Anesthesia and analgesia
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Anesthesia and analgesia · Mar 2002
Comparative StudyThe effects of abdominal opening on respiratory mechanics during general anesthesia in normal and morbidly obese patients: a comparative study.
Morbid obesity has a profound effect on respiratory mechanics and gas exchange. However, most studies were performed in morbidly obese patients before or after anesthesia. We tested the hypothesis that anesthesia and abdominal opening could modify the elastic and resistive properties of the respiratory system. ⋯ Obese patients also presented higher resistances of the total respiratory system, lung and chest wall, as well as "additional" lung resistance. Mainly in obese patients, laparotomy provoked a significant increase in lung compliance and decrease in "additional" lung resistance 1 h after the peritoneum was opened, which returned to original values after the peritoneum had been closed (P < 0.005). In obese patients, low respiratory compliance and higher airway resistance were mainly determined by the lung component.
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Anesthesia and analgesia · Mar 2002
The antinociceptive and histologic effect of sciatic nerve blocks with 5% butamben suspension in rats.
Butamben, a lipophilic local anesthetic of the ester class, produces a differential nerve block of long duration. Epidural and peripheral nerve blocks with butamben, formulated as a 5%--10% suspension, result in prolonged analgesia without significant motor blockade. We evaluated the effect of butamben sciatic nerve block on antinociception using the rat paw formalin test, as well as withdrawal latencies to thermal stimulation, and assessed histologic changes in the nerve. After right sciatic nerve block with butamben 5% or saline, responses to intradermal injection of 5% formalin were recorded in randomly selected groups of 6 animals each on days 1, 2, 5, 10, 21, and 28. In an additional group of 8 thermal challenges to both hind paws were recorded at 1, 2, 5, 7, 10, 14, 17, 21, and 28 days after right sciatic butamben 5% blocks. Butamben injection decreased the formalin-induced flinches on days 2, 5, 10, 21 and 28 and decreased thermal challenges on days 1 through 17. Histologic changes were minimal. This study demonstrates a prolonged antinociceptive effect from butamben nerve block to both formalin-induced nociception and heat hyperalgesia, without an effect on gross motor function or histologic morphology. ⋯ Butamben 5% nerve blocks produced a prolonged antinociceptive effect to formalin-induced nociception and heat hyperalgesia, without significant motor effect or evidence of substantial histologic changes.
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Anesthesia and analgesia · Mar 2002
Case Reports Randomized Controlled Trial Clinical TrialFast-track eligibility of geriatric patients undergoing short urologic surgery procedures.
Our primary objective was to assess the feasibility of geriatric patients (>65 yr) bypassing the postanesthesia care unit (PACU) after ambulatory surgery. A secondary objective was to compare recovery profiles when using three different maintenance anesthetics. Ninety ASA physical status I--III consenting outpatients (>65 yr) undergoing short urologic procedures were randomly assigned to one of three anesthetic treatment groups. After a standardized induction with fentanyl and propofol, anesthesia was maintained with propofol (75-150 microg center dot kg(-1) center dot min(-1) IV), isoflurane (0.7%-1.2% end tidal), or desflurane (3%-6% end tidal), in combination with nitrous oxide 70% in oxygen. In all three groups, the primary anesthetic was titrated to maintain an electroencephalographic-bispectral index value of 60-65. Recovery times, postanesthesia recovery scores, and therapeutic interventions in the PACU were recorded. Although emergence times were similar in the three groups, the time to achieve a fast-track discharge score of 14 was significantly shorter in patients receiving desflurane compared with propofol and isoflurane (22 +/- 23 vs 33 +/- 25 and 44 +/- 36 min, respectively). On arrival in the PACU, a significantly larger percentage of patients receiving desflurane were judged to be fast-track eligible compared with those receiving either isoflurane and propofol (73% vs 43% and 44%, respectively). The number of therapeutic interventions in the PACU was also significantly larger in the Isoflurane group when compared with the Propofol and Desflurane groups (21 vs 11 and 7, respectively). In conclusion, use of desflurane for maintenance of anesthesia should facilitate PACU bypass ("fast-tracking") of geriatric patients undergoing short urologic procedures. ⋯ Geriatric outpatients undergoing brief urologic procedures more rapidly achieve fast-tracking discharge criteria after desflurane (versus isoflurane and propofol) anesthesia. Use of isoflurane was also associated with an increased need for nursing interventions in the early recovery period compared with desflurane and propofol.
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Anesthesia and analgesia · Mar 2002
Randomized Controlled Trial Comparative Study Clinical TrialTramadol infusion for postthoracotomy pain relief: a placebo-controlled comparison with epidural morphine.
We compared continuous IV tramadol as an alternative to neuraxial or systemic opioids for the management of postthoracotomy pain in a prospective, randomized, double-blinded, controlled study. General anesthesia was supplemented by thoracic epidural analgesia with 0.25% bupivacaine. At rib approximation, patients received one of the following: IV tramadol (150-mg bolus followed by infusion, total 450 mg/24 h, n = 29), epidural morphine (2 mg, then 0.2 mg/h, n = 30), or patient-controlled analgesia (PCA) morphine only (n = 30). All patients received PCA morphine and rescue morphine as necessary postoperatively. For the first 24 h, pain and sedation scores and respiratory, cardiovascular, and side effect measures were monitored. There was no significant difference in pain scores and PCA morphine use between tramadol and epidural morphine. Pain scores at rest and on coughing were lower in the Tramadol and Epidural Morphine groups than in the PCA Morphine group at various time points over the first 12 h. The Tramadol and Epidural Morphine groups used significantly less hourly PCA morphine than the PCA Morphine group at specific time points in the first 10 h. Vital capacities in the Tramadol group were significantly closer to baseline values at the 20-h point than in the PCA Morphine group. We conclude that an intraoperative bolus of tramadol followed by an infusion was as effective as epidural morphine and avoided the necessity of placing a thoracic epidural catheter. ⋯ A prospective, randomized, double-blinded, placebo-controlled study of postthoracotomy pain relief showed that IV tramadol in the form of a bolus followed by continuous infusion was as effective as epidural morphine. The use of tramadol avoids the necessity of placing a thoracic epidural catheter.
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Anesthesia and analgesia · Mar 2002
Randomized Controlled Trial Comparative Study Clinical TrialThe prophylactic effect of tropisetron on epidural morphine-related nausea and vomiting: a comparison of dexamethasone with saline.
Tropisetron is a 5-hydroxytryptamine subtype 3 receptor antagonist that is primarily used in the prevention of chemotherapy-induced nausea and vomiting. We evaluated the prophylactic effect of tropisetron on postoperative nausea and vomiting associated with epidural morphine. Dexamethasone and saline served as controls. One-hundred twenty women (n = 40 in each of three groups) undergoing abdominal total hysterectomy under epidural anesthesia were enrolled in this randomized, double-blinded, and placebo-controlled study. At the end of surgery, Group 1 received IV tropisetron 5 mg, whereas Groups 2 and 3 received dexamethasone 5 mg and saline, respectively. We found that tropisetron did not significantly reduce the occurrence of nausea and vomiting associated with epidural morphine. Dexamethasone, however, reduced the total incidence of nausea and vomiting from 59% to 21% (P < 0.01) and the percentage of patients requiring rescue antiemetic from 38% to 13% (P < 0.05). We conclude that IV tropisetron 5 mg did not prevent the occurrence of postoperative nausea and vomiting associated with epidural morphine. IV dexamethasone 5 mg was effective for this purpose. ⋯ We compared the prophylactic IV administration of tropisetron 5 mg to prevent postoperative nausea and vomiting (PONV) associated with epidural morphine with dexamethasone 5 mg and saline in women undergoing hysterectomy. We found that tropisetron 5 mg did not significantly reduce the occurrence of PONV associated with epidural morphine. Dexamethasone 5 mg was effective for this purpose.