We thank Dr Robin et al. for their letter [1] in response to our review on the updated PROSPECT guidelines for pain management for total hip arthroplasty [2]. They contend that intrathecal morphine is not appropriate for total hip arthroplasty pain management. In fact, they reiterate the benefits (the pros) and potential adverse effects (the cons) of using intrathecal morphine that have been explicitly discussed in our publication. Nevertheless, we would like to point out that the concerns of late respiratory depression with 0.1 mg intrathecal morphine have not been documented [3, 4]. Also, while same day surgery protocols certainly are emerging in some leading institutions, and we agree that intrathecal morphine may not be appropriate in this patient population, most total hip arthroplasty patients throughout the world still stay in hospital for at least a day after surgery. As clearly noted in the discussion section of our paper, the resources for administering regional analgesia may be lacking in many hospitals throughout the world, and thus the simple measure of intrathecal morphine may be an adequate alternative. Importantly, we are not aware of evidence that intrathecal morphine delays mobilisation as claimed by Robin et al.

We value the suggestion that the PENG block might be a useful technique for postoperative analgesia after total hip arthroplasty; however, the PROSPECT methodology does not allow firm recommendations on a technique about which no published randomised controlled trials are available. During the review period of our literature search, until December 2019, we were not able to identify any studies on the PENG block. Of note, PROSPECT methodology [5] also requires that the analgesic intervention should prove efficacious in addition to basic analgesia (i.e. paracetamol and non-steroidal anti-inflammatory drugs or cyclooxygenase-2 specific inhibitor), and have an acceptable side-effect profile. In other words, any new technique should be superior to the currently used approach with regard to analgesic efficacy and adverse effects, as well as clinical usefulness with regard to early recovery.

我们感谢 Robin 博士等人。他们的信 [ 1 ] 以回应我们对更新的全髋关节置换术疼痛管理 PROSPECT 指南的审查 [ 2 ]。他们认为鞘内注射吗啡不适用于全髋关节置换术的疼痛管理。事实上，他们重申了使用鞘内注射吗啡的好处（优点）和潜在的不利影响（缺点），这些都在我们的出版物中明确讨论过。尽管如此，我们想指出的是，鞘内注射 0.1 mg 吗啡引起的晚期呼吸抑制问题尚未得到记录 [ 3, 4]。此外，虽然一些领先机构肯定会出现当日手术方案，并且我们同意鞘内注射吗啡可能不适合该患者群体，但全世界大多数全髋关节置换术患者在手术后仍需住院至少一天。正如我们论文的讨论部分明确指出的那样，世界上许多医院可能缺乏用于管理区域镇痛的资源，因此鞘内注射吗啡的简单测量可能是一种适当的替代方法。重要的是，我们不知道如 Robin 等人所声称的鞘内吗啡延迟动员的证据。

我们重视 PENG 阻滞可能是全髋关节置换术后镇痛的有用技术的建议；然而，PROSPECT 方法不允许对没有发表的随机对照试验可用的技术提出明确的建议。在我们的文献检索审查期间，直到 2019 年 12 月，我们无法确定任何关于 PENG 区块的研究。值得注意的是，PROSPECT 方法 [ 5] 还要求除基本镇痛（即扑热息痛和非甾体抗炎药或环氧合酶-2 特异性抑制剂）外，镇痛干预应证明有效，并具有可接受的副作用特征。换言之，任何新技术在镇痛效果和不良反应方面，以及在早期恢复方面的临床实用性方面都应该优于目前使用的方法。