We thank Joosten et al.1 for their letter to the editor. We read their comments with interest.
We realize that at the time of publication, work had been published on the association between acute kidney injury (AKI) and blood pressure targets in the operating room; however, when the study was designed, this association had not yet come to light. For this reason, we did not incorporate hemodynamic parameter analysis in our primary outcome.
In response to the second comment, the protocol was executed by a limited number of anesthesiologists, all of whom had contributed to the design of the protocol, which should have assured a greater compliance. But we will have a more definitive answer on compliance rate after we have finished our in-depth analysis of all hemodynamic measures.
Additionally, we thank Wuethrich et al.2 for their letter to the editor. We read their comments with interest.
We agree with Dr Wuethrich that postoperative ileus is multifactorial, of which perioperative fluid balance may only be one component. As described in the Methods,3 we used the same terminology and definitions for complications used in Shabsigh et al.4 We apologize for mischaracterizing the Wuethrich et al.5 article as lacking adequate definition of the terms ileus and constipation, as they are indeed provided in the appendix. However, because that definition of ileus does not completely correspond with the definition provided by Shabsigh et al.,4 there is still some difficulty in aligning the Wuethrich et al. study’s results with other studies. Specifically, the Wuethrich et al. article did not include the second half of the Shabsigh et al. definition of ileus: “or the intolerance of oral intake by postoperative day 5 resulting in patient fasting with or without nasogastric tube placement or antiemetics.”
In response to the other comments: diuretics were not used routinely; they were used only at the discretion of the surgeon for patients who clinically appeared fluid-overloaded based on weight gain, peripheral edema, brain natriuretic peptide, and/or chest x-ray or in patients who were on routine diuretics preoperatively for other medical reasons. Methylnaltrexone was used perioperatively as an opioid antagonist. For the administration of systemic opioids, we believe that randomization should maintain similarity between the arms, thus we did not standardize administration, but we suspect that impact should be the same in each arm. We have found at our institution that we have fewer episodes of hypotension with first out-of-bed trials if the bupivacaine concentration used for epidural analgesia is kept low, without compromising pain control.
The authors declare no competing interests.