Goodman N W
University Department of Anaesthesia, Southmead Hospital, Bristol.
Br J Anaesth. 1995 Feb;74(2):129-33. doi: 10.1093/bja/74.2.129.
In the records of breathing from five of 32 patients in two previous studies, the distribution of expiratory times appeared bimodal. Records of breathing from another 40 patients anaesthetized for up to 1 h with propofol infusions were examined; there was clear evidence of bimodality in the distribution of expiratory time in 14 records. The bimodality was independent of tidal volume or inspiratory time, and seemed to be caused largely by differing durations of expiratory pause. In six records there was a change of state between unimodality and bimodality. There was no obvious common factor to explain the bimodality or why a change of state should occur.
在之前两项研究的32名患者中，有5名患者的呼吸记录显示呼气时间分布呈双峰状。对另外40名接受丙泊酚输注麻醉长达1小时的患者的呼吸记录进行了检查；在14份记录中，有明确证据表明呼气时间分布呈双峰状。双峰性与潮气量或吸气时间无关，似乎主要是由呼气暂停的持续时间不同所致。在6份记录中，存在单峰和双峰状态之间的转变。没有明显的共同因素来解释双峰性或为何会发生状态转变。
