Topical capsaicin 8% was developed for the treatment of peripheral neuropathic pain. The pain reduction is associated with a reversible reduction of epidermal nerve fiber density (ENFD). During its application, topical capsaicin 8% provokes distinct pain. In a randomized, double-blind study analyzed with a block factorial analysis of variance, we tested whether cooling the skin would result in reliable prevention of the application pain without inhibiting reduction of ENFD. A capsaicin 8% patch was cut into 4 quarters and 2 each were applied for 1 hour on the anterior thighs of 12 healthy volunteers. A randomization scheme provided for 1 of the application sites of each thigh to be pretreated with EMLA and the other with placebo, whereas both application sites of 1 thigh, also randomly selected, were cooled by cool packs, resulting in a site temperature of 20°C during the entire treatment period. The maximum pain level given for the cooled sites (visual analogue scale [VAS] 1.3 ± 1.4) proved to be significantly lower than for the non-cooled sites (VAS 7.5 ± 1.9) (P < .0001). In contrast, there was no significant difference in application pain between the sites pretreated with EMLA or with placebo (VAS 4.1 ± 3.6 vs 4.8 ± 3.5, P = .1084). At all application sites, ENFD was significantly reduced by 8.0 ± 2.8 (ENF/mm ± SD, P < .0001), that is, 70%, with no significant differences between the sites with the different experimental conditions. In conclusion, cooling the skin to 20°C reliably prevents the pain from capsaicin 8% patch application, whereas EMLA does not. ENFD reduction is not inhibited by cooling.
Background: Upper-limb trauma is a common indication for surgery in children, and general anaesthesia remains the method of choice for these procedures, even though suitable techniques of brachial plexus block are available and fast provision of regional anaesthesia offers a number of distinct advantages. Methods: A retrospective analysis was performed of the data of a large cohort of children undergoing ultrasound-guided brachial plexus blocks during a 4-yr period at a major trauma centre with a catchment area of 3.5 million. A total of 565 cases were sourced from two independently operating patient documentation systems. Patient data were stratified into age groups with block success as the primary outcome parameter. The influence of age on the incidence of block failure was assessed with logistic regression. Results: The block failure rate was 5.1%, starting at 1.2% in the youngest (0e3 yr), then continuously increasing up to 12.5% in the oldest (15e18 yr) but also smallest group. Age emerged as an independent predictor of block failure with an odds ratio of 1.115 and a 95% confidence interval of 1.014e1.226 (P¼0.025). No complications were observed. Conclusions: In a cohort of children receiving real-world care, with regional blocks performed by a range of anaesthetists with different skill levels, a success rate of 94.9% for upper-limb blocks in children under various levels of sedation was observed. Upper-limb blocks can be performed with high probability of success and an excellent margin of safety; this particularly applies to small children. Clinical trial registration: NCT03842423.
The present data show that the anticipation of an i.v. infusion of nonopioid analgesic drug improves VAS significantly, probably through expectation-related mechanisms. However, single dose i.v. infusions of nonopioid analgesic drugs fail to improve pain intensity and spinal mobility in CLBP patients on chronic opioid treatment, even immediately after the infusion.
Summary
Data on safety and success rates of ultrasound‐guided caudal blockade, performed on sedated children with an uninstrumented airway, are scarce. We performed a retrospective observational study of validated data from April 2014 to December 2020 in a paediatric cohort where the initial plan for anaesthetic management was sedation and caudal epidural without general anaesthesia or airway instrumentation. We examined success rates of this approach and rates of block failure and block‐related complications. In total, 2547 patients ≤ 15 years of chronological age met inclusion criteria. Among the 2547 cases, including 453 (17.8%) former preterm patients, caudal‐plus‐sedation success rate was 95.1%. The primary anaesthesia plan was abandoned for general anaesthesia in 124 cases. Pain‐related block failure in 83 (3.2%) was the most common cause for conversion. Complications included 39 respiratory events and 9 accidental spinal anaesthetics. Higher odds of pain‐related block failure were associated with higher body weight (adjusted OR 1.063, 95%CI 1.035–1.092, p < 0.001) as well as with mid‐abdominal surgery (e.g. umbilical hernia repair) (adjusted OR 15.11, 95%CI 7.69–29.7, p < 0.001), whereas extreme (< 28 weeks) former prematurity, regardless of chronological age, was associated with higher odds (adjusted OR 3.62, 95%CI 1.38–9.5, p = 0.009) for respiratory problems. Ultrasound‐guided caudal epidural, performed under sedation with an uninstrumented airway, is an effective technique in the daily clinical routine. Higher body weight and mid‐abdominal surgical procedures are risk factors for pain‐related block failure. Patients who, regardless of chronological age, had been born as extreme preterm babies are at the highest risk for respiratory events.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.