Finholt D A, Henry D B, Raphaely R C
Can Anaesth Soc J. 1985 Jul;32(4):326-9. doi: 10.1007/BF03011335.
This study determined which variables affected endotracheal tube "leak" pressures in 80 surgical patients, two weeks to 11 years of age, intubated with uncuffed tracheal tubes. We defined "leak" pressure as the inspiratory pressure needed to cause an audible escape of gas around the endotracheal tube. "Leak" pressure was measured after varying either head position, tracheal tube depth within the trachea, fresh gas flow rate, or degree of neuromuscular block. "Leak" pressure increased progressively from 16.9 +/- 1.3 cmH2O with complete patient paralysis to 30.6 +/- 1.4 cmH2O following 100 per cent recovery of neuromuscular function. Turning the head from a neutral position to one side increased "leak" pressure from 14.7 +/- 1.7 cmH2O to 24.4 +/- 2.5 cmH2O. Varying tracheal tube depth or fresh gas flow rate produced no significant change in "leak" pressure. Thus, there may be marked variability in "leak" pressure, depending on head position and degree of neuromuscular blockade. Keeping the patient fully paralyzed with the head in a neutral position provides a reliable and consistent method for measuring "leak" pressures.
本研究确定了哪些变量会影响80名年龄在2周至11岁、使用无套囊气管导管进行插管的外科手术患者的气管导管“漏气”压力。我们将“漏气”压力定义为导致气体在气管导管周围可闻逸出所需的吸气压力。在改变头部位置、气管导管在气管内的深度、新鲜气体流速或神经肌肉阻滞程度后测量“漏气”压力。随着患者从完全麻痹状态逐渐恢复，“漏气”压力从16.9±1.3 cmH₂O逐渐增加到神经肌肉功能完全恢复后的30.6±1.4 cmH₂O。将头部从中立位置转向一侧，“漏气”压力从14.7±1.7 cmH₂O增加到24.4±2.5 cmH₂O。改变气管导管深度或新鲜气体流速对“漏气”压力没有显著影响。因此，根据头部位置和神经肌肉阻滞程度，“漏气”压力可能存在显著差异。使患者头部保持中立位置并完全麻痹，为测量“漏气”压力提供了一种可靠且一致的方法。
