Anesthesia and analgesia
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Anesthesia and analgesia · Jul 2001
Randomized Controlled Trial Clinical TrialThe dose-response relationship for clonidine added to a postoperative continuous epidural infusion of ropivacaine in children.
Epidurally administered clonidine enhances the quality and duration of postoperative analgesia when it is used as an adjunct to local anesthetics in children. We investigated the dose-response relationship for epidural clonidine when added to a continuous postoperative epidural infusion of ropivacaine. By use of an observer-blinded design, 55 pediatric patients (1-4 yr old) were randomly given a postoperative epidural infusion of plain ropivacaine 0.1% 0.2 mg. kg(-1). h(-1) (Group R), ropivacaine 0.08% 0.16 mg. kg(-1). h(-1) plus clonidine 0.04 microg. kg(-1). h(-1) (Group RC1), ropivacaine 0.08% 0.16 mg. kg(-1). h(-1) plus clonidine 0.08 microg. kg(-1). h(-1) (Group RC2), or ropivacaine 0.08% 0.16 mg. kg(-1). h(-1) plus clonidine 0.12 microg. kg(-1). h(-1) (Group RC3). A clear dose-response relationship could be identified for a continuous infusion of epidural clonidine, with clonidine dosages in the 0.08-0.12 microg. kg(-1). h(-1) range providing improved postoperative analgesia (reduced Children's Hospital of Eastern Ontario pain score, increased time to first supplemental analgesic demand, and a reduced total number of doses of supplemental analgesics during the first 48 h after surgery). Analgesia was improved without any signs of increased sedation or other side effects. The adjunct use of epidural clonidine in the dosage range of 0.08-0.12 microg. kg(-1). h(-1) appears effective and safe for use in children. ⋯ The addition of clonidine (0.08-0.12 microg.kg(-1).h(-1))to a continuous epidural infusion of ropivacaine was found to improve postoperative pain relief in children. No clinically significant signs of sedation or other side effects were observed.
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Anesthesia and analgesia · Jul 2001
Biography Historical ArticlePioneers in epidural needle design.
In this article we discuss the development of epidural needles and the historical factors leading to their invention. The most popular needles are described and their inventors acknowledged.
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Anesthesia and analgesia · Jul 2001
Randomized Controlled Trial Clinical TrialA randomized trial of tranexamic acid to reduce blood transfusion for scoliosis surgery.
Pediatric patients who undergo posterior spinal fusion surgery to correct scoliosis often require multiple blood transfusions. Tranexamic acid is a synthetic antifibrinolytic drug that reduces transfusion requirements in cardiac surgery and total knee arthroplasty. We evaluated the efficacy of prophylactic tranexamic acid to reduce perioperative blood transfusion requirements in a prospective, double-blinded, placebo control study. Forty patients, 9-18 yr of age, were randomized to either tranexamic acid (initial dose of 10 mg/kg and infusion of 1 mg. kg(-1). h(-1)) or placebo (isotonic saline). Perioperative management was standardized. A uniform transfusion threshold for noncell saved red blood cells was 7.0 g/dL. The total amount of blood transfused in the perioperative period was significantly reduced in the Tranexamic group (P = 0.045). No thrombotic complications were detected in either group. The administration of prophylactic tranexamic acid in patients with scoliosis undergoing posterior spinal fusion surgery has the potential to reduce perioperative blood transfusion requirements. ⋯ The administration of prophylactic tranexamic acid in patients with scoliosis who are undergoing posterior spinal fusion surgery has the potential to reduce perioperative blood transfusion requirements.
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Anesthesia and analgesia · Jul 2001
Clinical TrialThe relationship between hirudin and activated clotting time: implications for patients with heparin-induced thrombocytopenia undergoing cardiac surgery.
Anticoagulation with recombinant hirudin (r-hirudin) (Refludan) has been suggested as an alternative to heparin for patients with heparin-induced thrombocytopenia requiring cardiac surgery. We sought to develop a modified activated coagulation time (ACT) that would allow quantification of the levels of r-hirudin required during cardiopulmonary bypass (CPB). Twenty-one patients scheduled for elective cardiac surgical procedures requiring CPB were enrolled in this IRB-approved study. R-hirudin was added to blood specimens obtained before heparin administration (before CPB) and 30 min after heparin neutralization with protamine (after CPB) to result in concentrations of 0, 2, 4, 6, 7, or 8 microg/mL. Kaolin/ACT and complete blood count measurements were assayed in native specimens (first 10 patients, Phase I) or in specimens mixed with equal volumes of commercial normal plasma (second 11 patients, Phase II). In Phase I, good (r(2) = 0.83) linear relationships between ACT values and r-hirudin concentrations (< or =4 microg/mL) were observed in specimens obtained before CPB. However, ACT values were markedly prolonged (P < 0.0001) by r-hirudin in specimens obtained after CPB, with ACT values generally exceeding the ACT's detection limit (>999 s) at hirudin concentrations >2 microg/mL. In patient specimens mixed with normal plasma (Phase II), ACT/hirudin relationships (i.e., hirudin/ACT slope values obtained with hirudin concentration < or =4 microg/mL) in the post-CPB period (0.022 +/- 0.004 microg. mL(-1). s(-1)) were similar (P = 0.47) to those (0.019 +/- 0.004 microg. mL(-1). s(-1)) obtained in the pre-CPB period. Accordingly, a significant relationship between normal plasma-supplemented ACT values and predilution hirudin concentration was obtained in the post-CPB (hirudin = 0.039ACT - 4.34, r(2) = 0.91) period. Although our data demonstrate that the ACT test cannot be used to monitor hirudin during CPB, the addition of 50% normal plasma to post-CPB hemodiluted blood specimens yields a consistent linear relationship between hirudin concentration and ACT values up to a predilution concentration of 8 microg/mL. Plasma-modified ACT may be useful in monitoring hirudin anticoagulation during CPB. ⋯ A modified activated clotting time test system that may be helpful in monitoring hirudin anticoagulation in patients with heparin-induced thrombocytopenia during cardiac surgery with cardiopulmonary bypass is described.
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Anesthesia and analgesia · Jul 2001
Randomized Controlled Trial Clinical TrialThe clinical and biochemical effects of propofol infusion with and without EDTA for maintenance anesthesia in healthy children undergoing ambulatory surgery.
We conducted this randomized, double-blinded, comparative, parallel-group study to determine whether adding EDTA to propofol would affect the clinical profile, calcium and magnesium homeostasis, or renal function in healthy children. After the induction of anesthesia with halothane, 69 ambulatory surgical patients (1 mo to <17 yr old), received propofol without EDTA (n = 33) or propofol with EDTA (n = 36). Blood samples were obtained for the measurement of ionized calcium, ionized magnesium, and laboratory indicators of renal function. Hemodynamic measurements, recovery, and adverse events were recorded. Propofol with EDTA produced no significant effects on clinical efficacy or renal function. Propofol and propofol EDTA produced a statistically significant decrease from baseline in serum concentrations of ionized calcium and magnesium during infusion (P<0.05), but with no apparent clinical effect. Hemodynamic measurements generally remained stable and were similar for both groups. Statistically significant changes in systolic blood pressure, mean arterial pressure, and heart rate were not considered clinically significant. Adverse events were mild or moderate. The addition of EDTA does not alter the clinical profile of propofol in pediatric ambulatory surgical patients. With or without EDTA, propofol is associated with a decrease in ionized calcium with no apparent clinical effect. ⋯ The addition of EDTA does not alter the clinical profile of propofol in pediatric ambulatory surgical patients. With or without EDTA, propofol is associated with a decrease in ionized calcium with no apparent clinical effect.