The effect of cisatracurium and rocuronium on cisatracurium precurarization and the priming principle

Study objective To demonstrate the effect of administering a precurarizing dose of cisatracurium or rocuronium on the speed of onset of cisatracurium, and to review the possible mechanisms and value of the priming principle. Design Double-blind, randomized, controlled trial. Setting Inpatient anesthesia in a university teaching hospital. Patients 90 ASA physical status I and II patients undergoing elective surgery requiring endotracheal intubation. Interventions Three groups of 30 patients each were investigated. Following induction of anesthesia with fentanyl and propofol, Group 1 received cisatracurium 0.015 mg.k-1, Group 2 received rocuronium 0.09 mg·kg-1, and Group 3 (control) received normal saline. Six minutes after priming, Groups 1 and 2 received cisatracurium 0.135 mg·kg-1 whereas Group 3 received cisatracurium 0.15 mg·kg-1. Measurements and main results In each group, first twitch height and the train-of-four ratios were recorded every 10 seconds after the initial priming dose. Intubation was attempted after the first twitch height became less than 15% of baseline. The decrease in the train-of-four ratios at 6 minutes was 0.97 for cisatracurium and 0.85 for rocuronium. The onset of muscle relaxation was significantly faster after priming with cisatracurium and rocuronium (71.7 ± 21.3 and 65 ± 19.8 sec, respectively) compared with control (148.7 ± 43.1 sec). Females receiving both muscle relaxants had a faster onset of paralysis than did males (65.9 ± 20.6 vs. 79.2 ± 20.6 and 55 ± 14.5 vs. 71.7 ± 20.4 sec). Intubation conditions were either excellent or satisfactory in all patients. Conclusions Six minutes after precurarization, there is no significant difference between rocuronium and cisatracurium when used as priming drugs. An even faster onset time with both drugs was demonstrated in females. The use of priming doses of 25% to 30% of ED 95 may cause symptomatic muscle weakness. The mechanisms of the priming principle are discussed. © 2004 by Elsevier Inc.link_to_subscribed_fulltex

Therapy of chronic non-malignant pain with opioids

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The ASA physical status classification: inter-observer consistency

The American Society of Anesthesiologists (ASA) physical status classification system has previously been shown to be inconsistently applied by anaesthetists. One hundred and sixty questionnaires were sent out to all specialist anaesthetists in Hong Kong. Ten hypothetical patients, identical to those of a similar study undertaken 20 years ago, each with different types and degrees ofphysical disability were described. Respondents were asked about their country of training and type of anaesthetic practice and to assign an ASA classification status for each patient. Ninety-seven questionnaires were returned (61%) after two mailings. Agreement for each patient within groups, between groups and overall comparisons were made. Percentage of agreement was between 31 to 85%. Overall correlation was only fair in all groups (Kappa indices: 0.21-0.4). We found that the current pattern of inter-observer inconsistency of classification was similar to that 20 years ago and exaggerated between locally and overseas trained specialists (P<0.05). The validity of the ASA system, its usefulness and the need for a new, more precise scoring system is discussed.link_to_subscribed_fulltex

Functional improvement after physiotherapy with a continuous infusion of local anaesthetics in patients with complex regional pain syndrome

Three patients were referred to our pain clinic with evidence of complex regional pain syndrome in their extremities. Two presented at the atrophic stage with joint contractures. Multiple analgesics had been prescribed without long-lasting relief. Physiotherapy was required to improve physical activity but was severely limited by pain. We instituted local anaesthetic infusion with the possibility of self-supplementation to facilitate physiotherapy; two via brachial plexus catheters for hand pain and one via epidural catheter for knee pain. Although their resultant pain scores were variable after cessation of local anaesthetic infusion, all the affected joints exhibited marked improvement in range of movement. We propose that this technique is a useful option for patients in all stages of complex regional pain syndrome where the emphasis is now directed toward functional improvement. © Acta Anaesthesiologica Scandinavica 47 (2003).link_to_subscribed_fulltex

Long-term therapy of chronic non-malignant pain with potent opioids in an active police officer

PURPOSE: To report the successful long-term use of methadone and tramadol in treating low back pain in a marine police officer. Principal findings: The patient sustained a work-related injury having fallen down stairs while on duty in 1990. After multiple operations for a prolapsed L5/S1 intervertebral disk, he was first seen at our pain clinic in 1994. Numerous systemic medications, invasive procedures, physiotherapy and psychotherapy were used to treat his pain, but without sustained effect. Methadone was started in late 1995 and tramadol in 2000. The current maintenance doses are methadone 20 mg and tramadol 200 mg, both twice daily. Apart from some initial disruption, the patient was soon able to return to full time work. Regular performance reports from his supervisors have always been excellent. CONCLUSION: The use of methadone in this police officer with chronic low back pain has been very successful despite the demanding nature of his job. The controversy surrounding, and further suggestions regarding long-term use of opioid therapy for non-malignant pain are discussed.link_to_subscribed_fulltex

Brachial plexus infusion of ropivacaine with patient-controlled supplementation

Purpose: To report the use of continuous brachial plexus analgesia to facilitate physiotherapy Clinical Features: A 34-yr-old man had contractures of the fingers of his dominant hand following a crush injury in 1996. After several operations, he continued to experience severe pain and disability. In order to facilitate pain-free active and passive physiotherapy, we performed an axiliary brachial plexus block. After insertion of a brachial plexus catheter via the axilla, analgesia was continued for a period of one week using a 3 ml-hr-1 background infusion of ropivacaine 0.2% with the facility for additional patient-controlled 1 ml boluses. Both active and passive physiotherapy was carried out daily for the entire week. Conclusion: This technique was successful with no major complications and resulted in a marked reduction in pain, with improved range of finger movement and general upper limb function.link_to_subscribed_fulltex