Anesthesia and analgesia
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Anesthesia and analgesia · Jan 2006
Randomized Controlled Trial Comparative StudyThe dose of succinylcholine required for excellent endotracheal intubating conditions.
In this prospective, randomized, double-blind, placebo-controlled study, we attempted to define the dose of succinylcholine that provides excellent intubation conditions in patients within 60 s during simulated rapid-sequence induction of anesthesia. Anesthesia was induced in 180 patients with 2 microg/kg fentanyl and 2 mg/kg propofol. After loss of consciousness, patients were randomly allocated to receive 0.3, 0.5, 1.0, 1.5, or 2.0 mg/kg succinylcholine or saline solution (control group). ⋯ The incidence of excellent intubating conditions was significantly more frequent (P < 0.001) in patients receiving succinylcholine than in the controls and in patients who received 2.0 mg/kg succinylcholine (P < 0.05) than in those who received 0.3 mg/kg succinylcholine. The calculated doses of succinylcholine (and their 95% confidence intervals) that are required to achieve excellent intubating conditions in 50% and 80% of patients at 60 s are 0.39 (0.29-0.51) mg/kg and 1.6 (1.2-2.0) mg/kg, respectively. It appears that there are no advantages to using doses of succinylcholine larger than 1.5 mg/kg.
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Anesthesia and analgesia · Jan 2006
Randomized Controlled Trial Comparative StudyMiddle ear pressure changes during anesthesia with or without nitrous oxide are similar among airway devices.
We tested the hypothesis that middle ear pressure (MEP) is influenced by the choice of airway device during anesthesia with or without nitrous oxide (N2O) in the gas mixture. Eighty consecutive anesthetized, paralyzed ventilated patients (ASA physical status I-II, 18-65 yr) were randomly allocated for airway management with the orally inserted tracheal tube, classic laryngeal mask airway, ProSeal laryngeal mask airway, or laryngeal tube suction with or without N2O 66% in the gas mixture. MEP was measured from both ears in random order by a blinded observer before induction of anesthesia and every 10 min for 70 min. ⋯ MEP was unchanged in the air groups but increased in the N2O groups with N2O (P < 0.0001) and decreased with air (P < 0.02). Baseline values for MEP were similar, but MEP was always higher for the N2O groups (P < 0.001). We conclude that the choice of airway device does not influence MEP among orally inserted tracheal tube, classic laryngeal mask airway, ProSeal laryngeal mask airway, and laryngeal tube suction during anesthesia with or without N2O in the gas mixture.
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Anesthesia and analgesia · Jan 2006
Randomized Controlled Trial Comparative StudyStimulating popliteal catheters for postoperative analgesia after hallux valgus repair.
Stimulating catheters have been recently introduced in clinical practice. We assessed the efficacy of stimulating and nonstimulating catheter placement for pain control and local anesthetic requirements after hallux valgus repair with continuous sciatic popliteal nerve block in this comparative, randomized, blinded-to-observer study of 48 patients. A stimulating catheter was placed in groups S-125 and S-0625. ⋯ Lower median (range) VAS scores for pain (0-100 points) were found in group S-125 at 6-8 h postoperatively when compared with groups S-0625 and NS-125: 5 (0-17.5) versus 60 (15-80) and 70 (25-80), respectively (P < 0.05); and lower VAS scores for pain were also found in group S-125 at 19-23 h when compared with group NS-125: 0 (0-0) and 7.5 (0-10), respectively (P < 0.05). Fewer patients required IV opioid analgesia in group S-125 than in groups S-0625 and NS-125: 0, 5, and 7 patients, respectively (P < 0.05). We conclude that efficacy in pain control was increased with stimulating catheter placement.
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Anesthesia and analgesia · Jan 2006
Randomized Controlled Trial Comparative StudyContinuous positive airway pressure breathing increases the spread of sensory blockade after low-thoracic epidural injection of lidocaine.
Factors affecting the distribution of sensory blockade after epidural injection of local anesthetics remain incompletely clarified. To evaluate if increasing intrathoracic pressure affects the spread of thoracic epidural anesthesia, we randomized 20 patients who received an epidural catheter at the T7-8 or T8-9 intervertebral space into 2 groups. The control group (n = 10) received an epidural test dose of 4 mL lidocaine 2% during spontaneous breathing at ambient pressure. ⋯ The total number of segments blocked was 7 (median, interquartile range 2.25) in the control group and 11 (interquartile range 3.5) in the continuous positive airway pressure group (P = 0.004). The number of segments blocked caudad to the injection site was 3 (median, interquartile range 3.5) in the control group and 6 (interquartile range 2.25) in the continuous positive airway pressure group (P = 0.005). We conclude that continuous positive airway pressure increases the spread of sensory blockade in thoracic epidural anesthesia, primarily by a more caudad extension of sensory blockade.
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Anesthesia and analgesia · Jan 2006
Comparative StudyA comparison of state and response entropy versus bispectral index values during the perioperative period.
Cerebral monitoring indices are associated with a large degree of inter-patient variability and electrical signal interference during surgery. We designed this clinical study to test the hypothesis that use of the spectral entropy (Entropy) module is associated with less frequent intraoperative interference with the displayed indices than the bispectral index (BIS) monitor when used during general anesthesia with propofol and desflurane. Thirty consenting patients scheduled for major laparoscopic surgery procedures were enrolled in this prospective study. ⋯ During the maintenance period, the responses to changes in propofol and desflurane concentrations were consistent with all three indices. Finally, the entropy indices were less interfered with by the electrocautery unit during the operation (12% versus 62% for the BIS monitor). Because the average selling prices of the Entropy and BIS disposable electrode strips (14.25 dollars versus 14.95 dollars USD, respectively) are comparable, we conclude that the Entropy module is a cost-equivalent alternative to the BIS monitor.