Anaesthesia
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Comparative Study
Speed of spinal vs general anaesthesia for category-1 caesarean section: a simulation and clinical observation-based study.
Controversy exists as to whether effective spinal anaesthesia can be achieved as quickly as general anaesthesia for a category-1 caesarean section. Sixteen consultants and three fellows in obstetric anaesthesia were timed performing spinal and general anaesthesia for category-1 caesarean section on a simulator. ⋯ The median (IQR [range]) times (min:s) for spinal procedure, onset of spinal block and general anaesthesia were 2:56 (2:32-3:32 [1:22-3:50]), 5:56 (4:23-7:39 [2:9-13:32]) and 1:56 (1:39-2:9 [1:13-3:12]), respectively. The limiting factor in urgent spinal anaesthesia is the unpredictable time needed for adequate surgical block to develop.
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Seven different models of oxygen concentrators were purchased. The manufacturer's data were evaluated by a ranking method for operation at high temperature and high relative humidity, power consumption, warranty and cost. Measurements were then made of the oxygen concentration produced at maximum operating temperature. ⋯ All models delivered low oxygen concentrations at 40 °C and 95% relative humidity. Only two models delivered >82% at 35 °C and 50% relative humidity. Concentrators intended for use in countries with limited resources should be evaluated before they are purchased, by independent experts, using the methods described herein.
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The importance of minimising aortocaval compression during cardiopulmonary resuscitation in late pregnancy is widely accepted. Current European guidelines suggest employing manual displacement of the uterus with left lateral tilt to achieve this. Several methods for producing lateral tilt have been described; however, the optimum method is unknown. ⋯ Chest compressions were least effective with the human wedge (p=0.02). Effectiveness of chest compressions with lateral tilt was comparable to that reported previously in supine manikin studies. We recommend the use of dedicated foam or hard wedges rather than pillows or the human wedge for producing lateral tilt during cardiopulmonary resuscitation.
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Cardiac arrest is associated with a very high rate of mortality, in part due to inadequate tissue perfusion during attempts at resuscitation. Parameters such as mean arterial pressure and end-tidal carbon dioxide may not accurately reflect adequacy of tissue perfusion during cardiac resuscitation. We hypothesised that quantitative measurements of tissue oxygen tension would more accurately reflect adequacy of tissue perfusion during experimental cardiac arrest. ⋯ After the return of spontaneous circulation, all measured parameters including brain oxygen tension recovered to baseline levels. Muscle tissue oxygen tension followed a similar trend as the brain, but with slower response times. We conclude that measurements of brain tissue oxygen tension, which more accurately reflect adequacy of tissue perfusion during cardiac arrest and resuscitation, may contribute to the development of new strategies to optimise perfusion during cardiac resuscitation and improve patient outcomes after cardiac arrest.