Continuous epidural analgesia with bupivacaine-fentanyl versus patient-controlled analgesia with i.v. morphine for postoperative pain relief after knee ligament surgery

BACKGROUND: Both epidural analgesia and intravenous patient-controlled analgesia (PCA) have been found efficacious after various types of surgery. We compared the efficacy, safety, side effects and patient satisfaction of these methods in a randomized double-blind fashion after elective anterior cruciate ligament reconstruction of the knee. METHODS: Fifty-six patients had an epidural catheter placed at the L2-L3 interspace. Spinal anaesthesia with 15 mg of plain bupivacaine 5 mg/ml was performed at the L3-L4 interspace. After surgery the patients were randomly divided into three groups: 19 received a continuous epidural infusion with bupivacaine 1 mg/ml and fentanyl 10 mg/ml (F10), 19 patients received bupivacaine 1 mg/ml and fentanyl 5 microg/ml (F5) and 18 patients received saline (S). The rate of the epidural infusions was 0.1 ml kg(-1) h(-1). Each patient could also use an intravenous (i.v.) PCA device with 40 microg/kg bolus doses of morphine with a lockout period of 10 min and a maximum dose 240 microg kg(-1) h(-1). At the end of surgery ketoprofen 100 mg i.v. was given and continued orally three times a day. Patients were assessed for pain with a visual analogue scale (VAS) at rest and during activity, side effects and satisfaction at 3, 9 and 20 h. RESULTS: Both epidural infusions (F10, F5) provided better analgesia than epidural saline plus i.v. PCA (S) (P<0.05). There was slightly less nausea in the S group (NS). In spite of the difference in the quality of pain relief, there was no difference between the groups in patient satisfaction regarding analgesic therapy. CONCLUSION: Epidural infusion of fentanyl (1 microg kg(-1) h(-1) or 0.5 microg kg(-1) h(-1)) and bupivacaine (0.1 mg kg(-1) h(-1)) provided better pain relief but more side effects than intravenous morphine patient-controlled analgesia after knee ligament surgery. Almost all patients in all groups were satisfied with their pain relief.     

Influence of opioids on the vascular tone of isolated porcine coronary artery segments

BACKGROUND: It was the aim of this study to elucidate the influence of opioids on coronary vascular tone using the model of isolated porcine coronary artery segments. METHODs: We studied the effects of fentanyl (0.01, 0.1, 1.0 microg ml(-1)), alfentanil (0.1, 1.0, 10 microg ml(-1)), and sufentanil (0.01, 0.1, 1.0 microg ml(-1)) on the contractile response to three vasoconstrictors, acetylcholine, histamine and serotonin. RESULTS: Fentanyl (0.1, 1.0 microg x ml(-1)) dose-dependently attenuated the contractile response to acetylcholine, but not to histamine and serotonin. There were no differences in fentanyl's vasorelaxing potency between rings with intact and denuded endothelium. Alfentanil and sufentanil did not exert any significant influence on any of the vasoconstrictors tested. CONCLUSION: It is concluded that, in isolated porcine coronary artery rings, fentanyl at high concentrations has an attenuating effect on acetylcholine-induced contractions, which is independent of endothelial function, whereas alfentanil and sufentanil do not influence coronary vascular tone.     

The pharmacokinetics of anesthetic drugs and adjuvants during cardiopulmonary bypass

The institution of cardiopulmonary bypass during cardiac surgery has profound effects on the plasma concentration of drugs and thus their therapeutic effectiveness. These changes occur through acute hemodilution, altered plasma protein binding, hypotension, as well as the use of hypothermia and heparin administration. Isolation of the lungs from the circulation and the possible sequestration of drugs in the bypass circuit also affect drug plasma concentrations on bypass. The individual characteristics of the drug in question are also important in determining the final plasma concentration: Lipid soluble drugs with a high volume of distribution may be more readily taken up by bypass equipment, but the initial fall in concentration at the start of cardiopulmonary bypass may be more readily counteracted by back diffusion into plasma, if large tissue stores have accumulated. The extent of the drug's plasma protein binding is of importance as the effective free fraction in plasma for highly bound drugs will be sensitive to changes in plasma protein binding brought on by factors such as hemodilution, heparin administration as well as alpha, acid-glycoprotein binding. Clearly the fate of drugs administered before or on bypass is complex and can only be accurately determined by specific studies evaluating drug plasma concentrations. This review updates the available data on anesthetics and drugs used during cardiac surgery in order that anesthetists may predict better the likely effect of drugs administered before or during cardiopulmonary bypass.     

Functional antagonism by calcium of an intrinsic opioid mechanism in the guinea-pig isolated ileum

In the guinea-pig isolated ileum, elevation of the extracellular concentration of calcium attenuated the excitatory influence of the opiate antagonist, naloxone, upon peristalsis. Application of 4-aminopyridine, which enhances calcium influx into cells, had a still more pronounced effect. Further, 4-aminopyridine impaired the inhibitory action of both morphine and the presynaptic α-adrenergic agonist, clonidine, upon peristalsis.The present data are consistent with the view that the intestinal mechanism subjected to naloxone blockade may function similarly to that proposed to explain the action of narcotics or of presynaptic α-adrenergic agonists upon other preparations. This mode of action may involve a reduction in the quantity of intracellular free ionized calcium available to the stimulus-release-coupling mechanism.     

Nonopioid perioperative analgesia in head and neck cancer surgery: A systematic review

ObjectiveManagement of postoperative pain after head and neck cancer surgery is a complex issue, requiring a careful balance of analgesic properties and side effects. The objective of this review is to discuss the efficacy and safety of multimodal analgesia (MMA) for these patients.MethodsPubmed, Cochrane, Embase, Scopus, and clinicaltrials.gov were systematically searched for all comparative studies of patients receiving MMA (nonsteroidal anti‐inflammatory drugs (NSAIDs), acetaminophen, anticonvulsants, local anesthetics, and corticosteroids) for head and neck cancer surgeries. The primary outcome was additional postoperative opioid usage, and secondary outcomes included subjective pain scores, complications, adverse effects, and 30‐day outcomes.ResultsA total of five studies representing 592 patients (MMA, n = 275; non‐MMA, n = 317) met inclusion criteria. The most commonly used agents were gabapentin, NSAIDs, and acetaminophen (n = 221), NSAIDs (n = 221), followed by corticosteroids (n = 35), dextromethorphan (n = 40), and local nerve block (n = 19). Four studies described a significant decrease in overall postoperative narcotic usage with two studies reporting a significant decrease in hospital time. Subjective pain scores widely varied with two studies reporting reduced pain at postoperative day 3. There were no differences in surgical outcomes, medical complications, adverse effects, or 30‐day mortality and readmission rates.ConclusionMMA is an increasingly popular strategy that may reduce dependence on opioids for the treatment of postoperative pain. A variety of regimens and protocols are available for providers to utilize in the appropriate head and neck cancer patient.     

The ‘Hyperactive’ Child

A new, more apt designation, attentional deficit disorder (ADD), may help dispel some of the myths that have surrounded the “hyperactive” child. An abnormally high level of physical activity is a common but not universal finding in these children but is not their central problem. In most affected children, early diagnosis and specific drug treatment can ward off the often disastrous psychiatric and social consequences of ADD.     

Developing Effective Hospice Staff Support Groups: Pilot Test of an Innovative Training Program

Although hospice staff support groups are frequently cited as a valuable resource in coping with hospice work stress, few guidelines exist for implementing a successful group experience. This article summarizes a pilot study of a 12-week audiotape staff support group training program for hospice and oncology workers developed collaboratively by the author and the UCLA California Self-Help Center. Two West Coast hospice groups participated in the study. Group members reported a high degree of satisfaction with the tape program and their group experience. Burnout scores were not significantly affected by the group experience. Preliminary data on coping strategies, implications for the development and strengthening social support networks in the hospice, and suggestions for future research efforts are discussed.     

Overdose Risk with Opioids for Chronic Noncancer Pain

ABSTRACT

Timely and important studies are reviewed and commentaries provided by leading palliative care clinicians. Clinical scenarios, symptoms, interventions, and treatment-related adverse events addressed in this issue are overdose risk with opioids in chronic pain; pain in the primary care setting; methadone products and risk of QT prolongation; zolendronic acid and circulating cancer cells; statins and deep venous thrombosis; and treatment for cancer-associated anorexia-cachexia syndrome.     

Pharmacotherapeutic options for complex regional pain syndrome

Introduction: Complex regional pain syndromes (CRPS) are rare painful conditions characterized by considerable variability in possible triggering factors, usually traumatic, and in the clinical scenario. The limited knowledge of the pathophysiological mechanisms has led to countless treatment attempts with multiple conservative and surgical options that act by different mechanisms of action.

Areas covered: In this narrative review, the authors discuss key points about CRPS definitions, diagnostic criteria and pitfalls, pathophysiological hypotheses, and treatment strategies with particular reference to pharmacotherapy. The article was based on a literature search using PubMed while the available guidelines for the management of CRPS were also examined.

Expert opinion: According to the quality of evidence, pharmacological interventions for CRPS seem to be more effective all the more so when they act on peripheral mechanisms, particularly on nociceptive pain, and when applied early in the disease, while reliable evidence about central mechanisms of chronic pain in CRPS is lacking. In our opinion, drug therapy should be preferred as early as possible, particularly in warm forms of CRPS to prevent significant functional limitation, psychological distress, and social and economic fallout.