Pain
-
Recent literature suggests that the withdrawal of remifentanil (RF) infusion can be associated with hyperalgesia in clinical and nonclinical settings. We performed a systematic review and a meta-analysis of randomized controlled trials with cross-over design, to assess the effect of discontinuing RF infusion on pain intensity and areas of hyperalgesia and allodynia in healthy volunteers. Nine studies were included. ⋯ The area of hyperalgesia was larger after RF withdrawal (SMD: 0.55; 95% CI: 0.27-0.84; P = 0.001; I 2 = 0%). The area of allodynia did not vary between treatments. These findings suggest that the withdrawal of RF induces a mild but nonclinically relevant degree of hyperalgesia in HVs, likely linked to a reduced pain threshold.
-
Meta Analysis
The association between parent mental health and pediatric chronic pain: a systematic review and meta-analysis.
Mental health problems are common among parents of children with chronic pain and associated with worse outcomes for the child with chronic pain. However, the effect sizes of these associations between parent mental health and pediatric chronic pain vary widely across studies. The aim of this systematic review and meta-analysis was to generate pooled estimates of the (1) prevalence of mental health problems among parents of children with chronic pain and (2) associations between parent mental health and the (2a) presence of child chronic pain and (2b) functioning of children with chronic pain. ⋯ Poorer parent mental health was significantly associated with the presence of chronic pain (anxiety: OR = 1.91 [1.51-2.41]; depression: OR = 1.90 [1.51-2.38]; general distress: OR = 1.74 [1.47-2.05]) and worse related functioning (ie, pain intensity, physical functioning, anxiety and depression symptoms; r s = 0.10-0.25, all P s < 0.05) in children. Moderator analyses were generally nonsignificant or could not be conducted because of insufficient data. Findings support the importance of addressing parent mental health in the prevention and treatment of pediatric chronic pain.
-
Randomized Controlled Trial
Choice over placebo administration enhances open-label placebo hypoalgesia.
Many studies indicate that deceptively administered placebos can improve pain outcomes. However, the deception involved presents an ethical barrier to translation because it violates informed consent and patient autonomy. Open-label placebos (OLPs), inert treatments that are openly administered as placebos, have been proposed as an ethically acceptable alternative. ⋯ Of interest, there was no evidence for OLP hypoalgesia without choice relative to natural history. Furthermore, variability in pain intensity did not affect OLP hypoalgesia. The current findings present novel evidence that choice over treatment administration may be a cheap and effective strategy for boosting the efficacy of OLPs in the clinical care of pain.
-
In the peripheral nervous system, spontaneous activity in sensory neurons is considered to be one of the 2 main drivers of chronic pain states, alongside neuronal sensitization. Despite this, the precise nature and timing of this spontaneous activity in neuropathic pain is not well-established. Here, we have performed a systematic search and data extraction of existing electrophysiological literature to shed light on which fibre types have been shown to maintain spontaneous activity and over what time frame. ⋯ However, because of the highly specialised nature of the electrophysiological methods used to measure spontaneous activity, there is also a high degree of variability and uncertainty around these results. Specifically, there are very few directly controlled experiments, with less directly comparable data between human and animals. Given that spontaneous peripheral neuron activity is considered to be a key mechanistic feature of chronic pain conditions, it may be beneficial to conduct further experiments in this space.
-
Chronic overlapping pain conditions (COPCs) refer to conditions that have similar central nervous system pathophysiologic mechanisms driving widespread pain as well as common comorbid symptoms such as fatigue and problems with sleep, memory, and mood. If COPCs predict the onset of long COVID, this could offer a valuable orientation for long COVID-related research and clinical care. This retrospective cohort study aimed to determine whether having a COPC predicts the onset of long COVID features using US electronic health records and 1:1 propensity score matching without replacement. ⋯ In the noninfected cohort, COPCs increased the risk by 1.57 (95% CI = 1.56, 1.59). These findings reinforce the likelihood that nociplastic mechanisms play a prominent role in long COVID. Recognizing that this ubiquitous nonspecific syndrome occurs frequently in the population can inform precision medicine therapies that avoid the pitfalls of viewing long COVID exclusively in the framework of postinfectious disease.