Anaesthesia
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Comparative Study
Anaesthetic properties of pregnanolone emulsion. A comparison with alphaxolone/alphadolone, propofol, thiopentone and midazolam in a rat model.
The anaesthetic properties of pregnanolone emulsion, a new steroid preparation for intravenous administration, were evaluated in rats and compared to those of Althesin, propofol, thiopentone and midazolam. The therapeutic index was found to be 50% higher than that of Althesin and 6-8 times higher than those of propofol, thiopentone and midazolam. Induction with pregnanolone emulsion was reliable and fast, with only minor excitatory side effects, although induction time was longer compared to Althesin, propofol and thiopentone. ⋯ Recovery was rapid and smooth, and the proportion of sleeping time to recovery time was higher than found for the other four anaesthetics. No cumulative effects were seen on repeated administration and there were no venous sequelae. The results indicate that pregnanolone emulsion may provide a short-acting, less cumulative and less toxic alternative to existing intravenous anaesthetic agents.
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The application of low frequency (10 Hz) electrical current for 5 minutes to an acupuncture needle placed at the P6 (Neiguan) point is as effective as manual needling in the reduction of emetic sequelae in women premedicated with nalbuphine 10 mg for a minor gynaecological operation carried out under a standard anaesthetic. Both were slightly, but not significantly, better than the antiemetic properties of cyclizine 50 mg.
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A survey of the recognition and management of 21 unintentional dural punctures that occurred in a series of 3500 obstetric epidurals is presented. In seven cases, dural puncture was not recognised at the time of occurrence and two patients may have subsequently received mixed epidural and subarachnoid analgesia. In two patients with dural puncture in whom air had been used to locate the epidural space, cerebrospinal fluid did not drip from the hub of the needle. ⋯ The provision of an epidural infusion of Hartmann's solution for 24 hours, together with bed rest, appeared to delay the onset of dural puncture headache rather than prevent it entirely. Blood patching was required only in five of the 21 patients but was entirely successful. The implications of these observations in relationship to obstetric epidural practice are discussed.
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Comparative Study
One lung anaesthesia. Cardiovascular and respiratory function compared during conventional ventilation and high frequency jet ventilation.
Ten patients about to undergo left-sided thoracotomy for carcinoma of the lung were entered into a crossover trial to compare cardiovascular and respiratory function during high frequency jet ventilation and conventional mechanical ventilation for one lung anaesthesia. All patients were anaesthetised with a standard technique using double lumen tubes and placed in the lateral position with the left chest open. ⋯ Surgical conditions were satisfactory during both methods of ventilation and satisfactory gas exchange occurred. It was, however, more difficult to assess adequacy of ventilation during high frequency jet ventilation and the routine use of this method of ventilation is not recommended during one lung anaesthesia.