Anaesthesia
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Randomized Controlled Trial
The effect of gel lubrication on cuff leakage of double lumen tubes during thoracic surgery.
High-volume, low-pressure tracheal cuffs of disposable double lumen tubes may offer limited protection to the dependent lung if fluid leaks through folds in the inflated cuffs. This study was undertaken to determine the incidence of fluid leakage past the tracheal cuff and whether gel lubrication reduces the incidence. Fifty-five patients were randomly assigned to receive a double lumen tube with or without gel lubrication. ⋯ Three patients were excluded. Dye leakage was seen in 12/27 and 3/25 patients in the unlubricated and lubricated group, respectively (p = 0.014). Gel lubrication significantly reduces fluid leakage past the tracheal cuff of a double lumen tube and should be considered for all thoracic surgical patients requiring one-lung ventilation.
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Randomized Controlled Trial Comparative Study
Study of a combined percutaneous local anaesthetic and the TDS system for venepuncture.
Transdermal Delivery System (TDS) is a liquid formulation which can be applied to the skin via a metered pump spray to deliver drug across skin. This placebo controlled, double blind trial compared anaesthetic properties of two TDS systems (TDS alpha and TDS beta) with placebo. The active and placebo treatments were applied to the dorsum of the hands, bilaterally and simultaneously for 5 min on 100 healthy volunteers. ⋯ Lidocaine plasma levels were assessed at 0 and 2 h. The VRS and VAS results show that TDS beta significantly decreased pain score compared to placebo (p < 0.02). Blood lidocaine at 2 h post application was also higher for TDS beta than for TDS alpha, suggesting that a 5 min application of TDS beta was effective in delivering local anaesthetic and accelerating the onset of skin anaesthesia prior to venous cannulation in adults.
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Randomized Controlled Trial Comparative Study
Haemodynamic effects of the prone position: a comparison of propofol total intravenous and inhalation anaesthesia.
The haemodynamic changes of the prone position were investigated in 40 ASA I-II patients undergoing lumbar spine surgery. Patients were randomly assigned, following propofol intravenous induction, to receive maintenance of anaesthesia using either isoflurane 1-1.2% in air or target controlled propofol 3 microg.ml(-1) infusion. Measurements of non-invasive blood pressure, heart rate and cardiac output were made in the supine position. ⋯ Cardiac output measurements were made using a non-invasive cardiac output monitor. We found a significant reduction in cardiac index in both groups and a significantly greater change with propofol compared to isoflurane on turning supine to prone (CI change 0.4 vs 0.7 l.min(-1).m(-2) p = 0.001 and SVRI change 89 vs 177 dyne.s(-1).cm(-5), p = 0.041). We conclude that turning healthy patients prone produces a clinically significant reduction in cardiac output, the change being greater during maintenance of anaesthesia using propofol compared to isoflurane.
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Randomized Controlled Trial
Minimum local anaesthetic dose (MLAD) of intrathecal levobupivacaine and ropivacaine for Caesarean section.
We determined the minimum local anaesthetic dose (MLAD) of spinal levobupivacaine and ropivacaine for Caesarean section. Ninety women were randomly allocated to two groups and received 3 ml of study solution by a combined spinal/epidural technique. The initial dose was 12 mg for levobupivacaine and 17 mg for ropivacaine groups. ⋯ Effective or ineffective responses determined, respectively, a 0.3 mg decrease or increase of the same drug for the next patient in the same group, using up-down sequential allocation. The MLAD of levobupivacaine was 10.58 mg (CI 95%: 10.08-11.09) and the MLAD of ropivacaine 14.22 mg (CI 95%: 13.67-14.77), using the Dixon and Massey formula. The potency ratio between spinal levobupivacaine and spinal ropivacaine was 1.34.
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Randomized Controlled Trial Comparative Study
A comparison of the Soft Seal disposable and the Classic re-usable laryngeal mask airway.
Many new supraglottic airway devices have been recently introduced, their development motivated by the need for a single-use equivalent to the original re-usable laryngeal mask airway. We performed a randomised cross-over study in spontaneously breathing patients comparing the re-usable Laryngeal Mask Airway-Classic (LMA) and the disposable Soft Seal Laryngeal Mask in sizes 3, 4 and 5. Sixty patients had an LMA and a disposable laryngeal mask placed in random order. ⋯ The disposable laryngeal mask required significantly less air to inflate the cuff to produce a seal (10 [10-25] ml with disposable laryngeal mask and 15 [10-30] ml with laryngeal mask) and the cuff pressure produced was significantly lower (35 [20-80] cmH(2)O with disposable laryngeal mask and 75 [20-120] cmH(2)O with LMA). Data are median and range. We conclude that the disposable laryngeal mask is an acceptable alternative to the re-usable LMA.