The attributable mortality of sepsis for acute kidney injury: a propensity-matched analysis based on multicenter prospective cohort study

BackgroundBoth sepsis and AKI are diseases of major concern in intensive care unit (ICU). This study aimed to evaluate the excess mortality attributable to sepsis for acute kidney injury (AKI).MethodsA propensity score-matched analysis on a multicenter prospective cohort study in 18 Chinese ICUs was performed. Propensity score was sequentially conducted to match AKI patients with and without sepsis on day 1, day 2, and day 3–5. The primary outcome was hospital death of AKI patients.ResultsA total of 2008 AKI patients (40.9%) were eligible for the study. Of the 1010 AKI patients with sepsis, 619 (61.3%) were matched to 619 AKI patients in whom sepsis did not develop during the screening period of the study. The hospital mortality rate of matched AKI patients with sepsis was 205 of 619 (33.1%) compared with 150 of 619 (24.0%) for their matched AKI controls without sepsis (p = 0.001). The attributable mortality of total sepsis for AKI patients was 9.1% (95% CI: 4.8–13.3%). Of the matched patients with sepsis, 328 (53.0%) diagnosed septic shock. The attributable mortality of septic shock for AKI was 16.2% (95% CI: 11.3–20.8%, p < 0.001). Further, the attributable mortality of sepsis for AKI was 1.4% (95% CI: 4.1–5.9%, p = 0.825).ConclusionsThe attributable hospital mortality of total sepsis for AKI were 9.1%. Septic shock contributes to major excess mortality rate for AKI than sepsis.Registration for the multicenter prospective cohort studyregistration number ChiCTR-ECH-13003934     

Early detection of acute kidney injury: emerging new biomarkers

SUMMARY:   Acute kidney injury (AKI) has recently become the preferred term to describe the syndrome of acute renal failure (ARF) with 'failure' or 'ARF' restricted to patients who have AKI and need renal replacement therapy. ¹ This allows capture of the broader clinical spectrum of modest reductions in creatinine, which are themselves known to be associated with major increases in both short- and long-term mortality risk. ^2–5 It is hoped that this change in nomenclature will facilitate an expansion of our understanding of the underlying pathophysiology and also facilitate definitions of AKI, which allow comparisons among clinical trials of patients with similar duration and severity of illness. This review will cover the need for early detection of AKI and the role of urinary and plasma biomarkers, including enzymuria. The primary message is that use of existing criteria to diagnose AKI, namely elevation of the serum creatinine with or without oliguria, results in identification that is too late to allow successful intervention. New biomarkers are essential to change the dire prognosis of this common condition.     

Postpartum acute kidney injury: a review of 99 cases

Postpartum acute kidney injury (PPAKI) constitutes an important cause of obstetric AKI. It is associated with high maternal and fetal mortality in developing nations. The aim of this study is to survey the etiology and outcomes of PPAKI in a tertiary care Indian hospital. Ninety-nine patients, without prior comorbidities, treated for PPAKI, between 2005–2014 at M.S. Ramaiah Medical College, were included for analysis in this retrospective, observational study. AKI was analyzed in terms of maximal stage of renal injury attained as per RIFLE criteria. Outcomes included requirement for renal replacement therapy (RRT), maternal and fetal outcomes. PPAKI constituted 60% of all obstetric AKI cases. Median maternal age was 23 years and 52% of patients were primigravidas. Mean serum creatinine was 4.1?mg/dL. Failure (33%) and injury (31%) were the major categories as per RIFLE criteria. Thirty-nine percent of cases required RRT. Sepsis, particularly puerperal sepsis, was the leading causes of PPAKI (75% of cases) and maternal mortality (94% of deaths). Maternal and fetal mortality were 19% and 22% respectively. The incidence of cortical necrosis was 10.3%. Three patients required long-term RRT. In conclusion, consistent with other Indian literature, we report a high incidence of PPAKI. We found incremental mortality on moving from “Risk” to “Failure” category of RIFLE. PPAKI was associated with high maternal and fetal mortality with sepsis being the leading cause. Our study highlights the need for provision of better quality of maternal care and fetal monitoring to decrease mortality associated with PPAKI in developing countries.     

Association of chronic kidney disease with outcomes in chronic heart failure: a propensity-matched study

Background. Chronic kidney disease (CKD) is associated withincreased mortality in patients with heart failure (HF). However,its association with hospitalization in HF patients has notbeen well studied. Methods. Of 7788 patients in the Digitalis Investigation Grouptrial, 3527 had CKD, defined by an estimated glomerular filtrationrate (GFR) <60 ml/min/1.73 m² body surface area (BSA). Propensityscores for CKD were calculated using a multivariable logisticregression model and used to match 2399 pairs of patients withand without CKD. Matched Cox regression analyses were used toestimate association of CKD with outcomes. Results. All-cause hospitalization occurred in 1636 (rate, 4233/10 000person-years) and 1587 (rate, 3733/10 000 person-years)patients respectively, with and without CKD (matched hazardratio [HR] for CKD, 1.18, 95% confidence interval [CI], 1.08–1.29;P < 0.0001). Matched HR for cardiovascular and HF hospitalizationwere respectively 1.17 (95% CI, 1.06–1.28, P = 0.002)and 1.28 (95% CI, 1.13–1.45, P < 0.0001). Comparedto GFR 60 ml/min/1.73 m² BSA, HR for all-cause hospitalizationfor GFR 45–59 and <45 ml/min/1.73 m² BSA were respectively1.04 (95% CI, 0.94–1.16; P = 0.422) and 1.58 (95% CI,1.34–1.87; P < 0.0001). Similarly, HR for all-causedeath for GFR 45–59 and <45 ml/min/1.73 m² BSA wererespectively 1.03 (95% CI, 0.90–1.18; P = 0.651) and 1.70(95% CI, 1.40–2.07; P < 0.0001). Matched HR for deathdue to cardiovascular causes and progressive HF were respectively1.24 (95% CI, 1.09–1.40; P = 0.001) and 1.42 (95% CI,1.16–1.72; P = 0.001). Conclusion. CKD was associated with increased mortality andhospitalization in ambulatory patients with chronic HF, whichincreased progressively with worsening kidney function.     

Renal dysfunction in acute stroke: an independent predictor of long-term all combined vascular events and overall mortality

Background. Acute stroke is the third leading cause of deathin western societies after ischemic heart disease and cancer.Although it is an emergency disease sharing the same atheroscleroticrisk factors with ischemic heart disease, the association ofrenal function and stroke is poorly investigated. The presentstudy aims at assessing renal function status in patients withacute stroke and investigate any prognostic significance onthe outcome. Methods. This is a prospective study of hospitalized first-everstroke patients over 10 years. The study population comprised1350 patients admitted within 24 h from stroke onset and followedup for 1 to 120 months or until death. Patients were dividedin 3 groups on the basis of the estimated Glomerular FiltrationRate (eGFR) that was calculated from the abbreviated equationof the Modification Diet for Renal Disease in ml/min/1.73m²of body surface area: Group-A comprised patients who had eGFR> 60, group-B those with 30 eGFR 60 and group-C patientswith eGFR < 30. Patients with Acute Kidney Injury (AKI) wereexcluded from the study. The main outcome measures were overallmortality and the composite new cardiovascular events (myocardialinfarction, recurrent stroke, vascular death) among the 3 groupsduring the follow-up period. Results. Almost 1/3 (28.08%) of our acute stroke patients presentedwith moderate (group B) or severe (group C) renal dysfunctionas estimated by eGFR. After adjusting for basic demographic,stroke risk factors and stroke severity on admission, eGFR wasan independent predictor of stroke mortality at 10 years. Patientsin groups B and C had an increased probability of death duringfollow-up: Hazard ratio = 1.21 with 95% CI 1.01–1.46,p < 0.05 and Hazard ratio = 1.76 with 95% CI 1.14–2.73,p < 0.05 respectively, compared to patients belonging togroup A. The probability of death from any cause was significantlydifferent among groups (log rank test 55.4, p = 0.001) duringthe follow-up period: in group-A patients it was 62.8 (95% CI57.6–68.1), in group-B 77.3 (95% CI 68.5–86.1) andin group-C 89.2 (95% CI 75.1–100). During the follow-upperiod 336 new cardiovascular events occurred. The probabilityto have a new composite cardiovascular event was also significantlydifferent among the 3 groups (log rank test 21.1, p = 0.001):in group-A patients it was 45.2 (95% CI 38.7–51.7), ingroup-B 67.4 (95% CI 56.2–78.6) and in group-C 77.6 (95%CI 53.5–100). Conclusion.Renal function on admission appears to be a significantindependent prognostic factor for long term mortality and newcardiovascular morbidity over a 10-year period.     

Outcomes of critically ill patients with acute kidney injury in COVID-19 infection: an observational study

BackgroundEarly reports indicate that AKI is common during COVID-19 infection. Different mortality rates of AKI due to SARS-CoV-2 have been reported, based on the degree of organic dysfunction and varying from public to private hospitals. However, there is a lack of data about AKI among critically ill patients with COVID-19.MethodsWe conducted a multicenter cohort study of 424 critically ill adults with severe acute respiratory syndrome (SARS) and AKI, both associated with SARS-CoV-2, admitted to six public ICUs in Brazil. We used multivariable logistic regression to identify risk factors for AKI severity and in-hospital mortality.ResultsThe average age was 66.42 ± 13.79 years, 90.3% were on mechanical ventilation (MV), 76.6% were at KDIGO stage 3, and 79% underwent hemodialysis. The overall mortality was 90.1%. We found a higher frequency of dialysis (82.7% versus 45.2%), MV (95% versus 47.6%), vasopressors (81.2% versus 35.7%) (p < 0.001) and severe AKI (79.3% versus 52.4%; p = 0.002) in nonsurvivors. MV, vasopressors, dialysis, sepsis-associated AKI, and death (p < 0.001) were more frequent in KDIGO 3. Logistic regression for death demonstrated an association with MV (OR = 8.44; CI 3.43–20.74) and vasopressors (OR = 2.93; CI 1.28–6.71; p < 0.001). Severe AKI and dialysis need were not independent risk factors for death. MV (OR = 2.60; CI 1.23–5.45) and vasopressors (OR = 1.95; CI 1.12–3.99) were also independent risk factors for KDIGO 3 (p < 0.001).ConclusionCritically ill patients with SARS and AKI due to COVID-19 had high mortality in this cohort. Mortality was largely determined by the need for mechanical ventilation and vasopressors rather than AKI severity.     

Hepatic ischemia reperfusion injury is associated with acute kidney injury following donation after brain death liver transplantation

Donation after cardiac death liver transplant recipients have an increased frequency of acute kidney injury (AKI). This suggests that hepatic ischemia‐reperfusion injury may play a critical role in the pathogenesis of AKI after liver transplantation. The aim of this single‐center study was to determine if hepatic ischemia‐reperfusion injury, estimated by peak peri‐operative serum amino‐transferase (AST), is associated with AKI following donation after brain death (DBD) liver transplantation. A total of 296 patients received 298 DBD liver transplants from January 2007 to June 2011. The incidence of AKI was 35.9%. AKI was a risk factor for chronic kidney disease (P = 0.037) and mortality (P = 0.002). On univariate analysis, peak AST correlated with peak creatinine (P < 0.001) and peak change in creatinine from baseline (P < 0.001). Peak AST was higher in AKI patients (P < 0.001). The incidence of AKI in patients with a peak AST of <1500, 1500–2999 and ≥3000 U/l was 26.1%, 39.8% and 71.2%, respectively (P < 0.001). On multiple logistic regression analysis, peak AST was independently associated with the development of AKI (P < 0.001). In conclusion, hepatic ischemia‐reperfusion injury demonstrates a strong relationship with peri‐operative AKI in DBD liver transplant recipients.     

Critically ill,tubular injury,delayed early recovery: characteristics of acute kidney disease with renal oxalosis

ObjectsThis study aimed to analyze the clinicopathological features of acute kidney disease (AKD) with renal oxalosis.MethodsData for biopsy-proven AKD with oxalosis diagnosed from Jan 2011 to Oct 2018 was collected. The underlying diseases, dietary habits, clinical and pathological characteristics of newly emerging kidney disease were analyzed. The long-term renal prognosis was observed.ResultsA total of 23 patients were included, comprised of 18 men and 5 women with a mean age of 51.6 ± 15.9 years. The peak Scr was 669.9 ± 299.8 μmol/L, and 95.7% of patients had stage 3 acute kidney injury (AKI). Drug-induced tubulointerstitial nephritis (TIN) was the most common cause (65.2%) of AKD, followed by severe nephrotic syndrome (17.4%). All patients had pathological changes indicating TIN, and 11 patients were complicated with the newly emerging glomerular disease (GD). The risk of oxalosis caused by increased enterogenous oxalate absorption accounted for only 26.1%, and others came from new kidney diseases. The majority (75%) of abundant (medium to severe) oxalosis occurred in patients without GD. There were no significant differences in the score for tubular injury (T-IS) and interstitial inflammation with different severities of oxalosis. Rate of Scr decrease (ΔScr%) at 2 weeks was negatively correlated with the severity of oxalosis (R = −0.542, p = 0.037), score for T-IS (R = −0.553, p = 0.033), and age (R = −0.736, p = 0.002). The decrease in Scr at 4 weeks was correlated with T-IS (R = −0.433), but had no correlation with oxalosis.ConclusionsThe present findings revealed that 95.7% of AKD with secondary renal oxalosis occurred in critically ill patients. AKD from tubular injury was the prominent cause. Severe oxalosis contributed to delayed early recovery of AKD.     

Incidence and mortality of postoperative acute kidney injury in non-dialysis patients: comparison between the AKIN and KDIGO criteria

Objectives This retrospective study determines whether the kidney disease: improving global outcomes (KDIGO) criteria are superior to acute kidney injury network (AKIN) criteria in detecting non-dialysis AKI events and predicting mortality in chronic kidney disease (CKD) patients after surgery. Methods Surgical patients who were admitted to the intensive care unit were enrolled. Non-dialysis AKI cases were defined using either KDIGO or AKIN creatinine criteria and stratified by CKD stages. The adjusted hazard ratios (AHRs) for in-hospital mortality are compared to those without AKI. The cumulative survival curves and the predictability for mortality are accessed by Kaplan–Meier method and calculating the area under the curve (AUC) for the receiver operating characteristic (ROC) curve, respectively. Results From a total of 826 postoperative patients, the overall in-hospital mortality rate was 11.6% (96 cases) and that for AKI according to KDIGO and AKIN criteria was 30.0% (248 cases) and 31.0% (256 cases). The cumulative survival curve stratified by CKD and AKI stages were comparable between KDIGO and AKIN criteria. The discriminative power for mortality stratified by CKD stages for KDIGO and AKIN criteria are as followed: all subjects: 0.678 versus 0.670 (both ps?<0.001); non-CKD: 0.800 versus 0.809 (both ps?<0.001); early-stage CKD: 0.676 versus 0.676 (both ps?<0.001); late-stage CKD: 0.674 versus 0.660 (ps were?<0.001 and 0.003). Conclusion The KDIGO criteria are superior to AKIN criteria in predicting mortality after surgery, especially in those with advanced CKD.     

The incidence of acute kidney injury in patients with traumatic brain injury

There is limited information on the incidence of acute kidney injury (AKI) in patients with traumatic brain injury (TBI) although AKI may contribute to morbidity and mortality. We investigated the incidence of AKI in patients with moderate and severe TBI and the association of AKI with risk factors and outcomes in these patients.

We studied all TBI patients over 16 years of age admitted to the two designated trauma hospitals in the state of Victoria, Australia from 1 January to 31 December 2008. Patients were included if they had head trauma and presented with a Glasgow coma scale (GCS) <13. Prospectively collected data from the hospital trauma registries, ICUs, and pathology databases were analyzed retrospectively. Risk injury failure loss end (RIFLE) criteria were used to categorize renal function.

The incidence of AKI was 9.2% (19/207). Patients who developed AKI were older, had higher severity of illness scores, and a lower GCS. Overall 42.1% of these patients died in hospital compared with 18.1% in patients without AKI. In univariable linear regression analysis, age, severity of illness, and admitting hospital were associated with AKI. After multivariable logistic regression, the occurrence of AKI was associated with age (p < 0.001) and higher APACHE III scores (p = 0.016).

AKI is relatively common even in patients with TBI. Its association with age and APACHE III scores helps identify patients at higher risk of AKI.