Anaesthesia and intensive care
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Anaesth Intensive Care · Mar 2017
Randomized Controlled Trial Comparative StudyAmbu® AuraGain™ versus LMA Supreme™ Second Seal™: a randomised controlled trial comparing oropharyngeal leak pressures and gastric drain functionality in spontaneously breathing patients.
Newer second generation supraglottic airway devices may perform differently in vivo due to material and design modifications. We compared performance characteristics of the Ambu® AuraGain™ and LMA Supreme™ Second Seal™ in 100 spontaneously breathing anaesthetised patients in this randomised controlled study. We studied oropharyngeal leak pressures (OLP) (primary outcome) and secondarily, ease of insertion, success rates, haemodynamic response, time to insertion, and complications of usage. ⋯ One AuraGain and six LMA Supremes failed to be placed within the stipulated 120 seconds trial definition of 'success'; these patients had risk factors for failed supraglottic insertion. In conclusion, both devices had similar OLPs and performed satisfactorily. However, the AuraGain resulted in less postoperative sore throat despite being harder to and taking longer to, insert.
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Anaesth Intensive Care · Mar 2017
Review Case ReportsDelivery of anoxic gas mixtures in anaesthesia: case report and review of the struggle towards safer standards of care.
In 1983 a patient at The Alfred Hospital, Melbourne died during general anaesthesia for emergency surgery, in the weeks following maintenance to the operating theatre gas supply. In the ensuing investigation, it was revealed that he had been given 100% nitrous oxide throughout the anaesthetic due to the inadvertent crossing of the nitrous oxide and oxygen pipelines during the repair work. In this article we review the published literature on the delivery of hypoxic and anoxic gas mixtures, and the associated morbidity and mortality. ⋯ We consider the risks to patient safety when technological advances outpaced the implementation of essential safety standards. We investigate the events that pushed the development of safer standards of anaesthetic practice and patient monitoring, which have contributed to modern day theatre practice. Finally, we consider the risks that still exist in the hospital environment, and the need for on-going vigilance.
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Anaesth Intensive Care · Mar 2017
A pilot study using preoperative cerebral tissue oxygen saturation to stratify cardiovascular risk in major non-cardiac surgery.
This prospective pilot study evaluated whether low preoperative cerebral tissue oxygen saturation is associated with unfavourable outcomes after major elective non-cardiac surgery. Eighty-one patients over 60 years of age, American Society of Anesthesiologists physical status 3 or 4, were recruited. Resting cerebral tissue oxygen saturation was recorded on room air, and after oxygen supplementation, using cerebral oximetry. ⋯ Room air cerebral tissue oxygen saturation was significantly associated with major adverse events (odds ratio 1.36 (95% CI 1.03-1.79), P=0.03). Saturation levels ≤68% carried a positive likelihood ratio of 2.2 for death or severe morbidity, P=0.04. A definitive trial is required to confirm if cerebral oximetry can be used to stratify the cardiovascular risk of patients presenting for non-cardiac surgery.
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Anaesth Intensive Care · Mar 2017
Randomized Controlled TrialValidation of a difficult endotracheal intubation simulator designed for use in anaesthesia training.
There is a need for a validated endotracheal intubation trainer that has variable difficulty settings for the training and assessment of medical practitioners. In this study three anatomical modifications were retrofitted to a commercial manikin and then validated. These modifications included restricted movements of the mandible as well as changes to the upper incisors. ⋯ The time for the novice and intermediate groups improved significantly by the fourth attempt, novice 15 seconds (CI 5.4, 24.6, P=0.002) and intermediate 10 seconds (CI 1.0, 19.0, P=0.03). Other aspects of validity were also satisfied during this study. A high degree of validity was established for these modifications, which can be retrofitted to an existing manikin and then used for teaching or assessment.
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Anaesth Intensive Care · Mar 2017
Global tidal variations, regional distribution of ventilation, and the regional onset of filling determined by electrical impedance tomography: reproducibility.
The reproducibility of the regional distribution of ventilation and the timing of onset of regional filling as measured by electrical impedance tomography lacks evidence. This study investigated whether electrical impedance tomography measurements in healthy males were reproducible when electrodes were replaced between measurements. Part 1: Recordings of five volunteers lying supine were made using electrical impedance tomography and a pneumotachometer. ⋯ The timing of regional onset of filling was reproducible and could prove clinically valuable. The reproducibility of the tidal variation indicates that non-reproducibility of the ventilation distribution was probably a biological difference and not measurement error. Other causes of variability such as electrode placement variability or lack of stabilisation when accounted for did not improve the reproducibility of the ventilation distribution.