British journal of anaesthesia
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Many publications, including the instructions accompanying central venous catheters, state that it is negligent to site the catheter tip in the right atrium. If the catheter tip is above the carina on a post-procedure radiograph then it is generally accepted that the catheter lies outside the right atrium. It is also recommended that the catheter tip should lie in the long axis of the superior vena cava without acute abutment to the vein wall. We performed a retrospective audit of the position of central venous catheter tips on routine post-procedure chest radiographs in intensive care unit patients, to see if these potentially conflicting requirements had been met. ⋯ We suggest that for left-sided catheters placement of the tip below the carina is more likely to result in a satisfactory placement.
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Randomized Controlled Trial Comparative Study
Comparison of efficacy of oxybutynin and tolterodine for prevention of catheter related bladder discomfort: a prospective, randomized, placebo-controlled, double-blind study.
Bladder discomfort related to intraoperative catheterization of urinary bladder is a distressing symptom and more so in patients awakening from anaesthesia. These symptoms are similar to symptoms of overactive bladder. Muscarinic receptor antagonists have been reported to be effective in the treatment of overactive bladder. This study was therefore undertaken to evaluate the efficacy of oxybutynin and tolterodine in preventing catheter related bladder discomfort. ⋯ Pretreatment with either oxybutynin or tolterodine reduces the incidence and severity of catheter related bladder discomfort.
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Randomized Controlled Trial
Large volume N2O uptake alone does not explain the second gas effect of N2O on sevoflurane during constant inspired ventilation.
The second gas effect (SGE) is considered to be significant only during periods of large volume N(2)O uptake (VN(2)O); however, the SGE of small VN(2)O has not been studied. We hypothesized that the SGE of N(2)O on sevoflurane would become less pronounced when sevoflurane administration is started 60 min after the start of N(2)O administration when VN(2)O has decreased to approximately 125 ml min(-1), and that the kinetics of sevoflurane under these circumstances would become indistinguishable from those when sevoflurane is administered in O(2). ⋯ We confirmed the existence of a SGE of N(2)O. Surprisingly, when using an Fa of 65% N(2)O, the magnitude of the SGE was the same with large or small VN(2)O. The classical model and the graphical representation of the SGE alone should not be used to explain the magnitude of the SGE. We speculate that changes in ventilation/perfusion inhomogeneity in the lungs during general anaesthesia result in a SGE at levels of VN(2)O previously considered by most to be too small to exert a SGE.
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Multicenter Study
Relationship between perioperative troponin elevation and other indicators of myocardial injury in vascular surgery patients.
In 2000 the European Society of Cardiology and the American College of Cardiology published a consensus document revising the definition of myocardial infarction. The usefulness of this revised definition has been challenged. It has been suggested that, rather than any release of cardiac troponin being potentially diagnostic of myocardial infarction, a diagnostic threshold consistent with significant myocardial injury should be defined. ⋯ These data suggest that further studies are required to define the optimal cardiac troponin diagnostic threshold for the diagnosis of myocardial infarction in the non-cardiac surgery population.
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A computer controlled infusion device for S(+) ketamine was used in combination with a Diprifusor device to provide anaesthesia for 20 ASA I or II patients undergoing elective colonoscopy. The aim of the study was to assess the performance of the pharmacokinetic model for S(+) ketamine used in the delivery algorithm of the device. ⋯ It was necessary to modify the original published pharmacokinetic parameters incorporated into the S(+) ketamine delivery system in order to simulate improved PK performance during short procedures (<1 h duration) where propofol was concurrently administered. This improved performance was confirmed in a further prospective study.