ABSTRACT
Background: Critically ill patients with Coronavirus 2019 (COVID-19) disease may develop multiple organ failure. Direct and indirect viral effects may lead to kidney damage and sometimes need for kidney replacement therapy (KRT) (1). During COVID-19 pandemic the proportion of patients needing KRT increased in contrast with shortage of staff and resources. Therefore, the questions intensivists/nephrologists faced at that time were: who, when, how and with which results. This study aimed to analyze the characteristics of COVID-19 critically ill patients treated with KRT, with particular interest in KRT management and outcomes. Method(s): This is a retrospective monocenter study including a cohort of adult patients admitted to an Italian intensive care unit (ICU) in Padua for SARS COV-2 disease with the need for KRT, during the period from March 2020 to February 2022. We collected information at KRT initiation, reviewing medical history, clinical and laboratory data, as well as clinical severity indices such as Simplified Acute Physiology Score (SAPS) and Sequential Organ Failure Assessment (SOFA) scores. Baseline serum creatinine was defined as value 7-365 days prior to admission;when unavailable, Modification of Diet in Renal Disease (MDRD) estimation was used. Acute kidney injury (AKI) was defined according to KDIGO criteria. We also reviewed KRT indication and prescription: choice of catheter placement, modality, prescribed dose, anticoagulation regimen. Complications related to KRT were evaluated and outcomes of this cohort referred to ICU mortality and renal recovery, as defined by acute dialysis quality improvement 2017. We expressed continuous variables as medians (interquartile interval [IQR]) and categorical variables as numbers (percent). Result(s): Of all three-hundred ninety-eight patients with confirmed positive nasopharyngeal molecular swab for Sars COV-2 2019 admitted to our ICU, 55 (13.8%) patients underwent KRT. Patients were predominantly male (74.5%), with a median age of 69 years [IQR 61-75] and the BMI stands at around 28 kg/m2 [IQR 25-31 kg/m2]. The most common comorbidities in this group were arterial hypertension (36 patients [64%]), type II diabetes mellitus (7 patients [12.5%]), vasculopathy (7 patients [12.5%]). Chronic renal disease was present in a large portion of our population (36%), with variable severity staging (stage 1: 1.8%;stage 2: 1.8%;stage 3: 10.9%;stage 4: 3.6%;stage 5 without dialysis: 5.4%;stage 5 with dialysis: 12.7%). Baseline serum creatinine was available for almost half of the patients (47.3%) and median value was 1.05 mg/dL (IQR 0.86-1.4 mg/dL). In our cohort KRT was indicated primarily to support renal function (82%). Modulation of inflammation was the reason to start KRT in a minority of our cohort (2%), even though in 16% of patients the indication relied both on renal support and modulate inflammation. The most common indication for renal support was fluid overload (76%), followed by uremia (58%), electrolytes disturbance (15%) and acid-base disorder (11%). At time of KRT initiation AKI was diagnosed in 89% of patients: 16.4% with stage 1, 20% with stage 2, 54.5% with stage 3. The analyzed cohort was severely ill at the time of KRT indication (with a median SOFA score of 16 [IQR 14- 18], SAPS score of 69 [IQR 60-74]), had moderate/severe acute respiratory failure (median paO2/FiO2 ratio of 121 [IQR 89-170]) and cardiovascular impairment (median vasoactive inotropic score of 19 [IQR 6-31]). 3 (5.5%) patients needed ECMO support. The preferred site of catheter placement was right or left femoral vein (83.6%). To limit circuit clotting, we prescribed preferably continuous veno-venous hemodiafiltration (CVVHDF) (73%) with polyacrylonitrile (AN69) filter membrane (66%). To modulate inflammation in 7 patients (12,5%), the Oxiris filter was indicated combined with CVVHDF modality and in 3 (5%) the Septex filter combined with continuous veno-venous hemodialysis. Regional citrate anticoagulation was the first-choice regimen in association with prophylactic or therape tic systemic heparin anticoagulation (64%), followed by no anticoagulation regimen (12.5%) and systemic heparin anticoagulation regimen (9%). Median dose prescribed was 30,6 ml/kg/h (IQR 28-35). The median KRT time for patient was 312 hours (IQR119-644 hours). Complications related to KRT were frequent (78%): hypophosphatemia (97.6%), hypomagnesemia (76.7%), need for transfusion (12.5%), thromboembolism (3.6%) and citrate accumulation (3.6%). Upon discharge from ICU, 27 patients died (49.1%), with a median ICU stay of 28 days (IQR 17-37 days) and 28 patients survived (50.9%) with a median ICU stay of 29 days (IQR 12-41 days). Among ICU survivors, 15 (54%) were still dependent on dialysis treatment, while 13 (46%) recovered renal function, with a median serum creatinine value at discharge of 1.6 mg/dL (IQR 0.8-2.4 mg/dL). Conclusion(s): In our experience due to severity of COVID-19 disease, one on seven patients admitted in ICU needed treatment with KRT to support kidney function and/or modulate inflammation. KRT prescription was based on patient needs and staff expertise. Once KRT started, complications were frequent, and it needed appropriate monitoring. Prognosis was poor: half of the patients died during ICU stay, while among survivors more than 50% were dialysis-dependent upon ICU discharge.
ABSTRACT
Background: Recent and emerging data suggest that patients with coronavirus disease 2019 (COVID-19) disease can experience as common sequela an acute kidney injury (AKI), suggesting a stronger relationship among COVID-19 and kidney damage organ. Until to 20,6% of critically ill adults with COVID-19 admitted to intensive care units (ICU) develop AKI treated with renal replacement therapy (AKI-RRT), with higher risk to die and a significantly economic burden of illness. The newer topic of COVID-19 disease and AKI-RRT has gained interest over the last months, and to date, the information is limited to single-center experiences with homogeneous population and focused on mortality rate. Indeed, data on long-term outcomes among critically ill patients with AKIRRT associated to COVID-19 are scarce: survival long-term rate and dialysis dependance in this defined population are still unknown. Among critically ill patients with AKI-RRT-associated COVID-19, we aimed to describe outcomes of death and RRT-dependence at almost 3-month follow-up from RRT initiation. We also aimed to estimate the probability of this subgroup to be alive and dialysis-free at 6 months. Method(s): This single-center, retrospective, follow-up study was conducted on the ICU of the University Padua Hospital in the Northeast of Italy. From March 2020 to January 2022, patients hospitalized in the ICU, aged >= 18 years, and treated with RRT due to COVID-19-associated AKI were included. Data for the declared outcomes were collected at almost 3-month from RRT initiation. Exclusion criteria were age<18 years and end-stage renal disease requiring dialysis. Statistical analysis was performed using the software "Statistical Package for the Social Sciences" (SPSS, version 28 for macOS, IBM, Corp, New York, USA). Epidemiological and clinical characteristics were summarized by standard descriptive statistics. Continuous variables were expressed as mean and standard deviation, and categorical ones as percentage distribution of variables was assumed. To evaluate the probability of KRT independence from start to follow-up we used R studio with the package "survival". We perform the analysis accounting for death as competing risk. Result(s): We identified a cohort of fifty-five patients with COVID-19 disease developed AKI-RRT, of whom nine were excluded. In total 46 patients were considered eligible. 81% were male, with a mean age of 68,04 +/-9,5 years at time of inclusion and a mean weight of 90,02+/-16,86 Kg;12 patients (26%) had a history of chronic-kidney-disease (stage 1 8,33%, stage 2 8,33%, stage 3 50%, stage 4 16,6%, stage 5 16,66%) and mean creatinine value was 1,32+/-1,04 mg/dl. Comorbidity reported in clinical medical history was also investigated (hypertension 67,4%, diabetes mellitus 23,9%, peripheral vascular disease 10,9%, steroid therapy 4,3%, BPCO 2,2%). All of them were mechanically ventilated with a mean Horowitz index of 138,44+/-76,7;for 39 patients (81,3%) vasoactive drugs were prescribed and in 3 cases ECMO support was needed. The median time to RRT initiation was 8 days (interquartile range 2-12). On April 30, 2022, 31 (67,4%) patients had died of whom 25 died during ICU stay (at a median time of 29 days, interquartile range 15,5-92 days);18 participants (39,1%) had been discharged from ICU with a median length of stay of 34 days (interquartile range 28,2-65 days). In ICU survivors, the median overall duration of RRT was 386 days (interquartile range 160-672 days). After a median follow-up time of 489 days (interquartile range 261- 534) since RRT initiation, 3 patients (16,6%) were RRT-dependent and 4 (22,2%) had died, while the remaining 11 (61,1%) were alive and RRT-free. Kaplan-Meier curve for probability of RRT-independence is shown in Figure 1. We calculated a probability of RRT-independence of 23% (CI 13-39%) at 6 months since RRT initiation. Conclusion(s): With the limitation of the small sample and the retrospective nature of the study, these findings indicate that despite the high mortality rate in ICU of the subgroup of COVID-19 and AKI-RRT patients, there is up to 23% chance of renal recovery at 6 months.