BACKGROUND: Complex regional pain syndrome (CRPS) is a chronic pain condition that usually occurs in a limb following trauma or surgery. It is characterised by persisting pain that is disproportionate in magnitude or duration to the typical course of pain after similar injury. There is currently no consensus regarding the optimal management of CRPS, although a broad range of interventions have been described and are commonly used. This is the first update of the original Cochrane review published in Issue 4, 2013.
OBJECTIVES: To summarise the evidence from Cochrane and non-Cochrane systematic reviews of the efficacy, effectiveness, and safety of any intervention used to reduce pain, disability, or both, in adults with CRPS.
METHODS: We identified Cochrane reviews and non-Cochrane reviews through a systematic search of Ovid MEDLINE, Ovid Embase, Cochrane Database of Systematic Reviews, CINAHL, PEDro, LILACS and Epistemonikos from inception to October 2022, with no language restrictions. We included systematic reviews of randomised controlled trials that included adults (≥18 years) diagnosed with CRPS, using any diagnostic criteria. Two overview authors independently assessed eligibility, extracted data, and assessed the quality of the reviews and certainty of the evidence using the AMSTAR 2 and GRADE tools respectively. We extracted data for the primary outcomes pain, disability and adverse events, and the secondary outcomes quality of life, emotional well-being, and participants' ratings of satisfaction or improvement with treatment. MAIN RESULTS: We included six Cochrane and 13 non-Cochrane systematic reviews in the previous version of this overview and five Cochrane and 12 non-Cochrane reviews in the current version. Using the AMSTAR 2 tool, we judged Cochrane reviews to have higher methodological quality than non-Cochrane reviews. The studies in the included reviews were typically small and mostly at high risk of bias or of low methodological quality. We found no high-certainty evidence for any comparison. There was low-certainty evidence that bisphosphonates may reduce pain intensity post-intervention (standardised mean difference (SMD) -2.6, 95% confidence interval (CI) -1.8 to -3.4, P = 0.001; I2 = 81%; 4 trials, n = 181) and moderate-certainty evidence that they are probably associated with increased adverse events of any nature (risk ratio (RR) 2.10, 95% CI 1.27 to 3.47; number needed to treat for an additional harmful outcome (NNTH) 4.6, 95% CI 2.4 to 168.0; 4 trials, n = 181). There was moderate-certainty evidence that lidocaine local anaesthetic sympathetic blockade probably does not reduce pain intensity compared with placebo, and low-certainty evidence that it may not reduce pain intensity compared with ultrasound of the stellate ganglion. No effect size was reported for either comparison. There was low-certainty evidence that topical dimethyl sulfoxide may not reduce pain intensity compared with oral N-acetylcysteine, but no effect size was reported. There was low-certainty evidence that continuous bupivacaine brachial plexus block may reduce pain intensity compared with continuous bupivacaine stellate ganglion block, but no effect size was reported. For a wide range of other commonly used interventions, the certainty in the evidence was very low and provides insufficient evidence to either support or refute their use. Comparisons with low- and very low-certainty evidence should be treated with substantial caution. We did not identify any RCT evidence for routinely used pharmacological interventions for CRPS such as tricyclic antidepressants or opioids.
AUTHORS' CONCLUSIONS: Despite a considerable increase in included evidence compared with the previous version of this overview, we identified no high-certainty evidence for the effectiveness of any therapy for CRPS. Until larger, high-quality trials are undertaken, formulating an evidence-based approach to managing CRPS will remain difficult. Current non-Cochrane systematic reviews of interventions for CRPS are of low methodological quality and should not be relied upon to provide an accurate and comprehensive summary of the evidence.
Numerous interventions for neuropathic pain (NeuP) are available, but its treatment remains unsatisfactory. We systematically summarized evidence from systematic reviews (SRs) of randomized controlled trials on interventions for NeuP. Five electronic databases were searched up to March 2015. Study quality was analyzed using A Measurement Tool to Assess Systematic Reviews. The most common interventions in 97 included SRs were pharmacologic (59%) and surgical (15%). The majority of analyzed SRs were of medium quality. More than 50% of conclusions from abstracts on efficacy and approximately 80% on safety were inconclusive. Effective interventions were described for painful diabetic neuropathy (pregabalin, gabapentin, certain tricyclic antidepressants [TCAs], opioids, antidepressants, and anticonvulsants), postherpetic neuralgia (gabapentin, pregabalin, certain TCAs, antidepressants and anticonvulsants, opioids, sodium valproate, topical capsaicin, and lidocaine), lumbar radicular pain (epidural corticosteroids, repetitive transcranial magnetic stimulation [rTMS], and discectomy), cervical radicular pain (rTMS), carpal tunnel syndrome (carpal tunnel release), cubital tunnel syndrome (simple decompression and ulnar nerve transposition), trigeminal neuralgia (carbamazepine, lamotrigine, and pimozide for refractory cases, rTMS), HIV-related neuropathy (topical capsaicin), and central NeuP (certain TCAs, pregabalin, cannabinoids, and rTMS). Evidence about interventions for NeuP is frequently inconclusive or completely lacking. New randomized controlled trials about interventions for NeuP are necessary; they should address safety and use clear diagnostic criteria.
Post-operative pain affects millions of patients worldwide and the post-operative period has high rates of morbidity and mortality. Some of this morbidity may be related to analgesics. The aim of this review was to provide an update of current knowledge of adverse events (AE) associated with the most common perioperative non-opioid analgesics: paracetamol, non-steroidal anti-inflammatory drugs (NSAIDs), glucocorticoids (GCCs), gabapentinoids and their combinations. The review is based on data from systematic reviews with meta-analyses of analgesic efficacy and/or adverse effects of perioperative non-opioid analgesics, and randomised trials and cohort/retrospective studies. Generally, data on AE are sparse and related to the immediate post-operative period. For paracetamol, the incidence of AEs appears trivial. Data are inconclusive regarding an association of NSAIDs with mortality, cardiovascular events, surgical bleeding and renal impairment. Anastomotic leakage may be associated with NSAID usage. No firm evidence exists for an association of NSAIDs with impaired bone healing. Single-dose GCCs were not significantly related to increased infection rates or delayed wound healing. Gabapentinoid treatment was associated with increased sedation, dizziness and visual disturbances, but the clinical relevance needs clarification. Importantly, data on AEs of combinations of the above analgesics are sparse and inconclusive. Despite the potential adverse events associated with the most commonly applied non-opioid analgesics, including their combinations, reporting of such events is sparse and confined to the immediate perioperative period. Knowledge of benefit and harm related to multimodal pain treatment is deficient and needs clarification in large trials with prolonged observation.
Complex regional pain syndrome (CRPS) is a chronic pain condition that usually occurs in a limb following trauma or surgery. It is characterised by persisting pain that is disproportionate in magnitude or duration to the typical course of pain after similar injury. There is currently no consensus regarding the optimal management of CRPS, although a broad range of interventions have been described and are commonly used. This is the first update of the original Cochrane review published in Issue 4, 2013.
OBJECTIVES:
To summarise the evidence from Cochrane and non-Cochrane systematic reviews of the efficacy, effectiveness, and safety of any intervention used to reduce pain, disability, or both, in adults with CRPS.
METHODS:
We identified Cochrane reviews and non-Cochrane reviews through a systematic search of Ovid MEDLINE, Ovid Embase, Cochrane Database of Systematic Reviews, CINAHL, PEDro, LILACS and Epistemonikos from inception to October 2022, with no language restrictions. We included systematic reviews of randomised controlled trials that included adults (≥18 years) diagnosed with CRPS, using any diagnostic criteria. Two overview authors independently assessed eligibility, extracted data, and assessed the quality of the reviews and certainty of the evidence using the AMSTAR 2 and GRADE tools respectively. We extracted data for the primary outcomes pain, disability and adverse events, and the secondary outcomes quality of life, emotional well-being, and participants' ratings of satisfaction or improvement with treatment.
MAIN RESULTS:
We included six Cochrane and 13 non-Cochrane systematic reviews in the previous version of this overview and five Cochrane and 12 non-Cochrane reviews in the current version. Using the AMSTAR 2 tool, we judged Cochrane reviews to have higher methodological quality than non-Cochrane reviews. The studies in the included reviews were typically small and mostly at high risk of bias or of low methodological quality. We found no high-certainty evidence for any comparison. There was low-certainty evidence that bisphosphonates may reduce pain intensity post-intervention (standardised mean difference (SMD) -2.6, 95% confidence interval (CI) -1.8 to -3.4, P = 0.001; I2 = 81%; 4 trials, n = 181) and moderate-certainty evidence that they are probably associated with increased adverse events of any nature (risk ratio (RR) 2.10, 95% CI 1.27 to 3.47; number needed to treat for an additional harmful outcome (NNTH) 4.6, 95% CI 2.4 to 168.0; 4 trials, n = 181). There was moderate-certainty evidence that lidocaine local anaesthetic sympathetic blockade probably does not reduce pain intensity compared with placebo, and low-certainty evidence that it may not reduce pain intensity compared with ultrasound of the stellate ganglion. No effect size was reported for either comparison. There was low-certainty evidence that topical dimethyl sulfoxide may not reduce pain intensity compared with oral N-acetylcysteine, but no effect size was reported. There was low-certainty evidence that continuous bupivacaine brachial plexus block may reduce pain intensity compared with continuous bupivacaine stellate ganglion block, but no effect size was reported. For a wide range of other commonly used interventions, the certainty in the evidence was very low and provides insufficient evidence to either support or refute their use. Comparisons with low- and very low-certainty evidence should be treated with substantial caution. We did not identify any RCT evidence for routinely used pharmacological interventions for CRPS such as tricyclic antidepressants or opioids.
AUTHORS' CONCLUSIONS:
Despite a considerable increase in included evidence compared with the previous version of this overview, we identified no high-certainty evidence for the effectiveness of any therapy for CRPS. Until larger, high-quality trials are undertaken, formulating an evidence-based approach to managing CRPS will remain difficult. Current non-Cochrane systematic reviews of interventions for CRPS are of low methodological quality and should not be relied upon to provide an accurate and comprehensive summary of the evidence.
