SGEM#304: Treating Acute Low Back Pain – It’s Tricky, Tricky, Tricky

Date: October 9th, 2020 Guest Skeptic: Dr. Sergey Motov is an Emergency Physician in the Department of Emergency Medicine, Maimonides Medical Center in New York City. He is also one of the world’s leading researchers on pain management in the emergency department, specifically the use of ketamine. His twitter handle is @PainFreeED. Reference: Friedman et al. Ibuprofen Plus Acetaminophen Versus Ibuprofen Alone for Acute Low Back Pain: An Emergency Department-based Randomized Study. AEM 2020. Case: A 41-year-old man without a significant past medical history presents to the emergency department (ED) with a chief complaint of lower back pain that started 48 hours prior to the ED visits after attempting to move a couch in his house. He describes the pain as sharp, constant, non-radiating, and 6/10 in intensity. Pain gets worse with movement and minimal bending. The pain is limiting his usual activities included his ability to go to work. He denies weakness or numbness of the legs as well as bowel or bladder dysfunctions. You perform a physical exam and note prominent tender area to palpation at the right lumbar region. You explain to the patient the most likely diagnosis is a muscle strain. Your usual approach is to treat this type of case scenario with Ibuprofen. The patient asked you if Ibuprofen alone will be strong enough to control his pain. Background: Pain is one of the most frequent reasons to attend an ED. Low back pain (LBP) is responsible for 2.3% of all ED visits resulting in 2.6 million visits each year in the USA (Friedman et al Spine 2010). We have covered back pain a number of times on the SGEM. SGEM#87: Let Your Back Bone Slide (Paracetamol for Low-Back Pain) SGEM#173: Diazepam Won’t Get Back Pain Down SGEM#240: I Can’t Get No Satisfaction for My Chronic Non-Cancer Pain The SGEM bottom line from SGEM#240 was: There appears to be no long-term analgesics benefits from prescribing opioids for chronic non-cancer pain (nociceptive and neuropathic). However, their use is associated with increased adverse events. The American College of Emergency Physicians (ACEP) has updated their clinical policy on prescribing opioids for adult ED patients. There are no Level A recommendations, one Level B recommendation and multiple Level C recommendations (ACEP June 2020) In adult patients experiencing opioid withdrawal, is emergency department-administered buprenorphine as effective for the management of opioid withdrawal compared with alternative management strategies? Level B Recommendations: When possible, treat opioid withdrawal in the emergency department with buprenorphine or methadone as a more effective option compared with nonopioid-based management strategies such as the combination of α2-adrenergic agonists and antiemetics Many other pharmaceutical treatments besides opioids have been tried to address acute LBP pain with limited success. These include: acetaminophen (Williams et al Lancet 2014), muscle relaxants (Friedman et al JAMA 2015), NSAIDs (Machado et al Ann Rheum Dis 2017), steroids (Balakrishnamoorthy et al Emerg Med J 2014) and benzodiazepines (Friedman et al Ann Emerg Med 2017). Pain outcomes for patients with LBP are generally poor; One week after an ED visit in an unselected LBP population, 70% of patients report persistent back pain–related functional impairment and 69% report continued analgesic use (Friedman et al AEM 2012). There are a number of non-pharmaceutical treatment modalities that have also been tried to treat low back pain. They include: CBT and mindfulness (Cherkin et al JAMA 2016), chiropractic (Paige et al JAMA 2017), physical therapy (Paolucci et al J Pain Research 2018) and acupuncture (Colquhoun and Novella Anesthesia and Analgesia 2013). None of these other treatments has high-quality evidence supporting their use. Nonsteroidal anti-inflammatory drugs (NSAIDs) are recommended as first-line medication therapy for patients with acute LBP.  Acetaminophen is often used for acute LBP, although it is unlikely to be effective when used as monotherapy. Whether or not combining an NSAID with acetaminophen can improve patient outcomes is unknown. Clinical Question: Is the addition of acetaminophen to ibuprofen better than ibuprofen alone in treating ED patients with acute, non-traumatic, non-radicular low back pain? Reference: Friedman et al. Ibuprofen Plus Acetaminophen Versus Ibuprofen Alone for Acute Low Back Pain: An Emergency Department-based Randomized Study. AEM 2020. Population: Adults aged 21 to 69 years who presented to the ED primarily for management of acute non-traumatic, non-radicular, musculoskeletal LBP with Roland Morris Disability Questionnaire (RMDQ)score of >5. The RMDQ is a 24-item questionnaire commonly used to measure LBP and related functional impairment. The scale goes from 0 (no impairment) to 24 (maximum impairment). Exclusions: “non- musculoskeletal etiology of low back, such as urinary tract infection or influenza-like illness; radicular pain, defined as pain radiating below the gluteal folds in a dermatomal distribution; pain duration > 2 weeks (336 hours); or a baseline LBP frequency of once per month or more frequently. Patients with substantial, direct trauma to the back within the previous month were excluded as were those who were unavailable for follow-up, those who were pregnant or breastfeeding, patients with a chronic pain syndrome defined as use of any analgesic medication on a daily or near-daily basis, and those who were allergic to or intolerant of the investigational medications.” Intervention: Combination ofibuprofen 600mg plus acetaminophen 500 to 1000mg, orally, every 6 hours. Comparison: Monotherapy of Ibuprofen 600mg plus placebo,orally, every 6 hours. Outcome: Primary Outcome: Improvement of LBP on the RMDQ between ED discharge and the 7-day telephone follow-up.  Secondary Outcomes: 1 week and 48 hours after ED discharge were as follows: 1) participants’ worst LBP during the previous 24 hours, using a four-item ordinal scale (severe, moderate, mild, or none); 2) the frequency of LBP during the previous 24 hours using a five-item scale (not at all, rarely, sometimes, usually, always); 3) the frequency of any analgesic or LBP medication use during the previous 24 hours; 4) satisfaction with treatment, as measured by response to the question, “The next time you have back pain, do you want to take the same medications you’ve been taking this past week?”; 5) the day post–ED discharge the participant was able to return to usual activities; and 6) the frequency of visits to any health care provider. Authors’ Conclusions: “Among ED patients with acute, nontraumatic, non-radicular LBP, adding acetaminophen to ibuprofen does not improve outcomes within 1 week.” Quality Checklist for Randomized Clinical Trials: The study population included or focused on those in the emergency department. Yes The patients were adequately randomized. Yes The randomization process was concealed. Yes The patients were analyzed in the groups to which they were randomized. Yes The study patients were recruited consecutively (i.e. no selection bias). Yes The patients in both groups were similar with respect to prognostic factors. Yes All participants (patients, clinicians, outcome assessors) were unaware of group allocation. Yes All groups were treated equally except for the intervention. Yes Follow-up was complete (i.e. at least 80% for both groups). Yes All patient-important outcomes were considered. Yes The treatment effect was large enough and precise enough to be clinically significant. No Key Results: They screened 605 patients for eligibility and were able to randomize 120. The mean age was 41 years, 52% were men, mean duration of symptoms was 48 hours and 80% were working at least 30 hours a week. No statistical difference between ibuprofen plus acetaminophen and ibuprofen alone in back pain improvement at one week. Primary Outcome: Mean improvement of RMDQ (+/-SD) at 1 week Combo 11.1 (+/- 10.7) vs Mono 11.9 (+/- 9.7) Between group difference 0.8 (95% CI -3.0 to 4.7) Secondary Outcomes:  Participants’ worst LBP during the previous 24 hours, using a four-item ordinal scale (severe, moderate, mild, or none): No statistical difference Frequency of LBP during the previous 24 hours using a five-item scale (not at all, rarely, sometimes, usually, always): More frequent in combination group Frequency of any analgesic or LBP medication use during the previous 24 hours: No statistical difference Satisfaction with treatment, as measured by response to the question, “The next time you have back pain, do you want to take the same medications you’ve been taking this past week?” No statistical difference How many days post–ED discharge the participant was able to return to usual activities: No statistical difference Frequency of visits to any health care provider: No statistical difference 1. Ibuprofen Dosing: They used 600mg of ibuprofen in this trial rather than 400mg. Unlike opioid analgesics, NSAID dosing is limited by their “analgesic ceiling”, meaning there is a dose-analgesic response. Above certain doses, NSAIDs produce more side effects or harms without providing additional analgesia. Our team has published evidence supporting this on both ibuprofen (Motov et al Ann Emerg Med 2019) and ketorolac (Motov et al Ann Emerg Med 2017). The ketorolac paper was covered on SGEM#175. 2. External Validity: This study was conducted in two urban EDs serving a socioeconomically depressed population. Socioeconomic factors have been shown to be associated with an increased risk of pain (Poleshuckand Green Pain 2008). It is unclear if this data could be applied to other populations. 3.