Patientenkontrollierte Analgesie (PCA) bei ambulanten Tumorschmerzpatienten

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.     

Schwere Atemdepression durch unkorrekt verschlossene Pharmacia CADD-PCA-5200-Pumpe

CASE REPORT: We report a case of severe respiratory depression during postoperative patient-controlled analgesia (PCA) in a 14-year-old boy. The medication cassette of a Pharmacia CADD-PCA 5200 was not properly connected, which led to a free-flow infusion of about 85 mg piritramide (strong mu-opioid agonist) within 15 min; the patient lost consciousness and developed apnea. He was successfully treated with artificial ventilation via ambu-bag and 0.2 mg naloxone i. v. The incident occurred approx. 2 h after the start of postoperative medication, when other infusions (suspended above the PCA device level) had been stopped, making the free-flow opioid infusion possible. As the PCA device was in a bedside pump enclosure, the disconnection was not immediately apparent. DISCUSSION: Although PCA is considered a safe method, it can have potentially lethal complications: Technical problems or serious handling errors involve the risk of large volumes of analgesics being infused within a very short time. Therefore, we recommend apparative monitoring (e. g., pulse oximetry) as a necessary condition for the safe use of PCA.     

Low-dose lidocaine reduces secondary hyperalgesia by a central mode of action

Sodium channel blockers are approved for intravenous administration in the treatment of neuropathic pain states. Preclinical studies have suggested antihyperalgesic effects on the peripheral as well as the central nervous system. The objective of this study was to determine mechanisms of action of low-dose lidocaine in experimental induced, secondary hyperalgesia. In a first experimental trial, participants (n=12) received lidocaine systemically (a bolus injection of 2 mg/kg in 10 min followed by an intravenous infusion of 2 mg kg(-1)h(-1) for another 50 min). In a second trial, a modified intravenous regional anesthesia (IVRA) was administered to exclude possible central analgesic effects. In one arm, patients received an infusion of 40 ml lidocaine, 0.05%; in the other arm 40 ml NaCl, 0.9%, served as a control. In both trials capsaicin, 20 microgram, was injected intradermally and time course of capsaicin-induced pain, allodynia and hyperalgesia as well as axon reflex flare was determined. The capsaicin-induced pain was slightly reduced after systemic and regional application of the anesthetic. The area of pin-prick hyperalgesia was significantly reduced by systemic lidocaine, whereas the inhibition of hyperalgesia was absent during regional administration of lidocaine. In contrast, capsaicin-induced flare was significantly decreased after both treatments. We conclude that systemic lidocaine reduces pin-prick hyperalgesia by a central mode of action, which could involve blockade of terminal branches of nociceptors. A possible role for tetrodotoxin resistant sodium channels in the antihyperalgesic effect of low-dose lidocaine is discussed.     

Postoperative transkutane elektrische Nervenstimulation (TENS)

BACKGROUND: The aim of this study was to determine whether 3 days of TENS therapy postoperatively after shoulder operations would result in better pain relief and/or reduced analgesic intake when compared to placebo. METHOD: The study was carried out randomized, double-blind and placebo controlled. Thirty patients were randomized to two groups. The verum group received TENS SM1AKS 80 Hz 6 mA and the placebo group received TENS SM1AKS 80 Hz 0 mA. The pain was assessed pre-operatively using the Hamburg Pain Adjective List. Premedication and Anaesthesia were standardized. TENS was applied to the patients immediately postoperatively for 8 hours and then on the following days 5 times daily for 45 minutes. The effectiveness was evaluated postoperatively using a visual analogue scale (rest, activity), the Hamburg Pain Adjective List and postoperative analgesic consumption. RESULTS: The visual analogue scale at rest and on activity showed no significant difference between the groups. Postoperative analgesic consumption of morphine hydrochloride in the first 24 hours was at time 8 hours postoperative significantly and at all other time points markedly less in the verum group compared to the placebo group. The sensory secondary scale score of the "Hamburg Pain Adjective List" was significantly lower postoperatively compared to preoperatively in the verum group. CONCLUSION: We were able to show in this study that TENS applied postoperatively after shoulder surgery clearly reduced analgesic consumption in the first 72 hours. Furthermore there was a significant difference in the pain scores using the "Hamburg Pain Adjective List" in favour of the verum group. TENS applied postoperatively is a effective, simple modality with few side-effects.     

Psychologisches Prophylaxetraining zur Bewältigung postoperativer Schmerzen

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.     

Low-dose Lidocaine Suppresses Experimentally Induced Hyperalgesia in Humans

Background: The antinociceptive effects of systemically administered local anesthetics have been shown in various conditions, such as neuralgia, polyneuropathy, fibromyalgia, and postoperative pain. The objective of the study was to identify the peripheral mechanisms of action of low-dose local anesthetics in a model of experimental pain.

Methods: In a first experimental trial, participants (n = 12) received lidocaine systemically (a bolus injection of 2 mg/kg in 10 min followed by an intravenous infusion of 2 mg [middle dot]-1 [middle dot] h-1 for another 50 min). In a second trial, modified intravenous regional anesthesia was administered to exclude possible central analgesic effects. In one arm, patients received an infusion of 40 ml lidocaine, 0.05%; in their other arm, 40 ml NaCl, 0.9%, served as a control. In both trials, calibrated tonic and phasic mechanical and chemical (histamine) stimuli were applied to determine differentially the impairment of tactile and nociceptive perception.

Results: Mechanical sensitivity to touch, phasic mechanical stimuli of noxious intensity, and heat pain thresholds remained unchanged after systemic and regional application of the anesthetic. In contrast, histamine-induced itch (intravenous regional anesthesia), axon reflex flare (systemic treatment), and development of acute mechanical hyperalgesia during tonic pressure (12 N; 2 min) of an interdigital web was significantly suppressed after both treatments.     

Challenging the equipotency calculation for transdermal buprenorphine: four case studies

AIMS: Opioids produce analgesia via different pain pathways. The aim of these case studies was to address the issue of opioid rotation or switching, raising the important issue of conversion ratios between different compounds and routes of administration. RESULTS: We present two cases of neuropathic pain and two cases of nociceptive pain with a significant neuropathic component, which were successfully treated with transdermal buprenorphine after the failure of other opioids. CONCLUSION: In each case, effective pain relief was produced by a lower dose than the proposed equipotency ratio of 1:75 would indicate, suggesting that a ratio of 1:110 to 1:115 may be more appropriate.