Anaesthesia
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Randomized Controlled Trial Comparative Study
A randomised crossover comparison of manikin ventilation through Soft Seal(®) , i-gel™ and AuraOnce™ supraglottic airway devices by surf lifeguards.
Forty surf lifeguards attempted to ventilate a manikin through one out of three supraglottic airways inserted in random order: the Portex® Soft Seal®; the Intersurgical® i-gel™; and the Ambu® AuraOnce™. We recorded the time to ventilate and the proportion of inflations that were successful, without and then with concurrent chest compressions. The mean (SD) time to ventilate with the Soft Seal, i-gel and AuraOnce was 35.2 (7.2)s, 15.6 (3.3)s and 35.1 (8.5) s, respectively, p < 0.0001. ⋯ The mean (SD) tidal volumes through the Soft Seal, i-gel and AuraOnce were 0.65 (0.14) l, 0.50 (0.16) l and 0.39 (0.19) l, respectively. Most lifeguards (85%) preferred the i-gel. Ventilation through supraglottic airway devices may be considered for resuscitation by surf lifeguards.
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Drawing samples from an indwelling arterial line is the method of choice for frequent blood analysis in adult critical care areas. Sodium chloride 0.9% is the recommended flush solution for maintaining the patency of arterial catheters, but it is easy to confuse with glucose-containing bags on rapid visual examination. The unintentional use of a glucose-containing solution has resulted in artefactually high glucose concentrations in blood samples drawn from the arterial line, leading to insulin administration causing hypoglycaemia and fatal neuroglycopenic brain injury. ⋯ We also make recommendations about storage, arterial pressure monitoring and sampling systems and techniques. Finally, we make recommendations about glucose monitoring and insulin administration. It is intended that adherence to these guidelines will reduce the frequency of sample contamination errors in arterial line use and capture events, when they do occur, before they cause patient harm.
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Observational Study
A prospective observational study of stroke volume responsiveness to a passive leg raise manoeuvre in healthy non-starved volunteers as assessed by transthoracic echocardiography.
Current guidelines for intra-operative fluid management recommend the use of increments in stroke volume following intravenous fluid bolus administration as a guide to subsequent fluid therapy. To study the physiological premise of this paradigm, we tested the hypothesis that healthy, non-starved volunteers would develop an increment in their stroke volume following a passive leg raise manoeuvre. Subjects were positioned supine and stroke volume was measured by transthoracic echocardiography at baseline, 30 s, 1 min, 3 min and 5 min after passive leg raise manoeuvre to 45°. ⋯ Of the 11 volunteers evaluated, five (45%) had stroke volume increases of greater than 10%. Mean (SD) maximum percentage change in cardiac index was 14.8 (9.7)% (p = 0.004). A wide variation in baseline stroke volume and response to the passive leg raise manoeuvre was seen, suggesting greater heterogeneity in the normal population than current clinical guidelines recognise.