Anesthesia and analgesia
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Anesthesia and analgesia · Jun 2004
Randomized Controlled Trial Comparative Study Clinical TrialThe neuromuscular effects and tracheal intubation conditions after small doses of succinylcholine.
Succinylcholine 1.0 mg/kg usually produces excellent tracheal intubation conditions in 60 s. Recovery of respiratory muscle function after this dose, however, is not fast enough to forestall oxyhemoglobin desaturation when ventilation cannot be assisted. In this study, we investigated whether smaller doses of succinylcholine can produce satisfactory intubation conditions fast enough to allow rapid sequence induction with a shorter recovery time. Anesthesia was induced with fentanyl/propofol and maintained by propofol infusion and N(2)O in O(2). After the induction, 115 patients were randomly allocated to five groups according to the dose of succinylcholine (0.3 mg/kg, 0.4 mg/kg, 0.5 mg/kg, 0.6 mg/kg, or 1.0 mg/kg). Evoked adductor pollicis responses to continuous 1-Hz supramaximal ulnar nerve stimulation were recorded using acceleromyography. Tracheal intubation conditions were graded 60 s after succinylcholine administration. Onset time, maximal twitch depression, time to initial twitch detection after paralysis, and to 10%, 25%, 50%, and 90% twitch height recovery were recorded. Time to initial diaphragmatic movement as well as time to resumption of regular spontaneous respiratory movements were calculated. Onset times ranged between 82 s and 52 s, decreasing with increasing doses of succinylcholine but not differing between 0.6 and 1 mg/kg. Maximum twitch depression was similar after 0.5, 0.6, and 1 mg/kg (98.2%-100%). Recoveries of twitch height and apnea time were dose-dependent. Intubation conditions were often unacceptable after 0.3- and 0.4-mg/kg doses. Acceptable intubation conditions were achieved in all patients receiving a 0.5, 0.6, and 1 mg/kg dose of succinylcholine. Intubation conditions in patients receiving 0.6 and 1 mg/kg were identical, whereas times to T(1) = 50% and 90% and time to regular spontaneous reservoir bag movements were significantly shorter in the 0.6-mg/kg dose group (5.78, 7.25, and 4.0 min, respectively) versus patients receiving 1 mg/kg (8.55, 10.54, and 6.16 min, respectively). The use of 0.5 to 0.6 mg/kg of succinylcholine can produce acceptable intubation conditions 60 s after administration. The conditions achieved after 0.6 mg/kg are similar to those after 1.0 mg/kg. These smaller doses are associated with faster twitch recovery and shorter apnea time. ⋯ In normal healthy patients, succinylcholine 0.6 mg/kg produces clinical intubation conditions identical to the traditional 1.0-mg/kg dose but is associated with a shorter recovery time.
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Anesthesia and analgesia · Jun 2004
Randomized Controlled Trial Comparative Study Clinical TrialTime-related cuff pressures of the laryngeal tube with and without the use of nitrous oxide.
The Laryngeal tube (VBM Medizintechnik, Sulz, Germany), a new supraglottic airway, consists of an airway tube, two cuffs, and two distal apertures between the two cuffs. One concern with the use of this device is ischemic change to the oropharyngeal mucosa. We studied the time-course change of the intracuff pressure (which reflects the pharyngeal pressure) of the laryngeal tube during anesthesia with and without nitrous oxide. After insertion of a laryngeal tube, 24 patients were randomly allocated to 1 of 2 groups. In one group (group N or nitrous oxide group), 66% nitrous oxide was used, whereas in the other group nitrous oxide was not used (group A or air group). In both groups, sevoflurane was used to maintain anesthesia. Time-course changes of the intracuff pressure and postoperative airway complications were recorded. In group N, the intracuff pressure significantly increased over time (P < 0.001; the maximal pressure: 120 cm H(2)O), whereas in group A the intracuff pressure remained stable. The intracuff pressure was significantly higher in group N than in group A (P < 0.0001; 95% confidence intervals for difference: 6-20 cm H(2)O at 30 min). Postoperatively, two patients in group A and one patient in group N complained of mild sore throat. ⋯ Nitrous oxide may increase pharyngeal pressure by the cuffs of the laryngeal tube, and thus it is advisable to monitor and adjust the intracuff pressure of the laryngeal tube during anesthesia to minimize possible ischemic changes to the oropharynx.
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Anesthesia and analgesia · Jun 2004
Comparative StudyBrief postoperative delirium in hip fracture patients affects functional outcome at three months.
It is unclear how brief postoperative delirium (DEL) affects functional outcomes. In this study, we sought to determine if patients with brief postoperative DEL (<6-wk duration) have different living situations when compared with non-DEL patients after hip fracture repair. In a prospective study, patients admitted to the geriatric hip fracture service were assessed every postoperative day for the presence of DEL using the confusion assessment method (CAM) score. Patients were reassessed at 6 wk and 3 mo postoperatively for CAM score, current living situation, and activities of daily living. Group comparisons were tested after dividing patients into two groups: DEL (DEL; [+] CAM at any time during the postoperative period while in the hospital); no-DEL (no DEL; [-] CAM throughout the postoperative period while in the hospital). The study included 92 patients of whom 26 (28%) were CAM (+) after surgery. At 6 wk follow-up, n = 81; at 3 mo follow-up, n = 76. Eight patients died during the study. At 6 wk and 3 mo, a larger percentage of DEL patients were not living with a family member (27% versus 8% patients not living with a family member at 3 mo follow-up in DEL and no-DEL, respectively). There was no difference in activities of daily living by 3 mo. We conclude that brief postoperative DEL lasting <6 wk is a determining factor for poor long-term functional outcome after hip fracture repair, because it significantly impacts the ability to live independently. ⋯ Brief postoperative delirium lasting <6 wk is a determining factor for poor long-term functional outcome after hip fracture repair, because it significantly impacts the ability to live independently.
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Anesthesia and analgesia · Jun 2004
Comparative StudyHeparinase-modified thrombelastography in term and preterm neonates.
Thrombelastography (TEG) appears to be a promising test to assess coagulation in infants and children. TEG enables a rapid assessment of hemostatic function with only 300 microL of whole blood and provides information about plasmatic coagulation, platelet function, and fibrinolysis. In this study, we used TEG to assess the coagulation system of preterm and term neonates to determine the effects of their deficient coagulation factor levels on global hemostatic function. Heparinase-modified TEG, platelet and red blood cell count, plasma fibrinogen, and prothrombin time were assessed in four groups of clinically stable infants: severely preterm (gestational age [GA], 27-31 wk), moderately preterm (GA, 32-36 wk), term (GA, 36-40 wk), and former preterm (corrected GA, 34-40 wk). Healthy adult volunteers served as a control group. When compared with the adult group, thromboelastography revealed no defects in coagulation from groups of clinically stable infants, documenting the functional integrity of coagulation despite, in part, decreased conventional coagulation variables. Because clinically stable preterm and term infants show a relatively small incidence of bleeding, despite prolonged conventional coagulation tests, TEG may better reflect the hemostatic potential of these patients compared with conventional coagulation tests. ⋯ This study assessed the coagulation of preterm and term infants by thrombelastography and found functional integrity of coagulation despite, in part, decreased conventional coagulation variables.
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Anesthesia and analgesia · Jun 2004
Comparative StudyMuscular injury after succinylcholine and electroconvulsive therapy.
Both succinylcholine and seizures cause muscular injury during electroconvulsive therapy. We compared the muscular damage in two groups of patients. The psychiatric patient group received succinylcholine for electroconvulsive therapy. The surgical patient group received succinylcholine for endotracheal intubation. Serum myoglobin was measured as a marker for muscular injury and myalgic symptoms were also recorded. Serum myoglobin increased from baseline in both groups at 5 and 20 min. The surgical patients, however, had a higher myoglobin level than the psychiatric patients at 5 and 20 min after the administration of succinylcholine (P < 0.001). The median (range) of myoglobin concentration at 20 min in psychiatric patients was 32.6 (23.1-60.1) ng/mL, compared with 61.2 (31.6-1687.0) ng/mL in surgical patients. The incidence of myalgia was not different between the two groups. In conclusion, we unexpectedly conclude that the psychiatric patients who received electroconvulsive therapy had less effect of muscular damage associated with succinylcholine than the surgical patients did. ⋯ Both succinylcholine and electroconvulsive therapy cause muscular injury. However, we unexpectedly found that psychiatric patients who received succinylcholine and electroconvulsive therapy had less muscular damage than surgical patients who received succinylcholine for intubation. Therefore, appropriate use of succinylcholine can attenuate the muscular damaging effect from the therapy.