British journal of anaesthesia
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Randomized Controlled Trial Comparative Study Clinical Trial
Evaluation of pressure changes in a new design tracheal tube cuff, the Portex Soft Seal, during nitrous oxide anaesthesia.
We have measured pressure changes in a newly designed tracheal tube cuff, the Portex Soft Seal, during nitrous oxide anaesthesia compared with a Mallinckrodt Lo-Contour tube and a Portex Profile tube. The pressure increases in both control groups were significantly greater than those with the new design (P < 0.0001 in each case). The mean increase in pressure in the Mallinckrodt Lo-Contour tube cuff was 9.9 (SD 3.4) mm Hg compared with 10.3 (1.8) mm Hg in the Portex Profile tube cuff and 2.1 (1.5) mm Hg in the Portex Soft Seal tube cuff. We conclude that the Portex Soft Seal cuff prevented a significant increase in intracuff pressure during nitrous oxide anaesthesia.
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Randomized Controlled Trial Clinical Trial
Effect of omitting regular ACE inhibitor medication before cardiac surgery on haemodynamic variables and vasoactive drug requirements.
Adverse events during coronary artery bypass graft (CABG) surgery have been described in patients receiving angiotensin converting enzyme (ACE) inhibitors, including hypotension on induction of anaesthesia and an increase in vasoconstrictor requirements after cardiopulmonary bypass (CPB). Omitting regular ACE inhibitor medication before surgery may improve cardiovascular stability during anaesthesia. We evaluated prospectively the effect of omitting regular ACE inhibitor medication before CABG surgery on haemodynamic variables and use of vasoactive drugs. ⋯ However, these patients required more vasodilators to control hypertension after CPB and in the early postoperative period. There was no difference in hypotension on induction of anaesthesia or in the use of vasoconstrictors after CPB. We conclude that omitting ACE inhibitors before surgery did not have sufficient advantage to be recommended routinely.
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Randomized Controlled Trial Comparative Study Clinical Trial
Antagonism of rapacuronium using edrophonium or neostigmine: pharmacodynamics and pharmacokinetics.
We have studied the pharmacodynamics and pharmacokinetics of rapacuronium (Org 9487) in 70 healthy patients. Neuromuscular transmission was monitored using TOF stimulation of the ulnar nerve and mechanomyography of the adductor pollicis muscle. Half of the patients were given a single dose of rapacuronium 1.5 mg kg-1 and the remainder rapacuronium 1.5 mg kg-1 with three incremental doses of 0.5 mg kg-1, each given when T1/T0 had recovered to 25%. ⋯ A three-compartment pharmacokinetic model was justified. Typical values for clearance and initial volume of distribution (V1) were 4.4 ml kg-1 min-1 and 94.8 ml kg-1, respectively. In females, clearance was decreased by 38.5% compared with males and V1 was decreased by 25% in patients aged more than 65 yr.
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Randomized Controlled Trial Clinical Trial
Posterior epidural space depth: safety of the loss of resistance and hanging drop techniques.
We have compared skin to epidural space distance (SED) and tip to tip distance (TTD), a measure of posterior epidural space depth (PESD), in 40 patients with a 27-gauge Whitacre needle after identification of the epidural space using the hanging drop (HD) or loss of resistance (LOR) to air technique. After the LOR technique, TTD was found to be 2 mm greater than that after the HD technique, whereas SED was the same. We conclude that identification of the epidural space can be performed successfully with both techniques, but with a diminished risk of dural damage after LOR compared with the HD technique.
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Sedation is an important component of patient comfort in the intensive care unit (ICU), especially in those undergoing mechanical ventilation. Sedation that is too light or too deep can have important consequences, and therefore assessment of the degree of sedation should be an important part of patient management. Although there are many methods available to assess the degree of sedation, none is ideal. ⋯ There were no significant differences in mean or highest levels between patients in the two phases (mean 2.89 (SD 0.11) vs 2.67 (0.13), P = 0.22; highest 3.16 (0.11) vs 3.10 (0.14), P = 0.78). However, the lowest level was significantly greater in patients in the second phase than in those in the first phase (2.61 (0.11) vs 2.16 (0.13); P = 0.011), indicating that the number of patients with excessive sedation was significantly reduced with the introduction of this scale. Thus the use of this scale can have a real clinical impact for patients undergoing mechanical ventilation, principally by avoiding excessive sedation.