Anesthesia and analgesia
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Opioids occupy a position of unsurpassed clinical utility in the treatment of pain of many etiologies. However, recent reports in laboratory animals and humans have documented the occurrence of hyperalgesia when the administration of opioids is abruptly tapered or discontinued, a condition known as opioid-induced hyperalgesia (OIH). In these studies we documented that rats administered morphine (40 mg. kg(-1). day(-1) for 6 days) via subcutaneous osmotic minipumps demonstrated thermal hyperalgesia and mechanical allodynia for several days after the cessation of morphine administration. Additional experiments using a rat model of incisional pain showed that that attributable to OIH were additive with the hyperalgesia and allodynia that resulted from incision. In our final experiments we observed that if naloxone is administered chronically before incision then discontinued (20 mg. kg(-1). day(-1) for 6 days), the hyperalgesia and allodynia that result from hind paw incision was markedly reduced. In contrast, naloxone 1 mg/kg administered acutely after hind paw incision increased hyperalgesia and allodynia. We conclude that the chronic administration of exogenous opioid receptor agonists and antagonists before incision can alter the hyperalgesia and allodynia observed in this pain model, perhaps by altering intrinsic opioidergic systems involved in setting thermal and mechanical nociceptive thresholds. ⋯ The chronic administration of opioids followed by abrupt cessation can lead to a state of hyperalgesia. In these studies we demonstrate that the hyperalgesia from opioid cessation and from hind paw incision are additive in rats. We suggest that failure to take into consideration preoperative opioid use can lead to excessive postoperative pain.
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Anesthesia and analgesia · Jul 2001
Maternal mortality during hospital admission for delivery: a retrospective analysis using a state-maintained database.
This study reports the overall age- and race-specific delivery mortality ratios from January 1984 to December 1997 and medical and demographic risk factors associated with maternal death during hospital admission for delivery. We performed a retrospective case control study using patient records from a state-maintained anonymous database of all nonfederal Maryland hospitals that performed deliveries from 1984 to 1997. Variables studied included patient demographics and International Classification of Diseases, 9th Revision, Clinical Modification, diagnosis, and procedure codes. Mortality was the outcome variable. Of the 822,591 hospital admissions for delivery during the 14-yr study period, there were 135 deaths. The overall delivery mortality ratio was 16.4. The most common diagnoses associated with mortality during hospital admission for delivery included preeclampsia/eclampsia (22.2%), postpartum hemorrhage/obstetric shock (22.2%), pulmonary complications (14%), blood clot and/or amniotic embolism (8.1%), and anesthesia-related complications (5.2%). The identification of medical and demographic risk factors may have significant implications creating initiatives aimed at decreasing the public health burden associated with maternal mortality. ⋯ This study reports the medical and demographic risk factors associated with maternal death during hospital admission for delivery by using a state-maintained database. This information could prove useful in the creation of initiatives aimed at decreasing the public health burden associated with maternal mortality.
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Anesthesia and analgesia · Jul 2001
Randomized Controlled Trial Clinical TrialNalbuphine versus propofol for treatment of intrathecal morphine-induced pruritus after cesarean delivery.
In this prospective, randomized, double-blinded study, we compared the efficacy of nalbuphine and propofol for treating intrathecal morphine-induced pruritus after cesarean delivery. One-hundred-eighty-one parturients who developed moderate to severe pruritus after the administration of intrathecal morphine were randomly allocated into two groups. One group received 3 mg IV nalbuphine (n = 91), and the other received 20 mg IV propofol (n = 90). The improvement of pruritus and other adverse effects was determined at 10 min after study drug administration. The treatment success rate was higher in the Nalbuphine group than in the Propofol group (83% vs 61%; P < 0.001). Among the successfully treated patients, recurrence rates of moderate to severe pruritus within 4 h were not significantly different (nalbuphine 9% versus propofol 7%; P = 0.76). Other side effects, such as decreased analgesia, increased nausea, vomiting, increased sedation, pain on injection, and dizziness, were not significantly different between groups. Sedation and pain on injection, which were the two most common side effects, were minor and clinically inconsequential. ⋯ Nalbuphine was superior to propofol for the treatment of intrathecal morphine-induced pruritus after cesarean delivery.