A sequential, multiple-assignment, randomized trial of analgesic strategies for acute musculoskeletal Pain.

BACKGROUND: Most methodologically rigorous, ED-based, comparative effectiveness analgesic studies completed in the last two decades failed to find a clinically important difference between the comparators. We believe that many of these comparative effectiveness studies were biased towards the null hypothesis because some ED patients with intense pain will respond to relatively mild interventions. We hypothesized that including a run-in period would alter the results of an acute pain RCT. METHODS: We conducted a sequential, multiple-assignment, randomized study. Adults with acute moderate/severe musculoskeletal pain were randomized (3:1 ratio) to run-in period or no run-in. We administered 650 mg acetaminophen to run-in participants. Those run-in patients who reported insufficient relief one-hour later were randomized (1:1 ratio) to ibuprofen 800mg PO or ketorolac 20mg PO as were all participants randomized to no run-in. The primary outcome was achieving a clinically important improvement, defined as improvement ≥1.3 on a 0-10 scale. We built a logistic regression model including run-in/no run-in, ketorolac/ibuprofen, age and sex. RESULTS: Of 307 participants who received acetaminophen, 100 (32.6%) reported inadequate relief and were randomized to an NSAID. Of the 100 patients randomized to no run-in, 84/100 (84%) achieved the primary outcome versus 246/287 (86%) run-in participants (95% CI for difference = 2%:-7,10%). Among run-in participants who received an NSAID, 82/99(83%) achieved the primary outcome versus 84/100(84%) no run-in participants (p = 0.82). Among all ibuprofen participants, 44/49(90%) randomized to run-in and 42/50(84%) randomized to no run-in achieved the primary outcome. Among all ketorolac participants, 38/50(76%) randomized to run-in and 42/50 (84%) randomized to no run-in achieved the primary outcome. We observed the following results in a multivariable analysis: OR for ketorolac versus ibuprofen:0.60 (95% CI: 0.28, 1.28); OR for run-in versus no run-in:0.91(95% CI: 0.43, 1.93). CONCLUSIONS: Among patients with acute musculoskeletal pain, using an acetaminophen first strategy did not alter pain outcomes.

Frequency of Persistent Opioid Use 6 Months After Exposure to IV Opioids in the Emergency Department: A Prospective Cohort Study.

BACKGROUND: As rates of opioid use disorder in the general population have increased, some have questioned whether IV opioids should be used routinely for treatment of acute severe pain in the emergency department (ED). OBJECTIVES: We determined the incidence of persistent opioid use among opioid-naïve patients exposed to IV opioids in the ED. METHODS: This was a prospective observational cohort study conducted in two EDs in the Bronx, NY. Opioid-naïve adults with severe pain who received IV opioids in the ED were followed-up 6 months later by telephone interview and review of the state opioid prescription database. We defined persistent opioid use as filling 6 or more prescriptions for opioids in the 6 months following the ED visit or an average of one prescription per month. RESULTS: We screened 1555 patients. Of these, 506 patients met entry criteria and provided analyzable data. Morphine was the IV opioid most frequently administered in the ED (478, 94%), followed by hydromorphone (20, 4%). Of the 506, 8 (2%) received both IV morphine and hydromorphone and 63 (12%) participants were prescribed an opioid for use after the ED visit. One patient/506 (0%) met our apriori criteria for persistent opioid use within 6 months. CONCLUSION: Among 506 opioid naïve ED patients administered IV opioids for acute severe pain, only one used opioids persistently during the subsequent 6 months.

Topical Diclofenac Versus Oral Ibuprofen Versus Diclofenac + Ibuprofen for Emergency Department Patients With Acute Low Back Pain: A Randomized Study.

STUDY OBJECTIVE: Topical nonsteroidal anti-inflammatory drugs (NSAIDs) are useful for a variety of musculoskeletal injuries. It is not known whether topical NSAIDs should be used for patients presenting with acute nonradicular musculoskeletal low back pain. METHODS: We conducted a randomized, placebo-controlled double-blind study in which patients 18 to 69 years of age visiting the emergency department (ED) with acute, nontraumatic, nonradicular, musculoskeletal low back pain were randomized at the time of discharge to treatment with 400 mg oral ibuprofen + placebo topical gel, 1% diclofenac topical gel + oral placebo, or 400 mg ibuprofen + 1% diclofenac topical gel. We measured outcomes using the Roland Morris Disability Questionnaire (RMDQ), a 24-item yes/no instrument about the effect of back pain on a respondent's daily activities. The primary outcome was change in RMDQ score between ED discharge and 2 days later. Medication-related adverse events were elicited by asking whether the study medications caused any new symptoms. RESULTS: In total, 3,281 patients were screened for participation, and 198 were randomized. Overall, 36% of the population were women, the mean age was 40 years (standard deviation, 13), and the median RMDQ score at baseline was 18 (25th to 75th percentile: 13 to 22), indicating substantial low back-related functional impairment. In total, 183 (92%) participants provided primary outcome data. Two days after the ED visit, the ibuprofen + placebo group had improved by 10.1 (95% confidence interval [CI] 7.5 to 12.7), the diclofenac gel + placebo group by 6.4 (95% CI 4.0 to 8.8), and the ibuprofen + diclofenac gel by 8.7 (95% CI 6.3 to 11.1). The between-group differences were as follows: ibuprofen versus diclofenac, 3.7 (95% CI 0.2 to 7.2); ibuprofen versus both medications 1.4 (95% CI -2.1 to 4.9); and diclofenac versus both medications, 2.3 (95% CI -5.7 to 1.0). Medication-related adverse events were reported by 3/60 (5%) ibuprofen patients, 1/63 (2%) diclofenac patients, and 4/64 (6%) patients who received both. CONCLUSION: Among patients with nontraumatic, nonradicular acute musculoskeletal low back pain discharged from an ED, topical diclofenac was probably less efficacious than oral ibuprofen. It demonstrated no additive benefit when coadministered with oral ibuprofen.

A Randomized, Placebo-Controlled Study of Intranasal Fentanyl as an Analgesic Adjunct For Incision and Drainage of Abscess.

BACKGROUND: Incision and drainage (I&D) of abscesses is one of the most painful procedures performed in emergency departments (EDs). OBJECTIVE: We tested the following hypothesis: The addition of intranasal fentanyl to the standard practice of local infiltration with lidocaine would provide better pain control than lidocaine alone for adult ED patients undergoing I&D. METHODS: This was a randomized, double-blind study. Participants received 2 µg/kg of intranasal fentanyl or a comparable amount of intranasal water in addition to local lidocaine infiltration. The primary outcome, which we assessed immediately after the I&D was completed, was a summary 0-10 pain score for which we asked study subjects to provide a number depicting their entire experience with the procedure. RESULTS: During a 19-month enrollment period, we screened 176 patients for eligibility and enrolled 49; 25 received placebo and 24 received fentanyl. Baseline characteristics were comparable. Mean (standard deviation) summary pain scores were as follows: fentanyl 6.2 (3.3) and placebo 7.0 (3.2). The 95% confidence interval for a rounded between-group difference of 0.9 was -1.1 to 2.6. CONCLUSIONS: In this small study, the addition of intranasal fentanyl did not substantially impact the pain scores of ED patients undergoing I&D.

Effect of a Single Dose of Oral Opioid and Nonopioid Analgesics on Acute Extremity Pain in the Emergency Department: A Randomized Clinical Trial.

Importance: The choice of analgesic to treat acute pain in the emergency department (ED) lacks a clear evidence base. The combination of ibuprofen and acetaminophen (paracetamol) may represent a viable nonopioid alternative. Objectives: To compare the efficacy of 4 oral analgesics. Design, Settings, and Participants: Randomized clinical trial conducted at 2 urban EDs in the Bronx, New York, that included 416 patients aged 21 to 64 years with moderate to severe acute extremity pain enrolled from July 2015 to August 2016. Interventions: Participants (104 per each combination analgesic group) received 400 mg of ibuprofen and 1000 mg of acetaminophen; 5 mg of oxycodone and 325 mg of acetaminophen; 5 mg of hydrocodone and 300 mg of acetaminophen; or 30 mg of codeine and 300 mg of acetaminophen. Main Outcomes and Measures: The primary outcome was the between-group difference in decline in pain 2 hours after ingestion. Pain intensity was assessed using an 11-point numerical rating scale (NRS), in which 0 indicates no pain and 10 indicates the worst possible pain. The predefined minimum clinically important difference was 1.3 on the NRS. Analysis of variance was used to test the overall between-group difference at P = .05 and 99.2% CIs adjusted for multiple pairwise comparisons. Results: Of 416 patients randomized, 411 were analyzed (mean [SD] age, 37 [12] years; 199 [48%] women; 247 [60%] Latino). The baseline mean NRS pain score was 8.7 (SD, 1.3). At 2 hours, the mean NRS pain score decreased by 4.3 (95% CI, 3.6 to 4.9) in the ibuprofen and acetaminophen group; by 4.4 (95% CI, 3.7 to 5.0) in the oxycodone and acetaminophen group; by 3.5 (95% CI, 2.9 to 4.2) in the hydrocodone and acetaminophen group; and by 3.9 (95% CI, 3.2 to 4.5) in the codeine and acetaminophen group (P = .053). The largest difference in decline in the NRS pain score from baseline to 2 hours was between the oxycodone and acetaminophen group and the hydrocodone and acetaminophen group (0.9; 99.2% CI, -0.1 to 1.8), which was less than the minimum clinically important difference in NRS pain score of 1.3. Adverse events were not assessed. Conclusions and Relevance: For patients presenting to the ED with acute extremity pain, there were no statistically significant or clinically important differences in pain reduction at 2 hours among single-dose treatment with ibuprofen and acetaminophen or with 3 different opioid and acetaminophen combination analgesics. Further research to assess adverse events and other dosing may be warranted. Trial Registration: clinicaltrials.gov Identifier: NCT02455518.

L-type calcium channels reduce ROS generation in cerebellar granule cells following kainate exposure.

Cerebellar granule cells (CGC) deprived of serum or trophic factors develop sensitivity to kainate neurotoxicity that is mediated by the alpha-amino-3-hydroxy-5-methyl-isoxazole proprionic acid (AMPA) subtypes of glutamate receptors (GluR). The L-type voltage-gated calcium channel (L-type VGCC) blocker nifedipine increases the potency of kainate 50-fold. Thus, one goal of this laboratory is to determine the underlying protective mechanism triggered by calcium influx through this channel. The cell-permeable heavy metal chelator N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine effected complete protection against kainate treatment in the presence of nifedipine, as did the iron chelator deferoxamine. The chelatable heavy metal pool decreased approximately 70% immediately following treatment with kainate, but did not change following kainate/nifedipine treatment. Tetramethylrhhodamine ethyl ester (TMRE) fluorescence, an indicator of mitochondrial membrane potential, decreased approximately 70% following kainate treatment but displayed a more modest decrease ( approximately 15%) when CGC were treated with kainate/nifedipine. Reactive oxygen species (ROS) formation decreased in CGC immediately following kainate treatment but was slightly elevated following kainate/nifedipine treatment. Electron microscopic examinations of the CGC indicated severe swelling and distortion of mitochondria immediately following kainate/nifedipine treatment and the appearance of mitochondrial herniations, whorls, and bridges 2 h later, features that were rarely observed following kainate treatment. These results support the hypothesis that calcium entry through L-type VGCCs protects CGC during kainate treatment by lowering the chelatable heavy metal pool and the mitochondrial membrane potential, thereby mitigating the formation of ROS.