Burkhard Gustorff

Background Capsaicin 8% patch reduces peripheral neuropathic pain. Based on the concept of neuropathic pain (NeP) in mixed low back pain (LBP) it is hypothesized, that an exclusively lumbar capsaicin 8% patch is an effective treatment of mixed LBP. The aim is a proof of this concept and to identify predictors of responsiveness. Methods This prospective stratified study included 54 chronic, mixed, LBP patients with spontaneous pain >3/10 on the NRS (0-10) and a painDETECT Questionnaire (PDQ) score >12 meaning possible or likely (>18) NeP. Pain intensity, PDQ, and quantitative sensory testing (QST) were assessed at baseline. After a one-hour capsaicin 8% treatment on the low back, follow-up was carried out regularly over three months. Response was determined at one month (≥30% pain reduction) and predictors were compared accordingly. Results The average change in pain intensity at week four was -1.1 (-0.50;-1.71, 95%CI, p < 0.001). Twenty-one (39%) patients responded at one month with a mean pain reduction of -3.1 (-4.0;-2.3, 95%CI) and even 10 of the 21 responders showed a ≥ 50% pain reduction. No pain reduction was seen in 33 (61%) patients (p = 0.42). Responders and non-responders did not differ at any baseline parameter: NRS (p = 0.85), PDQ score (p = 0.47), duration of pain (median of 48 and 36 months) nor QST profiles. Conclusions Lumbar capsaicin 8% patch is an effective treatment in about 40% of chronic patients with mixed neuropathic LBP. However, predictors for response could not be identified.

Objective: The aim of this research is to analyze analgesic efficacy of the 5% lidocaine medicated plaster in two randomized, double-blinded, placebo-controlled, crossover studies in 16 healthy volunteers using capsaicin and sunburn pain models. Methods: Lidocaine and placebo plasters were simultaneously applied to forearms and thighs at contralateral body sites for three alternating 12-h plaster-on/plaster-off periods. Between the second and third plaster-on period, 4.2-cm circular spots on both pretreated thighs were irradiated with three times the individual minimal erythema dose of UVB light. After the last plaster-on period, 20 μl of 0.1% capsaicin was injected intradermally into both forearms. The study was repeated using a single 12-h plaster application. Results: The area of pinprick hyperalgesia was diminished by 53% (p < 0.003) in the capsaicin model and by 84% (p < 0.0001) in the sunburn model; the intensity of mechanical hyperalgesia to rigid filaments (8 – 512 mN) was reduced in both models. Cold pain perception threshold was reduced (19.7°C ± 8.0 vs 21.8°C ± 6.8 for placebo, p < 0.05, sunburn). Similar effects were observed in the 12-h exposure study. No effect was seen on capsaicin-induced spontaneous pain and flare size, or blood flow in the sunburn area, and heat hyperalgesia in either study. Conclusions: Lidocaine plaster effectively treats mechanical hyperalgesia and cold pain.

Background: Data on the incidence of neuropathic pain (NeP) in Austria, its general characteristics and consequences for the quality of life (QOL) are still lacking. The prevalence in the United Kingdom is 8%.Methods: A representative survey (n=7707) was carried out. Patients with NeP were identified using previously validated criteria and subsequently asked to complete a questionnaire on QOL and detailed pain characteristics.Results: The prevalence of NeP was 3.3% (n=260). A higher prevalence was found in 41–50‐year‐olds (26%) and 51–60 year olds (24%). Pain was long lasting (>1 year: 66%; >5 years: 41%) and severe at onset (mean 6.8; numerical rating scale) as well as later (mean 4.7; 20% 8 or higher). Strong or predominant restriction of daily activities was reported in 65%, strong or predominant sleep disturbances in 60%, feelings of depression in 34% and anxiety in 25%.Conclusion: For the first time, data on the prevalence of NeP in Austria are available. Pain patterns in those affected are characteristic and impact on QOL as well as pain intensity are severe.

Background. Brachytherapy presents the anaesthetist with unique problems. Information on anaesthesia for brachytherapy, however, is limited. The aim of this paper is to report on our experience involving a large number of brachytherapy procedures. Methods. A retrospective analysis of records of 1622 anaesthetic procedures in 952 patients is presented. Records were analysed in respect of patient data, tumour localization, brachytherapy treatment and the type and duration of anaesthetic procedures. Results. More than one-third of patients were at high risk (ASA III or IV) and 40% were more than 60 yr. Repetitive treatments were performed on half of the patients. Breast cancer was the most common indication. The average duration of anaesthesia for pelvic brachytherapy was more than 3 h, with a high degree of variability. Regional anaesthesia was used in 30% of all cases and was the predominant technique for pelvic brachytherapy. Spinal catheter techniques represented a high proportion of those receiving regional anaesthesia. Complications resulting from regional and general anaesthesia were minor and no serious incidents occurred. Conclusions. Based on a large number of procedures, this study gives an example of anaesthetic management in brachytherapy. A substantial minority of patients would be considered high risk for surgical intervention. Regional anaesthesia was the principal technique used when dealing with tumours of the lower body.

The clinical use of an intravenous opioid testing can help to predict whether opioids will be beneficial. The determination of individual opioid responsiveness justifies subsequent long‐term opioid treatment and is generally recommended. An overview over current testing procedures is given with particular regard to choice of opioid, maximum dose, determination of endpoints and duration of testing and recovery.Remifentanil testing is a new approch and is studied in a randomized placebo‐controlled cross‐over study in 24 patients suffering from severe non‐cancer pain. An ascending infusion of remifentanil and placebo respectively was titrated against endpoints. The testing allowed a disctinction between 11 opioid‐responders and 13 non‐responders. Complete recovery after end of infusion was rapid with a reach of baseline conditions after 25 min in all patients. Thus the complete remifentanil testing procedure required at utmost 1 h. In conclusion, remifentanil testing offers a more rapid procedure allowing the routine use in an ambulatory setting.