Fluid overload and acute kidney injury

Acute kidney injury is commonly encountered in critically ill patients, and is associated with worse outcomes. Fluid therapy is a key component in the management of these patients, often leading to fluid overload, especially in the setting of septic acute kidney injury. Emerging data overwhelmingly suggest that fluid overload in these patients may be associated with adverse outcomes. Management of such patients should include a strategy of early guided resuscitation, followed by careful assessment of fluid status, and early initiation of renal replacement therapy as soon as it is deemed safe, aiming for a neutral or negative fluid balance. This review will focus on the pathophysiological link between fluid overload and acute kidney injury, mechanisms of organ dysfunction in fluid overload, and strategies for management.     

Acute kidney injury in a postpartum woman with paroxysmal nocturnal hemoglobinuria: A case report and literature review

Paroxysmal nocturnal hemoglobinuria is a rare clonal hematopoietic stem cell disorder characterized by intravascular hemolysis, hemoglobinuria, and inflammatory thrombotic state. Intravascular hemolysis in paroxysmal nocturnal hemoglobinuria (PNH) can lead to acute and chronic renal injury through hemoglobin‐mediated toxicity. A 32‐year‐old pregnant woman with myelodysplastic syndrome was admitted to our hospital with severe preeclampsia. Shortly after an urgent caesarean section, she became obtunded and showed signs of acute kidney injury (AKI) with anuria, severe intravascular hemolysis, and hypermagnesemia. She was diagnosed with PNH with a positive Ham test and flow cytometry analysis. Renal magnetic resonance imaging revealed decreased signal intensity in the renal cortex due to hemosiderin deposition. Hemodialysis, plasma exchange, and administration of corticosteroids ameliorated her clinical condition and renal function. This case illustrates that careful management is required to prevent postpartum AKI in pregnant women with PNH.     

Renal replacement therapy in the critically ill patient with acute kidney injury

The mortality of patients with acute renal failure (ARF) has remained unacceptably high for many years, with renal replacement therapy (RRT) remaining the mainstay of treatment. Clinical research has hitherto been hindered by a lack of a universal definition. However, changes are upon us in the shape of a new term, acute kidney injury (AKI), proposed to encompass the spectrum of ARF, along with a new definition and staging system. There is a renewed optimism that the establishment of clinical databases and the utilization of new clinical biomarkers will catalyze the development of new therapeutic strategies. In the interim, we must optimize the delivery of RRT to patients with AKI. It is remarkable how few studies are currently available in the literature to guide medical practitioners on the key issues of initiation, modality, type of buffer, dose of RRT, vascular access, and anticoagulation. On the horizon, the outcomes of two major clinical trials comparing doses and modalities of RRT in AKI are eagerly awaited.     

Acute kidney injury secondary to chlorine dioxide use for COVID-19 prevention

Chlorine dioxide has been historically used as a disinfecting agent for drinking water supplies and surfaces. Widespread use as an alternative option for prevention and treatment of COVID-19 has emerged due to a lack of specific treatment. We present the case of a 55-year-old male who developed acute kidney injury and disseminated intravascular coagulation after chlorine dioxide prophylactic ingestion, with regression after therapy with hemodialysis.     

Predictors of post‐hospitalization recovery of renal function among patients with acute kidney injury requiring dialysis

Introduction: Acute kidney injury (AKI) requiring dialysis complicates 1% of all hospital admissions, and up to 30% of survivors will still require dialysis at hospital discharge. There is a paucity of data to describe the postdischarge outcomes or to guide evidence‐based dialysis management of this vulnerable population. Methods: Single‐center, retrospective analysis of 100 consecutive patients with AKI who survived to hospital discharge and required outpatient dialysis. Data collection included baseline characteristics, hospitalization characteristics, and outpatient dialysis treatment variables. Primary outcome was dialysis independence 90 days after discharge. Findings: Overall, 43% of patients recovered adequate renal function to discontinue dialysis, with the majority recovering within 30 days post discharge. Worse baseline renal function was associated with lower likelihood of renal recovery. In the first week postdischarge, patients with subsequent nonrecovery of renal function had greater net fluid removal (5.3 vs. 4.1 L, P = 0.037), higher ultrafiltration rates (6.0 vs. 4.7 mL/kg/h, P = 0.041) and more frequent intradialytic hypotension (24.6% vs. 9.3% with 3 or more episodes, P = 0.049) compared to patients that later recovered. Discussion: A significant proportion of AKI survivors will recover renal function following discharge. Outpatient intradialytic factors may influence subsequent renal function recovery.     

Management of acute kidney injury in neurotrauma

Fortunately, the incidence of acute kidney injury (AKI) in neurotrauma is low and decreasing. Whereas the majority of AKI occurs in older patients with pre-existing chronic kidney disease, neurotrauma typically occurs in children and young adults with normal renal function. The development of outreach trauma teams has improved initial resuscitation, reducing both volume responsive and volume unresponsive cases of AKI. Most cases occur in the setting of multiple organ trauma with muscle injury, or patients who subsequently develop multiple organ failure. Once AKI has developed and renal replacement therapy is required, continuous modalities of renal replacement therapy offer an advantage to the patient with compromised cerebral perfusion and intracranial hypertension, by reducing the rate of change in serum urea, compared with standard intermittent therapies of hemodialysis and hemofiltration, thus minimizing abrupt changes in serum osmolality. Continuous hemodialysis and hemofiltration are better suited to maintain a normal or high serum sodium and thermal losses through the extracorporeal circuit, than peritoneal dialysis. Dialyzers should preferably be minimally bioincompatible and of a small surface area. In patients at risk of intracranial hemorrhage and those with invasive intracranial monitoring, systemic anticoagulants should either be avoided or regional anticoagulants should be used.     

Hemolysis‐induced acute kidney injury following cardiac surgery: A case report and review of the literature

Acute kidney injury is a common complication following cardiac surgery. Even small increases in creatinine levels are associated with increases in morbidity and mortality. Numerous factors such as hemolysis can contribute to the development of acute kidney injury after cardiac surgery. We present a rare case of severe hemolysis related to cardiopulmonary bypass resulting in kidney injury and requiring dialysis. The patient's renal function gradually recovered when hemolysis was improved. After follow‐up for 3 months, his creatinine levels returned to normal. We discussed the pathogenesis of this hemolysis‐related kidney dysfunction, the causes of hemolysis during cardiac surgery, and a new treatment option.     

Can dialyzer membrane selection affect outcomes in patients with acute kidney injury requiring dialysis?

The choice of dialyzer membrane may potentially affect not only solute clearances but also blood-dialyzer interactions. Although on one hand alteration of the dialyzer surface or pore size to increase inflammatory mediator loss may potentially be beneficial for patients with acute kidney injury (AKI), dialyzer membrane interactions, which precipitate intradialytic hypotension, may worsen AKI. Several years ago cellulosic membrane dialyzers were shown to reduce both patient survival and renal recovery in patients with AKI. This review looks at the earlier studies of dialyzer membrane choice and outcomes in AKI, besides discussing the newer developments in membrane technology for patients with AKI.     

Acute renal failure and chronic kidney disease following liver transplantation

Acute renal failure (ARF) and chronic kidney disease (CKD) are common complications after liver transplantation (LTx). The incidence of ARF post-LTx varies between 48% and 94%; 8% to 17% of patients require renal replacement therapy (RRT). The most common cause of ARF early after LTx is ischemic acute tubular necrosis, followed later by cyclosporine toxicity and sepsis. Preoperative serum creatinine >1.5 mg/dL and early hepatic allograft dysfunction are risk factors for the occurrence of postoperative ARF. Of patients with ARF due to the hepatorenal syndrome, approximately two-thirds will recover, although recovery may be delayed 3 months or longer after LTx. Mortality after LTx is affected modestly by the presence of ARF pretransplant (<2-fold increase), but increases markedly (up to 8-fold) in the face of ARF posttransplant. Mortality does not appear to be influenced by the mode of RRT used. The risk of CKD after LTx is approximately 18% at 5 years and increases to approximately 25% by 10 years after transplantation. Calcineurin inhibitor toxicity is the most common cause. Specific prognosticators for predicting CKD after LTx are presently lacking. The occurrence of CKD after LTx markedly impairs long-term survival.     

Biomarkers upon discontinuation of renal replacement therapy predict 60‐day survival and renal recovery in critically ill patients with acute kidney injury

Introduction: There is no consensus on the specific indications for weaning critically ill patients with acute kidney injury (AKI) off renal replacement therapy (RRT). This study aimed to explore the prognostic value of several biomarkers measured upon discontinuation of RRT for their value in predicting 60‐day survival and renal recovery in an effort to add knowledge to the decision‐making process regarding RRT withdrawal. Methods: We prospectively enrolled 102 patients with AKI who required RRT from the intensive care unit. Serum osteopontin (sOPN), serum interleukin 6 (sIL‐6), serum cystatin C (sCysC), sIL‐18, serum neutrophil gelatinase‐associated lipocalin and urinary IL‐18 and urinary neutrophil gelatinase‐associated lipocalin were measured upon discontinuation of RRT. Patients were followed up at 60 days for survival and renal recovery. Findings: Patients who survived showed lower levels of all serum and urinary biomarkers. Serum OPN (OR 1.029, 95% CI 1.013–1.047, P = 0.001), diabetes (OR 23.157, 95% CI 4.507–118.981, P < 0.001) and APACHE II score (OR 1.308, 95% CI 1.121–1.527, P = 0.001) were independent predictors of 60‐day mortality. Patients whose sOPN values fell within the highest and middle tertiles showed 5.25‐ and 2.31‐fold increased risks of mortality, respectively, compared with that of patients in the lowest tertile. The addition of sOPN to the clinical model resulted in significant net reclassification improvement of 0.453 (P = 0.026) and an integrated discriminative index of 0.155 (P = 0.032). Lower levels of sOPN and sIL‐6 were associated with greater odds of 60‐day survival (AUC 0.812 and 0.741). The AUC value for predicting survival reached its highest level when all biomarkers were combined with urine output (UO) and urinary and serum creatinine upon discontinuation of RRT (0.882). Lower sCysC performed as well as higher UO in predicting 60‐day renal recovery with the greatest AUC of 0.743. Discussion: Upon discontinuation of RRT, serum and urinary biomarkers, particularly sOPN, may predict 60‐day survival and renal recovery in critically ill patients with AKI. The serum levels of OPN, IL‐6 and CysC may be useful when considering withdrawal of RRT on the basis of conventional indicators.     

Acute kidney injury after near drowning: The way from the beach to hemodialysis

Acute kidney injury (AKI) occurs in many different situations and may have a variable prognosis influenced by clinical setting, underlying cause, and comorbidity. This is important because of the high mortality and morbidity risk affecting many people around the world. Near‐drowning related AKI requiring hemodialysis is very seldom reported in literature. Although cardiovascular and respiratory disorders are more frequently seen after this entity, we aimed to emphasize this rare but dangerous complication in near‐drowning patients.     

Comparison of risk factors for contrast‐induced acute kidney injury between patients with and without diabetes

Although it is well known that diabetics are at a higher risk of contrast‐induced acute kidney injury (CI‐AKI) than nondiabetic patients, the reason for this discrepancy is not well known. Thus, in this study, we compared the predisposing factors for CI‐AKI between patients with and without diabetes. We prospectively studied 290 consecutive in‐hospital patients including 88 diabetics undergoing coronary angiography or a percutaneous coronary intervention in Kowsar hospital, and we compared risk factors for CI‐AKI between diabetic and nondiabetic patients. CI‐AKI was defined as RIFLE criteria within 48 hours after contrast exposure. The incidence of CR‐AKI was significantly higher in diabetic patients compared with nondiabetics (P<0.05). The incidence of CI‐AKI was significantly higher in patients with diabetes and left‐ventricular ejection fraction ≤40%, hypercholesterolemia, serum creatinine ≥1.1 mg/dL, estimated glomerular filtration rate (eGFR) <90 mL/min, Contrast volume ≥80 (mL), maximum safe contrast volume factor of 1.5, and dehydration, while in nondiabetics, a significantly higher incidence of CR‐AKI was observed in those with serum creatinine ≥1.1 mg/dL (P=0.02) and/or eGFR<60 mL/min (P=0.01). Multiple logistic regression analysis showed hyperchlosteremia to be the strongest predictor of AKI (P=0.01, B:14.5) in diabetics, followed by eGFR<90 (P=0.05, B:12.4) but, in nondiabetics, only eGFR<60 predicted the occurrence of CI‐AKI (P=0.04, B:2.3). It seems that the predisposing factors to CI‐AKI differ in diabetics and nondiabetics. In patients with diabetes, hypercholesterolemia is the strongest predictor of CI‐AKI, followed by eGFR and diabetics are at risk for CI‐AKI in the early stage of chronic kidney disease (stage 2), accounting for the higher incidence of CI‐AKI in them.     

The possibility of renal function recovery in chronic hemodialysis patients should not be overlooked: Single center experience

Chronic hemodialysis is implemented when irreversible loss of kidney function occurs. Sometimes renal recovery is overlooked. From January 2005 to December 2014, we identified 28 patients hemodialyzed for more than 3 months who had renal replacement therapy discontinued. The group consisted of 17 (57.7%) males and 11 (42.3%) females. Patients were 18–87 years old. Time of hemodialysis ranged from 3 to 97 months. Of note, 14 (50%) patients were referred from local dialysis units for solution of vascular access problems. In 13 (46.2%) patients dialysis was abandoned within the first 6 months, in 5 (17.8%) patients between 6 and 12 months, and in 10 (35.7%) patients beyond 12 months. Estimated dialysis‐free survival was 94.4% (SE 0.054) and 82% (SE 0.095) at 12 and 24 months, respectively. All physicians must be aware of possible kidney function improvement. In patients with preserved diuresis fall in periodical urea or creatinine measurements might be a sign of renal recovery.     

Attention deficit and hyperactivity disorder tendency and unintentional injury among adolescents in China

This study aims to investigate the association between ADD tendency, with or without hyperactivity, and all types of unintentional injuries among adolescents. This study was a population-based health survey utilising a two-stage random cluster sampling design. The study was conducted among high school students in Nanning, the capital city of the Guangxi Province, China. Subjects were recruited from the total population of adolescents who attended high school years 1, 2, and 3 with ages ranging from 13 to 17 years. Information on ADD was collected by trained health professional via personal interviews. Other information, including unintentional injury was collected via a self-report health survey questionnaire. One thousand and twenty-nine (n = 1429) students were recruited with 115 (7.9%) identified as having a high ADD tendency, and 340 (22.6%) reported as having experienced an injury in the last 3 months. After adjusting for other potential confounding factors, results from the logistic regression analyses indicated that adolescents who scored high on the ADD tendency had an increased risk of injury by about 70% as compared to those who scored low (OR = 1.68, 95%CI = 1.18–2.40). ADD tendency has been identified as a potential risk factor of injury among adolescents. Screening for risk factors can be considered as a potential preventive strategy.     

Carnitine deficiency in children receiving continuous renal replacement therapy

Carnitine deficiency is known to occur in chronic hemodialysis; however, the effect of continuous renal replacement therapy (CRRT) on carnitine homeostasis has not been studied. We hypothesized that children receiving CRRT are at risk for deficiency because of continuous removal, absent intake, decreased production, and comorbidities related to critical illness. Records of patients with acute kidney injury receiving CRRT at Children's National Health System between 2011 and 2014 were reviewed for total carnitine (TC), free carnitine (FC), feeding modality, severity of illness, and survival outcome. The proportion of carnitine‐deficient patients at baseline, 1, 2, and ≥3 weeks on CRRT were compared by chi‐square, and relationships with other variables assessed by Pearson's correlation and logistic regression. The study group included 42 CRRT patients, age 7.9 + 1.1 years. At baseline, 30.7% and 35.7% of patients were TC and FC deficient. Within 1 week, 64.5% (P = 0.03) and 70% (P = 0.03) were TC and FC deficient, and prevalence of deficiency increased to 80% (P = 0.01) and 90% (P = 0.008) by 2 weeks; 100% of patients were TC and FC deficient after being on CRRT for ≥3 weeks (P = 0.005 and P = 0.01, respectively, vs. baseline). TC and FC levels negatively correlated with days on CRRT (r = ?0.39, P = 0.001 and r = ?0.35, P = 0.005). Patients with TC and FC deficiency had 5.9 and 4.9 greater odds of death than those with normal levels (P = 0.02 and P = 0.03). Carnitine is significantly and rapidly depleted with longer time on CRRT, and carnitine deficiency is associated with increased mortality. Consequences of deficiency and benefits of supplementation in the pediatric CRRT population should be investigated.     

Fitness-to-drive after mild traumatic brain injury: Mapping the time trajectory of recovery in the acute stages post injury

Introduction

Little is known about the trajectory of recovery in fitness-to-drive after mild traumatic brain injury (mTBI). This means that health-care professionals have limited evidence on which to base recommendations to this cohort about driving.

Objective

To determine fitness-to-drive status of patients with a mTBI at 24 h and two weeks post injury, and to summarise issues reported by this cohort about return to driving.

Method

Quasi-experimental case-control design. Two groups of participants were recruited: patients with a mTBI (n = 60) and a control group with orthopaedic injuries (n = 60). Both groups were assessed at 24 h post injury on assessments of fitness-to-drive. Follow-up occurred at two weeks post injury to establish driver status.

Main Measures

Mini mental state examination, occupational therapy-drive home maze test (OT–DHMT), Road Law Road Craft Test, University of Queensland-Hazard Perception Test, and demographic/interview form collected at 24 h and at two weeks.

Results

At the 24 h assessment, only the OT–DHMT showed a difference in scores between the two groups, with mTBI participants being significantly slower to complete the test (p = 0.01). At the two week follow-up, only 26 of the 60 mTBI participants had returned to driving. Injury severity combined with scores from the 24 h assessment predicted 31% of the variance in time taken to return to driving. Delayed return to driving was reported due to: “not feeling 100% right” (n = 14, 23%), headaches and pain (n = 12, 20%), and dizziness (n = 5, 8%).

Conclusion

This research supports existing guidelines which suggest that patients with a mTBI should not to drive for 24 h; however, further research is required to map factors which facilitate timely return to driving.