ABSTRACT
Background: Intradialytic hypotension (IH) is a relatively common complication in patients with acute kidney injury (AKI) who undergoes Kidney Replacement Therapy (KRT) and it could be the potential factor for non-recovery due to ischemic events. It is known that high ultrafiltration rate (UFR) is associated with worse outcomes, a recent recommendation to limit UFR to less than 13 ml/hr/kg has been widely accepted among nephrologists. Continuous kidney replacement therapy (CKRT) is the modality of choice in critically ill patients with hemodynamic instability;however, during COVID 19 pandemic a shortage of resources was evident and other modalities such as sustained low-efficiency dialysis was used in this population. As of today, there is not a universally accepted definition of IH, accordingly a safe UFR goal in critically ill patients it is still unknown in the different KRT modalities. The aim of this study was to analyze the differences in demographical, clinical and KRT prescriptions among critically ill patients with AKI related COVID-19 who developed intradialytic hypotension. Method(s): A prospective, observational, single-center study was performed between April 2020 and December 2021. Critically ill patients with COVID-19 and AKI who required KRT were included. Blood and dialysate flow rates, dialysate temperature, dialysate sodium, bicarbonate and potassium prescriptions were recorded. Body weight and height were obtained from the medical records. Body mass index (BMI) were calculated and interpretated according to WHO recommendations. Ideal body weight (IBW) was calculated using Hamwi equations. Intradialytic hypotension was defined as KDOQI;drop in SBP >= 20mmHg drop in SBP or > 10mmHg in MAP. Result(s): Two hundred sixty-three patients were included in the study, the majority were male, the average age was 60 years and a third of the population was diabetic. A total of 1,942 sessions were prescribed (289 hemodiafiltration (HDF), 1,455 intermittent hemodialysis (IHD), 198 prolonged intermittent renal replacement therapy (PIRRT)). Development of hypotension were reported in 1,059 sessions (55%). No differences between all modalities of KRT were observed HDF 15% vs 15%, IHD 74% vs 76% and PIRRT 11% vs 9% respectively for hypotension or non-hypotension groups (p = 0.27). Differences were statistically significant for sex (p=<0.001), age (p=0.054), UFR prescription (p=<0.001), norepinephrine use (p=<0.001) and dialysate bicarbonate (p=0.001). Age, gender male, and norepinephrine doses were independently associated with the development of hypotension in multivariate logistic regression. Linear regression for norepinephrine and development of hypotension beta0.61 (95% CI 0.38-0.85, p<0.001). Conclusion(s): In our study, the prevalence of intradialytic hypotension was greater than reported in literature probably associated with an exaggerated inflammatory response and need for mechanical ventilation. KRT modality and UFR were not associated with development IDH, however the main risk factor associated was norepinephrine initial dose. Further prospective studies are needed for assessment of a safe ultrafiltration rate in critically-ill patients.