Characteristics, Outcomes and 60-Day Hospital Mortality of ICU Patients with COVID-19 and Acute Kidney Injury

Incidence, pathophysiology, risk factors, histopathology, and outcomes of COVID-19-induced acute kidney injury: A narrative review

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has led to a significant burden on global healthcare systems. COVID-19-induced acute kidney injury (AKI) is among one of the complications, that has emerged as a critical and frequent condition in COVID-19 patients. This AKI among COVID-19 patients is associated with poor outcomes, and high mortality rates, especially in those with severe AKI or requiring renal replacement therapy. COVID-19-induced AKI represents a significant complication with complex pathophysiology and multifactorial risk factors. Indeed, several pathophysiological mechanisms, including direct viral invasion of renal cells, systemic inflammation, endothelial and thrombotic abnormalities as well as nephrotoxic drugs and rhabdomyolysis are believed to underlie this condition. Moreover, histopathological and immunohistopathological findings commonly observed in postmortem studies include acute tubular necrosis, glomerular injury, and the presence of viral particles within renal tissue and urine. Identified risk factors for developing AKI vary among studies, depending on regions, underlying conditions, and the severity of the disease. Moreover, histopathological and immunohistopathological findings commonly observed in postmortem studies include show acute tubular necrosis, glomerular injury, and viral particles within renal tissue and urine. While, identified risk factors for developing AKI vary among studies, according to regions, underlying conditions, and the gravity of the disease. This narrative review aims to synthesize current knowledge on the incidence, pathophysiology, risk factors, histopathology, and outcomes of AKI induced by COVID-19.

Survival of critically ill people with COVID-19 and acute kidney injury undergoing hemodialysis in public and private hospitals in Joinville: a cohort study, 2020-2021

OBJECTIVE

To compare the 90-day survival of critically ill people with COVID-19 and acute kidney injury in intensive care units (ICU) of public and private hospitals.

METHODS

This was a retrospective cohort study of critically ill people with COVID-19 and acute kidney injury undergoing hemodialysis in Joinville, Santa Catarina state.

RESULTS

The 90-day survival rate in public ICU was 15.7% (95%CI 8.4; 25.1), while in private ICU it was 37.7% (95%CI 24.9; 50.5%). In the multivariate analysis adjusted for sociodemographic variables (Hazard ratio (HR) 2.01; 95%CI 1.31; 3.08) and comorbidities (HR 2.09; 95%CI 1.30; 3.37), admission to a public ICU was associated with a higher risk of death. After including severity of illness, admission to a public ICU was not associated with an increased risk of death compared to private ICU (HR 0.79; 95%CI 0.45; 1.42).

CONCLUSION

Measures implemented during the COVID-19 pandemic may have reduced inequalities between health systems for critically ill patients with acute kidney injury.

Risk factors and outcome of acute kidney injury in critically ill patients with SARS-CoV-2 pneumonia: a multicenter study

OBJECTIVE

To assess incidence, risk factors and impact of acute kidney injury(AKI) within 48 h of intensive care unit(ICU) admission on ICU mortality in patients with SARS-CoV-2 pneumonia. To assess ICU mortality and risk factors for continuous renal replacement therapy (CRRT) in AKI I and II patients.

DESIGN

Retrospective observational study.

SETTING

Sixty-seven ICU from Spain, Andorra, Ireland.

PATIENTS

5399 patients March 2020 to April 2022.

MAIN VARIABLES OF INTEREST

Demographic variables, comorbidities, laboratory data (worst values) during the first two days of ICU admission to generate a logistic regression model describing independent risk factors for AKI and ICU mortality. AKI was defined according to current international guidelines (kidney disease improving global outcomes, KDIGO).

RESULTS

Of 5399 patients included 1879 (34.8%) developed AKI. These patients had higher ICU mortality and AKI was independently associated with a higher ICU mortality (HR 1.32 CI 1.17-1.48; p < 0.001). Male gender, hypertension, diabetes, obesity, chronic heart failure, myocardial dysfunction, higher severity scores, and procalcitonine were independently associated with the development of AKI. In AKI I and II patients the need for CRRT was 12.6% (217/1710). In these patients, APACHE II, need for mechanical ventilation in the first 24 h after ICU admission and myocardial dysfunction were associated with risk of needing CRRT. AKI I and II patients had a high ICU mortality (38.5%), especially if CRRT were required (64.1% vs. 34,8%; p < 0.001).

CONCLUSIONS

Critically ill patients with SARS-CoV-2 pneumonia and AKI have a high ICU mortality. Even AKI I and II stages are associated with high risk of needing CRRT and ICU mortality.

Evaluation of Clinical Characteristics of Critically Ill COVID-19 Patients With Renal Failure

INTRODUCTION

This study aimed to investigate the clinical characteristics and prognostic factors of critically ill COVID-19 patients with renal failure admitted to the ICU.

METHODS

We analyzed 300 adult patients with SARS-CoV-2 infection admitted to the ICU between November 1, 2020, and June 1, 2022. Demographic data, renal function parameters, and outcomes were collected and analyzed.

RESULTS

The median age was 72 years, and 54.3% were men. Mechanical ventilation was required for 86.3% of patients, with 71.0% needing invasive ventilation. Renal failure was present in 43.3% of patients at ICU admission, significantly associated with older age, higher mechanical and invasive ventilation needs, and increased ICU mortality (76.9% vs. 51.8%, p<0.001). Patients with renal failure had elevated levels of urea, creatinine, C-reactive protein (CRP), D-dimer, white blood cell (WBC), neutrophil (Neu), and procalcitonin (PCT) (p<0.001 for all). Among patients with acute kidney injury (AKI), those with AKI had significantly higher median age (75 vs. 66 years, p<0.001), mechanical ventilation requirement (93.6% vs. 74.3%, p<0.001) and ICU mortality (79.1% vs. 35.4%, p<0.001). Elevated levels of urea (76 vs. 44 mg/dL, p<0.001) and creatinine (1.4 vs. 0.8 mg/dL, p<0.001), as well as inflammatory markers CRP and D-dimer (p=0.001), were observed in AKI patients. Survivors had lower median age (66.0 vs. 74.0 years, p<0.001) and lower prevalence of chronic kidney disease (CKD) (4.5% vs. 12.8, p=0.019) and AKI (34.8% vs. 78.7%, p<0.001). Non-survivors exhibited higher levels of urea, creatinine, lactate dehydrogenase (LDH), CRP, ferritin, and D-dimer (p<0.001 for all).

CONCLUSION

Renal failure and AKI are prevalent in critically ill COVID-19 patients and are associated with worse outcomes. Elevated creatinine and urea levels at ICU admission are significant predictors of ICU mortality, underscoring the importance of early recognition and management of renal impairment in these patients.

Long-term outcome of COVID-19 patients with acute kidney injury requiring kidney replacement therapy

BACKGROUND

Limited data existed on the burden of coronavirus disease 2019 (COVID-19) renal complications and the outcomes of the most critical patients who required kidney replacement therapy (KRT) during intensive care unit (ICU) stay. We aimed to describe mortality and renal function at 90 days in patients admitted for COVID-19 and KRT.

METHODS

A retrospective cohort study of critically ill patients admitted for COVID-19 and requiring KRT from March 2020 to January 2022 was conducted in an Italian ICU from a tertiary care hospital. Primary outcome was mortality at 90 days and secondary outcome was kidney function at 90 days.

RESULTS

A cohort of 45 patients was analyzed. Mortality was 60% during ICU stay and increased from 64% at the time of hospital discharge to 71% at 90 days. Among 90-day survivors, 31% required dialysis, 38% recovered incompletely, and 31% completely recovered renal function. The probability of being alive and dialysis-free at 3 months was 22%.

CONCLUSIONS

Critically ill patients with COVID-19 disease requiring KRT during ICU stay had elevated mortality rate at 90 days, with low probability of being alive and dialysis-free at 3 months. However, a non-negligible number of patients completely recovered renal function.

Obesity aggravates acute kidney injury resulting from ischemia and reperfusion in mice

In critically ill patients, overweight and obesity are associated with acute respiratory distress syndrome and acute kidney injury (AKI). However, the effect of obesity on ischemia-reperfusion injury (IRI)-induced AKI is unknown. We hypothesized that obesity would aggravate renal IRI in mice. We fed mice a standard or high-fat diet for eight weeks. The mice were divided into four groups and submitted to sham surgery or IRI: obese, normal, normal + IRI, obese, and obese + IRI. All studies were performed 48 h after the procedures. Serum glucose, cholesterol, and creatinine clearance did not differ among the groups. Survival and urinary osmolality were lower in the obese + IRI group than in the normal + IRI group, whereas urinary neutrophil gelatinase-associated lipocalin levels, tubular injury scores, and caspase 3 expression were higher. Proliferating cell nuclear antigen expression was highest in the obese + IRI group, as were the levels of oxidative stress (urinary levels of thiobarbituric acid-reactive substances and renal heme oxygenase-1 protein expression), whereas renal Klotho protein expression was lowest in that group. Expression of glutathione peroxidase 4 and peroxiredoxin 6, proteins that induce lipid peroxidation, a hallmark of ferroptosis, was lower in the obese + IRI group. Notably, among the mice not induced to AKI, macrophage infiltration was greater in the obese group. In conclusion, greater oxidative stress and ferroptosis might aggravate IRI in obese individuals, and Klotho could be a therapeutic target in those with AKI.

Biochemical Predictors of Acute Kidney Injury in Critically Ill COVID-19 Patients

It is estimated that 50% of patients with coronavirus disease 2019 (COVID-19) have varying degrees of renal involvement. In this clinical biomarker development research, we examined in a retrospective study design the temporal changes in biochemical laboratory parameters in relation to the development of acute kidney injury (AKI). In a sample of 399 patients admitted from May 2020 to May 2021 to a tertiary health care intensive care unit (ICU), the incidence of AKI was 27.3%, and the median time to AKI was on 7th day of ICU admission. Most common etiology of AKI was kidney hypoperfusion. Within 72 h of developmental of low blood pressure, 63.76% developed AKI. The likelihood of AKI was higher in those with elevated serum ferritin, aspartate transaminase, and thrombocytopenia (low platelet count). A cutoff value of 750.3 ng/mL [area under the ROC curve (AUC) = 0.777] for serum ferritin, and 40.05 U/L for alanine aminotransferase (AUC = 0.677) 1 day before development of AKI displayed, respectively, a sensitivity of 76.2% and 64.3%, whereas the specificity was 69.5% and 64.1%, respectively, for these two biochemical predictors. A cutoff value of platelets (152.50 × 10⁹/L [AUC = 0.75]) measured 4 days before development of AKI, displayed 83.3% sensitivity and 16.4% specificity. Taken together, our study thoroughly examined the temporal association of various clinical and laboratory parameters with AKI and prediction models were developed as per results of the time series data. These observations in a tertiary health care setting contribute to ongoing efforts for biomarker discovery and development using routine biochemical tests so as to forecast AKI in patients with COVID-19.

COVID-19 and acute kidney injury in German hospitals 2020

INTRODUCTION

The SARS-CoV-2 pandemic is a major challenge for patients, healthcare professionals, and populations worldwide. While initial reporting focused mainly on lung involvement, the ongoing pandemic showed that multiple organs can be involved, and prognosis is largely influenced by multi-organ involvement. Our aim was to obtain nationwide retrospective population-based data on hospitalizations with COVID-19 and AKI in Germany.

MATERIALS & METHODS

We performed a query of G-DRG data for the year 2020 via the Institute for the hospital remuneration system (Institut für das Entgeltsystem im Krankenhaus GmbH, InEK) data portal and therefore included hospitalizations with a secondary diagnosis of RT-PCR proven COVID-19 infection, aged over 15 years. We included hospitalizations with acute kidney injury (AKI) stages 1 to 3. Age-specific and age-standardized hospitalization and in-hospital mortality rates (ASR) per 100.000 person years were calculated, with the German population of 2011 as the standard.

RESULTS

In 2020, there were 16.776.845 hospitalizations in German hospitals. We detected 154.170 hospitalizations with RT-PCR proven COVID-19 diagnosis. The age-standardized hospitalization rate for COVID-19 in Germany was 232,8 per 100.000 person years (95% CI 231,6-233,9). The highest proportion of hospitalizations associated with COVID-19 were in the age group over 80 years. AKI was diagnosed in 16.773 (10.9%) of the hospitalizations with COVID-19. The relative risk of AKI for males was 1,49 (95%CI 1,44-1,53) compared to females. Renal replacement therapy (RRT) was performed in 3.443 hospitalizations, 20.5% of the hospitalizations with AKI. For all hospitalizations with COVID-19, the in-hospital mortality amounted to 19.7% (n = 30.300). The relative risk for in-hospital mortality was 3,87 (95%CI 3,80-3,94) when AKI occurred. The age-standardized hospitalization rates for COVID-19 took a bimodal course during the observation period. The first peak occurred in April (ASR 23,95 per 100.000 person years (95%CI 23,58-24,33)), hospitalizations peaked again in November 2020 (72,82 per 100.000 person years (95%CI 72,17-73,48)). The standardized rate ratios (SRR) for AKI and AKI-related mortality with the overall ASR for COVID-19 hospitalizations in the denominator, decreased throughout the observation period and remained lower in autumn than they were in spring. In contrast to all COVID-19 hospitalizations, the SRR for overall mortality in COVID-19 hospitalizations diverged from hospitalizations with AKI in autumn 2020.

DISCUSSION

Our study for the first time provides nationwide data on COVID-19 related hospitalizations and acute kidney injury in Germany in 2020. AKI was a relevant complication and associated with high mortality. We observed a less pronounced increase in the ASR for AKI-related mortality during autumn 2020. The proportion of AKI-related mortality in comparison to the overall mortality decreased throughout the course of the pandemic.

Long-Term Follow up of Renal and Other Acute Organ Failure in Survivors of Critical Illness Due to Covid-19

BACKGROUND

Little is known about the long-term health sequelae and outcomes of various organ failures in ICU survivors of Covid-19. The aim of our research was to study the characteristics of 120-day ICU survivors of the initial pandemic surge and report their long term (>6 months) outcomes.

METHODS

We conducted a telephone questionnaire-based follow up study of 120- day survivors of Covid-19 admitted to ICUs at Montefiore Medical Center, Bronx, NY from 3/10/2020 to 4/11/2020. The study period was 2 months (11/1/2020-12/31/2020).

RESULTS

126 out of 300 (42%) survived to 120-days post-hospital discharge. The median age of survivors was 54 (47-61) years. Seventy-eight (62%) patients developed acute kidney injury (AKI); thirty-five (44.9%) of them required renal replacement therapy (RRT). One hundred-five (83.3%) required invasive mechanical ventilation; ten of them required tracheotomy. 103 (81.7%) completed the telephone questionnaire-based study, at a median (IQR) of 216.5 (200-234.5) days after hospital discharge. 29 (28.2%) patients reported persistent shortness of breath, 24, (23.3%) complained of persistent cough, and persistent anosmia in 9 (8.8%). AKI resolved completely in 58 (74.4%) patients. Of 35 AKI patients who required initiation of RRT during hospitalization, 27 (77%) were liberated from RRT and 20 (57%) had resolution of AKI. Of 20 patients without AKI resolution, 12 developed chronic kidney disease, whereas 8 still require RRT. Thirty-three (32.4%) patients developed post-traumatic stress disorder (PTSD) and 10 (11.8%) reported major depression. Many of the patients (68%) regained baseline functional status. Readmissions occurred in 22.3% patients within first 6 months after discharge.

CONCLUSION

Persistent symptoms of long Covid have been reported in ICU survivors of Covid-19 for extended durations. Outcomes of Covid-19 associated acute kidney injury are excellent. There is a high incidence of PTSD and depression in COVID-19 ICU survivors. Functional outcomes are good, but these patients remain at increased risk of hospital readmission.

Comparison of Two Waves of COVID-19 in Critically Ill Patients: A Retrospective Observational Study

Background

The SARS-CoV-2 virus caused the global COVID-19 pandemic, with waxing and waning course. This study was conducted to compare outcomes in the first two waves, in mechanically ventilated patients.

Methods

This retrospective observational study included all mechanically ventilated COVID-19 patients above 18 years of age, between March 2020 and January 2021. Patients were grouped into first wave from March 2020 to July 2020, and second wave from August 2020 to January 2021. Outcome measures were mortality, the development of acute kidney injury (AKI), and need for renal replacement therapy (RRT). Univariate and multivariate cox regression analysis were used to delineate risk factors for the outcome measures.

Results

A total of 426 patients, 285 in the first wave and 185 in the second wave, were included. The incidence of AKI was significantly lower in the second wave (72% vs. 63%; p=0.04). There was no significant difference in mortality (70% vs. 63%; p=0.16) and need for RRT (36% vs. 30%; p=0.1). Risk factors for mortality were increasing age and AKI in both waves, and chronic kidney disease (CKD) (adj. HR 1.7; 95% CI 1.02-2.68; p=0.04) in the second wave. Risk factors for AKI were CKD in both the waves, while it was diabetes (adj. HR 1.4; 95% CI 1.02-1.95; p=0.04) and increasing age in the first wave. Remdesivir (adj. HR 0.5; 95% CI 0.3-0.7; p < 0.01) decreased the risk of AKI, and convalescent plasma (adj. HR 0.5; 95% CI 0.3-0.9; p=0.02) decreased the risk of mortality in the first wave, however, such benefit was not observed in the second wave.

Conclusions

Our study shows a decrease in the incidence of AKI in critically ill patients, however, the reason for this decrease is still unknown. Studies comparing the waves of the pandemic would not only help in understanding disease evolution but also to develop tailored management strategies.

Multidisciplinary basic and clinical research of acute kidney injury with COVID-19: Pathophysiology, mechanisms, incidence, management and kidney transplantation

Acute kidney injury (AKI) linked to coronavirus disease 2019 (COVID-19) has been identified in the course of the disease. AKI can be mild or severe and that is dependent on the presence of comorbidities and the severity of COVID-19. Among patients who had been hospitalized with COVID-19, some were admitted to intensive care unit. The etiology of AKI associated with COVID-19 is multifactorial. Prevention of severe AKI is the prime task in patients with COVID-19 that necessitates a battery of measurements and precautions in management. Patients with AKI who have needed dialysis are in an increased risk to develop chronic kidney disease (CKD) or a progression of their existing CKD. Kidney transplantation patients with COVID-19 are in need of special management to adjust the doses of immunosuppression drugs and corticosteroids to guard against graft rejection but not to suppress the immune system to place the patient at risk of developing a COVID-19 infection. Immunosuppression drugs and corticosteroids for patients who have had a kidney transplant has to be adjusted based on laboratory results and is individualized aiming at the protection of the transplanted from rejection.

CytoSorb Rescue for COVID-19 Patients With Vasoplegic Shock and Multiple Organ Failure: A Prospective, Open-Label, Randomized Controlled Pilot Study

To investigate the effect of extracorporeal cytokine reduction by CytoSorb (CytoSorbents, Monmouth Junction, NJ) on COVID-19–associated vasoplegic shock.

Latin American registry of renal involvement in COVID-19 disease. The relevance of assessing proteinuria throughout the clinical course

The Latin American Society of Nephrology and Hypertension conducted a prospective cohort, multinational registry of Latin American patients with kidney impairment associated to COVID-19 infection with the objective to describe the characteristics of acute kidney disease under these circumstances. The study was carried out through open invitation in order to describe the characteristics of the disease in the region. Eight-hundred and seventy patients from 12 countries were included. Median age was 63 years (54-74), most of patients were male (68.4%) and with diverse comorbidities (87.2%). Acute kidney injury (AKI) was hospital-acquired in 64.7% and non-oliguric in 59.9%. Multiorgan dysfunction syndrome (MODS) due to COVID-19 and volume depletion were the main factors contributing to AKI (59.2% and 35.7% respectively). Kidney replacement therapy was started in 46.2%. Non-recovery of renal function was observed in 65.3%. 71.5% of patients were admitted to ICU and 72.2% underwent mechanical ventilation. Proteinuria at admission was present in 62.4% of patients and proteinuria during hospital-stay occurred in 37.5%. Those patients with proteinuria at admission had higher burden of comorbidities, higher baseline sCr, and MODS was severe. On the other hand, patients with de novo proteinuria had lower incidence of comorbidities and near normal sCr at admission, but showed adverse course of disease. COVID-19 MODS was the main cause of AKI in both groups. All-cause mortality of the general population was 57.4%, and it was associated to age, sepsis as cause of AKI, severity of condition at admission, oliguria, mechanical ventilation, non-recovery of renal function, in-hospital complications and hospital stay. In conclusion, our study contributes to a better knowledge of this condition and highlights the relevance of the detection of proteinuria throughout the clinical course.

Clinical Characteristics and Outcomes of COVID-19 Acute Respiratory Distress Syndrome Patients Requiring Invasive Mechanical Ventilation in a Lower Middle-Income Country

Background

COVID-19 related acute respiratory distress syndrome (ARDS) requires intensive care, which is highly expensive in lower-income countries. Outcomes of COVID-19 patients requiring invasive mechanical ventilation in Pakistan have not been widely reported. Identifying factors forecasting outcomes will help decide optimal care levels and prioritise resources.

Methods

A single-centre, retrospective study on COVID-19 patients requiring invasive mechanical ventilation was conducted from 1st March to 31st May 2020. Demographic variables, physical signs, laboratory values, ventilator parameters, complications, length of stay, and mortality were recorded. Data were analysed in SPSS ver.23.

Results

Among 71 study patients, 87.3% (62) were males, and 12.7% (9) were females with a mean (SD) age of 55.5(13.4) years. Diabetes mellitus and hypertension were the most common comorbidities in 54.9% (39) patients. Median(IQR) SOFA score on ICU admission and at 48 hours was 7(5-9) and 6(4-10), and median (IQR) APACHE-II score was 15 (11-24) and 13(9-23), respectively. Overall, in-hospital mortality was 57.7%; 25% (1/4), 55.6% (20/36) and 64.5% (20/31) in mild, moderate, and severe ARDS, respectively. On univariate analysis; PEEP at admission, APACHE II and SOFA score at admission and 48 hours; Acute kidney injury; D-Dimer>1.5 mg/L and higher LDH levels at 48 hours were significantly associated with mortality. Only APACHE II scores at admission and D-Dimer levels> 1.5 mg/L were independent predictors of mortality on multivariable regression (p-value 0.012 & 0.037 respectively). Admission APACHE II scores, Area under the ROC curve for mortality was 0.80 (95%CI 0.69-0.90); sensitivity was 77.5% and specificity 70% (cut-off ≥13.5).

Conclusion

There was a high mortality rate in severe ARDS. The APACHE II score can be utilised in mortality prediction in COVID-19 ARDS patients. However, larger-scale studies in Pakistan are required to assess predictors of mortality.

Acute Kidney Injury Secondary to Rhabdomyolysis and COVID-19: A Case Report and Literature Review

The viral infection causing COVID-19 most notably affects the respiratory system but can result in extrapulmonary clinical manifestations as well. Rhabdomyolysis-associated acute kidney injury (AKI) in the setting of COVID-19 is an uncommon complication of the infection. There is significant interest in this viral infection given its global spread, ease of transmission, and varied clinical manifestations and outcomes. This case report and literature review describes the symptoms, laboratory findings, and clinical course of a patient who developed AKI secondary to rhabdomyolysis and COVID-19, which will help clinicians recognize and treat this condition.

A review of Covid-19 and acute kidney injury: from pathophysiology to clinical results

Acute kidney injury (AKI) in hospitalized patients with COVID-19 is associated with higher mortality and a worse prognosis. Nevertheless, most patients with COVID-19 have mild symptoms, and about 5% can develop more severe symptoms and involve hypovolemia and multiple organ dysfunction syndrome. In a pathophysiological perspective, severe SARS-CoV-2 infection is characterized by numerous dependent pathways triggered by hypercytokinemia, especially IL-6 and TNF-alpha, leading to systemic inflammation, hypercoagulability, and multiple organ dysfunction. Systemic endotheliitis and direct viral tropism to proximal renal tubular cells and podocytes are important pathophysiological mechanisms leading to kidney injury in patients with more critical infection, with a clinical presentation ranging from proteinuria and/or glomerular hematuria to fulminant AKI requiring renal replacement therapies. Glomerulonephritis, rhabdomyolysis, and nephrotoxic drugs are also associated with kidney damage in patients with COVID-19. Thus, AKI and proteinuria are independent risk factors for mortality in patients with SARS-CoV-2 infection. We provide a comprehensive review of the literature emphasizing the impact of acute kidney involvement in the evolutive prognosis and mortality of patients with COVID-19.

Clinical characteristics and outcome of critically ill COVID-19 patients with acute kidney injury: a single centre cohort study

BACKGROUND

Acute kidney injury (AKI) is a common manifestation among patients critically ill with SARS-CoV-2 infection (Coronavirus 2019) and is associated with significant morbidity and mortality. The pathophysiology of renal failure in this context is not fully understood, but likely to be multifactorial. The intensive care unit outcomes of patients following COVID-19 acute critical illness with associated AKI have not been fully explored. We conducted a cohort study to investigate the risk factors for acute kidney injury in patients admitted to and intensive care unit with COVID-19, its incidence and associated outcomes.

METHODS

We reviewed the medical records of all patients admitted to our adult intensive care unit suffering from SARS-CoV-2 infection from 14th March 2020 until 12th May 2020. Acute kidney injury was defined using the Kidney Disease Improving Global Outcome (KDIGO) criteria. The outcome analysis was assessed up to date as 3rd of September 2020.

RESULTS

A total of 81 patients admitted during this period. All patients had acute hypoxic respiratory failure and needed either noninvasive or invasive mechanical ventilatory support. Thirty-six patients (44%) had evidence of AKI (Stage I-33%, Stage II-22%, Renal Replacement Therapy (RRT)-44%). All patients with AKI stage III had RRT. Age, diabetes mellitus, immunosuppression, lymphopenia, high D-Dimer levels, increased APACHE II and SOFA scores, invasive mechanical ventilation and use of inotropic or vasopressor support were significantly associated with AKI. The peak AKI was at day 4 and mean duration of RRT was 12.5 days. The mortality was 25% for the AKI group compared to 6.7% in those without AKI. Among those received RRT and survived their illness, the renal function recovery is complete and back to baseline in all patients.

CONCLUSION

Acute kidney injury and renal replacement therapy is common in critically ill patients presenting with COVID-19. It is associated with increased severity of illness on admission to ICU, increased mortality and prolonged ICU and hospital length of stay. Recovery of renal function was complete in all survived patients.

[COVID-19 and acute kidney injury in the intensive care unit]

Acute kidney injury (AKI) is a frequent and severe complication in coronavirus disease 2019 (COVID-19) patients in the intensive care unit. The development of COVID-19 associated AKI is closely linked to the severity of the disease course. The main risk factor for kidney failure requiring kidney replacement therapy is the necessity for invasive ventilation, whereby the onset of renal failure is often closely associated with the timing of intubation. Additionally, the risk factors for a severe course of COVID-19 have been shown to also be risk factors for renal failure. AKI in COVID-19 shows a high mortality and in some patients leads to chronic kidney disease; however, full recovery of kidney function in survivors who need dialysis is not uncommon. With respect to prevention and treatment of renal failure associated with COVID-19, the same recommendations as for AKI from other causes are valid (Kidney Disease: Improving Global Outcomes, KDIGO bundles). Due to the large numbers of patients in the setting of overwhelmed resources, the availability of extracorporeal renal replacement procedures can become critical, especially since hypercoagulation is frequent in COVID‑19. In order to avoid triage situations, in some centers acute peritoneal dialysis was used as an alternative to extracorporeal procedures.