Associations of fluid overload with mortality and kidney recovery in patients with acute kidney injury: A systematic review and meta-analysis

Influence of fluid accumulation on major adverse kidney events in critically ill patients - an observational cohort study

BACKGROUND

Fluid accumulation (FA) is known to be associated with acute kidney injury (AKI) during intensive care unit (ICU) stay but data on mid-term renal outcome is scarce. The aim of this study was to investigate the association between FA at ICU day 3 and major adverse kidney events in the first 30 days after ICU admission (MAKE30).

METHODS

Retrospective, single-center cohort study including adult ICU patients with sufficient data to compute FA and MAKE30. We defined FA as a positive cumulative fluid balance greater than 5% of bodyweight. The association between FA and MAKE30, including its sub-components, as well as the serum creatinine trajectories during ICU stay were examined. In addition, we performed a sensitivity analysis for the stage of AKI and the presence of chronic kidney disease (CKD).

RESULTS

Out of 13,326 included patients, 1,100 (8.3%) met the FA definition. FA at ICU day 3 was significantly associated with MAKE30 (adjusted odds ratio [aOR] 1.96; 95% confidence interval [CI] 1.67-2.30; p < 0.001) and all sub-components: need for renal replacement therapy (aOR 3.83; 95%CI 3.02-4.84), persistent renal dysfunction (aOR 1.72; 95%CI 1.40-2.12), and 30-day mortality (aOR 1.70; 95%CI 1.38-2.09), p all < 0.001. The sensitivity analysis showed an association of FA with MAKE30 independent from a pre-existing CKD, but exclusively in patients with AKI stage 3. Furthermore, FA was independently associated with the creatinine trajectory over the whole observation period.

CONCLUSIONS

Fluid accumulation is significantly associated with MAKE30 in critically ill patients. This association is independent from pre-existing CKD and strongest in patients with AKI stage 3.

The role of peritoneal dialysis in the treatment of acute kidney injury in neurocritical patients: a retrospective Brazilian study

BACKGROUND

Acute kidney injury (AKI) occurs frequently in the neurocritical intensive care unit and is associated with greater morbidity and mortality. AKI and its treatment, including acute kidney replacement therapy, can expose patients to a secondary greater brain injury. This study aimed to explore the role of peritoneal dialysis (PD) in neurocritical AKI patients in relation to metabolic and fluid control, complications related to PD and outcome.

METHODS

Neurocritical AKI patients were treated by PD (prescribed Kt/V = 0.40/session) using a flexible catheter and a cycler and lactate as a buffer.

RESULTS

A total of 58 patients were included. The mean age was 61.8 ± 13.2 years, 65.5% were in the intensive care unit, 68.5% needed intravenous inotropic agents, 72.4% were on mechanical ventilation, APACHE II was 16 ± 6.67 and the main neurological diagnoses were stroke (25.9%) and intracerebral haemorrhage (31%). Ischaemic acute tubular necrosis (iATN) was the most common cause of AKI (51.7%), followed by nephrotoxic ATN AKI (25.8%). The main dialysis indications were uraemia and hypervolemia. Blood urea and creatinine levels stabilised after four sessions at around 48 ± 11 mg/dL and 2.9 ± 0.4 mg/dL, respectively. Negative fluid balance and ultrafiltration increased progressively and stabilised around 2.1 ± 0.4 L /day. Weekly delivered Kt/V was 2.6 ± 0.31. The median number of high-volume PD sessions was 6 (4-10). Peritonitis and mechanical complications were not frequent (8.6% and 10.3%, respectively). Mortality rate was 58.6%. Logistic regression identified as factors associated with death in neurocritical AKI patients: age (odds ratio (OR) = 1.14, 95% confidence interval (CI) = 1.09-2.16, p = 0.001), nephrotoxic AKI (OR = 0.78, 95% CI = 0.69- 0.95, p = 0.03), mechanical ventilation (OR = 1.54, 95% CI = 1.17-2.46, p = 0.01), intracerebral haemorrhage as main neurological diagnoses (OR = 1.15, 95% CI = 1.09-2.11, p = 0.03) and negative fluid balance after two PD sessions (OR = 0.94, 95% CI = 0.74-0.97, p = 0.009).

CONCLUSION

Our study suggests that careful prescription may contribute to providing adequate treatment for most neurocritical AKI patients without contraindications for PD use, allowing adequate metabolic and fluid control, with no increase in the number of infectious, mechanical and metabolic complications. Mechanical ventilation, positive fluid balance and intracerebral haemorrhage were factors associated with mortality, while patients with nephrotoxic AKI had lower odds of mortality compared to those with septic and ischaemic AKI. Further studies are needed to investigate better the role of PD in neurocritical patients with AKI.

Doppler-based evaluation of intrarenal venous flow as a new tool to predict acute kidney injury: A systematic review and meta-analysis

Congestion is a common complication in the critical care setting, these patients are at increased risk of developing acute kidney injury (AKI). Congestive nephropathy (CN) has recently been described as a mechanism of worsening renal function, and evaluation of renal venous flow by pulsed Doppler (PD) is a useful tool to assess the presence of renal vein congestion. We comprehensively explore the ability of the PD in the evaluation of the intrarenal venous flow (IRVF) to predict the development of AKI in critically ill patients. We searched Pubmed-MEDLINE, Scopus, Embase, and Cochrane Library of Systematic Reviews (to 31th December 2021). We evaluated the association between Doppler-based Intrarenal venous flow demodulation and AKI. CN was defined as the presence of a pulsatile pattern (biphasic or monophasic) in the PD. A total of 4 articles (660 patients) were included in our systematic review, three of these in the metanalysis (413 patients): one study was excluded because its data were inadequate for pooling. Two studies originated in Europe and the other two in the United States. AKI occurrence ranged between 34 and 68%. Patients who developed AKI had a significant difference in PD pattern (continuous vs. pulsatile) in the IRVF (RR=0.46; 95% CI 0.28-0.76). Nevertheless, a large heterogeneity was observed among the studies (I2=68.7%; p=0.04). Albeit preliminary, these findings suggest that the presence of a pulsatile pattern in the PD of the IRVF may be involved in the development of AKI in the critically ill patient. The effect of alterations in the IRVF and renal function warrant further investigation.

Economic Analysis of Renal Replacement Therapy Modality in Acute Kidney Injury Patients With Fluid Overload

Acute kidney injury (AKI) and fluid overload (FO) are among the top reasons to initiate intermittent hemodialysis (IHD) or continuous renal replacement therapy (CRRT). Prior research suggests CRRT provides more precise volume control, but whether CRRT is cost-effective remains unclear. We assessed the cost-effectiveness of CRRT for volume control compared with IHD from a U.S. healthcare payer perspective.

DESIGN

Decision analytical model comparing health outcomes and healthcare costs of CRRT versus IHD initiation for AKI patients with FO. The model had an inpatient phase (over 90-d) followed by post-discharge phase (over lifetime). The 90-day phase had three health states: FO, fluid control, and death. After 90 days, surviving patients entered the lifetime phase with four health states: dialysis independent (DI), dialysis dependent (DD), renal transplantation, and death. Model parameters were informed by current literature. Sensitivity analyses were performed to evaluate results robustness to parametric uncertainty.

SETTING

ICU.

PATIENTS OR SUBJECTS

AKI patients with FO.

INTERVENTIONS

IHD or CRRT.

MEASUREMENTS AND MAIN RESULTS

The 90-day horizon revealed better outcomes for patients initiated on CRRT (survival: CRRT 59.2% vs IHD 57.5% and DD rate among survivors: CRRT 5.5% vs IHD 6.9%). Healthcare cost was 2.7% (+$2,836) higher for CRRT. Over lifetime, initial CRRT was associated with +0.313 life years (LYs) and +0.187 quality-adjusted life years (QALYs) compared with initial IHD. Even though important savings were observed for initial CRRT with a lower rate of DD among survivors (-$13,437), it did not fully offset the incremental cost of CRRT (+$1,956) and DI survival (+$12,830). The incremental cost-per-QALY gained with CRRT over IRRT was +$10,429/QALY. Results were robust to sensitivity analyses.

CONCLUSIONS

Our analysis provides an economic rationale for CRRT as the initial modality of choice in AKI patients with FO who require renal replacement therapy. Our finding needs to be confirmed in future research.

Feasibility and Efficacy of Sustained Low-Efficiency Dialysis in Critically Ill Children with Severe Acute Kidney Injury

OBJECTIVES

To examine the feasibility, efficacy, and safety of sustained low-efficiency dialysis (SLED) in hemodynamically unstable, critically ill children.

METHODS

Critically ill patients, 1-18 y old with hemodynamic instability (≥ 1 vasoactive drugs) and severe acute kidney injury (AKI) requiring kidney replacement therapy (KRT) in a tertiary care pediatric intensive care unit were prospectively enrolled. Patients weighing ≤ 8 kg or with mean arterial pressure < 5^th percentile despite > 3 vasoactive drugs, were excluded. Patients underwent SLED until hemodynamically stable and off vasoactive drugs, or lack of need for dialysis. The primary outcome was the proportion of patients in whom the first session of SLED was initiated within 12 h of its indication and completed without premature (< 6 h) termination. Efficacy was estimated by ultrafiltration, urea reduction ratio (URR), and equilibrated Kt/V. Other outcomes included: changes in hemodynamic scores, circuit clotting, adverse events, and changes in indices on point-of-care ultrasonography and echocardiography.

RESULTS

Between November 2018 and March 2020, 18 patients with median age 8.6 y and vasopressor dependency index of 83.2, underwent 41 sessions of SLED. In 16 patients, SLED was feasible within 12 h of indication. No session was terminated prematurely. Ultrafiltration achieved was 4.0 ± 2.2 mL/kg/h, while URR was 57.7 ± 16.2% and eKt/V 1.17 ± 0.56. Hemodynamic scores did not change significantly. Asymptomatic hypokalemia was the chief adverse effect. Sessions were associated with a significant improvement in indices on ultrasound and left ventricular function. Fourteen patients died.

CONCLUSIONS

SLED is feasible, safe, and effective in enabling KRT in hemodynamically unstable children with severe AKI.

Comprehensive Management of Blood Pressure in Patients with Septic AKI

Acute kidney injury (AKI) is one of the serious complications of sepsis in clinical practice, and is an important cause of prolonged hospitalization, death, increased medical costs, and a huge medical burden to society. The pathogenesis of AKI associated with sepsis is relatively complex and includes hemodynamic abnormalities due to inflammatory response, oxidative stress, and shock, which subsequently cause a decrease in renal perfusion pressure and eventually lead to ischemia and hypoxia in renal tissue. Active clinical correction of hypotension can effectively improve renal microcirculatory disorders and promote the recovery of renal function. Furthermore, it has been found that in patients with a previous history of hypertension, small changes in blood pressure may be even more deleterious for kidney function. Therefore, the management of blood pressure in patients with sepsis-related AKI will directly affect the short-term and long-term renal function prognosis. This review summarizes the pathophysiological mechanisms of microcirculatory disorders affecting renal function, fluid management, vasopressor, the clinical blood pressure target, and kidney replacement therapy to provide a reference for the clinical management of sepsis-related AKI, thereby promoting the recovery of renal function for the purpose of improving patient prognosis.

A Machine Learning Model to Predict Diuretic Resistance

BACKGROUND

Volume overload is a common complication encountered in hospitalized patients, and the mainstay of therapy is diuresis. Unfortunately, the diuretic response in some individuals is inadequate despite a typical dose of loop diuretics, a phenomenon called diuretic resistance. An accurate prediction model that predicts diuretic resistance using predosing variables could inform the right diuretic dose for a prospective patient.

METHODS

Two large, deidentified, publicly available, and independent intensive care unit (ICU) databases from the United States were used-the Medical Information Mart for Intensive Care III (MIMIC) and the Philips eICU databases. Loop diuretic resistance was defined as <1400 ml of urine per 40 mg of diuretic dose in 24 hours. Using 24-hour windows throughout admission, commonly accessible variables were obtained and incorporated into the model. Data imputation was performed using a highly accurate machine learning method. Using XGBoost, several models were created using train and test datasets from the eICU database. These were then combined into an ensemble model optimized for increased specificity and then externally validated on the MIMIC database.

RESULTS

The final ensemble model was composed of four separate models, each using 21 commonly available variables. The ensemble model outperformed individual models during validation. Higher serum creatinine, lower systolic blood pressure, lower serum chloride, higher age, and female sex were the most important predictors of diuretic resistance (in that order). The specificity of the model on external validation was 92%, yielding a positive likelihood ratio of 3.46 while maintaining overall discrimination (C-statistic 0.69).

CONCLUSIONS

A diuretic resistance prediction model was created using machine learning and was externally validated in ICU populations. The model is easy to use, would provide actionable information at the bedside, and would be ready for implementation in existing electronic medical records. This study also provides a framework for the development of future machine learning models.

Perfusion-based deresuscitation during continuous renal replacement therapy: A before-after pilot study (The early dry Cohort)

BACKGROUND

Active fluid removal has been suggested to improve prognosis following the resolution of acute circulatory failure. We have implemented a routine care protocol to guide fluid removal during continuous renal replacement therapy (CRRT). We designed a before-after pilot study to evaluate the impact of this deresuscitation strategy on the fluid balance.

METHODS

Consecutive ICU patients suffering from fluid overload and undergoing CRRT for acute kidney injury underwent a perfusion-based deresuscitation protocol combining a restrictive intake, net ultrafiltration (UFnet) of 2 mL/kg/h, and monitoring of perfusion (early dry group, N = 42) and were compared to a historical group managed according to usual practices (control group, N = 45). The primary outcome was the cumulative fluid balance at day 5 or at discharge.

RESULTS

Adjusted cumulative fluid balance was significantly lower in the early dry group (median [IQR]: -7784 [-11,833 to -2933] mL) compared to the control group (-3492 [-9935 to -1736] mL; p = 0.04). The difference was mainly driven by a greater daily UFnet (31 [22-46] mL/kg/day vs. 24 [15-32] mL/kg/day; p = 0.01). There was no significant difference between both groups regarding hemodynamic tolerance.

CONCLUSION

Our perfusion-based deresuscitation protocol achieved a greater negative cumulative fluid balance compared to standard practices and was hemodynamically well tolerated.

Nordic survey on assessment and treatment of fluid overload in intensive care

Introduction

Fluid overload in patients in the intensive care unit (ICU) is associated with higher mortality. There are few randomized controlled trials to guide physicians in treating patients with fluid overload in the ICU, and no guidelines exist. We aimed to elucidate how ICU physicians from Nordic countries define, assess, and treat fluid overload in the ICU.

Materials and methods

We developed an online questionnaire with 18 questions. The questions were pre-tested and revised by specialists in intensive care medicine. Through a network of national coordinators. The survey was distributed to a wide range of Nordic ICU physicians. The distribution started on January 5th, 2022 and ended on May 6th, 2022.

Results

We received a total of 1,066 responses from Denmark, Norway, Finland, Sweden, and Iceland. When assessing fluid status, respondents applied clinical parameters such as clinical examination findings, cumulative fluid balance, body weight, and urine output more frequently than cardiac/lung ultrasound, radiological appearances, and cardiac output monitoring. A large proportion of the respondents agreed that a 5% increase or more in body weight from baseline supported the diagnosis of fluid overload. The preferred de-resuscitation strategy was diuretics (91%), followed by minimization of maintenance (76%) and resuscitation fluids (71%). The majority declared that despite mild hypotension, mild hypernatremia, and ongoing vasopressor, they would not withhold treatment of fluid overload and would continue diuretics. The respondents were divided when it came to treating fluid overload with loop diuretics in patients receiving noradrenaline. Around 1% would not administer noradrenaline and diuretics simultaneously and 35% did not have a fixed upper limit for the dosage. The remaining respondents 63% reported different upper limits of noradrenaline infusion (0.05-0.50 mcg/kg/min) when administering loop diuretics.

Conclusion

Self-reported practices among Nordic ICU physicians when assessing, diagnosing, and treating fluid overload reveals variability in the practice. A 5% increase in body weight was considered a minimum to support the diagnosis of fluid overload. Clinical examination findings were preferred for assessing, diagnosing and treating fluid overload, and diuretics were the preferred treatment modality.

Acute Changes in Serum Creatinine Are Not a Meaningful Metric in Randomized Controlled Trials and Clinical Care

BACKGROUND

Acute changes in serum creatinine are labeled clinically as acute kidney injury (AKI). However, not all acute changes in serum creatinine are deleterious and need to be acted upon.

SUMMARY

Intravenous fluids in response to AKI should be judiciously administered, and volume overload should be avoided. Since congestion is the driver of poor outcomes in patients with acute decompensated heart failure and must be managed, AKI that occurs at the expense of decongestion does not confer increased risk. We still do not have evidence of therapies that reduce AKI which will translate into any meaningful improvements in clinical outcomes. Finally, particularly in the setting of application of therapies designed to reduce cardiorenal risk, acute changes in serum creatinine are often in the opposite direction of the ultimate clinical outcomes, both renal and nonrenal.

KEY MESSAGES

Given the complexities and the nuance of acute changes in serum creatinine, it has ruled itself as an unreliable surrogate for randomized controlled trials and often hinders appropriate care in the clinical setting.

Loop diuretics in adult intensive care patients with fluid overload: a systematic review of randomised clinical trials with meta-analysis and trial sequential analysis

BACKGROUND

Fluid overload is a risk factor for organ dysfunction and death in intensive care unit (ICU) patients, but no guidelines exist for its management. We systematically reviewed benefits and harms of a single loop diuretic, the predominant treatment used for fluid overload in these patients.

METHODS

We conducted a systematic review with meta-analysis and Trial Sequential Analysis (TSA) of a single loop diuretic vs. other interventions reported in randomised clinical trials, adhering to our published protocol, the Cochrane Handbook, and PRISMA statement. We assessed the risks of bias with the ROB2-tool and certainty of evidence with GRADE. This study was registered in the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42020184799).

RESULTS

We included 10 trials (804 participants), all at overall high risk of bias. For loop diuretics vs. placebo/no intervention, we found no difference in all-cause mortality (relative risk (RR) 0.72, 95% confidence interval (CI) 0.49-1.06; 4 trials; 359 participants; I2 = 0%; TSA-adjusted CI 0.15-3.48; very low certainty of evidence). Fewer serious adverse events were registered in the group treated with loop diuretics (RR 0.81, 95% CI 0.66-0.99; 6 trials; 476 participants; I2 = 0%; very low certainty of evidence), though contested by TSA (TSA-adjusted CI 0.55-1.20).

CONCLUSIONS

The evidence is very uncertain about the effect of loop diuretics on mortality and serious adverse events in adult ICU patients with fluid overload. Loop diuretics may reduce the occurrence of these outcomes, but large randomised placebo-controlled trials at low risk of bias are needed.

Impact of Double-Machine Replacement Protocol at Start of Continuous Renal Replacement Therapy in Vasopressor-Dependent Patients: A Retrospective Cohort Study

<b><i>Introduction:</i></b> When starting continuous renal replacement therapy (CRRT), vasopressor-dependent patients are at risk of hemodynamic instability. Thus far, only a few studies have analyzed the impact of CRRT circuit replacement for vasopressor-dependent patients. Hence, we compared the effect of double-machine replacement protocol (DMRP) with single-machine replacement protocol (SMRP) for CRRT circuit replacement in vasopressor-dependent patients. <b><i>Methods:</i></b> The medical records of 96 vasopressor-dependent patients treated with CRRT in the general intensive care unit of the Shunde Hospital, Southern Medical University, between January 2017 and April 2018 were retrospectively analyzed. The major measures of the SMRP included returning the blood to the patient and sealing access catheter with heparin and starting a new CRRT machine with a slow blood pump, while DMRP involved simultaneous drawing and return of blood with two machines using a slow blood pump for circuit replacement. The primary outcome measures were changes in vasopressor dose and hemodynamic parameters, and the secondary outcome measure was the pause time difference between the two groups during the period. <b><i>Results:</i></b> A total of 53 patients were treated with SMRP and 43 patients with DMRP. Heart rate was higher in the SMRP group as compared to the DMRP group (<i>p</i> &#x3c; 0.05). There were no significant changes in central venous pressure, mean arterial pressure, and vasopressor dose in either group (<i>p</i> &#x3e; 0.05). The patients in the DMRP group had a significant reduction in CRRT pause time (5.62 ± 0.69 min in DMRP group vs. 37.01 ± 8.72 min in SMRP group, <i>p</i> &#x3c; 0.01). The DMRP group needed a lower volume of circuit purging and priming fluid related to CRRT circuit replacement (0 mL in DMRP group vs. 463 mL in SMRP group). <b><i>Conclusions:</i></b> Implementation of the DMRP for CRRT circuit replacement had a slight hemodynamic effect on vasopressor-dependent patients. It also reduced the pause time and volume of circuit purging and priming fluid related to CRRT circuit replacement compared with SMRP.

Intravenous albumin for the prevention of hemodynamic instability during sustained low-efficiency dialysis: a randomized controlled feasibility trial (The SAFER-SLED Study)

Background

Hemodynamic instability is a frequent complication of sustained low-efficiency dialysis (SLED) treatments in the ICU. Intravenous hyperoncotic albumin may prevent hypotension and facilitate ultrafiltration. In this feasibility trial, we sought to determine if a future trial, powered to evaluate clinically relevant outcomes, is feasible.

Methods

This single-center, blinded, placebo-controlled, randomized feasibility trial included patients with acute kidney injury who started SLED in the ICU. Patients were randomized to receive 25% albumin versus 0.9% saline (control) as 100 mL boluses at the start and midway through SLED, for up to 10 sessions. The recruitment rate and other feasibility outcomes were determined. Secondary exploratory outcomes included ultrafiltration volumes and metrics of hemodynamic instability.

Results

Sixty patients (271 SLED sessions) were recruited over 10 months. Age and severity of illness were similar between study groups. Most had septic shock and required vasopressor support at baseline. Protocol adherence occurred for 244 sessions (90%); no patients were lost to follow-up; no study-related adverse events were observed; open label albumin use was 9% and 15% in the albumin and saline arms, respectively. Ultrafiltration volumes were not significantly different. Compared to the saline group, the albumin group experienced less hemodynamic instability across all definitions assessed including a smaller absolute decrease in systolic blood pressure (mean difference 10.0 mmHg, 95% confidence interval 5.2–14.8); however, there were significant baseline differences in the groups with respect to vasopressor use prior to SLED sessions (80% vs 61% for albumin and saline groups, respectively).

Conclusions

The efficacy of using hyperoncotic albumin to prevent hemodynamic instability in critically ill patients receiving SLED remains unclear. A larger trial to evaluate its impact in this setting, including evaluating clinically relevant outcomes, is feasible.

Trial registration ClinicalTrials.gov (NCT03665311); First Posted: Sept 11th, 2018. https://clinicaltrials.gov/ct2/show/NCT03665311?term=NCT03665311&draw=2&rank=1

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-021-00962-x.

Trial of Furosemide to Prevent Acute Kidney Injury in Critically Ill Children: A Double-Blind, Randomized, Controlled Trial

OBJECTIVE

To study whether furosemide infusion in early-onset acute kidney injury (AKI) in critically ill children would be associated with a reduced proportion of patients progressing to the higher stage (Injury or Failure) as compared to placebo.

METHOD

A double-blind, placebo-controlled, randomized pilot trial was conducted. The authors enrolled children aged 1-mo (corrected) to 12-y, who were diagnosed with AKI ("risk" stage) using pediatric-Risk, Injury, Failure, Loss, End stage kidney disease (p-RIFLE) criteria, and achieved immediate resuscitation goals within 24 h of admission. Participants received either furosemide (0.05 to 0.4 mg/kg/h) or placebo (5%-dextrose) infusion. The primary outcome was the proportion of patients progressing to a higher stage (injury or failure). Secondary outcomes were (i) need for renal replacement therapy, (ii) the effect on neutrophil gelatinase-associated lipocalin (urine and blood), (iii) fluid balance, (iv) adverse effects, (v) time to achieve renal recovery, (vi) duration of hospital stay and mechanical ventilation, and (vii) all-cause 28-d mortality.

RESULTS

The trial was stopped for futility, and data were analyzed on an intention-to-treat basis (furosemide-group: n = 38; placebo-group: n = 37). No significant difference was noted in the progression of AKI to a higher stage between furosemide and placebo groups (10.5% vs. 21.6%; relative risk = 0.49, 95% CI 0.16 to 1.48) (p = 0.22). There were no differences in the secondary outcomes between the study groups. All-cause 28-d mortality was similar between the groups (10.5% vs. 10.8%). No trial-related severe adverse events occurred.

CONCLUSIONS

Furosemide infusion in early-onset AKI did not reduce the progression to a higher stage of AKI. A future trial with large sample size is warranted.

Survey of U.S. Critical Care Practitioners on Net Ultrafiltration Prescription and Practice among Critically Ill Patients Receiving Kidney Replacement Therapy

INTRODUCTION

The current prescription and practice of net ultrafiltration among critically ill patients receiving kidney replacement therapy in the U.S. are unclear.

AIM OF THE STUDY

To assess the attitudes of U.S. critical care practitioners on net ultrafiltration (UFNET) prescription and practice among critically ill patients with acute kidney injury treated with kidney replacement therapy.

METHODS

A secondary analysis was conducted of a multinational survey of intensivists, nephrologists, advanced practice providers, and ICU and dialysis nurses practising in the U.S.

RESULTS

Of 1,569 respondents, 465 (29.6%) practitioners were from the U.S. Mainly were nurses and advanced practice providers (58%) and intensivists (38.2%). The median duration of practice was 8.7 (IQR, 4.2-19.4) years. Practitioners reported using continuous kidney replacement therapy (as the first modality in 60% (IQR 20%-90%) for UFNET. It was found that there was a significant variation in assessment of prescribed-to-delivered dose of UFNET, use of continuous kidney replacement therapy for UFNET, methods used to achieve UFNET, and assessment of net fluid balance during continuous kidney replacement therapy. There was also variation in interventions performed for managing hemodynamic instability, perceived barriers to UFNET, belief that early and protocol-based fluid removal is beneficial, and willingness to enroll patients in a clinical trial.

CONCLUSIONS

There was considerable practice variation in UFNET among critical care practitioners in the U.S., reflecting the need to generate evidence-based practice guidelines for UFNET.

The Role of Peritoneal Dialysis in the Treatment of Acute Kidney Injury in Patients With Acute-on-Chronic Liver Failure: A Prospective Brazilian Study

This study aimed to explore the role of peritoneal dialysis (PD) in acute-on-chronic liver disease (ACLD) in relation to metabolic and fluid control and outcome. Fifty-three patients were treated by PD (prescribed Kt/V = 0.40/session), with a flexible catheter, tidal modality, using a cycler and lactate as a buffer. The mean age was 64.8 ± 13.4 years, model of end stage liver disease (MELD) was 31 ± 6, 58.5% were in the intensive care unit, 58.5% needed intravenous inotropic agents including terlipressin, 69.5% were on mechanical ventilation, alcoholic liver disease was the main cause of cirrhosis and the main dialysis indications were uremia and hypervolemia. Blood urea and creatinine levels stabilized after four sessions at around 50 and 2.5 mg/dL, respectively. Negative fluid balance (FB) and ultrafiltration (UF) increased progressively and stabilized around 3.0 L and -2.7 L/day, respectively. Weekly-delivered Kt/V was 2.7 ± 0.37, and 71.7% of patients died. Five factors met the criteria for inclusion in the multivariable analysis. Logistic regression identified as risk factors associated with Acute Kidney Injury (AKI) in ACLD patients: MELD (OR = 1.14, CI 95% = 1.09-2.16, p = 0.001), nephrotoxic AKI (OR = 0.79, CI 95% = 0.61-0.93, p = 0.02), mechanical ventilation (OR = 1.49, CI 95% = 1.14-2.97, p < 0.001), and positive fluid balance (FB) after two PD sessions (OR = 1.08, CI 95% = 1.03-1.91, p = 0.007). These factors were significantly associated with death. In conclusion, our study suggests that careful prescription may contribute to providing adequate treatment for most Acute-on-Chronic Liver Failure (ACLF) patients without contraindications for PD use, allowing adequate metabolic and fluid control, with no increase in the number of infectious or mechanical complications. MELD, mechanical complications and FB were factors associated with mortality, while nephrotoxic AKI was a protective factor. Further studies are needed to better investigate the role of PD in ACLF patients with AKI.

Timing of Kidney Support Therapy in Acute Kidney Injury: What Are We Waiting For?

The optimal timing of kidney support therapy in critically ill patients with acute kidney injury (AKI) without life-threatening complications related to AKI is controversial. Recent multicenter, randomized, controlled studies have questioned the need for earlier initiation of therapy, despite one study showing a benefit in survival and others with no differences in mortality based on the timing of kidney support therapy initiation. These findings reflect the uncertainties in decisions to initiate kidney support therapy, which should ideally be individualized according to the patient's comorbidities, severity of illness, trajectory of kidney function, and urine output as well as requirements for fluid balance and solute removal. A delayed approach could translate into a potentially reduced burden of dialysis dependence in addition to saving health resources. However, we must ascertain what constitutes the waiting period and the benefits and risks associated with this approach. This article reviews the concept of timing of dialysis in AKI, performs a critical assessment of the most important clinical trials in this topic, discusses ongoing research and knowledge gaps, and defines key research issues to address in the future.

Association Between Acute Kidney Injury Duration and Outcomes in Critically Ill Children

OBJECTIVES

Acute kidney injury occurs frequently in children during critical illness and is associated with increased morbidity, mortality, and health resource utilization. We aimed to examine the association between acute kidney injury duration and these outcomes.

DESIGN

Retrospective cohort study.

SETTINGS

PICUs in Alberta, Canada.

PATIENTS

All children admitted to PICUs in Alberta, Canada between January 1, 2015, and December 31, 2015.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

In total, 1,017 children were included, and 308 (30.3%) developed acute kidney injury during PICU stay. Acute kidney injury was categorized based on duration to transient (48 hr or less) or persistent (more than 48 hr). Transient acute kidney injury occurred in 240 children (77.9%), whereas 68 children (22.1%) had persistent acute kidney injury. Persistent acute kidney injury had a higher proportion of stage 2 and stage 3 acute kidney injury compared with transient acute kidney injury and was more likely to start within 24 hours from PICU admission. Persistent acute kidney injury occurred more frequently in those with higher illness severity and in those admitted with shock, sepsis, or with a history of transplant. Mortality varied significantly according to acute kidney injury status: 1.8% of children with no acute kidney injury, 5.4% with transient acute kidney injury, and 17.6% with persistent acute kidney injury died during hospital stay (p < 0.001). On multivariable analysis adjusting for illness and acute kidney injury severity, transient and persistent acute kidney injury were both associated with fewer ventilation-free days at 28 days (-1.28 d; 95% CI, -2.29 to -0.26 and -4.85 d; 95% CI, -6.82 to -2.88), vasoactive support-free days (-1.07 d; 95% CI, -2.00 to -0.15 and -4.24 d; 95% CI, -6.03 to -2.45), and hospital-free days (-1.93 d; 95% CI, -3.36 to -0.49 and -5.25 d; 95% CI, -8.03 to -2.47), respectively.

CONCLUSIONS

In critically ill children, persistent and transient acute kidney injury have different clinical characteristics and association with outcomes. Acute kidney injury, even when its duration is short, carries significant association with worse outcomes. This risk increases further if acute kidney injury persists longer independent of the degree of its severity.

Position paper on liver and kidney diseases from the Italian Association for the Study of Liver (AISF), in collaboration with the Italian Society of Nephrology (SIN)

Liver and kidney are strictly connected in a reciprocal manner, in both the physiological and pathological condition. The Italian Association for the Study of Liver, in collaboration with the Italian Society of Nephrology, with this position paper aims to provide an up-to-date overview on the principal relationships between these two important organs. A panel of well-recognized international expert hepatologists and nephrologists identified five relevant topics: 1) The diagnosis of kidney damage in patients with chronic liver disease; 2) Acute kidney injury in liver cirrhosis; 3) Association between chronic liver disease and chronic kidney disease; 4) Kidney damage according to different etiology of liver disease; 5) Polycystic kidney and liver disease. The discussion process started with a review of the literature relating to each of the five major topics and clinical questions and related statements were subsequently formulated. The quality of evidence and strength of recommendations were graded according to the GRADE system. The statements presented here highlight the importance of strong collaboration between hepatologists and nephrologists for the management of critically ill patients, such as those with combined liver and kidney impairment.

Intravenous Albumin for Mitigating Hypotension and Augmenting Ultrafiltration during Kidney Replacement Therapy

Among its many functions, owing to its oversized effect on colloid oncotic pressure, intravascular albumin helps preserve the effective circulatory volume. Hypoalbuminemia is common in hospitalized patients and is found especially frequently in patients who require KRT either for AKI or as maintenance hemodialysis. In such patients, hypoalbuminemia is strongly associated with morbidity, intradialytic hypotension, and mortality. Intravenous albumin may be administered in an effort to prevent or treat hypotension or to augment fluid removal, but this practice is controversial. Theoretically, intravenous albumin administration might prevent or treat hypotension by promoting plasma refilling in response to ultrafiltration. However, clinical trials have demonstrated that albumin administration is not nearly as effective a volume expander as might be assumed according to its oncotic properties. Although intravenous albumin is generally considered to be safe, it is also very expensive. In addition, there are potential risks to using it to prevent or treat intradialytic hypotension. Some recent studies have suggested that hyperoncotic albumin solutions may precipitate or worsen AKI in patients with sepsis or shock; however, the overall evidence supporting this effect is weak. In this review, we explore the theoretical benefits and risks of using intravenous albumin to mitigate intradialytic hypotension and/or enhance ultrafiltration and summarize the current evidence relating to this practice. This includes studies relevant to its use in patients on maintenance hemodialysis and critically ill patients with AKI who require KRT in the intensive care unit. Despite evidence of its frequent use and high costs, at present, there are minimal data that support the routine use of intravenous albumin during KRT. As such, adequately powered trials to evaluate the efficacy of intravenous albumin in this setting are clearly needed.

Timing of continuous renal replacement therapy in severe acute kidney injury patients with fluid overload: A retrospective cohort study

PURPOSE

We aimed to evaluate the association of early versus late initiation of Continuous renal replacement therapy (CRRT) with mortality in patients with fluid overload.

METHODS

This was a retrospective cohort study of patients with fluid overload (FO) treated with CRRT due to severe acute kidney injury (AKI) between January 2015 and December 2017 in a mixed medical intensive care unit of a teaching hospital in Beijing, China. Patients were divided into early (≤15 h) and late (>15 h) groups based on the median time from ICU admission to CRRT initiation. The primary outcome was all-cause mortality at day 60. Multivariable Cox model analysis was used for analysis.

RESULTS

The study patients were male predominant (84/150) with a mean age of 64.8 ± 16.7 years. The median FO value before CRRT initiation was 10.1% [6.2-16.1%]. The 60-day mortality rates in the early vs the late CRRT groups were 53.9% and 73%, respectively. On multivariable Cox modelling, the late initiation of CRRT was independently associated with an increased risk of death at 60 days (HR 1.75, 95% CI 1.11-2.74, p = 0.015).

CONCLUSIONS

Early initiation of CRRT was independently associated with survival benefits in severe AKI patients with fluid overload.

Emerging applications of clinical ultrasonography

In this work, we introduce the numerous emerging areas and frontiers in the use of point-of-care ultrasonography. Of these, we review the following three: 1) the use of clinical ultrasonography in infectious and tropical diseases (we address its usefulness in the diagnosis and follow-up of the main syndromes, in tropical diseases, and in areas with scarce resources); 2) the usefulness of clinical ultrasonography in the assessment of response to volume infusion in severely ill patients (we review basic concepts and the main static and dynamic variables used for this evaluation); and 3) the use of clinical ultrasonography in the assessment of muscle mass in elderly patients with primary sarcopenia (we review the main muscles and measurements used for it).

Net ultrafiltration prescription survey in Europe

Background

Fluid overload is common in patients in the intensive care unit (ICU) and ultrafiltration (UF) is frequently required. There is lack of guidance on optimal UF practice. We aimed to explore patterns of UF practice, barriers to achieving UF targets, and concerns related to UF practice among practitioners working in Europe.

Methods

This was a sub-study of an international open survey with focus on adult intensivists and nephrologists, advanced practice providers, and ICU and dialysis nurses working in Europe.

Results

Four hundred eighty-five practitioners (75% intensivists) from 31 countries completed the survey. The most common criteria for UF initiation was persistent oliguria/anuria (45.6%), followed by pulmonary edema (16.7%). Continuous renal replacement therapy was the preferred initial modality (90.0%). The median initial and maximal rate of net ultrafiltration (UF^NET) prescription in hemodynamically stable patients were 149 mL/hr. (IQR 100–200) and 300 mL/hr. (IQR 201–352), respectively, compared to a median UF^NET rate of 98 mL/hr. (IQR 51–108) in hemodynamically unstable patients and varied significantly between countries.

Two-thirds of nurses and 15.5% of physicians reported assessing fluid balance hourly. When hemodynamic instability occurred, 70.1% of practitioners reported decreasing the rate of fluid removal, followed by starting or increasing the dose of a vasopressor (51.3%). Most respondents (90.7%) believed in early fluid removal and expressed willingness to participate in a study comparing protocol-based fluid removal versus usual care.

Conclusions

There was a significant variation in UF practice and perception among practitioners in Europe. Future research should focus on identifying the best strategies of prescribing and managing ultrafiltration in critically ill patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-020-02184-y.

Emerging applications of clinical ultrasonography

In this work, we introduce the numerous emerging areas and frontiers in the use of point-of-care ultrasonography. Of these, we review the following three: 1) the use of clinical ultrasonography in infectious and tropical diseases (we address its usefulness in the diagnosis and follow-up of the main syndromes, in tropical diseases, and in areas with scarce resources); 2) the usefulness of clinical ultrasonography in the assessment of response to volume infusion in severely ill patients (we review basic concepts and the main static and dynamic variables used for this evaluation); and 3) the use of clinical ultrasonography in the assessment of muscle mass in elderly patients with primary sarcopenia (we review the main muscles and measurements used for it).

Factors influencing liberation from mechanical ventilation in coronavirus disease 2019: multicenter observational study in fifteen Italian ICUs

BACKGROUND

A large proportion of patients with coronavirus disease 2019 (COVID-19) develop severe respiratory failure requiring admission to the intensive care unit (ICU) and about 80% of them need mechanical ventilation (MV). These patients show great complexity due to multiple organ involvement and a dynamic evolution over time; moreover, few information is available about the risk factors that may contribute to increase the time course of mechanical ventilation.The primary objective of this study is to investigate the risk factors associated with the inability to liberate COVID-19 patients from mechanical ventilation. Due to the complex evolution of the disease, we analyzed both pulmonary variables and occurrence of non-pulmonary complications during mechanical ventilation. The secondary objective of this study was the evaluation of risk factors for ICU mortality.

METHODS

This multicenter prospective observational study enrolled 391 patients from fifteen COVID-19 dedicated Italian ICUs which underwent invasive mechanical ventilation for COVID-19 pneumonia. Clinical and laboratory data, ventilator parameters, occurrence of organ dysfunction, and outcome were recorded. The primary outcome measure was 28 days ventilator-free days and the liberation from MV at 28 days was studied by performing a competing risks regression model on data, according to the method of Fine and Gray; the event death was considered as a competing risk.

RESULTS

Liberation from mechanical ventilation was achieved in 53.2% of the patients (208/391). Competing risks analysis, considering death as a competing event, demonstrated a decreased sub-hazard ratio for liberation from mechanical ventilation (MV) with increasing age and SOFA score at ICU admission, low values of PaO2/FiO2 ratio during the first 5 days of MV, respiratory system compliance (CRS) lower than 40 mL/cmH2O during the first 5 days of MV, need for renal replacement therapy (RRT), late-onset ventilator-associated pneumonia (VAP), and cardiovascular complications.ICU mortality during the observation period was 36.1% (141/391). Similar results were obtained by the multivariate logistic regression analysis using mortality as a dependent variable.

CONCLUSIONS

Age, SOFA score at ICU admission, CRS, PaO2/FiO2, renal and cardiovascular complications, and late-onset VAP were all independent risk factors for prolonged mechanical ventilation in patients with COVID-19.

TRIAL REGISTRATION

NCT04411459.

Estimation of Body Fluid Status by Fluid Balance and Body Weight in Critically Ill Adult Patients: A Systematic Review

BACKGROUND

The charting of daily fluid balances and measurement of body weight changes are two noninvasive methods commonly used in the intensive care unit for estimating body fluid status. The determination of body fluid status plays an important role in the management of critically ill patients where aggressive fluid resuscitation is often required. This can adversely affect patient outcomes if changes in fluid distribution are not detected early in patients who are susceptible to fluid overload.

AIM

To synthesize the best available evidence on the accuracy of daily fluid balance charting compared with the measurement of body weight for the estimation of body fluid status in critically ill adult patients.

METHODS

The review considered studies that investigated the accuracy of charting daily fluid balances or changes in body weight measurements or used both noninvasive methods in the estimation of body fluid status. The search sought to identify published, English language studies from 1980 until February 2018. Databases searched included MEDLINE, CINAHL, EMBASE, TRIP, Scopus, TROVE, ProQuest Dissertations, Australian and New Zealand Trials Registry, and Cochrane Central Register of Clinical Trials. Three reviewers independently assessed retrieved studies that matched inclusion criteria using standardized critical appraisal instruments.

RESULTS

The review included 13 cohort studies. Effectiveness of daily fluid balance charting was affected by inaccuracies observed in seven studies. Inability to obtain consecutive daily body weight measurements reduced the accuracy of monitoring changes in five studies. Seven studies found measurement of daily fluid balance inconsistent with changes in body weight.

LINKING EVIDENCE TO ACTION

The accuracy of charting fluid balance is suspect. Measurement of body weight is hard to accomplish. A combination of the two commonly used methods is more likely to be effective in estimating body fluid status than reliance on one single approach.

Effect of different hydration doses on renal function in patients with primary osteoporosis treated with zoledronic acid: A hospital-based retrospective cohort study

The objective was to investigate the association of different hydration doses and its effect on renal function in patients with primary osteoporosis treated with zoledronic acid.The subjects with primary osteoporosis treated with zoledronic acid at the First Affiliated Hospital of Chongqing Medical University, China, from January 2015 to December 2018 were included in this study. The subjects were classified according to different hydration doses. Renal function indexes before and after treatment were collected and adverse reactions recorded to analyze the changes in renal function associated with different hydration doses.The choice of the hydration dose treated with zoledronic acid deserves attention. The lower hydration dose is, the greater impact on renal function can be caused.

Comparison of Bioelectrical Impedance Analysis Parameters for the Detection of Fluid Overload in the Prediction of Mortality in Patients Admitted at the Emergency Department

BACKGROUND

Fluid overload (FO) in critically ill patients is associated with increased adverse events. This study aims to compare different bioelectrical impedance analysis (BIA) parameters that demonstrate FO and their association with 30-day mortality in critical patients admitted to the emergency department (ED).

METHODS

Five components of the BIA were obtained by multifrequency device-total body water (TBW), extracellular water (ECW), intracellular water (ICW), resistance (R), and reactance (Xc)-to calculate parameters (impedance vectors, impedance ratio, and the ratios of ECW to TBW, ECW to ICW, ECW to body surface area, TBW to height² , ICW to height² , Xc to height, and R to height) that have been used for the detection of FO. A concordance analysis (κ) was performed comparing every parameter with each other. Furthermore, different regression models (Cox regression) were created associating the FO for each parameter with 30-day mortality, adjusted for age, body mass index, sex, Sequential Organ Failure Assessment score, and serum albumin level.

RESULTS

A total of 142 patients were included in the study. Only FO by impedance vector analysis (relative risk [RR] = 6.4; 95% CI, 1.5-27.9; P = .01), impedance ratio (RR = 2.7; 95% CI, 1.1-7.1; P = .04), and R (RR = 2.6; 95% CI, 1.2-5.5; P = .02) increased the probability of 30-day mortality.

CONCLUSIONS

Different parameters that determine FO by BIA were associated with the mortality of patients admitted to the ED, but the impedance vector analysis was superior to any other parameter of the BIA.

Fluid Overload and Risk of Mortality in Critically Ill Patients

BACKGROUND

Fluid overload (FO) is a condition present in critical care units, and it is associated with clinical complications and worse outcomes for severe patients.

OBJECTIVE

The aim of this study was to verify if FO is a risk factor for mortality in critically ill patients.

METHODS

Retrospective study performed in a Brazilian intensive care unit, from January to March 2016, with patients older than 18 years and hospitalized for more than 24 hours. Demographic and clinical data, as well as fluid balance and overload, were analyzed to verify the risk factors for mortality. A logistic regression model was elaborated, and significance was set at P < .05.

RESULTS

There were 158 patients included, of which only 13 (8.2%) presented FO. Mortality was verified in individuals 30 (18.9%), of whom only 7 (23.3%) developed FO, which was lower in survivors 6 (4.9%), P = .001. In the simple regression model, the FO was significant (odds ratio [OR], 6.23; 95% confidence interval [CI], 2.04-19.53), P = .001. However, in the multiple regression model, there were significant findings only for mechanical ventilation (OR, 5.86; 95% CI, 2.10-18.12, P = .001), acute kidney injury (OR, 4.05; 95% CI, 1.53-11; P = .001), and noradrenaline (OR, 3.85; 95% CI, 1.01-9.51; P = .041); FO was not significant (OR, 3.68; 95% CI, 0.91-15.55; P = .069).

CONCLUSION

Fluid overload is higher in patients who died. Therefore, it was not considered a risk factor for mortality.

The endothelial glycocalyx: Structure and function in health and critical illness

OBJECTIVE

To conduct a narrative review of the current literature in reference to the structure and function of the endothelial glycocalyx (EG) and its contribution to the pathophysiology of conditions relevant to the veterinary emergency and critical care clinician. Novel therapies for restoring or preserving the EG will also be discussed.

DATA SOURCES

Online databases (PubMed, CAB abstracts, Scopus) were searched between January 1st 2017 and May 1st 2017 for English language articles without publication date restriction. Keywords included EG, endothelial surface layer, degradation, syndecan-1, heparan sulfate, critical illness, sepsis, trauma, and therapeutics.

DATA SYNTHESIS

The EG is a complex and important structure located on the luminal surface of all blood vessels throughout the body. It plays an important role in normal vascular homeostasis including control of fluid exchange across the vascular barrier. Loss or degradation of the EG has an impact on inflammation, coagulation, and vascular permeability and tone. These changes are essential components in the pathophysiology of many conditions including sepsis and trauma. A substantial body of experimental animal and human clinical research over the last decade has demonstrated increased circulating concentrations of EG degradation products in these conditions. However, veterinary-specific research into the EG and critical illness is currently lacking. The utility of EG degradation products as diagnostic and prognostic tools continues to be investigated and new therapies to preserve or improve EG structure and function are under development.

CONCLUSIONS

The recognition of the presence of the EG has changed our understanding of transvascular fluid flux and the pathophysiology of many conditions of critical illness. The EG is an exciting target for novel therapeutics to improve morbidity and mortality in conditions such as sepsis and trauma.

Endothelial Glycocalyx

The endothelial glycocalyx (EG) is the most luminal layer of the blood vessel, growing on and within the vascular wall. Shedding of the EG plays a central role in many critical illnesses. Degradation of the EG is associated with increased morbidity and mortality. Certain illnesses and iatrogenic interventions can cause degradation of the EG. It is not known whether restitution of the EG promotes the survival of the patient. First trials that focus on the reorganization and/or restitution of the EG seem promising. Nevertheless, the step "from bench to bedside" is still a big one.

Combination of Inferior Vena Cava Diameter, Hepatic Venous Flow, and Portal Vein Pulsatility Index: Venous Excess Ultrasound Score (VEXUS Score) in Predicting Acute Kidney Injury in Patients with Cardiorenal Syndrome: A Prospective Cohort Study

Background

Fluid overload is deleterious in critically ill patients. It can lead to venous congestion, thereby increasing venous pressure, theoretically increasing the backpressure, and thereby reducing renal blood flow. Venous congestion thus can be an important contributor to acute kidney injury (AKI), with no validated tools to objectively identify venous congestion bedside.

Materials and methods

Patients above 18 years admitted in ICU with a provisional diagnosis of cardiorenal syndrome were included in the study. Those with inadequate window, inferior vena cava (IVC) thrombus, and known case of cirrhosis with portal hypertension were excluded from the study. Patients underwent ultrasound examination with serial determination till AKI resolved or patient is initiated on dialysis. Venous excess ultrasound score (VEXUS) comprising inferior vena cava, hepatic vein waveform, and portal vein pulsatility was assessed.

Results

Thirty patients were enrolled for the study. The mean age was 59.53 ± 16.47 with 21 (70%) males. Mean sequential organ failure assessment (SOFA) score was 5.03 ± 1.97. Fourteen patients (46.7%) were in AKI stage 1, while eight patients (26.7%) were in AKI stage 2 and stage 3 each. Twenty patients (66.7%) had VEXUS grade III. Resolution of AKI injury showed significant correlation with improvement in VEXUS grade (p value 0.003). Similarly, there was significant association between changes in VEXUS grade and fluid balance (p value 0.006). There was no correlation between central venous pressure (CVP), left ventricular function, and right ventricular function with change in VEXUS grade.

Conclusion

The study shows that a combined grading of IVC, hepatic vein, and portal vein might reliably demonstrate venous congestion and aid in the clinical decision to perform fluid removal.

How to cite this article

Bhardwaj V, Vikneswaran G, Rola P, Raju S, Bhat RS, Jayakumar A, et al. Combination of Inferior Vena Cava Diameter, Hepatic Venous Flow, and Portal Vein Pulsatility Index: Venous Excess Ultrasound Score (VEXUS Score) in Predicting Acute Kidney Injury in Patients with Cardiorenal Syndrome: A Prospective Cohort Study. Indian J Crit Care Med 2020;24(9):783–789.

The effect of timing of initiation of renal replacement therapy on mortality: A retrospective case-control study

Purpose

To determine if earlier initiation of renal replacement therapy (RRT) is associated with improved survival in patients with severe acute kidney injury.

Methods

We performed a retrospective case-control study of propensity-matched groups with multivariable logistic regression using Akaike Information Criteria to adjust for non-matched variables in a surgical ICU in a tertiary care hospital.

Results

We matched 169 of 205 (82%) patients with new initiation of RRT (EARLY group) to 169 similar patients who did not initiate RRT on that day (DEFERRED group). Eighteen (11%) of DEFERRED eventually received RRT before discharge. By univariate analysis, ICU mortality was higher in EARLY (n = 60 (36%) vs. n = 23 (14%), p < 0.001) as was hospital mortality (n = 73 (43%) vs. n = 44 (26%), p = 0.001). Of the 18 RRT patients in DEFERRED, 12 (67%) died in ICU and 13 (72%) in hospital. After propensity matching and logistic regression, we found that EARLY initiation of RRT was associated with a more than doubling of ICU mortality (aOR = 2.310, 95% confidence interval = 1.254-4.257, p = 0.007). However, after similar adjustment, there was no difference in hospital mortality (aOR = 1.283, 95% CI = 0.753-2.186, p = 0.360).

Conclusions

While ICU mortality was increased in the EARLY group, there was no difference in hospital mortality between EARLY and DEFERRED groups.

Latent Trajectories of Fluid Balance Are Associated With Outcomes in Cardiac and Aortic Surgery

BACKGROUND

Fluid overload is common in critically ill patients and is associated with worse outcomes. The trends in fluid balance have not been investigated previously. This study used trajectory analysis to investigate the impact of fluid balance trends on patients who had undergone cardiac or aortic surgery.

METHODS

We analyzed patients who underwent cardiac or aortic surgery between August 2005 and March 2015. We excluded patients who died within the first 72 postoperative hours or received chronic dialysis before the surgery. Trajectories of urine and input-output during the first 3 postoperative days were analyzed using a latent class growth model. The primary outcomes were any stage of acute kidney injury (AKI) by Kidney Disease Improving Global Outcomes definition and de novo dialysis.

RESULTS

The in-hospital mortality was 6.6% (70 of the 1063 patients included). The fluid input-output balance trajectories had better association with the primary outcome than urine output trajectories did. The risk of AKI and de novo dialysis were highest in the group with progressively positive fluid balance adjusted by preoperative body weight (AKI: adjusted odds ratio, 7.10; 95% confidence interval, 2.02-24.93; de novo dialysis: odds ratio, 4.54; 95% confidence interval, 1.12-18.38).

CONCLUSIONS

A progressively positive fluid balance is associated with AKI and de novo dialysis in patients undergoing cardiac or aortic surgery.

The interactive effects of input and output on managing fluid balance in patients with acute kidney injury requiring continuous renal replacement therapy

Background

The interactive effect of cumulative input and output on achieving optimal fluid balance has not been well elucidated in patients with acute kidney injury (AKI) requiring continuous renal replacement therapy (CRRT). This study evaluated the interrelation of fluid components with mortality in patients with AKI requiring CRRT.

Methods

This is a retrospective observational study conducted with a total of 258 patients who were treated with CRRT due to AKI between 2016 and 2018 in the intensive care unit of Ewha Womans University Mokdong Hospital. The amounts of fluid input and output were assessed at 24-h and 72-h from the initiation of CRRT. The study endpoints were 7- and 28-day all-cause mortality.

Results

The mean patient age was 64.7 ± 15.8 years, and 165 (64.0%) patients were male. During the follow-up, 7- and 28-day mortalities were observed in 120 (46.5%) and 157 (60.9%) cases. The patients were stratified into two groups (28-day survivors vs. non-survivors), and the cumulative fluid balances (CFBs) at 24 h and 72 h were significantly higher in the 28-day non-survivors compared with the survivors. The increase in 24-h and 72-h CFB was significantly associated with an increase in 7- and 28-day mortality risks. To examine the interactive effect of cumulative input or output on the impact of CFB on mortality, we also stratified patients into three groups based on the tertile of 24-h and 72-h cumulative input or output. The increases in 24-h and 72-h CFBs were still significantly related to the increases in 7-day and 28-day mortality, irrespective of the cumulative input. However, we did not find significant associations between increase in 24-h and 72-h CFB and increase in mortality risk in the groups according to cumulative output tertile.

Conclusions

The impact of cumulative fluid balance on mortality might be more dependent on cumulative output. The physicians need to decrease the cumulative fluid balance of CRRT patients as much as possible and consider increasing patient removal.

Saline versus albumin fluid for extracorporeal removal with slow low-efficiency dialysis (SAFER-SLED): study protocol for a pilot trial

Background

Critically ill patients frequently develop acute kidney injury that necessitates renal replacement therapy (RRT). At some centers, critically ill patients who are hemodynamically unstable and require RRT are treated with slow low-efficiency dialysis (SLED). Unfortunately, hypotension is a frequent complication that occurs during SLED treatments and may limit the recovery of kidney function. Hypotension may also limit the amount of fluid that can be removed by ultrafiltration with SLED. Fluid overload can be exacerbated as a consequence, and fluid overload is associated with increased mortality.

Occasionally, intravenous albumin fluid is given to prevent or treat low blood pressure during SLED. The intent of doing so is to increase the colloid oncotic pressure in the circulation to draw in extravascular fluid, increase the blood pressure, and enable more aggressive fluid removal with ultrafiltration. Nonetheless, there is little evidence to support this practice and theoretical reasons why it may not be especially effective at augmenting fluid removal in critically ill patients. At the same time, albumin fluid is expensive.

As such, we present a protocol for a study to assess the feasibility of a randomized controlled trial evaluating the use of albumin fluid versus saline in critically ill patients receiving SLED.

Methods

This study is a single-center, double-blind, and randomized controlled pilot trial with two parallel arms. It involves randomly assigning patients receiving SLED treatment in the ICU to receive either albumin (25%) boluses or normal saline fluid boluses (placebo) to prevent and treat low blood pressure.

Discussion

The results of this pilot trial will help with planning a larger trial comparing the efficacy of the interventions in achieving fluid removal in critically ill patients with AKI on SLED. They will establish whether enough participants would participate in a larger study and accept the study procedures.

Trial registration

This trial is registered on ClinicalTrials.gov Identifier NCT03665311, registered on September 11, 2018.

Electronic supplementary material

The online version of this article (10.1186/s40814-019-0460-3) contains supplementary material, which is available to authorized users.

Nonischemic Causes of Cardiogenic Shock

Although cardiogenic shock is uncommon in the emergency department, it is associated with high mortality. Most cardiogenic shock is caused by ischemia, but nonischemic etiologies are essential to recognize. Clinicians should optimize preload, contractility, and afterload. Volume-responsive patients should be resuscitated in small aliquots, although some patients may require diuresis to improve cardiac output. Vasopressors are important to restore end-organ perfusion, and inotropes improve contractility. Intubation and positive pressure ventilation impact hemodynamics, which, depending on volume status, may be beneficial or deleterious. Knowing indications for mechanical circulatory support is important for timely consultation or transfer as indicated.

Forced fluid removal in intensive care patients with acute kidney injury: The randomised FFAKI feasibility trial

BACKGROUND

Accumulation of fluids is frequent in intensive care unit (ICU) patients with acute kidney injury and may be associated with increased mortality and decreased renal recovery. We present the results of a pilot trial assessing the feasibility of forced fluid removal in ICU patients with acute kidney injury and fluid accumulation of more than 10% ideal bodyweight.

METHODS

The FFAKI-trial was a pilot trial of forced fluid removal vs standard care in adult ICU patients with moderate to high risk acute kidney injury and 10% fluid accumulation. Fluid removal was done with furosemide and/or continuous renal replacement therapy aiming at net negative fluid balance > 1 mL/kg ideal body weight/hour until cumulative fluid balance calculated from ICU admission reached less than 1000 mL.

RESULTS

After 20 months, we stopped the trial prematurely due to a low inclusion rate with 23 (2%) included patients out of the 1144 screened. Despite the reduced sample size, we observed a marked reduction in cumulative fluid balance 5 days after randomisation (mean difference -5814 mL, 95% CI -2063 to -9565, P = .003) with forced fluid removal compared to standard care. While the trial was underpowered for clinical endpoints, no point estimates suggested harm from forced fluid removal.

CONCLUSIONS

Forced fluid removal aiming at 1 mL/kg ideal body weight/hour may be an effective treatment of fluid accumulation in ICU patients with acute kidney injury. A definitive trial using our inclusion criteria seems less feasible based on our inclusion rate of only 2%.

Fluid accumulation during acute kidney injury in the intensive care unit

INTRODUCTION

Fluid therapy is a ubiquitous intervention in patients admitted to the intensive care unit, but positive fluid balance may be associated with poor outcomes and particular in patients with acute kidney injury. Studies describing this have defined fluid overload either at specific time points or considered patients with a positive mean daily fluid balance as fluid overloaded. We wished to detail this further and performed joint model analyses of the association between daily fluid balance and outcome represented by mortality and renal recovery in patients admitted with acute kidney injury.

METHOD

We did a retrospective cohort study of patients admitted to the intensive care unit with acute kidney injury during a 2-year observation period. We used serum creatinine measurements to identify patients with acute kidney injury and collected sequential daily fluid balance during the first 5 days of admission to the intensive care unit. We used joint modelling techniques to correlate the development of fluid overload with survival and renal recovery adjusted for age, gender and disease severity.

RESULTS

The cohort contained 863 patients with acute kidney injury of whom 460 (53%) and 254 (29%) developed 5% and 10% fluid overload, respectively. We found that both 5% and 10% fluid overload was correlated with reduced survival and renal recovery.

CONCLUSION

Joint model analyses of fluid accumulation in patients admitted to the intensive care unit with acute kidney injury confirm that even a modest degree of fluid overload (5%) may be negatively associated with both survival and renal recovery.

Balanced Crystalloids versus Saline in Critically Ill Adults

BACKGROUND:

Both balanced crystalloids and saline are used for intravenous fluid administration among critically ill adults. Which results in better clinical outcomes remains unknown.

METHODS:

In a pragmatic, cluster-randomized, multiple-crossover trial in five intensive care units at an academic center, we assigned 15,802 adults to receive saline (0.9% sodium chloride) or balanced crystalloids (lactated Ringer’s solution or Plasma-Lyte A®), according to the randomization of the unit to which they were admitted. The primary outcome was Major Adverse Kidney Events within 30 days (MAKE30), i.e., the composite of death, new renal replacement therapy, or persistent creatinine elevation ≥ 200% of baseline – all censored at the first of hospital discharge or 30 days.

RESULTS:

In the balanced crystalloid group, 1,139 patients (14.3%) experienced MAKE30, compared to 1,211 patients (15.4%) in the saline group (marginal odds ratio, 0.91; 95% confidence interval, 0.84–0.99; conditional odds ratio, 0.90; 95% confidence interval, 0.82–0.99; P=0.04). Thirty-day in-hospital mortality was 10.3% in the balanced crystalloid group and 11.1% in the saline group (P=0.06). The incidence of new renal replacement therapy was 2.5% and 2.9% respectively (P=0.08), and the incidence of persistent creatinine elevation was 6.4% and 6.6% respectively (P=0.60).

CONCLUSIONS:

Among critically ill adults, the use of balanced crystalloids for intravenous fluid administration appeared to reduce the composite outcome of in-hospital mortality, new renal replacement therapy, and persistent renal dysfunction compared with the use of saline. (SMART-MED and SMART-SURG ClinicalTrials.gov numbers, NCT02444988 and NCT02547779.)

Optimal hydration volume among high-risk patients with advanced congestive heart failure undergoing coronary angiography

We investigated the relationship between weight-adjusted hydration volumes and the risk of developing contrast-induced acute kidney injury (CI-AKI) and worsening heart failure (WHF) and explored the relative safety of optimal hydration volumes in patients with advanced congestive heart failure (CHF) undergoing coronary angiography (CAG) or percutaneous coronary intervention. We included 551 patients with advanced CHF (New York Heart Association class > 2 or history of pulmonary edema) undergoing CAG (follow-up period 2.62 ± 0.9 years). There was a significant association between hydration volume-to-weight ratio (HV/W) (quintile Q1, Q2, Q3, Q4, and Q5) and the incidence of CI-AKI (3.7%, 14.6%, 14.3%, 21.1%, and 31.5%, respectively) and WHF (3.6%, 5.4%, 8.3%, 13.6%, and 19.1%, respectively) (all P-trend < 0.001). Receiver operating curve analysis indicated that HV/W = 15 mL/kg and the mean HV/W (60.87% sensitivity and 64.96% specificity) were fair discriminators for CI-AKI (C-statistic 0.696). HV/W >15 mL/kg independently predicted CI-AKI (adjusted odds ratio [OR] 2.33; P = 0.016) and WHF (adjusted OR 2.13; P = 0.018). Moreover, both CI-AKI and WHF were independently associated with increased long-term mortality. Thus, for high-risk patients with advanced CHF undergoing CAG, HV/W > 15 mL/kg might be associated with an increased risk of developing CI-AKI and WHF. The potential benefits of a personalized limitation of hydration volume need further evaluation.

Critical care for dengue in adult patients: an overview of current knowledge and future challenges

PURPOSE OF REVIEW

This review aims to update and summarize the current knowledge about clinical features, management, and risk factors of adult dengue patients requiring intensive care with consequently higher risk of mortality.

RECENT FINDINGS

Increasingly, there are more adult dengue patients who require intensive care. This may be due to a shift in epidemiology of dengue infection from mainly a pediatric disease toward adult disease. In addition, multiorgan dysfunction was observed to be a key risk factor for ICU admission and mortality. This may be due to older adults having preexisting comorbidities that potentially predispose to have multiple severe organ impairment. Interventions remain largely supportive but also require more evidence-based trials and treatment protocols.

SUMMARY

These findings highlight the common clinical manifestations of adult dengue patients and the challenges of clinical management in ICU. Risk factors for prediction of adult dengue patients who require ICU are available, but they lack validation and consistent study design for meta-analysis in future. Early recognition of these risk factors, with close monitoring and prompt clinical management, remains critical to reduce mortality.