British journal of anaesthesia
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Randomized Controlled Trial Clinical Trial
Magnesium sulphate enhances residual neuromuscular block induced by vecuronium.
Magnesium sulphate (MgSO4) is currently used for haemodynamic control during anaesthesia and the early postoperative period. We have investigated the effect of this treatment on residual neuromuscular block after administration of vecuronium. ⋯ MgSO4 caused rapid and profound recurarization in all 20 patients. MgSO4 decreased the amount of acetylcholine released at the motor nerve terminal and thus may lead to recurarization in patients previously exposed to neuromuscular blocking agents.
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Randomized Controlled Trial Clinical Trial
Effect of apparatus on functional residual capacity.
As the route of breathing and use of airway apparatus such as mask, mouthpiece and noseclip can alter breathing pattern, this study has used the helium dilution method to estimate the effects of mouthpiece and mask breathing on functional residual capacity (FRC) in the supine position, and the change in FRC that occurs between the sitting and supine positions while breathing by mouthpiece. In 13 normal subjects, breathing by mouthpiece, FRC was smaller, by a median of 1.07 litre (interquartile values 0.73-1.43 litre) in the supine compared with the sitting position (P < 0.01), but residual volume (RV) did not change significantly. FRC measured in the supine position was significantly greater when breathing by mask than by mouthpiece (0.25, 0.04-0.38 litre) and RV was greater by similar amounts (0.20, -0.02 to 0.49 litre). This difference may result from increased inspiratory activity while breathing via the mask.
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Randomized Controlled Trial Comparative Study Clinical Trial
Convective warming combined with vasodilator therapy accelerates core rewarming after coronary artery bypass surgery.
In a prospective, randomized, controlled study, we have investigated the effect of forced air warming on the rate of change of nasopharyngeal and rectal temperatures in 20 patients after coronary artery bypass grafting. All patients had nasopharyngeal temperatures less than 36 degrees C on arrival in the intensive care unit and received an infusion of glyceryl trinitrate 15 mg h-1, but none received inotropes. ⋯ The rates of increase in nasopharyngeal temperature were 0.4 and 0.95 degrees C h-1, respectively, in the control and Bair Hugger groups (P < 0.01) during the first 2 h after operation. Over the same period of time, rectal temperatures increased at a rate of 0.25 and 0.75 degrees C h-1 in the control and Bair Hugger groups, respectively (P < 0.01).
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Randomized Controlled Trial Clinical Trial
Postoperative analgesia by continuous extradural infusion of ropivacaine after upper abdominal surgery.
Ropivacaine is a new local anaesthetic with advantages that suggest an important role in the provision of postoperative analgesia. The main aim of this study was to investigate the dose-response relationship of extradural infusion of ropivacaine. We studied 36 ASA I-III patients undergoing upper abdominal surgery during general anaesthesia and extradural block (catheter insertion at T6-9) using 0.5% ropivacaine in a randomized, double-blind study. ⋯ Pain on coughing was significantly less in all ropivacaine groups than in the saline group after 4 h infusion (medians: saline 67 mm; 0.1% ropivacaine 44 mm; 0.2% ropivacaine 33 mm; 0.3% ropivacaine 0 mm) and for 0.2% and 0.3% ropivacaine at later times. Motor block was negligible throughout the infusion. Patient satisfaction was higher in the 0.2% and 0.3% ropivacaine groups than in the two other groups.
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Randomized Controlled Trial Clinical Trial
Is there implicit memory after propofol sedation?
Recent evidence indicates that implicit memory may be preserved during general anaesthesia. We tested for the presence of explicit and implicit memory in patients undergoing surgical procedures with local or regional anaesthesia and sedation with propofol. Initial i.v. boluses of propofol 0.5 mg kg-1 and fentanyl 1 microgram kg-1 were administered, followed by an infusion of propofol 50 micrograms kg-1 min-1. ⋯ However, the free association tests demonstrated significant priming. The mean number of critical free associations was 6.6 (SEM 0.4) compared with 5.5 (0.4) neutral free association (P < 0.05). In the absence of explicit memory, implicit memory persists after intraoperative sedation with propofol.