Anaesthesia
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Comparative Study
A needle guidance device compared to free hand technique in an ultrasound-guided interventional task using a phantom.
In this in vitro study, a needle guidance device and a 'free hand' technique for ultrasound guided needle insertion were compared in a simulated ultrasound-guided interventional task using a porcine phantom. Residents inexperienced in using ultrasonography were asked to insert a needle, using an in-plane techniques, and to make contact with metal rods at a depth of 2 and 4 cm in the phantom. ⋯ The residents ranked their satisfaction with the needle-guidance device significantly better than the 'free-hand' technique. This device may be beneficial when performing ultrasound guided peripheral nerve blocks, especially by inexperienced operators.
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Oxygen is the commonest drug prescribed in hospitals. The inhaled concentration is altered by the administered oxygen flow rate, the characteristics of the delivery device and the patient's respiratory pattern. Using healthy volunteers we measured the inspired oxygen concentration achieved with different devices both at rest and when the breathing pattern of respiratory failure was simulated by binding the subjects' chests until the forced expiratory volume in 1 s was reduced by > 50% and the respiratory rate was > 25 breaths.min(-1). ⋯ There was no statistically significant change with a nonrebreathing (reservoir) mask at 15 and 110 l.min(-1) or with a Vapotherm 2000i at 40 l.min(-1), humidified, via nasal prongs. We conclude that the F(I)o(2) delivered by high flow devices is unaffected when the breathing pattern of respiratory failure is simulated. The F(I)o(2) achieved at rest by a nonrebreathing mask (0.68) is less than that often quoted in the literature.
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Clinical Trial
An evaluation of conscious sedation using propofol and remifentanil for tension-free vaginal tape insertion.
Tension-free vaginal tape insertion is a recommended treatment for stress incontinence. There is evidence that intra-operative testing of continence by asking patients to cough may improve outcomes, but an optimal sedation regimen has not been determined. We prospectively evaluated the effectiveness of propofol and remifentanil infusions in 25 patients using pre- and post-sedation peak cough pressures and pain scores. ⋯ Pain scores (median, IQR [range]) were low for local anaesthetic infiltration (0, [0-1]) and first (0, [0-1]) and second (0, [0-3.5]) needle insertions. Of the 19 patients completing the ISAS, all felt safe and satisfied. Sedation using propofol and remifentanil provides acceptable analgesia, satisfaction and effective continence testing.
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The i-gel, a novel supraglottic airway, has been proposed for use during cardiopulmonary resuscitation. We evaluated the performance of this device in manikins and anaesthetised patients when used by novices: medical students, non-anaesthetist physicians and allied health professionals all unfamiliar with the i-gel. Fifty i-gels were placed in manikins. ⋯ One case of regurgitation and partial aspiration occurred. Our results suggest the i-gel is rapidly inserted in both manikins and patients by novice users and compares favourably to other supraglottic airways available. Further work determining safety and efficacy during cardiopulmonary resuscitation is required.
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This study evaluated the stability and the compatibility of mixtures of morphine sulphate, bupivacaine, and clonidine hydrochloride and of hydromorphone, bupivacaine, and clonidine hydrochloride, when used in constant flow implantable pumps under simulated clinical use conditions. The pumps were filled with drug mixtures and incubated at 37 degrees C for a period of 90 days. Aliquots were sampled monthly from the reservoir and catheter outlet and the drug concentrations analysed using validated chromatography methods. ⋯ Both drug mixtures were found to be stable over 90 days in the pump at 37 degrees C. All device materials retained acceptable mechanical performance following exposure. These results demonstrate that both drug mixtures are stable when maintained at simulated body temperature in an implantable infusion system for 90 days.