Commentary: Searching for liquid gold

Central MessageThe optimal timing of renal replacement therapy after cardiac surgery is unclear, but available perioperative care recommendations may still reduce the burden of postoperative renal injury.See Article page 193. The optimal timing of renal replacement therapy after cardiac surgery is unclear, but available perioperative care recommendations may still reduce the burden of postoperative renal injury. See Article page 193. Like prospectors scouring the reaches of the American frontier, many physicians regularly conduct their own kind of prospecting in the intensive care unit (ICU), seeking to optimize postoperative urine output in their patients after cardiac surgery. The association between renal dysfunction and adverse outcomes has been demonstrated numerous times—in cardiac surgery patients1Hu J. Chen R. Liu S. Yu X. Zou J. Ding X. Global incidence and outcomes of adult patients with acute kidney injury after cardiac surgery: a systematic review and meta-analysis.J Cardiothorac Vasc Anesth. 2016; 30: 82-89Abstract Full Text Full Text PDF PubMed Scopus (122) Google Scholar and others2Hoste E.A.J. Kellum J.A. Selby N.M. Zarbock A. Palevsky P.M. Bagshaw S.M. et al.Global epidemiology and outcomes of acute kidney injury.Nat Rev Nephrol. 2018; 14: 607-625Crossref PubMed Scopus (302) Google Scholar—but the decision for and timing of intervention are less clear. In their Expert Review, Merritt-Genore and colleagues3Merritt-Genore H. Sarber K.M. Thompson S. Accelerated versus delayed initiation of renal-replacement strategies following cardiac surgery.J Thorac Cardiovasc Surg Open. 2021; 6: 193-197Scopus (2) Google Scholar attempt to provide insight into this important question by examining the evidence for early and late initiation of renal replacement therapy (RRT) for acute renal injury or failure after cardiac surgery. The authors highlight a number of important issues related to RRT in cardiac surgery patients. Large studies and meta-analyses from the ICU literature have suggested that the timing of RRT does not affect outcomes, yet this conflicts with data derived from cardiac surgery patients. Early RRT seems to promote the maintenance of euvolemia with a consequently shorter ICU length of stay, although not consistently. Finally, in the cardiac surgery literature there is evidence to suggest that patients with advanced conditions such as right ventricular failure, recent heart transplantation, shock, or the need for mechanical circulatory support, may react differently to RRT than their counterparts, which certainly is biologically plausible. This review is limited by the heterogeneity of included studies, particularly with regard to their design, population, endpoints, and even definition of what constitutes early and late RRT. Much of the available data is derived from the general ICU population and not from cardiac surgery patients. As the authors rightly state and as is corroborated by the observed differences in data signals, enough factors exist to call into question whether cardiac surgery patients are sufficiently similar to the general ICU population for these results to be applicable. It can be argued that they are not. Nonetheless, although we agree wholeheartedly with the authors' recommendations designed to generate high-quality data that are directly applicable to cardiac surgery patients, there are still opportunities to translate available evidence to the bedside. It is clear that acute kidney dysfunction is harmful and that the consequences are worse with increasing severity.1Hu J. Chen R. Liu S. Yu X. Zou J. Ding X. Global incidence and outcomes of adult patients with acute kidney injury after cardiac surgery: a systematic review and meta-analysis.J Cardiothorac Vasc Anesth. 2016; 30: 82-89Abstract Full Text Full Text PDF PubMed Scopus (122) Google Scholar,2Hoste E.A.J. Kellum J.A. Selby N.M. Zarbock A. Palevsky P.M. Bagshaw S.M. et al.Global epidemiology and outcomes of acute kidney injury.Nat Rev Nephrol. 2018; 14: 607-625Crossref PubMed Scopus (302) Google Scholar Once a patient's renal function has deteriorated to the point when RRT is being considered, the opportunity for risk reduction of serious perioperative morbidity has likely passed. Thus, strategies to identify such patients early and to preemptively curb the progression of perioperative kidney injury are likely to pay dividends. With this in mind, the Enhanced Recovery After Cardiac Surgery Society recommends the use of urinary biomarkers to identify at-risk patients and goal-directed fluid therapy to guide perioperative resuscitation.4Engelman D.T. Ben Ali W. Williams J.B. Perrault L.P. Reddy V.S. Arora R.C. et al.Guidelines for perioperative care in cardiac surgery: enhanced recovery after surgery society recommendations.JAMA Surg. 2019; 154: 755-766Crossref PubMed Scopus (275) Google Scholar Until such time as more definitive data are available to guide the timing of RRT in cardiac surgery patients, the consistent implementation of such recommendations may be a useful process measure for units seeking to reduce the impact of postoperative renal-related morbidity and mortality. Accelerated versus delayed initiation of renal-replacement strategies following cardiac surgeryJTCVS OpenVol. 6PreviewVisual representation of the impact and controversy surrounding the timing of initiation for renal-replacement therapy for acute kidney injury after cardiac surgery. On the left side of the image is the impact of acute kidney injury on postoperative heart surgery patients. On the right are the considerations a provider must undertake when determining the appropriating timing for renal-replacement therapy for individual patients. Full-Text PDF Open Access

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.