British journal of anaesthesia
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We have assessed a prototype laryngeal mask airway (pLMA) in 50 anaesthetized children for ease of insertion, oropharyngeal leak pressures, gastric insufflation and fibreoptic position. The pLMA has a second smaller mask, which rests against the upper oesophageal sphincter, and a second cuff to increase the seal pressure of the glottic mask. All insertions were graded as easy and an effective airway was achieved in all patients. ⋯ One patient regurgitated clear fluid, but aspiration did not occur. On removal, blood staining was detected in three of 50 children. We conclude that the pLMA was easy to insert, facilitated high airway pressure ventilation and may provide some protection against gastric insufflation.
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We have compared the value of different variables used in the assessment of blood loss during progressive hypovolaemia and resuscitation under general anaesthesia in anaesthetized pigs. We measured mean arterial pressure (MAP), pulmonary capillary wedge pressure (PCWP), the negative component of the systolic arterial pressure variation (delta Down) and left ventricular end-diastolic area (LVEDa) using echocardiography. Blood was progressively withdrawn (up to 35 ml kg-1 in seven steps) and then reinfused after the same pattern. ⋯ The highest r values were obtained with MAP and LVEDa, and the highest nS value with delta Down. The least difference between withdrawal and reinfusion was with LVEDa, the lowest values of minWBV were with PCWP and LVEDa, and the highest value of maxRBV was obtained with PCWP. During progressive haemorrhage under general anaesthesia, LVEDa was an accurate variable for assessment of blood volume loss, delta Down contributed no further information compared with MAP, and PCWP was the most reliable variable for assessing return to baseline blood volume.