Andreas Schwarzer

Low pain intensity after opioid withdrawal as a first step of a comprehensive pain rehabilitation program predicts long-term nonuse of opioids in chronic noncancer pain.

Objectives:In specialized pain clinics there is an increasing number of patients with severe chronic noncancer pain (CNCP) despite long-term opioid medication. Few clinical studies show short-term pain relief after opioid withdrawal (OW). We have evaluated the relation between pain intensity after OW and long-term opioid nonuse. Methods:One hundred two consecutive patients with severe CNCP despite opioid medication (mean treatment duration, 43 mo) reported pain intensity (numerical rating scale, 0 to 10), Pain Disability Index, mood (CES-D), and quality of life (Short Form 36) before, shortly, and 12 to 24 months after inpatient OW. Total opioid withdrawal (n=78) or significant dose reduction (DR; n=24, mean reduction, 82%) was performed after individual decision. Opioid intake 12 to 24 months later, respectively dose increase ≥100% (DR group), was considered relapse. T tests, multivariable analysis of variance, logistic regression. Results:After OW current pain intensity significantly decreased on an average by 41% (6.4±2.4 vs. 3.8±2.5), maximal and average pain by 18% and 24%, respectively. Twelve to 24 months later 42 patients (41%) relapsed (31 of the total opioid withdrawal group, 6 of the DR group, 5 lost). Patients without later relapse showed significantly lower pain scores than the later relapsed patients already shortly after OW (5.0±2.2 vs. 5.9±2.1) and 12 to 24 months later (5.5±2.4 vs. 6.5±2.0). There was a significant relation between relapse probability and pain intensity immediately after OW. Conclusions:In many patients with severe CNCP, despite opioid medication, sustainable pain relief can be achieved if OW is included in the rehabilitation program. Consequently, we recommend OW for opioid-resistant CNCP before any opioid escalation. Lower pain intensity shortly after OW may predict the long-term opioid nonuse probability.

Phantomschmerzen – Pathomechanismen und Therapieansätze

About 80 % of all extremity amputations suffer from phantom limb pain following the operation. In this context, it is important to differentiate between painful phantom limb sensations, non-painful phantom limb sensations and residual limb pain. The pathophysiology of phantom limb pain is not fully understood. Current research findings ascribe a major pathophysiological role to cortical changes as well as a disturbed body perception. Peripheral and spinal mechanisms appear less relevant in the development of phantom limb pain. An essential part of the therapy is the pharmacological treatment with antidepressants, anticonvulsives and opioids. Another significant aspect of therapy is senso-motory training, important to mention here would be mirror therapy, lateralisation and motor imaging. In case of an elective amputation, an epidural or axiliar plexus catheter should be considered prior to the amputation. The perioperative treatment with ketamine is debated.

Sleep-disordered breathing decreases after opioid withdrawal: results of a prospective controlled trial.

Abstract An increased cardiovascular event rate in elderly patients under opioid medications was recently reported. One reason for this increase could be the occurrence of nocturnal apnea and hypoxia, as a consequence of sleep-disordered breathing (SDB). Using a controlled study, we prospectively analyzed SDB using polysomnography in a total of 18 patients before and after opioid withdrawal (opioid withdrawal group [OG]) and 14 patients before and after comprehensive pain management (without any strong-acting opioids) who served as the control group (CG). To analyze the differences, unpaired/paired t tests and Mann–Whitney U tests/Wilcoxon rank tests were used. At baseline, the OG presented more nocturnal apneas/hypopneas than the CG with an apnea–hypopnea index (AHI) of 41.4 ± 27.8 vs 21.8 ± 15.9 (P = 0.018). After treatment, the AHI decreased significantly only in the withdrawal group (OG: 16.7 ± 8.9; CG: 20.1 ± 12.9) (P < 0.01). Before treatment, none of the CG but half of the OG patients showed central apnea, which disappeared afterwards. A mean O2 saturation during rapid eye movement sleep lower than 90% was found in 27.5% of the OG patients before opioid withdrawal and in none of the patients after withdrawal (P < 0.01). The AHI was not significantly affected by body mass index, age, or sex. Obviously, nocturnal apnea and O2 desaturation occurred more frequently, as was clinically expected in patients with opioid intake; these findings may explain the opioid-associated cardiovascular morbidity. Thus, SDB may be a risk at lower opioid doses than hitherto described, and particular caution should be exercised in patients with comorbidities that might make them vulnerable to the consequences of SDB.

Changes of the Sensory Abnormalities and Cortical Excitability in Patients with Complex Regional Pain Syndrome of the Upper Extremity After 6 Months of Multimodal Treatment.

Objective. The most prominent sensory sign of the complex regional pain syndrome (CRPS) is blunt hyperalgesia, but longitudinal studies on its relation to the outcome of long-term multimodal treatment are lacking. Methods. We examined 24 patients with CRPS type I using standardized Quantitative Sensory Testing on the affected hand and the contralateral hand at baseline and 6 months following treatment. Somatosensory evoked potentials after single and paired-pulse stimulation of the median nerve were performed to assess the paired-pulse suppression (n = 19). Treatment response at follow-up was defined as pain relief > 30% and improved hand function. Statistics: Wilcoxon test, Pearson correlation. Results. At baseline, similar to previous studies, the pressure pain threshold (PPT) was significantly decreased and the pain response to repeated pinprick stimuli was significantly increased, while all detection thresholds were within the normal range without any difference between the later treatment responders and non-responders. After 6 months of treatment, the PPT increased significantly in the whole study group. However, the pressure hyperalgesia improved only in treatment responders (n = 17, P < 0.05), whereas there was no improvement in non-responders (n = 7). The rest of the sensory profile remained nearly unchanged. There was a correlation between the paired-pulse suppression and the PPT only at follow-up (r = 0.49, P < 0.05), but not at baseline, where low pressure pain threshold was associated with impaired paired-pulse suppression. Conclusion. Thus, the persistence of blunt hyperalgesia seems to be associated with impaired paired-pulse suppression, both representing maladaptive central nervous changes in CRPS, which may account for the treatment non-response in this subgroup.

Neuropathischer Schmerz und CRPS

Mit dem vorliegenden Beitrag mochten die Verfasser das Verstandnis fur die komplexen Aspekte bei neuropathischen Schmerzsyndromen, insbesondere bei Phantomschmerzen und dem CRPS (»complex regional pain syndrome«, alte Bezeichnung Morbus Sudeck) fordern sowie das Spektrum der multidisziplinaren Behandlungsoptionen aufzeigen. Einer ausfuhrlichen Beschreibung der Krankheitsbilder folgen detaillierte Ausfuhrungen zu den indizierten Behandlungsverfahren. In einem gesonderten Absatz wird die klinische Relevanz psychischer Komorbiditaten am Beispiel des CRPS dargestellt, die zwar nur bei einem begrenzten Anteil der Klientel auftreten, dann aber in besonderer Weise bei der Behandlung neuropathischer Schmerzen zu berucksichtigen sind. Der Beitrag schliest mit einem kritischen Resumee bezuglich des aktuellen Forschungs- und Versorgungsstandes.

Opioide in der Hausarztpraxis

ZusammenfassungIn den letzten Jahren werden immer häufiger stark wirksame Opioide für Patienten verordnet, die keine Tumorerkrankung haben. Daher sollte auch der Hausarzt mit den Indikationen und den allgemeinen Regeln zum Einsatz dieser Schmerzmittel vertraut, sicher in der Auswahl der Substanzen und bekannt mit den Strategien der Risikoreduktion sein.

Neuropathische Schmerzsyndrome unter besonderer Berücksichtigung von Phantomschmerzen und CRPS

Mit dem vorliegenden Beitrag mochten die Verfasser das Verstandnis fur die komplexen Aspekte bei neuropathischen Schmerzsyndromen, insbesondere bei Phantomschmerzen und dem CRPS(»complex regional pain syndrome «, alte Bezeichnung Morbus Sudeck ) fordern sowie das Spektrum der multidisziplinaren Behandlungsoptionen aufzeigen. Einer ausfuhrlichen Beschreibung der Krankheitsbilder folgen detaillierte Ausfuhrungen zu den indizierten Behandlungsverfahren. In einem gesonderten Absatz wird die klinische Relevanz psychischer Komorbiditaten am Beispiel des CRPS dargestellt, die zwar nur bei einem begrenzten Anteil der Klientel auftreten, dann aber in besonderer Weise bei der Behandlung neuropathischer Schmerzen zu berucksichtigen sind. Der Beitrag schliest mit einem kritischen Resumee bezuglich des aktuellen Forschungs- und Versorgungsstandes.