In patients undergoing maintenance hemodialysis (HD), intradialytic hypotension (IDH) is a recognized risk factor for cardiovascular disease and mortality [1]. IDH arises from an imbalance between vascular refilling, cardiac output, and ultrafiltration volume (Fig. 1). Recommendations for the effective prevention and management of IDH include interventions such as limiting interdialytic weight gain and optimized blood pressure-lowering medications, which can ultimately reduce IDH events and improve prognosis in maintenance HD patients [2]. IDH is a common complication in maintenance HD, so it has garnered significant clinical attention, resulting in extensive research. However, the significance of IDH during HD in patients with acute kidney injury (AKI) is less established than in end-stage kidney disease (ESKD) due to inherent differences in disease characteristics. Nevertheless, with the increasing prevalence of comorbidities, including hypertension and diabetes mellitus, and an aging population, the number of patients requiring dialysis for AKI has increased, leading to growing interest in appropriate dialysis modalities, interventions, and associated risk factors. Among the various risk factors in dialysis-requiring AKI patients, IDH can induce ischemic damage in multiple organs, including the kidneys, potentially delaying renal recovery or contributing to increased mortality and other adverse outcomes (Fig. 2).
Recently, Park et al. [3] analyzed 1,009 AKI patients undergoing intermittent HD and examined the relationship between IDH and intensive care unit (ICU) admission rates or all-cause mortality. Employing the same IDH criteria used in ESKD, they reported an IDH prevalence of 44.5%, with hazard ratios for mortality and ICU admission of 1.30 and 1.43, respectively, in the IDH group compared to the non-IDH group. Previous studies have also explored the significance of IDH in AKI patients undergoing dialysis. Augustine et al. [4] compared intermittent HD and continuous renal replacement therapy in AKI patients and reported that a decrease in mean arterial pressure was associated with impaired renal recovery and increased mortality. Similarly, Kim et al. [5] demonstrated that in patients transitioning from continuous renal replacement therapy to intermittent HD, those who experienced IDH had higher mortality and lower dialysis discontinuation rates. Additionally, studies conducted in ICU and outpatient settings involving AKI patients undergoing intermittent HD reported that IDH events were strongly associated with the development of ESKD [6,7]. While the present study aligns with previous research, its significance lies in its exclusive focus on patients whose initial dialysis modality was intermittent HD, its examination of the relationship between IDH events and important outcomes such as ICU admission and patient survival as primary endpoints, and its inclusion of a large sample size.
Several concerns must be addressed to establish more robust evidence on the significance of IDH in AKI patients. First, when analyzing outcomes in AKI patients requiring dialysis, underlying comorbidities serve as critical confounding factors. IDH events are more prevalent in patients with preexisting comorbidities, making it unclear whether IDH itself is a causative factor of poor clinical outcomes or merely a reflection of underlying disease severity. Further research on more homogeneous patient populations and subgroup analyses is required to clarify this relationship. Additionally, well-designed randomized controlled trials could provide more precise insights into the causal relationship between IDH and adverse clinical outcomes. Second, most studies on IDH in AKI currently apply the same definition as used in ESKD patients; however, the appropriateness of this definition for AKI remains unclear. Finally, it is necessary to determine whether replacing intermittent HD with continuous renal replacement therapy in patients at high risk of IDH could improve clinical outcomes or whether modified dialysis options such as slow low-efficiency dialysis could provide benefits. Addressing these concerns is crucial for advancing our understanding of IDH in AKI and optimizing treatment strategies for affected patients.
PDF Links
PubReader
ePub Link
XML Download
Full text via DOI
Download Citation
Print
