J. Jage

Opioid tolerance and dependence — do they matter?

The use of opioids has long been accepted as the standard of care in patients with cancer and acute pain. Opioids can further be used effectively in specific subgroups of patients with chronic nonmalignant pain states. While the development of tolerance and physical dependence are known effects of opioids in cancer and noncancer pain populations, these patients can not be regarded as addicted. However, long‐term therapy with short‐acting opioids predisposes to tolerance and addiction.

Efficacy of vertical infraclavicular plexus block vs. modified axillary plexus block: a prospective, randomized, observer-blinded study

Background:  Despite containing severe risks, infraclavicular approaches to the brachial plexus gained increasing popularity. Likewise, the vertical infraclavicular plexus block improved anesthesia compared to the standard axillary approach but contains the risk of pneumothorax. Therefore we modified the standard axillary technique by inserting a proximal directed catheter, referred to as a high axillary plexus block. We prospectively compared quality and onset of neural blockade after vertical infraclavicular plexus block (VIP) and high axillary plexus block (HAP) in two randomized groups (30 patients in each).

Postoperative analgesia in patients with substance use disorders: Part II

Summary The specific problems related to postoperative analgesia in patients with substance use disorders (SUD) concerning opioids, alcohol, benzodiazepines, barbiturates (Part I), cocaine, crack, amphetamines, amphetamine-like designer drugs (MDMA, ecstasy), LSD, and marijuana (Part II) are described. Whereas SUD with only one substance rarely occurs, the number of polysubstance abusers is increasing. Patients with SUD may have multiple organic diseases, impaired immune response psychiatric and behavioural abnormalities, and substance-induced disorders (intoxication, withdrawal, delerium, psychotic disorders), often associated with low compliance and craving behaviour. The perioperative management should be focused on three problems: (1) on the prevention of physical withdrawal symptoms and stressful complications in patients with SUD using CNS-depressants, (2) on the symptomatic treatment of the predominant affective withdrawal symptoms in patients suffering from SUD with CNS-stimulants, and (3) on the effective pain treatment. The analgesic therapy is often difficult and required for longer periods of time than in other patients. However, the principles of multimodal analgesia are as valid as in non-addicts. To be effective, systemic analgesia with paracetamol, NSAIDs and opioids has to be adapted as usual, but regional analgesia techniques should be preferred for postoperative pain relief. Patients enrolled in preoperative maintenance programmes (methadone, buprenorphine) need their daily maintenance dosage as baseline. This baseline therapy does not, however, induce analgesia. Therefore, these patients need additional short-acting opioids which have to be administered at higher dosages than usual (which do not cause respiratory depression due to opioid tolerance). The additional opioid does not increase the risk of relapse into active SUD. On the other hand, regional analgesia in patients who are enrolled in a maintenance programme does not mean withdrawal prophylaxis. These patients have an excellent analgesia, but they need their previously used maintenance opioid to prevent withdrawal. Special considerations will have to be made in patients with naltrexone. Recovering patients with a history of SUD have both an intensive fear of relapsing into the active SUD as well as fear of suffering from postoperative pain. These patients require an equally effective analgesia as other patients. Depending on the type of surgery and pain intensity they need atypical opioids (eg tramadol) or strong opioids (eg buprenorphine or morphine) as a part of balanced analgesia to the same degree as other patients. Withholding effective analgesic treatment can paradoxically lead to relapses in recovering patients. The common opinion of healthcare providers to withhold strong opioids from recovering patients with SUD is obsolete. However, in order to avoid psychotropic side effects the dosages of opioids, as well as the analgesic efficacy, should be monitored closely.

Medikamente zur postoperativen Schmerztherapie: Bewährtes und Neues

In part 1 of this review the perioperative aspects of the use of non-opioids (acetaminophen, dipyrone, traditional NSAR, coxibs) and in part 2 of opioids (weak opioids: tramadol, tilidine with naloxone, strong opioids: morphine, piritramide, oxycodone, hydromorphone, fentanyl, methadone, buprenorphine) and coanalgesics (gabapentinoids, ketamine) will be discussed. The main aim is to describe the relationship between analgesic efficacy and side effects to make clinical decisions easier in patients with preoperative renal, gastrointestinal, cardiovascular and other diseases. Some new aspects concerning perioperative administration of gabapentinoids and ketamine in patients with perioperative neuropathic pain are discussed.

Intraoperative tramadol reduces shivering but not pain after remifentanil-isoflurane general anaesthesia. A placebo-controlled, double-blind trial.

Background and objective Postoperative shivering and pain are frequent problems in patients recovering from anaesthesia with particularly high incidences being observed after remifentanil–isoflurane‐based general anaesthesia. The opioid tramadol is generally effective in preventing shivering and treating pain, but its effects are not characterized after remifentanil‐based general anaesthesia. This randomized, placebo‐controlled, double‐blind study evaluated the effects of intraoperative intravenous tramadol on postoperative shivering and pain after remifentanil‐based general anaesthesia. Methods After Ethics Committee approval, 60 patients scheduled for lumbar disc surgery were included. Surgery was performed under general anaesthesia (remifentanil, isoflurane). Patients were randomly assigned to receive 2 mg kg−1 tramadol in 30 mL 0.9% saline infused intravenously (n = 30) or 30 mL saline (n = 30) 45–30 min before skin closure. The following parameters were assessed every 10 min for 2 h: shivering, pain, postoperative nausea and vomiting, sedation, heart rate, non‐invasive blood pressure and peripheral oxygen saturation. The primary outcome variable was the incidence of shivering during the first 2 postoperative hours. Secondary variables were: shivering intensity, pain, postoperative nausea and vomiting, sedation, heart rate, non‐invasive blood pressure and peripheral oxygen saturation. Results Shivering was less frequent in patients treated with tramadol (20% vs. 70%, P = 0.0009) and was of lower intensity (severe shivering: 10% vs. 46.7%, P = 0.003). Pain scores were similar between the groups and all other secondary outcome variables failed to reveal significant differences. Conclusions Compared with placebo, intraoperative intravenous administration of 2 mg kg−1 tramadol reduces the incidence and extent of postoperative shivering without alterations in pain perception after lumbar disc surgery under remifentanil–isoflurane‐based general anaesthesia.

Postoperative Schmerztherapie Teil II

Die peripheren und rückenmarknahen Analgesieverfahren haben in der postoperativen Phase einen wichtigen Stellenwert (Tabelle 7). Die einmalige periphere Bolusinjektion erzeugt eine Schmerzfreiheit in der frühen postoperativen Phase, Kathetertechniken erlauben eine mehrtägige Analgesie. Der in einer Allgemeinnarkose operierte Patient ist in der c frühen postoperativen Phase gegenüber dem in Regionalanästhesie operierten Patienten unter Umständen benachteiligt. Er benötigt wesentlich früher ein Analgetikum [24a]. Sein Zustand bewegt sich nicht selten zwischen einem Überhang an sedierenden Narkotika und schmerzbedingter Unruhe, Hypertonie und Tachykardie. In dieser Phase muß die Opioidgabe besonders vorsichtig erfolgen. Andererseits wird der Patient durch starke Schmerzen belastet [53], kardiale Vorschädigungen können sich gravierend auswirken. Die epidurale Analgesie in Kombination mit einer Allgemeinanästhesie [31, 86] bietet beispielhaft den Vorteil, die Narkose bei gleichzeitig bestehender optimaler Analgesie auszuleiten. Der Gesamtsauerstoffverbrauch in der Aufwachphase ist im Vergleich zu dem nach alleiniger Allgemeinanästhesie reduziert [11], der Patient ist schmerzfrei und zufrieden.Günstige Auswirkungen einer effektiven epiduralen Analgesie auf den Gesundungsprozeß sind aus vielen Gründen zu erwarten [3, 5, 15, 18, 23, 29, 32]. Vor der Anwendung von Katheterverfahren zur längerdauernden Schmerztherapie müssen Kompetenzund Überwachungsprobleme geklärt sein. Ohne eine c Absprache mit dem Operateur und ohne die Einweisung der Pflegekräfte in die besonderen Probleme einer vielleicht tagelangen Epiduralkatheteranalgesie (Beeinträchtigung von Motorik, Kreislauf, Blasenund Darmfunktion, Minderung der Hautempfindlichkeit mit der Möglichkeit des nicht bemerkten Entstehens von Druckstellen an den Fersen, Verschleierung neurologischer oder operativ bedingter Komplikationen) sollte diese nicht durchgeführt werden. Die postoperative Betreuung der epiduralen Analgesie erfordert anästhesiologische Verantwortlichkeit, die nur im Ausnahmefall auf die operativen Fachkollegen übertragbar ist [5a].

Epidural ropivacaine -- where are the benefits? A prospective, randomized, double-blind trial in patients with retropubic prostatectomy.

Background:  In comparison with bupivacaine, ropivacaine exhibits comparable anaesthetic effects but with less motor impairment and systemic toxicity. However, the analgesic potency may differ. For example, ropivacaine during obstetric epidural analgesia provides an approximately 40% lower analgesic potency than bupivacaine. Equal visual analogue pain scores require significantly higher dosages of ropivacaine, and general statements about a favourable benefit–risk profile relative to that of bupivacaine may therefore have limited clinical impact. We addressed this topic in a male pain model by evaluating the analgesic efficacy of epidural ropivacaine 0.2% vs. bupivacaine 0.125% after retropubic prostatectomy.

[Drugs for postoperative analgesia: routine and new aspects. Part 1: non-opioids].

In part 1 of this review the perioperative aspects of the use of non-opioids (acetaminophen, dipyrone, traditional NSAR, coxibs) and in part 2 of opioids (weak opioids: tramadol, tilidine with naloxone, strong opioids: morphine, piritramide, oxycodone, hydromorphone, fentanyl, methadone, buprenorphine) and coanalgesics (gabapentinoids, ketamine) will be discussed. The main aim is to describe the relationship between analgesic efficacy and side effects to make clinical decisions easier in patients with preoperative renal, gastrointestinal, cardiovascular and other diseases. Some new aspects concerning perioperative administration of gabapentinoids and ketamine in patients with perioperative neuropathic pain are discussed.

Intraoperative clonidine modulates sympathetic tone in the early postoperative period after remifentanil. A double blind, placebo-controlled study

Abstract Aim of the study : Severe pain following major surgery can impair the control of the cardiovascular system (CVS) by causing sympathetic stimulation, possibly leading to myocardial ischaemia. In this study we examine the influence of intraoperative intravenous (i.v.) clonidine infusion on postoperative analgesia and blood concentrations of noradrenaline and adrenaline after major gynaecological surgery. Methods : All patients underwent an abdominal hysterectomy under balanced general anaesthesia using the new opioid remifentanil. The patients were randomised to receive either 5 μg kg −1 of i.v. clonidine intraoperatively ( n =20), or placebo ( n =20). Over a period of 240 minutes postoperatively we assessed pain intensity, consumption of the opioid piritramide (a μ-receptor agonist) via an i.v. patient controlled analgesia device, together with blood pressure, heart rate, shivering, nausea, vomiting and sedation. Blood concentrations of adrenaline and noradrenaline in both groups were analysed using HPLC. Results : Postoperative pain intensity and opioid consumption were not influenced by intraoperative clonidine. Clonidine, however, did modulate the postoperative sympathetic tone, and the steep rise of plasma catecholamine concentrations, as part of the postoperative stress response, was clearly diminished. The haemodynamic effects of clonidine in the form of a significant reduction in mean arterial pressure and heart rate, were only seen in the first 15 minutes postoperatively. Conclusion : Intraoperative infusion of clonidine 5 μg kg −1 modulates the postoperative sympathetic tone after abdominal hysterectomy under anaesthesia with remifentanil, resulting in a decreased haemodynamic stress response. Surprisingly, a clonidine dose of 5 μg kg −1 had no influence on postoperative pain or opioid consumption.

Postoperativer Morphinexzess oder rationale Therapie?Eine ungewöhnliche Kasuistik zur Anwendung des Morphinäquivalents

ZusammenfassungWir berichten über eine 51-jährige Patientin mit 7-jähriger Mamma-Ca-Anamnese, bei der im August 2000 ein operativer Ersatz des 8. Brustwirbelkörpers vorgenommen wurde. Ab November 2000 klagte die Patientin über zunehmende belastungsabhängige Schmerzen wegen weiterer Wirbelkörpermetastasen, die laut Patientenakte zu folgender Schmerztherapie führten: Sechsstündlich 320 mg MST® per os, Durogesic® 100 μg/h transdermal, 40 mg Sevredol® per os achtstündlich und 800 mg Ibuprofen per os achtstündlich. Wegen fortbestehender Schmerzen und drohender Instabilität erfolgte eine dorsale Spondylodese Th4–L2. Unmittelbar nach Ende der Allgemeinanästhesie extreme Schmerzen, die in den ersten 120 min die fraktionierte intravenöse Injektion von insgesamt 660 mg Morphin erforderten; keine Übelkeit, stärkere Sedierung oder Atemdepression. Nach Befragung der Patientin stellte sich der präoperative tägliche Opioidverbrauch überraschenderweise um 60% höher als angenommen heraus. Die Analgesie wurde über Perfusor und i.v.-PCA mit Morphin fortgesetzt (mittlere parenterale Tagesdosierungen 600–800 mg). Im weiteren Verlauf erfolgte die Umstellung auf orales Morphin (2400 mg MST® per os + 400 mg Morphin-HCl per os bei Bedarf ein- bis zweimal/Tag) und Koanalgetika und die häusliche Entlassung nach 14 Tagen. Problemstellung. Einige Patienten mit tumorbedingten Schmerzen benötigen vor geplanten großen Operation sehr hohe Opioiddosierungen. Werden diese perioperativ nicht fortgesetzt und aktuell angepasst, tritt analgetische Unterversorgung ein. In der Kasuistik wird der Ablauf einer schwerwiegenden postoperativen analgetischen Unterversorgung bei einer Patientin mit hohen präoperativen Opioiddosierungen beschrieben. Grundzüge der postoperativen Dosisfindung bis in Extrembereiche und logistische Fallstricke werden erläutert.AbstractWe report on a 51-year-old female with a 7 year history of breast cancer. In August 2000 surgical replacement of the 8th thoracic vertebra was performed. From November 2000 the patient developed progressive pain, due to additional spine metastases, leading to a pain therapy (according to the patient record) as follows: MST® 320 mg oral 4 times daily, Durogesic® 100 μg/h transdermal, Sevredol® 40 mg oral 3 times daily and Ibuprofen 800 mg oral 3 times daily. Due to the risk of spinal instability and persisting pain a thoracic spondylodesis from Th 4–L 2 was performed. Parallel to arrival in the PACU the patient developed extremly intensive pain. Pain control was achieved by fractional injection of overall 660 mg morphine in the first 120 min. After interviewing the patient, opioid consumption surprisingly turned out to be 60% higher than presumed. Pain therapy was continued by infusion and PCA with morphine in a daily intravenous dosage of 600–800 mg. Consecutively the pain therapy was switched to oral morphine and co-analgesics and the patient was discharged home 14 days postoperatively. Problem. Some patients with chronic cancer pain are used to increased opioid dosages prior to planned surgery. In the perioperative setting these dosages have to be continued and adapted to current requirements, otherwise analgesic undersupply occurs. In our case report we describe a serious sequence of postoperative analgesic undersupply in an opioid consuming patient. The main principles of post-operative dosing and logistic pitfalls are illustrated.