We thank Yip et al. [1] for their interest in our article [2]. We had, of course, stressed how anaesthesia is a continuum from sedation [3]. We note that Yip et al. stress the close link between the state of ‘general anaesthesia’ on the one hand and need for ‘respiratory support’ on the other. The way they present their argument implies that one cannot achieve general anaesthesia without need for respiratory support.

Their conclusion is understandably borne out of clinical practice in delivering anaesthesia for surgery, where the aim is to achieve a depth of unconsciousness that invariably goes hand in hand with complete respiratory depression. However, it is not relevant to providing general anaesthesia at end of life. As we stressed in our paper, the key approach at end of life, as first described by Moyle [4] and others [5], is to induce anaesthesia in a controlled manner such that spontaneous ventilation is maintained. Not only is this possible in clinical practice, as has been extensively described, but there is a sound theoretical basis on which this can be expected [6].

We agree that the doctrine of double effect is unlikely to be a defence to a practice of rapid induction of anaesthesia, followed by unsupported respiration (and then death) when apnoea ensues. However, the doctrine can apply to death that occurs after several hours or days from slow induction of anaesthesia, when the patient at end-of-life has clearly been self-ventilating. This applies to existing practices in end-of-life care (e.g. morphine analgesia and terminal sedation), and would apply similarly to at least some forms of general anaesthesia at the end of life.

我们感谢 Yip 等人。[ 1 ] 因为他们对我们的文章 [ 2 ]感兴趣。当然，我们强调了麻醉是镇静的连续过程 [ 3 ]。我们注意到 Yip 等人。一方面强调“全身麻醉”状态与另一方面需要“呼吸支持”之间的密切联系。他们提出论点的方式意味着一个人无法在不需要呼吸支持的情况下实现全身麻醉。

他们的结论可以理解为手术麻醉的临床实践证实，其目的是达到无意识的深度，这总是与完全呼吸抑制密切相关。然而，它与在生命结束时提供全身麻醉无关。正如我们在论文中所强调的，正如 Moyle [ 4 ] 和其他人 [ 5 ]首次描述的那样，临终时的关键方法是以受控方式诱导麻醉，从而维持自主通气。正如已广泛描述的那样，这不仅在临床实践中是可能的，而且有一个可靠的理论基础可以预期 [ 6 ]。

我们同意双重效应的学说不太可能是对快速诱导麻醉的做法的辩护，然后在呼吸暂停发生时进行无支持的呼吸（然后是死亡）。然而，该学说可以适用于在缓慢诱导麻醉后数小时或数天后发生的死亡，此时患者在临终时显然已经进行了自我通气。这适用于临终护理的现有实践（例如吗啡镇痛和终末镇静），并且至少适用于临终时的某些形式的全身麻醉。