Follow-up Care of Critically Ill Patients With Acute Kidney Injury: A Cohort Study.

Rationale & Objective: To evaluate follow-up care of critically ill patients with acute kidney injury (AKI). Study Design: Retrospective cohort study. Setting & Participants: Patients admitted to the intensive care unit (ICU) with AKI in Alberta, Canada from 2005 to 2018, who survived to discharge without kidney replacement therapy or estimated glomerular filtration rate <15 mL/min/1.73 m2. Exposure: AKI (defined as ≥50% or ≥0.3 mg/dL serum creatinine increase). Outcomes: The primary outcome was the cumulative incidence of an outpatient serum creatinine and urine protein measurement at 3 months postdischarge. Secondary outcomes included an outpatient serum creatinine or urine protein measurement or a nephrologist visit at 3 months postdischarge. Analytical Approach: Patients were followed from hospital discharge until the first of each outcome of interest, death, emigration from the province, kidney replacement therapy (maintenance dialysis or kidney transplantation), or end of study period (March 2019). We used non-parametric methods (Aalen-Johansen) to estimate the cumulative incidence functions of outcomes accounting for competing events (death and kidney replacement therapy). Results: There were 29,732 critically ill adult patients with AKI. The median age was 68 years (IQR, 57-77), 39% were female, and the median baseline estimated glomerular filtration rate was 72 mL/min/1.73 m2 (IQR, 53-90). The cumulative incidence of having an outpatient creatinine and urine protein measurement at 3 months postdischarge was 25% (95% CI, 25-26). At 3 months postdischarge, 64% (95% CI, 64-65) had an outpatient creatinine measurement, 28% (95% CI, 27-28) had a urine protein measurement, and 5% (95% CI, 4-5) had a nephrologist visit. Limitations: We lacked granular data, such as urine output. Conclusions: Many critically ill patients with AKI do not receive the recommended follow-up care. Our findings highlight a gap in the transition of care for survivors of critical illness and AKI.

Myocardial Injury After Noncardiac Surgery in Major General Surgical Patients a Prospective Observational Cohort Study.

OBJECTIVE: The objective of this study was to determine the prognostic relevance, clinical characteristics, and 30-day outcomes associated with myocardial injury after noncardiac surgery (MINS) in major general surgery patients. BACKGROUND: MINS has been independently associated with 30-day mortality after noncardiac surgery. The characteristics and prognostic importance of MINS in major general surgical patients have not been described. METHODS: This was an international prospective cohort study of a representative sample of 22,552 noncardiac surgery patients 45 years or older, of whom 4490 underwent major general surgery in 24 centers in 13 countries. All patients had fifth-generation plasma high-sensitivity troponin T (hsTnT) concentrations measured during the first 3 postoperative days. MINS was defined as a hsTnT of 20-65 ng/L and absolute change >5 ng/L or hsTnT ≥65 ng/L secondary to ischemia. The objectives of the present study were to determine (1) whether MINS is prognostically important in major general surgical patients, (2) the clinical characteristics of major general surgical patients with and without MINS, (3) the 30-day outcomes for major general surgical patients with and without MINS, and (4) the proportion of MINS that would have gone undetected without routine postoperative monitoring. RESULTS: The incidence of MINS in the major general surgical patients was 16.3% (95% CI, 15.3-17.4%). Thirty-day all-cause mortality in the major general surgical cohort was 6.8% (95% CI, 5.1%-8.9%) in patients with MINS compared with 1.2% (95% CI, 0.9%-1.6%) in patients without MINS ( P <0.01). MINS was independently associated with 30-day mortality in major general surgical patients (adjusted odds ratio 4.7, 95% CI, 3.0-7.4). The 30-day mortality was higher both among MINS patients with no ischemic features (ie, no ischemic symptoms or electrocardiogram findings) (5.4%, 95% CI, 3.7%-7.7%) and among patients with 1 or more clinical ischemic features (10.6%, 95% CI, 6.7%-15.8%). The proportion of major general surgical patients who had MINS without ischemic symptoms was 89.9% (95% CI, 87.5-92.0). CONCLUSIONS: Approximately 1 in 6 patients experienced MINS after major general surgery. MINS was independently associated with a nearly 5-fold increase in 30-day mortality. The vast majority of patients with MINS were asymptomatic and would have gone undetected without routine postoperative troponin measurement.

Post-liver transplantation chronic kidney disease is associated with increased cardiovascular disease risk and poor survival.

Chronic kidney disease (CKD) is common following liver transplantation (LT). We aimed to investigate the frequency, risk factors, and impact of CKD on cardiovascular disease (CVD), graft, and patient survival. We analyzed 752 patients who received LT at the University of Alberta. Development of CKD was defined as eGFR <60 ml/min for greater than 3 months, intrinsic renal disease or presence of end-stage renal disease requiring renal replacement therapy. 240 patients were female (32%), and mean age at LT was 53 ± 11 years. CKD was diagnosed in 448 (60%) patients. On multivariable analysis, age (OR 1.3; P = 0.01), female sex (OR 3.3; P < 0.001), baseline eGFR (OR 0.83; P < 0.001), MELD (OR 1.03; P = 0.01), de novo metabolic syndrome (OR 2.3; P = 0.001), and acute kidney injury (OR 3.5; P < 0.001) were associated with CKD. A higher tacrolimus concentration to dose ratio was protective for CKD (OR 0.69; P < 0.001). CKD was associated with post-transplant CVD (26% vs. 16% P < 0.001), reduced graft (HR 1.4; P = 0.02), and patient survival (HR 1.3; P = 0.03). CKD is a frequent complication following LT and is associated with an increased risk of CVD and reduced graft and patient survival.

Derivation and External Validation of a Risk Index for Predicting Acute Kidney Injury Requiring Kidney Replacement Therapy After Noncardiac Surgery.

Importance: Severe acute kidney injury (AKI) is a serious postoperative complication. A tool for predicting the risk of AKI requiring kidney replacement therapy (KRT) after major noncardiac surgery might assist with patient counseling and targeted use of measures to reduce this risk. Objective: To derive and validate a predictive model for AKI requiring KRT after major noncardiac surgery. Design, Setting, and Participants: In this prognostic study, 5 risk prediction models were derived and internally validated in a population-based cohort of adults without preexisting kidney failure who underwent noncardiac surgery in Alberta, Canada, between January 1, 2004, and December 31, 2013. The best performing model and corresponding risk index were externally validated in a population-based cohort of adults without preexisting kidney failure who underwent noncardiac surgery in Ontario, Canada, between January 1, 2007, and December 31, 2017. Data analysis was conducted from September 1, 2019, to May 31, 2021. Exposures: Demographic characteristics, surgery type, laboratory measures, and comorbidities before surgery. Main Outcomes and Measures: Acute kidney injury requiring KRT within 14 days after surgery. Discrimination was assessed using the C statistic; calibration was assessed using calibration intercept and slope. Logistic recalibration was used to optimize model calibration in the external validation cohort. Results: The derivation cohort included 92 114 patients (52.2% female; mean [SD] age, 62.3 [18.0] years), and the external validation cohort included 709 086 patients (50.8% female; mean [SD] age, 61.0 [16.0] years). A total of 529 patients (0.6%) developed postoperative AKI requiring KRT in the derivation cohort, and 2956 (0.4%) developed postoperative AKI requiring KRT in the external validation cohort. The following factors were consistently associated with the risk of AKI requiring KRT: younger age (40-69 years: odds ratio [OR], 2.07 [95% CI, 1.69-2.53]; <40 years: OR, 3.73 [95% CI, 2.61-5.33]), male sex (OR, 1.55; 95% CI, 1.28-1.87), surgery type (colorectal: OR, 4.86 [95% CI, 3.28-7.18]; liver or pancreatic: OR, 6.46 [95% CI, 3.85-10.83]; other abdominal: OR, 2.19 [95% CI, 1.66-2.89]; abdominal aortic aneurysm repair: OR, 19.34 [95% CI, 14.31-26.14]; other vascular: OR, 7.30 [95% CI, 5.48-9.73]; thoracic: OR, 3.41 [95% CI, 2.07-5.59]), lower estimated glomerular filtration rate (OR, 0.97; 95% CI, 0.97-0.97 per 1 mL/min/1.73 m2 increase), lower hemoglobin concentration (OR, 0.99; 95% CI, 0.98-0.99 per 0.1 g/dL increase), albuminuria (mild: OR, 1.88 [95% CI, 1.52-2.33]; heavy: OR, 3.74 [95% CI, 2.98-4.69]), history of myocardial infarction (OR, 1.63; 95% CI, 1.32-2.03), and liver disease (mild: OR, 2.32 [95% CI, 1.66-3.24]; moderate or severe: OR, 4.96 [95% CI, 3.58-6.85]). In external validation, a final model including these variables showed excellent discrimination (C statistic, 0.95; 95% CI, 0.95-0.96), with sensitivity of 21.2%, specificity of 99.9%, positive predictive value of 38.1%, and negative predictive value of 99.7% at a predicted risk threshold of 10% or greater. Conclusions and Relevance: The findings suggest that this risk model can predict AKI requiring KRT after noncardiac surgery using routine preoperative data. The model may be feasible for implementation in clinical perioperative risk stratification for severe AKI.

Angiotensin-Converting Enzyme Inhibitor/Receptor Blocker, Diuretic, or Nonsteroidal Anti-inflammatory Drug Use After Major Surgery and Acute Kidney Injury: A Case-Control Study.

BACKGROUND: Acute kidney injury (AKI) is common after surgery and associated with increased mortality, costs, and lengths of hospitalization. We examined associations between angiotensin-converting enzyme inhibitor (ACEI)/angiotensin receptor blocker (ARB), diuretic, or nonsteroidal anti-inflammatory drug (NSAID) use after major surgery and AKI. MATERIALS AND METHODS: We conducted a nested case-control study of patients who underwent major cardiac, thoracic, general, or vascular surgery in Calgary, Alberta, Canada. Cases with AKI were matched on age, gender, and surgery type with up to five controls without AKI within 30-d after surgery. Adjusted odds ratios (ORs) for AKI were determined based on postoperative administration of ACEIs/ARBs, diuretics, or NSAIDs. RESULTS: Among 33,648 patients in the cohort, 2911 cases with AKI were matched to 9309 controls without AKI. Postoperative diuretic [OR = 1.96; 95% confidence interval (CI) = 1.68-2.29], but not ACEI/ARB (OR = 0.83; 95% CI = 0.72-0.95) or NSAID (OR = 1.12; 95% CI = 0.96-1.31), use was independently associated with higher odds of AKI (including stages 1 and 2/3 AKI) after all types of major surgery. There were increased adjusted odds of AKI 1 to 5 d after first exposure to diuretics and 1 d after first exposure to NSAIDs (but not after later exposures). Relationships between ACEI/ARB use and AKI varied by surgery type (p-interaction = 0.004), with lower odds of AKI observed among ACEI/ARB use after cardiac surgery (OR = 0.70; 95% CI = 0.57-0.81), but no difference after other major surgeries. CONCLUSIONS: Postoperative administration of diuretics and NSAIDs was associated with increased odds of AKI after major surgery. These findings characterize potentially modifiable medication exposures associated with AKI after surgery.

New Ileostomy Formation and Subsequent Community-onset Acute and Chronic Kidney Disease: A Population-based Cohort Study.

OBJECTIVE: The aim of this study was to examine relationships between ileostomy formation and subsequent kidney disease. SUMMARY AND BACKGROUND DATA: Colonic absorptive capacity loss from ileostomy formation can cause volume depletion and could result in kidney disease. METHODS: We conducted a population-based cohort study comparing patients who underwent ileostomy formation with or without bowel resection (ileostomy group) to patients who underwent bowel resection without ileostomy formation (reference group). Adjusted odds ratios (aORs) for community-onset acute kidney injury (AKI) within 3 months and new-onset chronic kidney disease (CKD) within 1 year following hospital discharge were determined. RESULTS: Among 19,889 patients, 4136 comprised the ileostomy group and 15,753 comprised the reference group; 1350 patients experienced community-onset AKI and 464 developed new-onset CKD. The aOR for community-onset AKI with ileostomy formation was 4.08 [95% confidence interval (CI) = 3.62-4.61] for any stage AKI, 7.08 (95% CI = 5.66-8.85) for stage ≥2 injury, and 7.67 (95% CI = 5.06-11.63) for stage 3 injuries. Community-onset AKI modified associations between ileostomy formation and new-onset CKD (P = 0.002). Odds of new-onset CKD were increased in the ileostomy group relative to the reference group for patients both with (aOR = 4.99; 95% CI = 3.42-7.28) and without (aOR = 2.45; 95% CI = 1.85-2.23) previous community-onset AKI episodes. In analyses comparing patients that underwent ileostomy formation and subsequent reversal within 1 year to the reference group without ileostomy, the relationship with new-onset CKD was attenuated for patients both with (aOR = 2.49; 95% CI = 1.50-4.12) and without (aOR = 0.97; 95% CI = 0.67-1.40) previous community-onset AKI episodes. CONCLUSIONS: Ileostomy formation is strongly associated with subsequent kidney disease. Vigilance for this complication and new strategies for prevention and treatment are necessary.

Costs and consequences of acute kidney injury after cardiac surgery: A cohort study.

OBJECTIVES: Acute kidney injury (AKI) is common after cardiac surgery. We quantified the mortality and costs of varying degrees of AKI using a population-based cohort in Alberta, Canada. METHODS: A cohort of patients undergoing cardiac surgery from 2004 to 2009 was assembled from linked Alberta administrative databases. AKI was classified by Kidney Disease Improving Global Outcomes stages of severity. Our outcomes were in-hospital mortality, length of stay, and costs; among survivors, we also examined mortality and costs at 365 days. Estimates were adjusted for demographic characteristics, comorbidities, and other covariates. RESULTS: Ten thousand one hundred seventy participants were included, of whom 9771 patients were discharged to community. Overall in-hospital mortality, costs, and length of stay were 4%, 7 days, and Can $34,000, respectively. Postcardiac surgery, AKI occurred in 25%. Compared with those without AKI, AKI was independently associated with increased in-hospital mortality across severity categories, with the highest risk (adjusted odds ratio, 37.1; 95% confidence interval, 26.3-52.1; P < .001) in patients who required acute dialysis. AKI severity was associated with increased hospital days and costs, with costs ranging from 1.21 for stage 1 AKI (95% confidence interval, 1.17-1.23) to 2.74 for acute dialysis (95% confidence interval, 2.49-3.00) (P < .001) times higher than in patients without AKI, after covariate adjustment. Postdischarge to 365 days, patients with AKI continued to experience increased costs up to 1.35-fold, and patients who required dialysis acutely continued to experience a 2.86-fold increased mortality. CONCLUSIONS: AKI remains an important indicator of mortality and health care costs postcardiac surgery.

Long-term outcomes of acute kidney injury and strategies for improved care.

Acute kidney injury (AKI), once viewed predominantly as a self-limited and reversible condition, is now recognized as a growing problem associated with significant risks of adverse long-term health outcomes. Many cohort studies have established important relationships between AKI and subsequent risks of recurrent AKI, hospital re-admission, morbidity and mortality from cardiovascular disease and cancer, as well as the development of chronic kidney disease and end-stage kidney disease. In both high-income countries (HICs) and low-income or middle-income countries (LMICs), several challenges exist in providing high-quality, patient-centered care following AKI. Despite advances in our understanding about the long-term risks following AKI, large gaps in knowledge remain about effective interventions that can improve the outcomes of patients. Therapies for high blood pressure, glycaemic control (for patients with diabetes), renin-angiotensin inhibition and statins might be important in improving long-term cardiovascular and kidney outcomes after AKI. Novel strategies that incorporate risk stratification approaches, educational interventions and new models of ambulatory care following AKI have been described, and some of these are now being implemented and evaluated in clinical studies in HICs. Care for AKI in LMICs must overcome additional barriers due to limited resources for diagnosis and management.

Secular Changes in Mortality and Hospitalization over Time in People with Kidney Failure or Severe CKD as Compared with Other Noncommunicable Diseases.

BACKGROUND: Few new treatments have been developed for kidney failure or CKD in recent years, leading to perceptions of slower improvement in outcomes associated with CKD or kidney failure than for other major noncommunicable diseases. METHODS: Our retrospective cohort study included 548,609 people with an incident noncommunicable disease, including cardiovascular diseases, diabetes, various cancers, and severe CKD or kidney failure treated with renal replacement (KF-RRT), treated in Alberta, Canada, 2004-2015. For each disease, we assessed presence or absence of 8 comorbidities; we also compared secular trends in relative (compared to a referent year of 2004) and absolute risks of mortality and mean annual days in the hospital associated with each disease after 1 year and 5 years. RESULTS: Comorbidities increased significantly in number over time for all noncommunicable diseases except diabetes, and increased most rapidly for CKD and KF-RRT. Significant but relatively small reductions over time in the risk ratio of mortality at 1 year occurred for nearly all noncommunicable diseases. Secular trends in the absolute risk of mortality were similar; CKD and KF-RRT had a relatively favorable ranking at 1 year. Breast cancer, KF-RRT, diabetes, and colorectal cancer displayed the largest relative reductions in number of hospital days at 1 year. Significant absolute reductions in the number of hospital days were observed for both KF-RRT and CKD; the former had the highest absolute reduction among all noncommunicable diseases. Results were similar at 5 years. CONCLUSIONS: We observed secular reductions in mortality and annual hospital days at 1 year and 5 years among incident patients with KF-RRT and severe CKD, as well as several other common noncommunicable diseases.

Multi-Disciplinary Vascular Access Care and Access Outcomes in People Starting Hemodialysis Therapy.

BACKGROUND AND OBJECTIVES: Fistulas, the preferred form of hemodialysis access, are difficult to establish and maintain. We examined the effect of a multidisciplinary vascular access team, including nurses, surgeons, and radiologists, on the probability of using a fistula catheter-free, and rates of access-related procedures in incident patients receiving hemodialysis. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We examined vascular access outcomes in the first year of hemodialysis treatment before (2004-2005, preteam period) and after the implementation of an access team (2006-2008, early-team period; 2009-2011, late-team period) in the Calgary Health Region, Canada. We used logistic regression to study the probability of fistula creation and the probability of catheter-free fistula use, and negative binomial regression to study access-related procedure rates. RESULTS: We included 609 adults (mean age, 65 [±15] years; 61% men; 54% with diabetes). By the end of the first year of hemodialysis, 102 participants received a fistula in the preteam period (70%), 196 (78%) in the early-team period (odds ratios versus preteam, 1.47; 95% confidence interval, 0.92 to 2.35), and 139 (66%) in the late-team period (0.85; 0.54 to 1.35). Access team implementation did not affect the probability of catheter-free use of the fistula (odds ratio, 0.87; 95% confidence interval, 0.52 to 1.43, for the early; and 0.89; 0.52 to 1.53, for the late team versus preteam period). Participants underwent an average of 4-5 total access-related procedures during the first year of hemodialysis, with higher rates in women and in people with comorbidities. Catheter-related procedure rates were similar before and after team implementation; relative to the preteam period, fistula-related procedure rates were 40% (20%-60%) and 30% (10%-50%) higher in the early-team and late-team periods, respectively. CONCLUSION: Introduction of a multidisciplinary access team did not increase the probability of catheter-free fistula use, but resulted in higher rates of fistula-related procedures.

Prognostic implications of adding urine output to serum creatinine measurements for staging of acute kidney injury after major surgery: a cohort study.

BACKGROUND: Current guidelines recommend staging acute kidney injury (AKI) according to the serum creatinine (SCr) or urine output (UO) criteria that achieve the highest stage. There is little information about the implications of adding UO to SCr measurements for staging AKI outside intensive care units and after cardiac surgery. METHODS: We performed a cohort study of all adults without end-stage renal disease who underwent major noncardiac surgery between January 2005 and March 2011 in Calgary, AB, Canada. Participants required at least two SCr and UO measurements to be included. We examined the implications of adding UO to SCr to stage AKI based on Kidney Disease: Improving Global Outcomes criteria. Logistic and linear regression models were used to examine the associations between AKI stage and 30-day mortality or hospital length of stay (LOS), respectively. RESULTS: A total of 4229 (17%) surgical patients had sufficient SCr and UO measurements for inclusion in the cohort. The apparent incidence of postoperative AKI substantially increased with the addition of UO to SCr criteria (8.1% with SCr alone versus 64.0% with SCr and UO). Mortality for a given stage of AKI was lower when UO was added to SCr criteria (0.3, 3.2, 1.9 and 3.0% for no AKI and Stages 1, 2 and 3, respectively) versus with SCr alone (1.2, 4.2, 15.4 and 12.8%). However, among participants without AKI based on the SCr criterion, the odds of mortality and mean LOS both significantly increased with lower UO. Models that reclassified AKI stage based on UO in addition SCr criteria had the best discrimination for mortality and LOS. CONCLUSIONS: Adding UO to SCr criteria substantially increases the apparent incidence of AKI on hospital wards and significantly changes the prognostic implications of AKI identification and staging. These measures should not be considered equivalent criteria in AKI staging.

A new model to predict acute kidney injury requiring renal replacement therapy after cardiac surgery.

BACKGROUND: Acute kidney injury after cardiac surgery is associated with adverse in-hospital and long-term outcomes. Novel risk factors for acute kidney injury have been identified, but it is unknown whether their incorporation into risk models substantially improves prediction of postoperative acute kidney injury requiring renal replacement therapy. METHODS: We developed and validated a risk prediction model for acute kidney injury requiring renal replacement therapy within 14 days after cardiac surgery. We used demographic, and preoperative clinical and laboratory data from 2 independent cohorts of adults who underwent cardiac surgery (excluding transplantation) between Jan. 1, 2004, and Mar. 31, 2009. We developed the risk prediction model using multivariable logistic regression and compared it with existing models based on the C statistic, Hosmer-Lemeshow goodness-of-fit test and Net Reclassification Improvement index. RESULTS: We identified 8 independent predictors of acute kidney injury requiring renal replacement therapy in the derivation model (adjusted odds ratio, 95% confidence interval [CI]): congestive heart failure (3.03, 2.00-4.58), Canadian Cardiovascular Society angina class III or higher (1.66, 1.15-2.40), diabetes mellitus (1.61, 1.12-2.31), baseline estimated glomerular filtration rate (0.96, 0.95-0.97), increasing hemoglobin concentration (0.85, 0.77-0.93), proteinuria (1.65, 1.07-2.54), coronary artery bypass graft (CABG) plus valve surgery (v. CABG only, 1.25, 0.64-2.43), other cardiac procedure (v. CABG only, 3.11, 2.12-4.58) and emergent status for surgery booking (4.63, 2.61-8.21). The 8-variable risk prediction model had excellent performance characteristics in the validation cohort (C statistic 0.83, 95% CI 0.79-0.86). The net reclassification improvement with the prediction model was 13.9% (p < 0.001) compared with the best existing risk prediction model (Cleveland Clinic Score). INTERPRETATION: We have developed and validated a practical and accurate risk prediction model for acute kidney injury requiring renal replacement therapy after cardiac surgery based on routinely available preoperative clinical and laboratory data. The prediction model can be easily applied at the bedside and provides a simple and interpretable estimation of risk.

Risk prediction models for acute kidney injury following major noncardiac surgery: systematic review.

BACKGROUND: Acute kidney injury (AKI) is a serious complication of major noncardiac surgery. Risk prediction models for AKI following noncardiac surgery may be useful for identifying high-risk patients to target with prevention strategies. METHODS: We conducted a systematic review of risk prediction models for AKI following major noncardiac surgery. MEDLINE, EMBASE, BIOSIS Previews and Web of Science were searched for articles that (i) developed or validated a prediction model for AKI following major noncardiac surgery or (ii) assessed the impact of a model for predicting AKI following major noncardiac surgery that has been implemented in a clinical setting. RESULTS: We identified seven models from six articles that described a risk prediction model for AKI following major noncardiac surgeries. Three studies developed prediction models for AKI requiring renal replacement therapy following liver transplantation, three derived prediction models for AKI based on the Risk, Injury, Failure, Loss of kidney function, End-stage kidney disease (RIFLE) criteria following liver resection and one study developed a prediction model for AKI following major noncardiac surgical procedures. The final models included between 4 and 11 independent variables, and c-statistics ranged from 0.79 to 0.90. None of the models were externally validated. CONCLUSIONS: Risk prediction models for AKI after major noncardiac surgery are available; however, these models lack validation, studies of clinical implementation and impact analyses. Further research is needed to develop, validate and study the clinical impact of such models before broad clinical uptake.

Fluid volume expansion and depletion in hemodialysis patients lack association with clinical parameters.

BACKGROUND: Achievement of normal volume status is crucial in hemodialysis (HD), since both volume expansion and volume contraction have been associated with adverse outcome and events. OBJECTIVES: The objectives of this study are to assess the prevalence of fluid volume expansion and depletion and to identify the best clinical parameter or set of parameters that can predict fluid volume expansion in HD patients. DESIGN: This study is cross-sectional. SETTING: This study was conducted in three hemodialysis units. PATIENTS: In this study, there are 194 HD patients. METHODS: Volume status was assessed by multifrequency bio-impedance spectroscopy (The Body Composition Monitor, Fresenius) prior to the mid-week HD session. RESULTS: Of all patients, 48 % (n = 94) were volume-expanded and 9 % of patients were volume-depleted (n = 17). Interdialytic weight gain was not different between hypovolemic, normovolemic, and hypervolemic patients. Fifty percent of the volume-expanded patients were hypertensive. Paradoxical hypertension was very common (31 % of all patients); its incidence was not different between patient groups. Intradialytic hypotension was relatively common and was more frequent among hypovolemic patients. Multivariate regression analysis identified only four predictors for volume expansion (edema, lower BMI, higher SBP, and smoking). None of these parameters displayed both a good sensitivity and specificity. LIMITATIONS: The volume assessment was performed once. CONCLUSIONS: The study indicates that volume expansion is highly prevalent in HD population and could not be identified using clinical parameters alone. No clinical parameters were identified that could reliably predict volume status. This study shows that bio-impedance can assist to determine volume status. Volume status, in turn, is not related to intradialytic weight gain and is unable to explain the high incidence of paradoxical hypertension.

MISE EN CONTEXTE: L'atteinte d'une volémie normale est primordiale dans le suivi des patients sous hémodialyse. Les états d'expansion et de contraction du volume hydrique sont associés aux complications majeures de l'insuffisance rénale et à une issue défavorable de la maladie. OBJECTIFS DE L'ÉTUDE: Cette étude visait à évaluer la prévalence de l'expansion et de la déplétion des fluides en situation d'hémodialyse. On a également voulu identifier les paramètres cliniques qui pourraient permettre de prévoir les épisodes d'expansion de volume hydrique chez les patients dialysés. CADRE ET TYPE D'ÉTUDE: Il s'agit d'une étude transversale qui s'est tenue dans trois unités d'hémodialyse, sur un total de 194 patients. METHODES: La volémie des Par spectroscopie de bio-impédance à multifréquence (« Body composition Monitor ¼ de Fresenius) tout juste avant la séance d'hémodialyse prévue en milieu de semaine. RÉSULTATS: De tous les patients qui ont participé à l'étude, une proportion de 48 % (n = 94) était en situation d'expansion volumique alors que 9 % (n = 17) se trouvaient en état de déplétion. Toutefois, la prise de poids interdialytique était semblable pour tous les patients, qu'ils aient été hypovolémiques, normovolémiques ou hypervolémiques avant la séance d'hémodialyse. Il est à noter que la moitié des patients (50 %) en situation d'expansion volémique souffraient également d'hypertension artérielle. De fait, l'hypertension artérielle paradoxale s'est avérée répandue parmi les patients dialysés (31 %), mais aucune variation notable de son incidence n'a été observée dans les différents groupes. Les cas d'hypotension intradialytiques quant à eux, se sont avérés relativement courants, particulièrement chez les sujets hypovolémiques avant la séance d'hémodialyse. L'analyse par régression multivariée n'a révélé que quatre indicateurs susceptibles d'aider à prévoir les épisodes d'expansion de volume : la présence d'œdème, un indice de masse corporelle faible, une pression artérielle systolique élevée avant l'hémodialyse, ainsi que le fait de fumer. Cependant, aucun de ces paramètres n'a présenté une spécificité au plan diagnostique ni une sensibilité particulière pour prévoir les épisodes d'expansion de volume. LIMITES DE L'ÉTUDE: La volémie des participants n'a été mesurée qu'une seule fois lors de cette étude. CONCLUSION: L'étude a révélé une prévalence élevée de l'expansion du volume hydrique chez les patients sous hémodialyse, mais il a été impossible de la détecter à l'aide des paramètres cliniques utilisés. Qui plus est, aucun des paramètres mesurés n'a permis d'anticiper avec certitude des variations de la volémie. Concernant la bio-impédance, les résultats ont révélé qu'elle pourrait aider à évaluer l'expansion de volume chez les patients dialysés. En revanche, cette dernière ne peut être associée directement à la prise de poids intradialytique pas plus qu'elle ne peut à elle seule expliquer la forte incidence d'hypertension artérielle paradoxale.

A modified Delphi process to identify process of care indicators for the identification, prevention and management of acute kidney injury after major surgery.

BACKGROUND: The outcomes of acute kidney injury (AKI) are well appreciated. However, valid indicators of high quality processes of care for AKI after major surgery are lacking. OBJECTIVES: To identify indicators of high quality processes of care related to AKI prevention, identification, and management after major surgery. DESIGN: A three stage modified Delphi process. SETTING: The study was conducted in Alberta, Canada using an online format. PARTICIPANTS: A panel of care providers from surgery, critical care, and nephrology. MEASUREMENTS: The degree of validity of candidate indicators were rated by panelists on a 7-point Likert scale that ranged from "strongly disagree" to "strongly agree". METHODS: A focused literature review was performed to identify candidate indicators. A modified Delphi process, with three rounds, was used to obtain expert consensus on the validity of potential process of care quality indicators. RESULTS: Thirty-three physicians participated (6 from surgery, 10 from critical care, and 17 from nephrology). A list of 58 potential process of care quality indicators for AKI after surgery was generated including 28 indicators from the initial literature review and 30 indicators suggested by panelists. Following the third round of questioning, 40 process of care indicators were identified with a high level of agreement for face validity; 16 of these reached high consensus among all panelists. LIMITATIONS: The consensus of panelists from Alberta, Canada may not be generalizable to other settings. The modified Delphi process did not focus on the feasibility of measuring these process indicators. CONCLUSIONS: These indicators can be used to measure and improve the quality of care for AKI after major surgery.

CONTEXTE: Les répercussions engendrées par l'insuffisance rénale aiguë (IRA) sont bien connues. Cependant, il n'existe toujours pas d'indicateurs de la qualité du processus de soin de l'IRA valides en phase postopératoire. OBJECTIFS DE L'ÉTUDE: Élaborer des indicateurs de la qualité des processus de soin en matière de prévention, d'identification et de prise en charge de l'IRA en phase postopératoire d'une chirurgie majeure. TYPE D'ÉTUDE: Processus Delphi modifié à trois étapes. LIEU DE L'ÉTUDE: L'étude a été effectuée en Alberta, Canada, par l'intermédiaire de questionnaires en ligne. PARTICIPANTS: Panel de professionnels de la santé des milieux suivants : chirurgie, soins intensifs et néphrologie. MESURES: Les panelistes ont évalué le degré de validité des indicateurs potentiels avec une échelle de Likert à 7 éléments, dont l'étendue se situait entre « fortement en désaccord ¼ (valeur originale : strongly disagree) et « fortement en accord ¼ (valeur originale : strongly agree). MÉTHODE: Une revue de la littérature ciblée a été effectuée pour faire ressortir les indicateurs pertinents. Une version modifiée du processus Delphi, comprenant trois étapes, a été utilisée dans le but d'obtenir l'avis des experts sur la validité des indicateurs potentiels en matière de qualité des processus de soin. RÉSULTATS: Trente-trois médecins ont participé au panel (6 chirurgiens, 10 intensivistes et 17 néphrologues). Une liste de 58 indicateurs potentiels de la qualité des processus de soin pour l'IRA en période postopératoire a été élaborée; celle-ci comprenait 28 indicateurs qui provenaient de la revue de la littérature et 30 qui avaient été suggérés par les panelistes. Après la troisième ronde de questionnaires, 40 indicateurs des processus de soins avaient été retenus pour leur validité apparente, avec un haut niveau d'accord parmi le panel, et 16 de ces indicateurs avaient atteint un fort consensus. LIMITES DE L'ÉTUDE: Le consensus qui provient du panel formé en Alberta, Canada, n'est peut-être pas généralisable à d'autres contextes. Le processus Delphi modifié ne s'est pas penché sur la faisabilité de la mesure des indicateurs de processus de soin. CONCLUSION: Ces indicateurs peuvent être utilisés pour mesurer et améliorer la qualité des soins de l'IRA en période postopératoire d'une chirurgie majeure.

Atypical antipsychotic drugs and the risk for acute kidney injury and other adverse outcomes in older adults: a population-based cohort study.

BACKGROUND: Several adverse outcomes attributed to atypical antipsychotic drugs, specifically quetiapine, risperidone, and olanzapine, are known to cause acute kidney injury (AKI). Such outcomes include hypotension, acute urinary retention, and the neuroleptic malignant syndrome or rhabdomyolysis. OBJECTIVE: To investigate the risk for AKI and other adverse outcomes associated with use of atypical antipsychotic drugs versus nonuse. DESIGN: Population-based cohort study. SETTING: Ontario, Canada, from 2003 to 2012. PATIENTS: Adults aged 65 years or older who received a new outpatient prescription for an oral atypical antipsychotic drug (n=97,777) matched 1:1 with those who did not receive such a prescription. MEASUREMENTS: The primary outcome was hospitalization with AKI (assessed by using a hospital diagnosis code and, in a subpopulation, serum creatinine levels) within 90 days of prescription for atypical antipsychotic drugs. RESULTS: Atypical antipsychotic drug use versus nonuse was associated with a higher risk for hospitalization with AKI (relative risk [RR], 1.73 [95% CI, 1.55 to 1.92]). This association was consistent when AKI was assessed in a subpopulation for which information on serum creatinine levels was available (5.46% vs. 3.34%; RR, 1.70 [CI, 1.22 to 2.38]; absolute risk increase, 2.12% [CI, 0.80% to 3.43%]). Drug use was also associated with hypotension (RR, 1.91 [CI, 1.60 to 2.28]), acute urinary retention (RR, 1.98 [CI, 1.63 to 2.40]), and all-cause mortality (RR, 2.39 [CI, 2.28 to 2.50]). LIMITATION: Only older adults were included in the study. CONCLUSION: Atypical antipsychotic drug use is associated with an increased risk for AKI and other adverse outcomes that may explain the observed association with AKI. The findings support current safety concerns about the use of these drugs in older adults. PRIMARY FUNDING SOURCE: Academic Medical Organization of Southwestern Ontario.

Association between angiotensin converting enzyme inhibitor or angiotensin receptor blocker use prior to major elective surgery and the risk of acute dialysis.

BACKGROUND: Some studies but not others suggest angiotensin converting enzyme inhibitor (ACEi) or angiotensin receptor blocker (ARB) use prior to major surgery associates with a higher risk of postoperative acute kidney injury (AKI) and death. METHODS: We conducted a large population-based retrospective cohort study of patients aged 66 years or older who received major elective surgery in 118 hospitals in Ontario, Canada from 1995 to 2010 (n = 237,208). We grouped the cohort into ACEi/ARB users (n = 101,494) and non-users (n = 135,714) according to whether the patient filled at least one prescription for an ACEi or ARB (or not) in the 120 days prior to surgery. Our study outcomes were acute kidney injury treated with dialysis (AKI-D) within 14 days of surgery and all-cause mortality within 90 days of surgery. RESULTS: After adjusting for potential confounders, preoperative ACEi/ARB use versus non-use was associated with 17% lower risk of post-operative AKI-D (adjusted relative risk (RR): 0.83; 95% confidence interval (CI): 0.71 to 0.98) and 9% lower risk of all-cause mortality (adjusted RR: 0.91; 95% CI: 0.87 to 0.95). Propensity score matched analyses provided similar results. The association between ACEi/ARB and AKI-D was significantly modified by the presence of preoperative chronic kidney disease (CKD) (P value for interaction < 0.001) with the observed association evident only in patients with CKD (CKD - adjusted RR: 0.62; 95% CI: 0.50 to 0.78 versus No CKD: adjusted RR: 1.00; 95% CI: 0.81 to 1.24). CONCLUSIONS: In this cohort study, preoperative ACEi/ARB use versus non-use was associated with a lower risk of AKI-D, and the association was primarily evident in patients with CKD. Large, multi-centre randomized trials are needed to inform optimal ACEi/ARB use in the peri-operative setting.

Improving prevention, early recognition and management of acute kidney injury after major surgery: results of a planning meeting with multidisciplinary stakeholders.

PURPOSE OF REVIEW: Acute kidney injury (AKI) is common after major surgery, and is associated with morbidity, mortality, increased length of hospital stay, and high health care costs. Although recent guidelines for AKI provide recommendations for identification of patients at risk, monitoring, diagnosis, and management of AKI, there is lack of understanding to guide successful implementation of these recommendations into clinical practice. SOURCES OF INFORMATION: We held a planning meeting with multidisciplinary stakeholders to identify barriers, facilitators, and strategies to implement recommendations for prevention, early identification, and management of AKI after major surgery. Barriers and facilitators to knowledge use for peri-operative AKI prevention and care were discussed. FINDINGS: Stakeholders identified barriers in knowledge (how to identify high-risk patients, what criteria to use for diagnosis of AKI), attitudes (self-efficacy in preventive care and management of AKI), and behaviors (common use of diuretics, non-steroidal anti-inflammatory drugs, withholding of intravenous fluids, and competing time demands in peri-operative care). Educational, informatics, and organizational interventions were identified by stakeholders as potentially useful elements for future interventions for peri-operative AKI. LIMITATION: Meeting participants were from a single centre. IMPLICATIONS: The information and recommendations obtained from this stakeholder's meeting will be useful to design interventions to improve prevention and early care for AKI after major surgery.

OBJECTIF DE L'ÉTUDE: L'insuffisance rénale aiguë (IRA) est fréquente à la suite d'une chirurgie importante et elle est associée à une morbidité, à une mortalité, à une hospitalisation prolongée et à des coûts élevés liés aux soins de santé. Bien que les lignes directrices récentes concernant l'IRA fournissent des recommandations pour déterminer les patients à risque, de même que pour contrôler, diagnostiquer et prendre en charge l'IRA, la compréhension fait défaut pour mener leur mise en place réussie dans la pratique clinique. SOURCES D'INFORMATION: Nous avons tenu une réunion de planification avec des acteurs pluridisciplinaires afin de cibler les obstacles, les appuis et les stratégies de mise en œuvre des recommandations pour la prévention, l'identification précoce et la prise en charge de l'IRA suite à une chirurgie importante. On a abordé les obstacles et les appuis à l'utilisation des connaissances dans la prévention périopératoire de l'IRA et les soins qui s'y rattachent. RÉSULTATS: Les acteurs ont déterminé les obstacles à la connaissance (comment identifier les patients à risque élevé, le choix de critères diagnostiques pour l'IRA), les attitudes (l'auto-efficacité dans les soins préventifs et la prise en charge de l'IRA), et les comportements (l'usage courant de diurétiques, d'anti-inflammatoires non stéroïdiens, la non-administration de solutés intraveineux, et les contraintes de temps dans les soins périopératoires). Les acteurs ont défini les interventions éducatives, informatiques et organisationnelles comme des éléments potentiellement utiles dans les interventions futures en soins périopératoires pour l'IRA. LIMITES DE L'ÉTUDE: Les participants à la réunion provenaient d'un seul et même centre. IMPACTS: Les informations et recommandations obtenues au cours de la réunion des acteurs seront utiles pour l'élaboration des interventions afin d'améliorer la prévention et les soins précoces relatifs à l'IRA suite à une chirurgie majeure.

Economic analysis of epoetin alfa in critically ill trauma patients.

BACKGROUND: Recent randomized control trials (RCTs) suggest that epoetin alfa reduces mortality in critically ill trauma patients; however, epoetin alfa is also costly and associated with adverse events. This study evaluates the cost-effectiveness of epoetin alfa in surgical trauma patients in an intensive care unit setting. METHODS: We constructed a decision analytic model to compare adjunctive use of epoetin alfa with standard care in trauma patients from the perspective of a Canadian payer. Baseline risks of events, relative efficacy, and resource use were obtained from RCTs and observational studies. One-way and probabilistic sensitivity analyses were conducted and longer time horizons explored through Markov models. RESULTS: Epoetin alfa was associated with a cost per quality-adjusted life year (QALY) gained of $89,958 compared with standard care at 1 year. One-way sensitivity analyses indicated that results were sensitive to plausible ranges of mortality risk, risk of thrombosis, relative risk of mortality, relative risk of thrombosis, and quality of life estimates. Cost-effectiveness acceptability curves generated from probabilistic sensitivity analysis indicated that the probability that epoetin alfa would be considered attractive ranged from 0% to 85% over a willingness-to-pay range of $25,000 to $120,000/QALY. Consideration of lifetime time horizons reduced the cost per QALY gained to $7,203, but results were sensitive to the effect of epoetin alfa on mortality. CONCLUSION: Although the cost per QALY gained with epoetin alfa use may fall into an acceptable range, there is significant uncertainty about its true cost-effectiveness. If data regarding long-term efficacy and safety are confirmed in future trials, epoetin alfa could potentially be cost-effective in this population. LEVEL OF EVIDENCE: Economic analysis, level I.