Anaesthesia
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Randomized Controlled Trial Comparative Study Clinical Trial
Changes in intra-ocular pressure during general anaesthesia. A comparison of spontaneous breathing through a laryngeal mask with positive pressure ventilation through a tracheal tube.
Changes in-intra-ocular pressure during spontaneous ventilation with a laryngeal mask were compared with controlled ventilation using a tracheal tube in 40 patients undergoing intra-ocular surgery under general anaesthesia. Intra-ocular pressure was measured before induction, after establishing the airway, at the end of the operation and after removal of the airway device. Anaesthesia was induced with propofol and maintained with enflurane and nitrous oxide in oxygen. ⋯ At the end of surgery, intra-ocular pressure (mmHg) was 11.2 and 8.6 during spontaneous or controlled ventilation respectively. One min after removal of the device, mean intra-ocular pressure (mmHg) in the tracheal tube group (16.0) was slightly higher than baseline (15.3) and was significantly higher than the laryngeal mask group (10.9) (p < 0.01). Spontaneous ventilation with a laryngeal mask is an acceptable alternative to controlled ventilation with tracheal intubation in elective intra-ocular surgery.
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Randomized Controlled Trial Comparative Study Clinical Trial
A comparison of three variable performance devices for postoperative oxygen therapy.
Eleven patients in the intensive care unit following major abdominal surgery with a nasogastric tube in situ and receiving oxygen via facemask were allocated to receive in a random sequence oxygen at 4 l.min-1 via a Hudson mask, nasal cannulae or a nasal catheter with foam collar at the distal end. A significantly greater PaO2 was achieved using both the nasal catheter with foam collar (p < 0.01) and Hudson mask (p < 0.05) compared to the nasal cannulae. ⋯ In the majority of postoperative patients in whom a variable performance device is indicated, nasal devices appear preferable in terms of patient comfort and compliance. The nasal catheter with foam collar produced a significantly greater PaO2 than nasal cannulae in patients with a nasogastric tube in situ.
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Randomized Controlled Trial Comparative Study Clinical Trial
Haemodynamic and plasma catecholamine responses during total intravenous anaesthesia for laryngomicroscopy. Thiopentone compared with propofol.
We compared the haemodynamic responses to endolaryngeal procedures during anaesthesia with propofol or thiopentone. Two minutes after administration of glycopyrronium 4 micrograms.kg-1 and alfentanil 17.5 micrograms.kg-1 anaesthesia was induced with either propofol 2.0 mg.kg-1 (n = 8) or thiopentone 5.0 mg.kg-1.min-1, respectively. Muscle relaxation was induced and maintained with suxamethonium. ⋯ With propofol, plasma adrenaline concentrations decreased significantly after induction and remained below baseline values throughout the procedure. After insertion of the operating laryngoscope the haemodynamic response was more pronounced with thiopentone than with propofol. Propofol blocks the catecholamine and haemodynamic responses to endolaryngeal procedures more effectively than thiopentone.