Renal Replacement Therapy Modality and Renal Recovery From ICU Acute Kidney Injury.

Critical Care Medicine www.ccmjournal. org e625 The authors reply: We appreciate the thoughtful response by Kanaoka et al (1) to our recent publication in Critical Care Medicine (2) and agree that this is an important area of research (3, 4). We recognize along with others working in this field that study of family members necessitates that family must be present and agreeable to participation. Family members who are unable or unwilling to visit the ICU are therefore not included in our study (2) resulting in sampling bias. For example, family members who are unable to take off work, perhaps reflecting economic status, would not be studied. Throughout our study (2) and other studies, we have grappled with this issue without finding a satisfying resolution to resolve sampling bias in studies of families of critically ill patients. We did not collect data on other potential stressors or baseline medical history of participants, so we may have missed some important variables that may influence cortisol levels and study outcomes such as sleep or sleep quality (5) or substances and habits known to interact with cortisol secretion. Social support is another possible confounder that may affect both cortisol levels and development of Post-Intensive Care Syndrome-Family, and we agree such variables should be included in future studies in the field. Regarding enrollment procedures, study coordinator time limitations restricted enrollment to one participant per day as we described in the methods. We do not believe the enrollment process introduced systematic bias, as coordinators approached family members without any preferences for patient or participant types, usually starting with the first room and moving through the unit until an enrollment occurred. Of note, the recruitment period spanned over a calendar year, encompassing all seasons. As Kanaoka et al (1) correctly indicated, cortisol levels vary by season. We did not analyze cortisol accounting for seasonal effects in our study (2), but this is an interesting possibility. In response to the letter by Kanaoka et al (1), we reviewed our data, and we did not find significant seasonal variation in our cortisol data. This may reflect our small sample size. Regarding the outcome of depression and posttraumatic stress disorder (PTSD), we apologize for the confusion. In the methods, we mentioned that we also report secondary outcomes including rates of depression and symptoms of PTSD, but we did not analyze these with respect to cortisol. We thank Kanaoka et al (1) for this suggestion, and we ran this analysis and found that PTSD and depression were not associated with salivary cortisol levels. The authors request for additional information about the family members mirrors our own interest in their outcome and well-being after a loved one’s critical illness. We hope that future studies further define family members at risk for negative psychologic outcomes, so that adverse outcomes can be mitigated both during and after a loved one’s ICU admission. Dr. Bulter received support for article research from Intermountain Research and Medical Foundation, and she disclosed government work. The remaining authors have disclosed that they do not have any potential conflicts of interest. Sarah J. Beesley, MD, Center for Humanizing Critical Care, Intermountain Healthcare, Salt Lake City, UT, and Pulmonary and Critical Care Medicine, Department of Medicine, University of Utah School of Medicine, Salt Lake City, UT; Ramona O. Hopkins, PhD, Center for Humanizing Critical Care, Intermountain Healthcare, Salt Lake City, UT, Psychology and Neuroscience Center, Department of Psychology, Brigham Young University, Provo, UT, and Pulmonary Division, Department of Internal Medicine, Intermountain Medical Center, Murray, UT; Julianne Holt-Lunstad, PhD, Psychology and Neuroscience Center, Department of Psychology, Brigham Young University, Provo, UT; Emily L. Wilson, Mstat, Center for Humanizing Critical Care, Intermountain Healthcare, Salt Lake City, UT, and Pulmonary Division, Department of Internal Medicine, Intermountain Medical Center, Murray, UT; Jorie Butler, PhD, Center for Humanizing Critical Care, Intermountain Healthcare, Salt Lake City, UT, Geriatrics Division, Department of Internal Medicine, University of Utah, Salt Lake City, UT, and Department of Psychology, University of Utah, Salt Lake City, UT; Kathryn G. Kuttler, PhD, Center for Humanizing Critical Care, Intermountain Healthcare, Salt Lake City, UT, and Homer Warner Center, Medical Informatics, Intermountain Healthcare, Salt Lake City, UT; James Orme, MD, Samuel M. Brown, MD, MS, Center for Humanizing Critical Care, Intermountain Healthcare, Salt Lake City, UT, Pulmonary and Critical Care Medicine, Department of Medicine, University of Utah School of Medicine, Salt Lake City, UT, and Pulmonary Division, Department of Internal Medicine, Intermountain Medical Center, Murray, UT; Eliotte L. Hirshberg, MD, MS, Center for Humanizing Critical Care, Intermountain Healthcare, Salt Lake City, UT, Pulmonary and Critical Care Medicine, Department of Medicine, University of Utah School of Medicine, Salt Lake City, UT, Pulmonary Division, Department of Internal Medicine, Intermountain Medical Center, Murray, UT, and Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City, UT