Anesthesia and analgesia
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Anesthesia and analgesia · Oct 2003
Behavioral monitoring and urine toxicology testing in patients receiving long-term opioid therapy.
No study has examined the role of urine toxicology in addition to behavioral monitoring in patients receiving opioid therapy for chronic pain. All patients maintained on chronic opioid therapy by the two senior authors at two university pain management centers were monitored for 3 yr with urine toxicology testing and for behaviors suggestive of inappropriate medication use. We retrospectively extracted demographic information, aberrant drug-taking behaviors, and urine toxicology information from the medical record. For 122 patients maintained on chronic opioid therapy, 43% (n = 53) had a "problem" (either positive urine toxicology or one or more aberrant drug-taking behaviors). Of patients with no behavioral issues, 21% (n = 26) had a positive urine screen for either an illicit drug or a nonprescribed controlled medication. Of patients with a negative urine screen, 14% (n = 17) had one or more behavioral issues. Monitoring both urine toxicology and behavioral issues captured more patients with inappropriate drug-taking behavior than either alone. Requiring a report of behavioral issues and urine toxicology screens for patients receiving chronic opioids creates a more comprehensive monitoring system than either alone. ⋯ Monitoring both urine toxicology and aberrant behavior in chronic-pain patients treated with opioids identified more problem patients than by monitoring either alone. The authors recommend routine urine testing on all patients prescribed opioids for noncancer pain and as a required element in all opioid analgesic studies.
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Anesthesia and analgesia · Oct 2003
The acute myotoxic effects of bupivacaine and ropivacaine after continuous peripheral nerve blockades.
Bupivacaine causes muscle damage. However, the myotoxic potency of ropivacaine is still unexplored. Therefore, we performed this study to compare the effects of bupivacaine and ropivacaine on skeletal muscle tissue in equipotent concentrations. Femoral nerve catheters were inserted into anesthetized minipigs, and 20 mL of either bupivacaine (5 mg/mL) or ropivacaine (7.5 mg/mL) was injected. Subsequently, bupivacaine (2.5 mg/mL) and ropivacaine (3.75 mg/mL) were continuously infused over 6 h. Control animals were treated with corresponding volumes of normal saline. Finally, muscle samples were dissected at injection sites. After processing and staining, histological patterns of muscle damage were blindly examined, scored (0 = no damage to 3 = myonecrosis), and statistically analyzed. After normal saline, only interstitial edema was found. Bupivacaine treatment caused severe tissue damage (score, 2.3 +/- 0.7), whereas ropivacaine induced fiber injury of a significantly smaller extent (score, 1.3 +/- 0.8). Furthermore, bupivacaine, but not ropivacaine, induced apoptosis in muscle fibers. In summary, both drugs induce muscle damage with similar histological patterns. Compared with bupivacaine, which induces both necrosis and apoptosis, the tissue damage caused by ropivacaine is significantly less severe. We conclude that ropivacaine's myotoxic potential is more moderate in comparison with that of bupivacaine. ⋯ After continuous peripheral nerve blockades, the long-acting local anesthetics bupivacaine and ropivacaine both induce fiber necrosis in porcine skeletal muscle tissue. In comparison with ropivacaine, bupivacaine causes tissue damage of a significantly larger extent and additionally induces apoptosis in skeletal muscle cells.
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Anesthesia and analgesia · Oct 2003
Case ReportsAnesthetic management for a five-day separation of craniopagus twins.
Craniopagus twinning is a rare form of the already uncommon entity of conjoint twins. With advances in medical technology and expertise, future attempts at surgical separation of these increasingly complex cases are likely to occur. Despite this, medical literature on the anesthetic management of these cases is sparse. The following case report details the anesthetic management and planning leading to and including the 5-dy separation of 11-mo-old craniopagus twins. The report emphasizes the importance of teamwork, communication, and advanced planning required in cases such as this. ⋯ The following case report documents the anesthetic planning and management leading to and including a 5-day separation of twins joined at the head. This case report also details the difficulties encountered during the unique combination of a rarely performed procedure and a long operating time.