Anaesthesia and intensive care
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Anaesth Intensive Care · May 1992
Alveolar oxygenation and mouth-to-mask ventilation: effects of oxygen insufflation.
The effect on alveolar oxygen fraction (FAO2) of insufflating oxygen under a mask (or through an inflow nipple provided in the mask) during simulated mouth-to-mask ventilation was investigated using a lung model. A variety of commercially produced masks were evaluated. Two patterns of artificial ventilation were applied: 1. 500 ml tidal volume at 20 breaths per minute, and 2. 900 ml tidal volume at 12 breaths per minute. ⋯ The relationship between oxygen flow and FAO2 was not linear however, and an oxygen flow rate of 10 l/min was adequate to generate FAO2's around 50% with either ventilatory pattern. The equilibrium FAO2 achieved was greater with smaller tidal volumes and with larger mask deadspace. We also found that several breaths were required for equilibration of FAO2 during each trial, supporting recommendations that several breaths should be given on commencement of artificial ventilation during cardiopulmonary resuscitation.
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Anaesth Intensive Care · May 1992
Randomized Controlled Trial Clinical TrialEfficacy of lignocaine in alleviating potassium chloride infusion pain.
A double-blind study was set up to investigate the effect of pretreatment with lignocaine on the incidence of potassium chloride infusion pain. Twenty-eight patients were randomly allocated into two equal groups. Patients in both groups were hypokalaemic and were scheduled for replacement consisting of potassium chloride 20 mmol diluted to 100 ml in dextrose 5% solution administered over two hours. ⋯ The incidence of potassium chloride infusion pain was significantly reduced in Group A. There was no adverse effect reported. This study demonstrates the efficacy of bolus dose of lignocaine in alleviating injection pain for the duration of a two-hour continuous infusion.