Prediction of persistent post-operative pain: Pain-specific psychological variables compared with acute post-operative pain and general psychological variables.

BACKGROUND: Psychological variables and acute post-operative pain are of proven relevance for the prediction of persistent post-operative pain. We aimed at investigating whether pain-specific psychological variables like pain catastrophizing add to the predictive power of acute pain and more general psychological variables like depression. METHODS: In all, 104 young male patients undergoing thoracic surgery for pectus excavatum correction were studied on the pre-operative day (T0) and 1 week (T1) and 3 months (T2) after surgery. They provided self-report ratings (pain-related: Pain Catastrophizing Scale, Pain Anxiety Symptoms Scale = PASS, Pain Vigilance and Awareness Questionnaire = PVAQ; general psychological: Screening for Somatoform Symptoms, State-Anxiety Inventory-X1, Center for Epidemiologic Studies Depression Scale = CES-D). Additional predictors (T1) as well as criterion variables (T2) were pain intensity (Numerical Rating Scale) and pain disability (Pain Disability Index). RESULTS: Three months after surgery, 25% of the patients still reported clinically relevant pain (pain intensity ≥3) and over 50% still reported pain-related disability. Acute post-operative pain as well as general psychological variables did not allow for a significant prediction of persistent post-operative pain; in contrast, pain-related psychological variables did. The best single predictors were PASS for pain intensity and PVAQ for pain disability. CONCLUSIONS: Pain-related psychological variables derived from the fear-avoidance model contributed significantly to the prediction of persistent post-operative pain. The best possible compilation of these measures requires further research. More general psychological variables may become relevant predictors later in the medical history. SIGNIFICANCE: Our results suggest that pain-specific psychological variables such as pain anxiety and pain hypervigilance add significantly to the prediction of persistent post-operative pain and might even outperform established predictors such as acute pain and general psychological variables. Clinicians might benefit from the development of time-economic screening tools based on these variables.

Emergent biomarker derived from next-generation sequencing to identify pain patients requiring uncommonly high opioid doses.

Next-generation sequencing (NGS) provides unrestricted access to the genome, but it produces 'big data' exceeding in amount and complexity the classical analytical approaches. We introduce a bioinformatics-based classifying biomarker that uses emergent properties in genetics to separate pain patients requiring extremely high opioid doses from controls. Following precisely calculated selection of the 34 most informative markers in the OPRM1, OPRK1, OPRD1 and SIGMAR1 genes, pattern of genotypes belonging to either patient group could be derived using a k-nearest neighbor (kNN) classifier that provided a diagnostic accuracy of 80.6±4%. This outperformed alternative classifiers such as reportedly functional opioid receptor gene variants or complex biomarkers obtained via multiple regression or decision tree analysis. The accumulation of several genetic variants with only minor functional influences may result in a qualitative consequence affecting complex phenotypes, pointing at emergent properties in genetics.

[Opioids for noncancer pain in the elderly]. / Opioide bei Nichttumorschmerz im höheren Lebensalter.

BACKGROUND: Opioids are increasingly used in the elderly. Side effects differ compared to other analgesics. PURPOSE: In this review article, special aspects about using opioids for noncancer pain in older people and in geriatric patients are identified. CURRENT SITUATION: So far randomized controlled trials for the indication of and comparison between various opioids have been performed in middle-aged patients and not exclusively in geriatric patients or elderly (> 75 years). Furthermore, the evidence for multimorbid elderly patients with respect to side effects is also very poor. RECOMMENDATIONS: The indication for opioid therapy should be narrow. The patient and their caregivers must be provided patient information regarding opioid therapy. The principle "start low, go slow" is highly recommended. To reduce the risk of falls, longer acting opioids should be used and short acting opioids should be avoided. Everyday relevant negative effects on cognition are possible in opioid use and have to be observed. As recommended in the recently published German guideline for long-term use of opioids in noncancer pain a critical check after 3 months and in case of dosing over 120 mg morphine equivalents is advisable, especially for older patients. Liver and kidney function and drug interactions have to be taken into consideration like in every age group.

[Psychological prophylaxis training for coping with postoperative pain. Long-term effects]. / Psychologisches Prophylaxetraining zur Bewältigung postoperativer Schmerzen. Langfristige Effekte.

INTRODUCTION: The present study was performed to investigate the effect of multidimensional psychological prophylaxis training focusing on coping with cognitive-emotional pain on recovery within the first 12 months after surgery. The training included the following three components: (1) education about pain, analgesia and psychological aspects of coping with pain, (2) training for coping with pain and (3) body-centered relaxation. MATERIAL AND METHODS: In the study 48 young male patients (surgical correction of a chest malformation) were assessed 1 day before surgery, at discharge and 3, 6 and 12 months postoperatively concerning postoperative pain intensity and pain disability as well as pain anxiety, pain catastrophizing and pain hypervigilance. Additionally, 24 of these patients received training on cognitive-emotional coping with pain 1 day before surgery and 1-3 days after surgery (each session 1 h). RESULTS: The proportion of patients with clinically relevant improvement was significantly higher in the training group compared to the control group. This was the case for acute pain intensity (approximately 1 week after surgery), pain disability 3 months later and pain anxiety 12 months after surgery. CONCLUSION: The resurgence of pain anxiety after 12 months could only be found in the control group and could be due to the upcoming surgical removal of the transsternal metal implant. The prophylaxis training can therefore be seen as a protective factor for long-term management of surgery-related consequences and future pain experiences.

[Circadian rhythm of PCA-based opioid consumption in children with chemotherapy-related mucositis]. / Zirkadianer Rhythmus des PCA-gesteuerten Opioidverbrauchs bei Kindern mit chemotherapiebedingter Mukositis.

BACKGROUND: In order to match the interindividual and intraindividual differences in opioid requirements of pediatric oncology patients with mucositis, patient-controlled analgesia (PCA) seems to be the optimal pain therapy option, but scientific data are lacking. METHOD: A retrospective chart review of PCA-treated children with mucositis was carried out over a 6-year period (2000-2006) at the university hospital for children in Erlangen. RESULTS: The median age of the patients was 12.6 years and they mainly suffered from forms of acute leukemia. Daily morphine equivalent dose (MED) requirements increased with the start of the PCA therapy from 14.5 mg/day to 18.7 mg/day (p=0.021; Wilcoxon test). Children required more opioids by bolus request during the night (10:01 p.m. to 06:00 a.m.; 6.28 mg; 13%) than during the other 8-hour intervals (06:01 a.m. to 02:00 p.m. and 02:01 p.m. to 10:00 p.m.; both 21.3 mg (43.5%) during the whole 10-day study period. In 8 out of 10 days there was a significant diurnal variation in opioid requirement with significantly lower requirement during the night (p<0.05 Friedman test). The median count of delivered and un-delivered bolus requests during the night was 0-1 and 0, respectively. CONCLUSION: PCA seems to be an ideal, dependable and feasible mode of analgesic administration for the individual titration of dose in children with chemotherapy-induced mucositis. This is expressed through the increase in daily self-administered opioid doses after starting PCA, the huge interindividual variability in opioid consumption and the rare event of an un-delivered bolus request during lock-out time. With the use of a background infusion, additional bolus requests are rare during the night.

[Multimodal group therapy for the elderly with chronic pain: concept and results in a before and after comparison]. / Multimodale Gruppentherapie bei Senioren mit chronischen Schmerzen : Konzept und Ergebnisse im Prä-post-Vergleich.

BACKGROUND: Multimodal pain therapy programs are increasingly being recommended as an effective treatment option also for elderly patients with chronic pain. However, data from Germany are limited. PATIENTS AND METHODS: A multimodal group program adapted to the specific needs of elderly pain patients over 70 years old (20 treatment days, over 10 weeks) was started in our pain clinic in June 2005. We evaluated clinical, psychometric and physical data at the beginning and at the end of the treatment program, and compared outcome results with a waiting list control group. RESULTS: A total of 24 patients (mean age 76.2+/-4.79 years) could be evaluated of which 21 patients suffered from musculoskeletal pain, 2 from neuropathic pain syndromes and 1 from headache. In the waiting-list control group 13 patients were included. There were no significant between-group differences regarding age, stages of chronification, pain intensity, duration of pain and pain diagnosis. CONCLUSIONS: A multimodal pain therapy program for elderly patients (over 70 years old) is an effective treatment option to reduce pain intensity and pain disability. Furthermore, life quality and physical performance improved. Long-term effects still have to be evaluated.

[Patient-controlled analgesia (PCA) in outpatients with cancer pain. Analysis of 1,692 treatment days]. / Patientenkontrollierte Analgesie (PCA) bei ambulanten Tumorschmerzpatienten. Analyse von 1692 Behandlungstagen.

INTRODUCTION: In the home-care setting, cancer pain patients in need of parenteral analgesia have to be switched to patient-controlled analgesia using portable pumps. But there is a paucity on data on the logistic requirements or the success rate of such a cost-intensive therapy performed by specialized home-care services. METHODS: In a retrospective study we analyzed data on care intensity, logistics and outcome of 46 consecutive palliative cancer patients with patient-controlled analgesia (PCA) in a home-care setting. RESULTS: On days 1, 2, and 3 of PCA the switch to parenteral analgesia resulted in a significant increase of the median daily opioid dose in comparison to the dose just prior to PCA. Concurrently, pain scores were significantly reduced. The median duration of PCA was 25 days (range 2-189 days). On average, each patient was seen by the home-care team every 7.4 days. The median duration of the home visits was 60 min (range, 10-190 min). Of the visits 20% were unscheduled, most of these visits being due to problems regarding analgesia. Most patients died at home. Insufficient analgesia required prefinal hospitalization in only a single case. CONCLUSION: If the indications are correct, intravenous PCA for palliative cancer pain patients results in higher opioid consumption and better pain control. Home-care PCA requires a lot of human and financial resources, but pain-related hospitalization can be prevented.

[Practical pain control in pediatric oncology. Recommendations of the German Society of Pediatric Oncology and Hematology, the German Association for the Study of Pain, the German Society of Palliative Care, and the Vodafone Institute of Children's Pain Therapy and Palliative Care]. / Praktische Schmerztherapie in der pädiatrischen Onkologie. Empfehlungen der Gesellschaft für Pädiatrische Onkologie und Hämatologie (GPOH), der Deutschen Gesellschaft zum Studium des Schmerzes (DGSS), der Deutschen Gesellschaft für Palliativmedizin (DGP) und des Vodafone-Stiftungsinstituts für Kinderschmerztherapie und Pädiatrische Palliativmedizin an der Vestischen Kinder- und Jugendklinik Datteln -- Universität Witten/Herdecke (IKP).

In pediatric oncology, optimal pain control is still a challenge. A structured pain history and the regular scoring of pain intensity using age-adapted measuring tools are hallmarks of optimal pain control. Psychological measures are as important as drug therapy in the prophylaxis or control of pain, especially when performing invasive procedures. Pain control is oriented toward the WHO multistep therapeutic schedule. On no account should the pediatric patient have to climb up the "analgesic ladder" - strong pain requires the primary use of strong opioids. Give opioids preferably by the oral route and by the clock - short-acting opioids should be used to treat breakthrough pain. Alternatives are i.v. infusion, patient-controlled analgesia, and transdermal applications. Constipation is the adverse effect most often seen with (oral) opioid therapy. Adverse effects should be anticipated, and prophylactic treatment should be given consistently. The assistance of pediatric nurses is of the utmost importance in pediatric pain control. Nurses deliver the basis for rational and effective pain control by scoring pain intensity and documenting drug administration as well as adverse effects. The nurses' task is also to prepare the patient for and monitor the patient during painful procedures. It is the responsibility of both nurse and doctor to guarantee emergency intervention during sedation whenever needed. In our guideline we comment on drug selection and dosage, pain measurement tools, and documentation tools for the purpose of pain control. Those tools may be easily integrated into daily routine.

[Long-term pediatric opioid based pain control. Case reports]. / Opioidtherapie chronischer Schmerzen bei Kindern. Fallbesprechungen.

Based on 4 case reports we focus on the peculiarities of long-term pediatric opioid based pain control. Case report #1, emphasizing the importance of adequate opioid dosing with reference to body weight, illustrates that with adequate management oral sustained-release opioid therapy is safe even in infants less than one year old. Case report #2 is the first report on the usage of buccal fentanyl citrate for pediatric break-through pain control. Case report #3 focuses on the adverse effects of opioid pain control in an infant with neurological impairment. Case report #4 reports on the successful tumor pain control using transdermal buprenorphine. We conclude that proven therapeutic strategies for opioid pain control as applied in adults may be adopted for the usage on children in pediatrics. However, it is mandatory to take into account both the pharmacokinetic and pharmacodynamic peculiarities of childhood.

[Pain assessment and pain treatment in the geriatric patient. Part II: pain treatment]. / Schmerzdiagnostik und -therapie in der Geriatrie. Teil II: Schmerztherapie.

A primary goal of pain treatment in geriatric patients consists of maintaining physical and mental function, which is a precondition of activity and participation. In patients with chronic pain, multidisciplinary treatment without excluding invasive procedures is the most effective approach. The medication ladder, suggested by the WHO initially for cancer pain, provides a guideline for pharmacological treatment. Due to age-dependent alterations in the kinetics and dynamics of pharmaceuticals, the titration of the medication follows the rule "start low and go slow." The same principle holds true for the maintenance or augmentation of physical activity in order to escape from the activity-deconditioning cycle. The training should be based on learning theories, include pain management strategies, and incorporate psychological approaches to facilitate the active participation of the patient in the treatment program. In hospitals and nursing homes, nurses play an important role in defining the need for pain treatment and in supervising the patient in the treatment process. Despite all these endeavors, a significant number of patients remains whose pain cannot be controlled sufficiently. Euthanasia on demand of the patient with untreatable pain is not admitted in Germany.

[Pain treatment in geriatric patients]. / Schmerztherapie in der Geriatrie.

A primary goal of pain treatment in geriatric patients is the maintenance of physical and mental functions. This is a precondition for activity and participation. In patients with chronic pain, multidisciplinary treatment, without excluding invasive procedures, is the most effective approach. The medication ladder, initially suggested by the WHO for cancer pain, provides a guideline for pharmacological treatment. Due to age-dependent alterations in the kinetics and dynamics of pharmaceuticals, the titration of the medication follows the rule "start low-go slow". The same principle holds true for the maintenance or augmentation of physical activity in order to escape from the activity-deconditioning cycle. Training should be based on learning theories, include pain management strategies, and incorporate psychological approaches to facilitate the active participation of the patient in the treatment program. In hospitals and nursing homes, nurses play an important role in defining the need for pain treatment and in supervising the patient in the treatment process. Despite these endeavours, a significant number of patients remain whose pain cannot be controlled sufficiently. Euthanasia on demand for a patient with untreatable pain is not admitted in Germany.

[Monitoring of patient-controlled analgesia by the nursing staff]. / Uberwachung der patientenkontrollierten Analgesie (PCA) durch den Pflegedienst auf Allgemeinstationen.

OBJECTIVE: Patient-controlled analgesia (PCA) is employed successfully on surgical wards. Continuous monitoring is important for the safety of the patient and the efficiency of this form of pain therapy. In the study we evaluated the regularity and completeness of monitoring data which had been collected by the nursing staff on the surgical wards. METHODS: Data on pain intensity, vital signs, and side effects were collected. Additionally, in the case of epidural analgesia, sensory and motor function were tested. In the first four hours after starting the PCA-pump, the nursing staff was instructed to document this data hourly (phase I), followed by a two hour interval until 8 am the next day (phase II). In general, monitoring was continued every four hours up to the discontinuation of the PCA; whereas in our study only forty hours (10 measurements) were included (phase III). Documentation protocols of 637 patients were evaluated and tested for the completeness of the data. RESULTS: In phase I, the data of 128 patients (20%) were complete. In 173 patients (27%) less than 50% of the data were documented. During phase II, only in 98 patients (15%) the data collection was complete. In 237 patients (37%) less than 50% of the measurements were determined. In phase III, in 205 patients (32%) all measurements, and in 104 patients (16%) less than 50% of the measurements were documented. CONCLUSION: Complications during PCA become manifest mainly during the first hours after starting the PCA-pump. Especially during these phases, documentation was found to be quite poor. This underlines the importance of an intense cooperation between acute-pain service and nursing staff with periodical training of the staff.

[A structured pain interview for geriatric patients]. / Ein strukturiertes Schmerzinterview für geriatrische Patienten.

BACKGROUND: In old age, assessment of pain often is hampered by sensory and cognitive deficits that do not allow the patients to fill in standardized questionnaires without help from significant others. Therefore, as an alternative, we developed a structured pain interview, and examined its properties and acceptance in a sample of geriatric patients with pain. METHODS: The interview covers site of pain, intensity of pain, its duration and persistency, pain related disability and, finally, emotional and cognitive variables. In addition, the interviewer addresses significant others to get information about medication, previous treatment, and residence, and administers the Mini-Mental-State-Examination (MMSE). The analysis includes 128 patients of pain centers older than 74 years, of whom 80% are female. RESULTS: Forty percent of the subjects score below the critical MMSE value < or =23 indicative of cognitive impairment. These patients are responsible for 36 out of a total of 39 missing values. A significant increase of missing values is observed in patients with a MMSE score below 10. Cognitive impairment goes along with greater functional and social disability. On the other hand, cognitive impairment is unrelated to localization, intensity, and duration of pain. The memory item of the MMSE can be used as a screening tool for cognitive impairment. Patients, who are unable to recall any of the three objects, comprise 80% of the total of missing values and demonstrate a low MMSE score. CONCLUSION: As long as geriatric patients are able to communicate verbally, they are most likely to profit from the structured pain interview in spite of existing cognitive impairment. A MMSE score <10 indicates that the interpretation of the data obtained may be difficult, especially due to a high frequency of missing values.

[Management of postoperative pain in children]. / Postoperative Schmerztherapie bei Kindern und Jugendlichen.

TREATMENT OF PAIN: Undertreatment of postoperative pain in children is a problem in clinical practice. This is due to a lack of both knowledge about age-specific aspects of physiology and pharmacology, and routine pain assessment. For example, the fear of side-effects prevents the adequate usage of opioids. It is of major importance to select a route of drug administration where the child feels comfortable with (avoid intramuscular injections). NON-OPIOID ANALGESICS: Non-opioid analgesics are recommended for basic pain treatment after minor surgical procedures. Instead of using the whole multitude of drugs available, the doctor should stick to those drugs he is familiar with (acetaminophen, ibuprofen, diclofenac, dipyrone). OPIOIDS: Opioid usage requires individual dose titration and careful monitoring of side-effects (respiratory monitoring, sedation score). The strong opioids piritramide and morphine may advantageously be administered as either continuous, or patient-controlled iv- infusion (PCA). FORMS OF THERAPY: In addition to infiltration anesthesia, intraoperatively applied nerve blocks provide excellent pain relief. Epidural analgesia with local anesthetics and/or opioids via a thoracic or lumbar epidural catheter is a therapeutic option after thoracic or abdominal surgery, or after extensive orthopedic or urological interventions. Adjuvant analgesics and nonpharmacologic interventions, i. e. transcutaneous electrical nerve stimulation (TENS), are primarily indicated in patients suffering from neuropathic pain. CONCLUSION: The establishment of pain services and the comprehensive education of both the nursing and the medical staff should help to improve postoperative pediatric pain therapy.

[Complex regional pain syndrome. Clinical and autonomic disorders during acute and chronic illness stages]. / Komplexes regionales Schmerzsyndrom. Klinik und autonome Störung während akuter und chronischer Krankheitsstadien.

In order to describe autonomic dysfunction and clinical outcome in complex regional pain syndrome (CRPS) 20 patients were followed-up. First investigation was performed in the acute stage of CRPS and the second investigation two years later after therapy (individual, not standardized). Skin temperature and sudomotor function (thermoregulatory sweating (TST) and quantitative sudomotor axon reflex (QSART)) were assessed, and a clinical follow-up was performed carefully. Skin temperature was warmer on the affected side at first investigation (p < 0.001) and colder at follow-up (p < 0.02). Sudomotor output was enhanced on the affected side both after TST (p < 0.005) and QSART (p < 0.05) at first investigation. At follow-up, however, while thermoregulatory sweating was still increased (p < 0.04) QSART was not different. While autonomic failure improves as assessed by clinical examination, therapy failed to alleviate pain significantly. But patients' self-assesment of therapy was mostly positive (16 of 20, p < 0.001). The present study has shown that the autonomic failure may be probably the result of central disturbances of thermoregulation, but secondary peripheral mechanisms also contribute to our findings. Individual based therapy seems to be efficacious for long term treatment, but for final judge controlled studies are required.

[Practice of pain control in paediatric oncology--recommendations of the quality-monitoring group of the German Society for Paediatric Oncology and Haematology (GPOH)]. / Praktische Schmerztherapie in der Kinderonkologie. Auszüge aus den Empfehlungen der Qualitätssicherungsgruppe der Gesellschaft für Pädiatrische Onkologie und Hämatologie (GPOH).

In paediatric oncology, optimal pain control is still a challenge.A structured pain history and the regular scoring of pain intensity using age-adapted measuring tools are hallmarks of optimal pain control. Psychological measures are as important as drug therapy in prophylaxis or control of pain, especially when performing invasive procedures. Pain control is oriented on the WHO analgesic ladder. On no account the paediatric patient should have to climb up the 'analgesic ladder'- strong pain requires the primary use of strong drugs. Opioids should be given by the oral route and by the clock - short acting opioids should be used to treat break-through pain. Alternatives are IV infusion and patient-controlled analgesia. Constipation is the adverse effect most often seen with (oral) opioid therapy. Adverse effects should be anticipated, and prophylactic treatment should be given consistently. The assistance of paediatric nurses is of utmost importance in paediatric pain control. Nurses' deliver the basis for rational and effective pain control by scoring pain intensity and documenting drug administration as well as adverse effects. The nurses task is also to prepare the patient for and monitor the patient during painful procedures. It is the responsibility of both nurse and doctor to guarantee emergency intervention during sedation whenever needed. In our paper we comment on drug selection and dosage, pain measurement tools, and documentation tools for the purpose of pain control. Those tools may be easily integrated into daily routine.

[Tramadol infusion for pain therapy following bladder exstrophy surgery in pediatric wards]. / Tramadol-Infusion zur Schmerztherapie nach grossen Blaseneingriffen auf Kinderstationen.

We investigated in 17 children (mean 7.1 years) the continuous administration of tramadol following augmentation cystoplasty or exstrophy reconstruction. Mean duration of the tramadol administration on the pediatric ward was 3.8 +/- 1.1 days (initial dosage 0.25 mg/kg/per hour, dose adjustment by the nursing staff). Mean tramadol consumption was 0.21 mg/kg/h on day 1 and was reduced to 0.08 mg/kg/per hour on day 4. Median pain score (assessed with ten-step scales) was 5 before treatment and between 2.5 (day 1) and 0.5 (day 5) during therapy. Lowest oxygen saturations (mean) ranged from 93.8% to 95.2%. Three patients (17.6%) suffered from nausea/vomiting on 3 of 64 treatment days (4.7%). Pruritus and extreme sedation did not occur. The continuous administration of tramadol is a simple and safe procedure following major urological surgery in children.