British journal of anaesthesia
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Randomized Controlled Trial Comparative Study Clinical Trial
Bolus dose remifentanil for control of haemodynamic response to tracheal intubation during rapid sequence induction of anaesthesia.
The effect of three bolus doses of remifentanil on the pressor response to laryngoscopy and tracheal intubation during rapid sequence induction of anaesthesia was assessed in a randomized, double-blind, placebo-controlled study in four groups of 20 patients each. After preoxygenation, anaesthesia was induced with thiopental 5-7 mg kg-1 followed immediately by saline (placebo) or remifentanil 0.5, 1.0 or 1.25 micrograms kg-1 given as a bolus over 30 s. Cricoid pressure was applied just after loss of consciousness. ⋯ Arterial pressure and heart rate were recorded at intervals until 5 min after intubation. Remifentanil 0.5 microgram kg-1 was ineffective in controlling the increase in heart rate and arterial pressure after intubation but the 1.0 and 1.25 micrograms kg-1 doses were effective in controlling the response. The use of the 1.25 micrograms kg-1 dose was however, associated with a decrease in systolic arterial pressure to less than 90 mm Hg in seven of 20 patients.
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of four methods for assessing airway sealing pressure with the laryngeal mask airway in adult patients.
We have compared four tests for assessing airway sealing pressure with the laryngeal mask airway (LMA) to test the hypothesis that airway sealing pressure and inter-observer reliability differ between tests. We studied 80 paralysed, anaesthetized adult patients. Four different airway sealing pressure tests were performed in random order on each patient by two observers blinded to each other's measurements: test 1 involved detection of an audible noise; test 2 was detection of end-tidal carbon dioxide in the oral cavity; test 3 was observation of the aneroid manometer dial as the pressure increased to note the airway pressure at which the dial reached stability; and test 4 was detection of an audible noise by neck auscultation. ⋯ Inter-observer reliability of all tests was classed as excellent. The manometric stability test had a higher mean airway sealing pressure (P < 0.0001) and better inter-observer reliability (P < 0.0001) compared with the three other tests. We conclude that for clinical purposes all four tests are excellent, but that the manometric stability test may be more appropriate for researchers comparing airway sealing pressures.
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Comparative Study
Liability of laryngeal mask airway devices to thermal damage from KTP and Nd:YAG lasers.
We have compared the liability of four laryngeal mask airway (LMA) devices (standard, flexible, intubating and reusable) and a tracheal tube to thermal damage from KTP and Nd:YAG lasers at two power densities used commonly in airway surgery: 570 W cm-2 and 1140 W cm-2. Eighty-five airway devices were tested: 24 standard LMA (silicone-based), 12 flexible LMA (silicone-based, metal wires), 24 disposable LMA (PVC-based), one intubating LMA (silicone and steel-based) and 24 PVC-based tracheal tubes. Comparisons were made during laser strike to eight different targets: the unmarked and marked part of the airway device tube; the unmarked part of the airway device tube after application of blood; the cuff filled with air or methylene blue dye; the unmarked flexible LMA tube on or between the metal wires; and the epiglottic elevator bar of the intubating LMA. ⋯ Print markings, blood and the metal wires of the flexible LMA reduced the thermal resistance of the tube. Filling the cuff with methylene blue dye increased the thermal resistance of all airway devices. We conclude that the silicone-based LMA devices were more thermal resistant to KTP and Nd:YAG laser strike than PVC-based devices with the exception of the disposable LMA cuff and the intubating LMA tube.
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Randomized Controlled Trial Comparative Study Clinical Trial
Levobupivacaine vs bupivacaine as infiltration anaesthesia in inguinal herniorrhaphy.
We have compared the anaesthetic and analgesic efficacy of levobupivacaine with that of racemic bupivacaine in 66 male patients undergoing ambulatory primary inguinal herniorrhaphy. Patients were allocated randomly in a double-blind manner to local infiltration anaesthesia (0.25% w/v 50 ml) with either racemic bupivacaine (n = 33) or levobupivacaine (n = 33). Scores for intraoperative pain and satisfaction with anaesthesia were recorded, together with perception of postoperative pain and need for supplementary postoperative analgesic medications in the first 48 h after operation. ⋯ Time averaged postoperative pain scores (48 h) were 8 (levobupivacaine) and 10 (bupivacaine) in the supine position, 13 (levobupivacaine) and 12 (bupivacaine) while rising from the supine position to sitting, and 9 (levobupivacaine) and 13 (bupivacaine) while walking (VAS; 100 mm = worst pain imaginable) (ns). There was no difference in the use of peroral postoperative analgesics between the two groups. We conclude that racemic bupivacaine and its S-enantiomer levobupivacaine had similar efficacy when used as local infiltration anaesthesia in inguinal herniorrhaphy.
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Randomized Controlled Trial Clinical Trial
Glycopyrrolate reduces nausea during spinal anaesthesia for caesarean section without affecting neonatal outcome.
We have tested the hypotheses that glycopyrrolate, administered immediately before induction of subarachnoid anaesthesia for elective Caesarean section, reduces the incidence and severity of nausea, with no adverse effects on neonatal Apgar scores, in a double-blind, randomized, controlled study. Fifty women received either glycopyrrolate 200 micrograms or saline (placebo) i.v. during fluid preload, before induction of spinal anaesthesia with 2.5 ml of 0.5% isobaric bupivacaine. Patients were questioned directly regarding nausea at 3-min intervals throughout operation and asked to report symptoms as they arose. ⋯ Patients in the group pretreated with glycopyrrolate reported a reduction in the frequency (P = 0.02) and severity (P = 0.03) of nausea. Glycopyrrolate also reduced the severity of hypotension, as evidenced by reduced ephedrine requirements (P = 0.02). There were no differences in neonatal Apgar scores between groups.