Anesthesia and analgesia
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Anesthesia and analgesia · May 2000
Randomized Controlled Trial Clinical TrialPostoperative analgesia for outpatient arthroscopic knee surgery with intraarticular clonidine and/or morphine.
Both clonidine, an alpha(2) agonist, and morphine, an opioid agonist, provide enhanced patient analgesia after arthroscopic knee surgery when administered via the intraarticular (IA) route. Clonidine potentiates morphine analgesia in the animal model. We designed this study to determine whether clonidine or morphine results in better analgesia and whether their combination would provide superior analgesia to either drug alone. ⋯ This study revealed a significant benefit from the individual IA administration of both clonidine and morphine. The combination of these drugs resulted in decreased postoperative pain and analgesic use, as well as an increased analgesic duration compared with either drug alone. We conclude that IA clonidine and morphine improved comfort compared with either drug alone in patients undergoing knee arthroscopy.
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Anesthesia and analgesia · May 2000
A retrospective examination of regional plus general anesthesia in children undergoing open heart surgery.
The use of regional anesthesia in combination with general anesthesia for children undergoing cardiac surgery is receiving increasing attention from clinicians. The addition of regional anesthesia may improve clinical outcomes and decrease costs as a result of the reduced need for postoperative mechanical ventilation. ⋯ We found no significant differences in the incidence of clinically significant changes in vital signs, oxygen desaturation, hypercarbia, or vomiting. Patients in the SAB group received significantly more sedative/analgesic interventions than those in the EPID group.
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Anesthesia and analgesia · May 2000
The in vitro effects of antithrombin III on the activated coagulation time in patients on heparin therapy.
Heparin requires antithrombin III (AT) to achieve anticoagulation, and patients on continuous small-dose heparin preoperatively experience decreased levels of AT-causing heparin resistance. When this occurs, 2-4 units of fresh frozen plasma ( approximately 1000 units of AT) are often administered to increase AT levels and restore heparin responsiveness. We evaluated purified human AT concentrate (Thrombate III; Bayer, Inc., Elkhart, IN) to restore in vitro anticoagulation responses in patients receiving heparin. Blood samples were obtained from cardiac surgery patients including 22 patients receiving heparin and 21 patients not receiving heparin preoperatively. Heparin was added to blood in final concentrations of 4.1, 5.4, and 6.8 U/mL (equivalent to 300, 400, and 500 U/kg), and kaolin-activated clotting times (ACTs) were determined with and without AT at a final concentration of 0.2 units/mL to mimic fresh frozen plasma administration. The mean duration of preoperative heparin therapy was 4.0 days (range 2-10 days). AT activity was 69% +/- 9% in patients receiving heparin and 92% +/- 8% in patients not receiving heparin (P < 0.01). Heparin >4.1 U/mL failed to further increase ACT values in all patients. Attempts to increase ACT in patients receiving heparin may require supplemental AT administration. Purified AT even in small doses significantly prolongs the ACT response to heparin. ⋯ In vitro addition of antithrombin III (0.2 U/mL) to heparinized blood samples (4.1-6.8 units of heparin/mL) from patients on previous heparin therapy increases sensitivity to supplemental heparin as reflected by significantly prolonged activated clotting time.
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Anesthesia and analgesia · May 2000
The effects of repeated doses of vasopressin or epinephrine on ventricular fibrillation in a porcine model of prolonged cardiopulmonary resuscitation.
This study evaluated ventricular fibrillation mean frequency and amplitude to predict defibrillation success in a porcine cardiopulmonary resuscitation (CPR) model using repeated administration of vasopressin or epinephrine. After 4 min of cardiac arrest and 3 min of CPR, 10 pigs were randomly assigned to receive either vasopressin (early vasopressin: 0.4, 0.4, and 0.8 units/kg, respectively, n = 5) or epinephrine (early epinephrine: 45, 45, and 200 microg/kg, respectively, n = 5). Another 11 animals were randomly allocated after 4 min of cardiac arrest and 8 min of CPR to receive every 5 min either vasopressin (late vasopressin: 0.4 and 0. 8 units/kg, respectively, n = 5) or epinephrine (late epinephrine: 45 and 200 microg/kg, n = 6). ⋯ In contrast to no epinephrine animals, all vasopressin animals were successfully defibrillated and survived 1 h (P < 0.05). Mean fibrillation frequency and amplitude predicted successful defibrillation and may serve as noninvasive markers to monitor continuing CPR efforts. Furthermore, vasopressin was superior to epinephrine in maintaining these variables above a threshold necessary for successful defibrillation.
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Anesthesia and analgesia · May 2000
Comparative StudyA comparison of hemodynamic changes after endotracheal intubation by using the lightwand device and the laryngoscope in normotensive and hypertensive patients.
We compared the effects of the lightwand technique on hemodynamic responses, time-to-intubation, number of attempts, and complications during tracheal intubation with those of direct-vision laryngoscopy in normotensive (LN and TN group; n = 20, respectively) and hypertensive (LH and TH group; n = 20, respectively) patients. Lightwand or laryngoscopic oral endotracheal intubation was performed after the induction of anesthesia with fentanyl and propofol and muscle relaxation with vecuronium. Systolic blood pressure, diastolic blood pressure, and heart rate were recorded, and the change from "before intubation" to "immediately after intubation" (DeltaP) in each variable was calculated. ⋯ The number of patients who complained of hoarseness was larger in the lightwand groups than in the laryngoscope groups (P < 0.05). We conclude that the lightwand technique significantly attenuates hemodynamic changes after intubation in comparison with the laryngoscopic technique in normotensive patients. However, in hypertensive patients, there is no difference in hemodynamic changes between the two techniques.