[Complex regional pain syndrome-An interdisciplinary view from the surgical consultation]. / Das komplexe regionale Schmerzsyndrom ­ eine interdisziplinäre Betrachtung aus der chirurgischen Sprechstunde.

Chronic pain disorders are common and have a substantial impact on the patients' daily life. The specific syndrome of complex regional pain syndrome (CRPS, Sudeck's disease) is comparatively rare and characterized by additional sensorimotor, vascular and trophic dysfunctions. The diagnosis is made based on the Budapest criteria and according to clinical symptoms. According to the German national guidelines, multimodal therapy includes drug, rehabilitative and psychosomatic approaches for the reduction of pain and restoration of functionality. Bisphosphonates, steroids and antiepileptic drugs are well-established as medicinal treatment but should always be used in combination with functional therapy. Interventional treatment options are reserved for patients with complicated and enduring symptoms and should be carried out in specialized centers. The course of the disease is highly individual and frequently requires a long-term interdisciplinary treatment.

Pain levels and patient comfort after lower limb arthroplasty comparing i.v. patient-controlled analgesia, continuous peripheral nerve block and neuraxial analgesia: a retrospective cohort analysis of clinical routine data.

BACKGROUND: Insufficient pain control after lower limb arthroplasty results in delayed recovery and increased risk for pain chronicization. The ideal kind of analgesia is still discussed controversially. We conducted a retrospective analysis of single-center routine data from a German university hospital, including patients receiving either total hip (THA) or knee arthroplasty (TKA). METHODS: All patients received general anesthesia. Patients undergoing THA received either continuous epidural ropivacaine infusion (0.133%, Epi) or patient-controlled analgesia (PCA) with the Wurzburg Pain Drip (tramadol, metamizole and droperidol, WPD) or with piritramide (Pir). After TKA, patients received either continuous femoral nerve block (ropivacaine 0.2%, PNB) or Pir. RESULTS: The analyzed cohort comprised 769 cases. Use of WPD after THA (n = 333) resulted in significantly reduced Numeric Rating Scale (NRS) values at rest, compared to Epi (n = 48) and Pir (n = 72) (.75 [IQR 1.14] vs. 1.17 [1.5], p = .02 vs. 1.47 [1.33], p < .0001) as well as maximum NRS scores (2.4 [1.7] vs. 3.29 [1.94], p < .001 vs. 3.32 [1.76], p < .0001). Positive feedback during follow-up visits was significantly increased in patients with a WPD PCA (p < .0001), while negative feedback (senso-motoric weakness/technical problems/nausea/dizziness/constipation) was particularly increased in Epi patients and lowest in those with WPD (p < .0001). After TKA, Pir (n = 131) resulted in significantly reduced NRS values at rest, compared to PNB (n = 185) (1.4 [1.4] vs. 1.6 [1.68], p = .02). Positive feedback was increased in patients with a Pir PCA in comparison with PNB (p = .04), while negative feedback was increased in PNB patients (p = .04). Overall, WPD presented with the lowest rate of any complications (8.7%), followed by Pir (20.2%), PNB (27.6%) and Epi (31.3%) (p < .001). CONCLUSIONS: In the assessed population, the use of a WPD PCA after THA offered better pain control and patient comfort in comparison with continuous epidural or piritramide-based analgesia. After TKA, the use of a Pir PCA provided superior analgesia and a lower complication rate compared to continuous PNB.

Pain drawing as a screening tool for anxiety, depression and reduced health-related quality of life in back pain patients: A cohort study.

BACKGROUND: Back pain patients are more likely to suffer from depression, anxiety and reduced quality of life. Pain drawing is a simple, frequently used anamnesis tool that facilitates communication between physicians and patients. This study analysed pain drawings to examine whether pain drawing is suitable as a screening tool for signs of anxiety, depression or reduced quality of life, as the detection of these symptoms is essential for successful treatment. METHODS: Pain drawings of 219 patients with lower back pain were evaluated retrospectively. Pain drawings are a schematic drawing of a human being. Six variables of the pain drawing were analysed. Subscales of the Hospital Anxiety and Depression Scale (HADS) and the Mental Component Summary (MCS) of the Short Form 12 (SF-12) were used to measure anxiety, depression and quality of life, respectively. Descriptive statistics, uni- and multivariate linear regression analyses and analysis of variance were performed. Logistic regression analyses were conducted for suitable variables. RESULTS: We revealed significant positive correlations between the variables "filled body surface" and "number of pain sites" and the anxiety (HADS-A) and depression subscales (HADS-D) of the HADS (p<0.01). The same predictors had significant negative correlations with the MCS (p<0.01). However, the sensitivity and specificity of the variable "number of pain sites" were too low compared to those for existing screening tests to consider it as a screening tool for anxiety, depression and quality of life (HADS-A: sensitivity: 45.2%, specificity: 83.3%; HADS-D: sensitivity: 61.1%, specificity: 51%; MCS: sensitivity: 21.2%, specificity: 85.7%). CONCLUSIONS: There were significant correlations between the amount of filled body surface and the number of pain sites in the pain drawing and anxiety, depression and quality of life. Although useful in routine clinical practice, pain drawing cannot be used as a screening tool based on our results.

Oxygen tension modulates inhibition of L-type calcium currents by isoflurane in human atrial cardiomyocytes.

BACKGROUND: Myocardial L-type Ca(2+) currents (I(Ca,L)) are inhibited by isoflurane in the presence of a partial pressure of oxygen (P(O2)) of 150 mmHg. In guinea pig cardiomyocytes, I(Ca,L) are inhibited by reduced oxygen tensions. The authors therefore analyzed the effects of P(O2) on I(Ca,L) in human cardiomyocytes and the effects of isoflurane at reduced P(O2). METHODS: Atrial cardiomyocytes were prepared from specimens of patients undergoing open-heart surgery and superfused with either a high or a low P(O2) (150 or 12 +/- 1 mmHg) while I(Ca,L) were measured with the whole cell patch clamp technique. RESULTS: Basal I(Ca,L) were not changed by the P(O2) (range, 9-150 mmHg) at 21 degrees or 36 degrees C. The reducing agent 1,4-dithiothreitol (DTT) left I(Ca,L) unaffected, and the oxidizing agent 5,5'-dithio-bis(2-nitrobenzoic acid) (DTNB) irreversibly inhibited I(Ca,L). The P(O2) significantly affected the inhibition of I(Ca,L) by isoflurane (1 minimum alveolar concentration) that decreased I(Ca,L) by 17 +/- 2.0% at the high P(O2) but only by 5.8 +/- 2.9% (P = 0.037) at the low P(O2). The inhibition of I(Ca,L) by isoflurane was also significantly diminished (P = 0.018) by a low P(O2) when isoflurane effects at both P(O2) conditions were compared in the same cell. CONCLUSIONS: In contrast to the situation in guinea pigs, basal I(Ca,L) in human atrial cardiomyocytes was not sensitive to acute P(O2) changes over a wide range. This might be explained by a lack of oxygen-sensitive splice variants of L-type calcium channel subunits. The P(O2), however, has a decisive role for the effects of isoflurane on I(Ca,L).