µg twice daily (BID), administered to relieve opioid-induced constipation (OIC), affects opioid analgesia in patients with chronic noncancer pain. METHODS: Data were pooled from 3 randomized, double-blind, placebo-controlled trials of lubiprostone in adults with chronic noncancer pain receiving stable opioid analgesia and who had documented OIC. In each study, lubiprostone 24 µg BID or placebo was administered for 12 weeks for relief of OIC using a common protocol. The Brief Pain Inventory short form (BPI-SF) was administered, and opioid use (expressed as morphine-equivalent daily dose [MEDD]) was recorded at baseline and months 1, 2, and 3. The BPI-SF provided patient scores for pain severity, the worst pain experienced in the past 24 hours, and pain interference with daily life. RESULTS: The pooled patient population (N = 1300) was predominately female (62.5%) and white (82.1%), with a mean age of 50.5 years. The MEDD was 97.5 mg (range, 5 to 3656 mg) in patients receiving placebo and 112.5 mg (range, 4 to 7605 mg) in patients treated with lubiprostone. Lubiprostone 24 µg BID treatment did not appear to affect opioid use or pain scores; changes from baseline were not significantly different with placebo vs. lubiprostone 24 µg BID at months 1, 2, and 3 for MEDD (P ≥ 0.435) and for BPI-SF scores for pain interference, pain severity, and worst pain (P ≥ 0.402). DISCUSSION: Lubiprostone 24 µg BID administered for relief of OIC in patients with chronic noncancer pain does not interfere with opioid analgesia.

Long-Term Safety and Efficacy of Lubiprostone in Opioid-induced Constipation in Patients with Chronic Noncancer Pain.

BACKGROUND: Chronic opioid analgesic use often causes opioid-induced constipation (OIC). This open-label extension study evaluated the safety and efficacy of lubiprostone, a chloride channel (ClC-2) activator, for treatment of OIC in patients with chronic noncancer pain. METHODS: Adults with OIC were enrolled from two 12-week, placebo-controlled, double-blind studies and received lubiprostone 24 µg twice daily for up to 9 months. OIC was defined as < 3 spontaneous bowel movements (SBMs)/week during the 2-week baseline period, of which ≥ 25% were characterized by hard to very hard stool consistency, subjectively incomplete evacuation, and/or moderate or worse straining. Inclusion criteria required consistent treatment with full opioid agonists ≥ 30 days prior to screening and throughout the study. RESULTS: All 439 patients who received lubiprostone were analyzed for safety and efficacy. Overall, 24.6% of patients reported treatment-related adverse events (AEs), most commonly nausea (5.0%), diarrhea (4.6%), headache (1.6%), and vomiting (1.4%). No treatment-related serious AEs were reported. Nausea and diarrhea each led to study discontinuation in 5 patients (1.1%); 2 cases each of nausea and diarrhea were rated as severe. Rescue medication usage decreased from month 1 (33.0%) to month 9 (18.6%). Mean weekly SBM frequency (1.4) was significantly increased from baseline at all months (P < 0.001, range 4.9 to 5.3). Straining, abdominal bloating, abdominal discomfort, stool consistency, constipation severity, and bowel habit regularity were significantly improved from baseline at all months (P < 0.001). CONCLUSIONS: Lubiprostone treatment was well tolerated and improved symptoms and signs of OIC in this 9-month, open-label study of patients with chronic noncancer pain.

Opioid titration and conversion in patients receiving morphine sulfate and naltrexone hydrochloride extended release capsules.

OBJECTIVE: To determine the number of steps and identify characteristics associated with attaining a stable dose of morphine sulfate and sequestered naltrexone extended release capsules (MS-sNT). PATIENTS AND METHODS: Data from an open-label, long-term multicenter study designed to assess the safety of MS-sNT for managing chronic (≥ 3 m), moderate-to-severe pain were analyzed post hoc. Initial MS-sNT dose was 20 mg twice daily (BID) for opioid-naïve patients and 50% to 75% of current daily opioid dose for opioid-experienced patients. Dose adjustments upward/downward were allowed throughout the study with ≥ 3 days between increases; opioid-experienced patients could increase ≥ 24 hours after initial drug dispensing. Nonopioid analgesics were permitted as rescue medication. Stable dose was defined post hoc as one maintained for 2 consecutive study visits. RESULTS: Overall, 69% of patients (n = 319/465) achieved a stable dose; 85% (n = 272) achieved a stable dose in ≤ 2 titration dose adjustments or "steps," and 96% (n = 305) achieved a stable dose in ≤ 4 steps. The mean time to stable dose was 28.9 days (standard deviation [SD], 34.1 days); the median was 12 days. A stable dose was achieved in 70% (118/168) of opioid-naïve patients (mean, 24.2 days [SD, 33.4 days]; median, 8 days) and 68% (201/297) of opioid-experienced patients (mean, 31.7 days [SD, 34.3 days]; median, 25 days). A stable dose was achieved by 79% (19/24) of patients who previously used morphine, 64% (27/42) who used oxycodone, 59% (47/79) who used hydrocodone, and 71% (83/117) who used multiple opioids. Baseline pain scores were similar between patients who did and did not achieve a stable dose. At the time of stable dose achievement, average, least, worst, and current pain were all decreased from baseline. CONCLUSIONS: The study provides information about anticipated rates of achieving stable opioid dose in patients who received MS-sNT for up to 1 year to manage chronic, moderate-to-severe pain. Both opioid-naïve and opioid-experienced patients achieved a stable dose of MS-sNT, generally in ≤ 2 steps. Opioid experience and previous opioid use may influence ability to achieve a stable dose and number of steps required. More studies are needed on the anticipated experience of opioid titration/conversion to help physicians and patients set expectations for initiation of and conversion between opioid therapies.

Long-term safety and efficacy of morphine sulfate and naltrexone hydrochloride extended release capsules, a novel formulation containing morphine and sequestered naltrexone, in patients with chronic, moderate to severe pain.

CONTEXT: Morphine sulfate and naltrexone hydrochloride extended release capsules contain extended-release pellets of morphine with a sequestered naltrexone core (MS-sNT). Taken whole, as intended, morphine is released to provide pain relief; if tampered with by crushing, naltrexone is released to mitigate subjective effects of morphine. OBJECTIVES: This open-label study assessed long-term (12-month) safety of MS-sNT in patients with chronic, moderate to severe pain. METHODS: Safety assessments included determining adverse events (AEs), laboratory assessments, and the Clinical Opiate Withdrawal Scale (COWS). Analgesic efficacy was assessed (diary) as worst, least, average, and current pain using an 11-point numeric scale (0=none; 10=worst). RESULTS: Of 465 patients receiving one or more doses, 160 completed the study. Most patients (81.3%) experienced one or more AEs, most commonly constipation (31.8%) or nausea (25.2%). Thirty-three patients (7.1%) reported serious AEs; one patient's severe gastrointestinal inflammation and colitis were considered possibly study drug-related. Most discontinuations (30%) occurred in the first month, most often because of AEs (23.7%). There were no clinically relevant changes in laboratory results or vital signs, and no clinically significant electrocardiogram changes deemed study drug-related. During each visit after Week 1, 5% or fewer patients had COWS scores indicating mild withdrawal symptoms (range, 0%-4.8%). Five patients, who did not take the study drug as instructed, had scores consistent with moderate withdrawal. MS-sNT yielded statistically significant improvements from baseline in mean scores for all pain diary items for all visits, except Week 1 for least pain. CONCLUSION: In this study population, when MS-sNT was taken as directed for chronic, moderate to severe pain for up to 12 months, most AEs were typical opioid-related side effects. Mean COWS scores remained low, indicating lack of withdrawal symptoms and appropriate transition off the study drug at completion.

Magnesium neuroprotection is limited in humans with acute brain injury.

Based on the results of preclinical models, magnesium sulfate (MgSO4) has gained attention as a putative neuroprotective agent. The negative results of a large-scale, randomized clinical trial using MgSO4 in acute stroke have tempered the initial enthusiasm for a neuroprotective benefit of the ion. Additional, large-scale clinical trials in stroke and other forms of brain injury are underway. This article reviews the central nervous system (CNS) physiology of Mg++, disordered Mg++ homeostasis in acute brain injury, preclinical and preliminary clinical foundations of current clinical trials, and the data regarding the CNS bio-availability of MgSO4 an important requisite for neuroprotective therapy. Although human studies have confirmed that moderate hypermagnesemia is well-tolerated and feasible, only modest elevation of cerebrospinal fluid (CSF) [Mg++] occurs. This modest increment of CSF [Mg++] in brain-injured humans occurs in the range of 10 to 19%. However, experimental evidence has yet to establish whether this modest elevation is sufficient for neuroprotection. Because of the limited CNS passage of the ion, further experimental work is needed to define the neuroprotective threshold of [Mg++] in the injured brain.

Analysis of the brain bioavailability of peripherally administered magnesium sulfate: A study in humans with acute brain injury undergoing prolonged induced hypermagnesemia.

OBJECTIVE: Based on preclinical investigations, magnesium sulfate (MgSO4) has gained interest as a neuroprotective agent. However, the ability of peripherally administered MgSO4 to penetrate the blood-brain barrier is limited in normal brain. The current study measured the passage of intravenously administered Mg into cerebrospinal fluid in patients with brain injury requiring ventricular drainage. DESIGN: A prospective evaluation of the cerebrospinal fluid total and ionized magnesium concentration, [Mg], during sustained hypermagnesemia was performed. SETTING: Neurosciences intensive care unit at a major teaching institution. PATIENTS: Thirty patients with acute brain injury secondary to subarachnoid hemorrhage, traumatic brain injury, primary intracerebral hemorrhage, subdural hematoma, brain tumor, central nervous system infection, or ischemic stroke were studied. INTERVENTIONS: Patients underwent 24 hrs of induced hypermagnesemia during which total and ionized cerebrospinal fluid [Mg] was measured. Serum [Mg] was adjusted to 2.1-2.5 mmol/L. Cerebrospinal fluid [Mg] was measured at baseline, at 12 and 24 hrs after onset of infusion, and at 12 hrs following infusion termination. MEASUREMENTS AND MAIN RESULTS: At baseline, total (1.25 +/- 0.14 mmol/L) and ionized (0.80 +/- 0.10 mmol/L) cerebrospinal fluid [Mg] was greater than serum total (0.92 +/- 0.18 mmol/L) and ionized (0.63 +/- 0.07 mmol/L) [Mg] (p < .05). Total (1.43 +/- 0.13 mmol/L) and ionized (0.89 +/- 0.12 mmol/L) cerebrospinal fluid [Mg] was maximally increased by 15% and 11% relative to baseline, respectively, during induced hypermagnesemia (p < .05). CONCLUSIONS: Hypermagnesemia produced only marginal increases in total and ionized cerebrospinal fluid [Mg]. Regulation of cerebrospinal fluid [Mg] is largely maintained following acute brain injury and limits the brain bioavailability of MgSO4.

Contemporary management of neuropathic pain for the primary care physician.

Neuropathic pain (NP), caused by a primary lesion or dysfunction in the nervous system, affects approximately 4 million people in the United States each year. It is associated with many diseases, including diabetic peripheral neuropathy, postherpetic neuralgia, human immunodeficiency virus-related disorders, and chronic radiculopathy. Major pathophysiological mechanisms include peripheral sensitization, sympathetic activation, disinhibition, and central sensitization. Unlike most acute pain conditions, NP is extremely difficult to treat successfully with conventional analgesics. This article introduces a contemporary management approach, that is, one that incorporates nonpharmacological, pharmacological, and interventional strategies. Some nonpharmacological management strategies include patient education, physical rehabilitation, psychological techniques, and complementary medicine. Pharmacological strategies include the use of first-line agents that have been supported by randomized controlled trials. Finally, referral to a pain specialist may be indicated for additional assessment, interventional techniques, and rehabilitation. Integrating a comprehensive approach to NP gives the primary care physician and patient the greatest chance for success.

Neurogenic pulmonary edema during intracranial endovascular therapy.

Neurogenic pulmonary edema (NPE) is a well-known complication of acute brain injury. Neurogenic stunned myocardium (NSM) occurs clinically in a significant subset of patients with NPE. A 49-year-old woman developed refractory cerebral vasospasm requiring angioplasty following a subarachnoid hemorrhage. During angioplasty, NPE with NSM manifested as acute pulmonary edema associated with elevated pulmonary artery occlusion pressure and reduced cardiac output. Evaluations disclosed a right insular infarction, cardiac wall motion abnormalities, and electrocardiographic characteristics of NSM. The NSM completely resolved, and the neurological outcome was good. A 56-year-old woman developed NPE during complicated coil embolization of an internal carotid artery aneurysm. Cardiac function was normal, and the NPE resolved with a brief period of mechanical ventilation and diuresis. The delayed appearance of NSM and NPE during endovascular therapy in these patients implies a degree of risk for sympathetically mediated cardiopulmonary dysfunction during complex intracranial endovascular procedures.

Severe phantom leg pain in an amputee after lumbar plexus block.

OBJECTIVES: To describe the onset of phantom leg pain in an amputee with the performance of a lumbar plexus block and the subsequent alleviation after the performance of a sciatic nerve block. CASE REPORT: A 72-year-old American Society of Anesthesiologists physical status III woman presented for left total hip arthroplasty. Her history was significant for a left below the knee amputation. Since the amputation she had suffered from intermittent phantom leg pain. A lumbar plexus block was performed for postoperative pain management. After the lumbar plexus block, the patient experienced severe pain radiating to the left phantom foot. Because of the severity of the phantom pain, a sciatic nerve block was performed. The phantom leg pain resolved within 5 minutes. The intraoperative care under general anesthesia was uneventful. After surgery the patient had continued blockade in both nerve distributions with excellent analgesia. Full recovery of the lumbar plexus and sciatic nerve function was present on the first postoperative day. CONCLUSION: The temporal relationship between the onset of the phantom leg pain and the lumbar plexus block suggests a causal relationship. In this case, it appears that ongoing peripheral input from the lumbar plexus may have been sufficient for the tonic inhibition of phantom pain in the sciatic distribution. The immediate reactivation of the phantom pain and its subsequent relief suggests dynamic processing of peripheral inputs by central neurons, which apparently is rapid and reversible in some cases of phantom pain.

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.