Ambulatory continuous peripheral nerve blocks to treat postamputation phantom limb pain: a multicenter, randomized, quadruple-masked, placebo-controlled clinical trial

Abstract

Supplemental Digital Content is Available in the Text. A 6-day ambulatory continuous peripheral nerve block reduces phantom limb pain and pain-induced physical and emotional dysfunction for at least 4 weeks after treatment.

Why science is less scientific than we think (and what to do about it): The 2022 Gaston Labat Award Lecture

“…We subsequently submitted a revised proposal using the reviewer’s preferred smallest meaningful clinical difference of 1.7 points between the treatment and placebo groups , and it was funded. On completing the study, we submitted the manuscript reporting that after 4 weeks, average phantom limb pain intensity was a mean of 3.0 in patients given local anesthetic vs 4.5 in those given placebo (p=0.003) 21. The manuscript was rejected with a reviewer explaining that while our primary endpoint was statistically significant, we had prospectively defined the minimal clinically important difference between treatment groups as 1.7, and we had found a difference of only 1.5 points; demonstrating that while the intervention did, in fact, decrease phantom limb pain, it failed to do so to a clinically relevant degree.…”

“…Gatekeeping permits statistical comparisons of many variables while retaining a study-wide type I error at a 0.05, increasing confidence in all comparisons and aiding interpretation and generalization of the results. In the phantom limb pain study described above, we prospectively specified a statistical gatekeeping strategy which elevated confidence in various secondary outcomes, the first of which was a scale that demonstrated pain’s interference on emotional and physical functioning was a mean of 11 for treated participants, vs 28 for the placebo group (lower scores=less interference; p=0.027) 21. Given that the results of multiple published investigations suggest that a mean group difference of 2 points on this scale indicates patients who are satisfied or improved with treatment,3 our finding of a difference of 17 points suggested a clinically significant improvement in the experimental over placebo treatments; and the results were subsequently published in different journals 21 24…”

“…Note that the combination of information improves interpretation of the results, and different formats may be valuable to differing stakeholders such as clinicians, patients, administrators, and other researchers. Adapted from Ilfeld et al 21. Some results are preliminary and should be used for demonstration purposes only (final analysis currently in preparation).…”

Altered bodily perceptions in chronic neuropathic pain conditions and implications for treatment using immersive virtual reality

“…The brain basis for these altered perceptions and pain is, as outlined previously, controversial, with the maladaptive plasticity (Flor et al, 1995), including white matter plasticity (Jiang et al, 2015), retained cortical representation (Makin et al, 2013), and peripherally driven (Birbaumer et al, 1997;Ilfeld et al, 2021) theories all having supporting and refuting evidence. It may be the case that these mechanisms are not mutually conclusive.…”

Ultrasound-guided Percutaneous Cryoneurolysis to Treat Chronic Postamputation Phantom Limb Pain: A Multicenter Randomized Controlled Trial

“…7 A recent randomized controlled trial reported that prolonging a peripheral nerve block using a 6-day continuous perineural local anesthetic infusion extended limb analgesia for at least 1 month. 8 These findings suggest that a peripheral nerve block of extended duration—lasting weeks or months rather than days—may allow prolonged cortical reorganization and provide lasting relief from phantom pain.…”