Extended daily dialysis in acute kidney injury patients: metabolic and fluid control and risk factors for death

Kinetics of Plasma Cytokines During Two Different Modalities of Extracorporeal Blood Purification in the Critically Ill Covid 19 Patients: A Cohort Study

Background

In the absence of direct therapy for COVID-19, extracorporeal blood treatment (EBT) could represent an option for cytokine removal.

Objective

This study aimed to describe and compare cytokine removal during intermittent haemodialysis (IHD) and continuous renal replacement therapy (CRRT) in COVID-19 patients with Acute Kidney Injury (AKI).

Methods

It was a cohort study that studied patients with COVID-19-related AKI according to KDIGO criteria and admitted at Intensive Care Unit (ICU). Blood samples were collected at the start and end of both IHD using high flux (HF) membranes (10 patients) and continuous venovenous haemodiafiltration (CVVHDF:10 patients) in two sessions for measuring 13 different plasma interleukins and calculating the cytokine removal rate.

Results

There was no difference between the two groups regarding mechanical ventilation, vasoactive drug, age or prognostic scores. Patients treated by CRRT presented higher levels of IL-2 and IL-8 than patients treated by IHD at dialysis start. Cytokine removal ranged from 9% to 78%. Patients treated by CRRT presented higher cytokine removal for IL-2, IL-6 IL-8, IP-10 and TNF. The removal rates of IL-4, IL-10, IL-17A, IFN, MCP-1 and TGF-B1 were similar in two groups. After one session of CVVHDF (24 h), IL-2 and IL-1β levels did not vary significantly, whereas IL-4, IL-6, IL-8, IL-10, IL-17A, TNF, IFN, IP-10, MCP-1, IL-12p70 and TGF-B1 decreased by 33.8–76%, and this decrease was maintained over the next 24 h. In IHD groups, IL-2, IL-6, TNF, IP-10 and IL-1β levels did not decrease significantly whereas IL-4, IL-8, IL-10, IL-17A, IFN, MCP-1, IL-12p70 and TGF-B1 decreased by 21.8–72%; however, cytokine levels returned to their initial values after 24 h.

Conclusion

Cytokine removal is lower in IHD using HF membranes than in CVVHDF, and in IHD the removal is transient and selective, which can be associated with mortality during cytokines storm-related COVID-19.

Acute Renal Replacement Therapy in Intensive Care Units versus Outside Intensive Care Units: Are They Different?

Introduction

Acute renal replacement therapy (RRT) is indicated when metabolic and fluid demands exceed total kidney capacity, and demand for kidney function is determined by non-renal comorbidities, severity of acute disease and solute and fluid burden; therefore, the criteria for commencing RRT and dialysis in intensive care units (ICUs) may be different to those outside ICUs.

Objective

We investigated whether criteria for commencing acute RRT and dialysis outside ICU were different to those in ICU and whether these differences affected patient mortality in either setting.

Methods

We performed a retrospective observational study evaluating acute kidney injury (AKI), Kidney Disease Improving Global Outcome 3 (KDIGO3) in adult patients undergoing RRT “in and outside” ICU from 2012 to 2018, in a Brazilian teaching hospital.

Results

We evaluated 913 adults with AKI KDIGO3 undergoing RRT; 629 (68.9%) outside ICU and 284 (31.1%) in ICU. Infections were the main cause of hospitalisation (34.4%). Septic and ischaemic AKI were the main aetiologies of AKI (50.8% and 32.9%, respectively), metabolic and fluid demand to capacity imbalance were the main indications for dialysis (69.7%), and intermittent haemodialysis (IHD) was the primary dialysis method (59.2%). The general mortality rate after 30 days was 59%. There were no differences in gender, age and main diagnosis between groups. Both groups were different in acute tubular necrosis index specific scores (ATN-ISS), AKI aetiology, elderly population, indications for dialysis, dialysis methods and mortality rates. In ICU, patients older than 65 years old, with septic AKI were more prevalent (49.1 versus 41.4%, and 55.1 versus 37.5%, respectively), while ischaemic and nephrotoxic AKI were less frequent (24.3 versus 37 and 10.2 versus 16.3%, respectively), and ATN-ISS was higher (0.74 ± 0.31 versus 0.58 ± 0.16). Similarly, metabolic and fluid demand to capacity imbalance as an indication for acute RRT, prolonged intermittent haemodialysis (PIRRT) and continuous renal replacement therapy (CRRT) were more frequent, while peritoneal dialysis (PD) was less frequent (74.6 versus 69.7%, 31.6 versus 22.4%, and 5.3 versus 17.8%, respectively), and mortality was higher (69 versus 54.7%, respectively). Logistic regression revealed that age, septic AKI and being “in” ICU were factors associated with death.

Conclusion

The criteria for commencing RRT and dialysis in ICU were different to those outside ICU; however, they did not impact on patient outcomes.

Renal replacement therapy in the ICU: intermittent hemodialysis, sustained low-efficiency dialysis or continuous renal replacement therapy?

PURPOSE OF REVIEW

Severe acute kidney injury in the ICU setting often requires renal replacement therapy (RRT). Intermittent hemodialysis (IHD), hybrid forms of RRT such as sustained low-efficiency dialysis (SLED), as well as continuous renal replacement therapy (CRRT) are the three common modalities of extracorporeal RRT used in the adult ICU setting in developed countries. This review summarizes recently published data regarding comparisons of these three RRT modalities on clinical outcomes (e.g., mortality and recovery of renal function) in severe acute kidney injury (AKI) patients.

RECENT FINDINGS

There is still controversy on the superiority of one RRT modality over another in terms of clinical outcomes in patients with AKI in ICU. Although there is increasing acceptance that CRRT should be used in hemodynamic unstable patients, its survival advantages over IHD remains unproven because of inadequate evidence from suitably powered randomized controlled trials (RCTs). Moreover, CRRT does not show superiority to intermittent renal replacement therapy (IRRT) in hemodynamic stable patients. Although patients receiving sustained low-efficiency dialysis appear to have lower mortality than CRRT, its survival benefit is largely derived from observational studies and is confounded by selection bias. Current literature supports no differences in mortality among the three RRT modalities. However, the effect of choice of RRT modality on short-term and long-term renal outcomes need further studies, especially larger RCTs and longer duration of follow-up.

SUMMARY

There is lack of solid evidence showing superiority of any mode of RRT in patients with severe AKI in terms of patient survival. However, based on observational data, IHD treatment of AKI may delay renal recovery. Patients' hemodynamic status, coexisting medical conditions, local expertise, and availability of staff and resources as well as potential effect on long-term renal outcomes should be taken into consideration when selecting modalities of RRT for adult ICU patients.

Intensivist nurse performance in the collaborative model of continuous hemodialysis: links with patient safety

OBJECTIVE

To describe the Intensive Care Unit nurse's role in the management of continuous hemodialysis within the scope of the collaborative model, analyzing it regarding the links with patient safety.

METHOD

A descriptive, qualitative, exploratory study based on the Reason safety model performed at the Intensive Care Unit of a specialized hospital, with nurses working in the direct management of continuous hemodialysis, who were interviewed using a script with its contents being thematically analyzed.

RESULTS

23 nurses participated. The role of the intensive care nurse in continuous hemodialysis involves performing preparation/planning and monitoring/follow-up activities, based on interaction with technology and the application of specialized knowledge. The adopted collaborative model reflects on its qualification and availability in relation to the activities that need to be performed, with repercussions on patient safety.

CONCLUSION

There are weaknesses in the participation by intensive care nurses in this continuous hemodialysis model which require elaboration of defensive barriers for the safety of the system.

Mortality and Recovery of Renal Function in Acute Kidney Injury Patients Treated with Prolonged Intermittent Hemodialysis Sessions Lasting 10 versus 6 Hours: Results of a Randomized Clinical Trial

PURPOSE

This trial aimed to compare mortality and recovery of renal function in acute kidney injury (AKI) patients treated with different durations of prolonged hemodialysis (PHD) sessions (6 h versus 10 h).

METHODOLOGY

We included patients with sepsis-associated AKI, >18 years, who are in use of a norepinephrine (lower than 0.7 ucg/kg/min).

RESULTS

One hundred and ninety-four patients were treated with 531 sessions of PHD (G1=104 and G2=90 patients). The two groups were similar in age and SOFA. There was no significant difference in hypotension, hypokalemia, and anticoagulation during PHD sessions. The two groups showed differences in filter clotting, hypophosphatemia, and treatment discontinuation (12.3 versus 23.1%, p=0.002; 15.5 versus 25.8%, p=0.005; and 7.9 versus 15.6%, p=0.008, respectively). There was no difference in fluid balance (FB) before and after PHD sessions. Death and complete recovery of renal function were similar (81.3 versus 82.2%, p=0.87 and 21 versus 31.2%, p=0.7, respectively). At logistic regression, the positive FB before and after dialysis was identified as risk factor for death, while volume overload after three PHD sessions and predialysis creatinine were negatively associated with recovery of renal function in 28 days.

CONCLUSION

There was no difference in the mortality and recovery of renal function of AKI patients submitted to different durations of PHD and sessions lasting 10 h presented higher filter clotting, hypophosphatemia, and treatment discontinuation. ISRCTN Registry number is ISRCTN33774458.

Prolonged intermittent renal replacement therapy in children

Wide ranges of age and weight in pediatric patients makes renal replacement therapy (RRT) in acute kidney injury (AKI) challenging, particularly in the pediatric intensive care unit (PICU), wherein children are often hemodynamically unstable. Standard hemodialysis (HD) is difficult in this group of children and continuous veno-venous hemofiltration/dialysis (CVVH/D) has been the accepted modality in the developed world. Unfortunately, due to cost constraints, CVVH/D is often not available and peritoneal dialysis (PD) remains the common mode of RRT in resource-poor facilities. Acute PD has its drawbacks, and intermittent HD (IHD) done slowly over a prolonged period has been explored as an alternative. Various modes of slow sustained IHD have been described in the literature with the recently introduced term prolonged intermittent RRT (PIRRT) serving as an umbrella terminology for all of these modes. PIRRT has been widely accepted in adults with studies showing it to be as effective as CVVH/D but with an added advantage of being more cost-effective. Pediatric data, though scanty, has been promising. In this current review, we elaborate on the practical aspects of undertaking PIRRT in children as well as summarize its current status.

Evaluation of Intermittent Hemodialysis in Critically Ill Cancer Patients with Acute Kidney Injury Using Single-Pass Batch Equipment

BACKGROUND

Data on renal replacement therapy (RRT) in cancer patients with acute kidney injury (AKI) in the intensive care unit (ICU) is scarce. The aim of this study was to assess the safety and the adequacy of intermittent hemodialysis (IHD) in critically ill cancer patients with AKI.

METHODS AND FINDINGS

In this observational prospective cohort study, 149 ICU cancer patients with AKI were treated with 448 single-pass batch IHD procedures and evaluated from June 2010 to June 2012. Primary outcomes were IHD complications (hypotension and clotting) and adequacy. A multiple logistic regression was performed in order to identify factors associated with IHD complications (hypotension and clotting). Patients were 62.2 ± 14.3 years old, 86.6% had a solid cancer, sepsis was the main AKI cause (51%) and in-hospital mortality was 59.7%. RRT session time was 240 (180-300) min, blood/dialysate flow was 250 (200-300) mL/min and UF was 1000 (0-2000) ml. Hypotension occurred in 25% of the sessions. Independent risk factors (RF) for hypotension were dialysate conductivity (each ms/cm, OR 0.81, CI 0.69-0.95), initial mean arterial pressure (each 10 mmHg, OR 0.49, CI 0.40-0.61) and SOFA score (OR 1.16, CI 1.03-1.30). Clotting and malfunctioning catheters (MC) occurred in 23.8% and 29.2% of the procedures, respectively. Independent RF for clotting were heparin use (OR 0.57, CI 0.33-0.99), MC (OR 3.59, CI 2.24-5.77) and RRT system pressure increase over 25% (OR 2.15, CI 1.61-4.17). Post RRT blood tests were urea 71 (49-104) mg/dL, creatinine 2.71 (2.10-3.8) mg/dL, bicarbonate 24.1 (22.5-25.5) mEq/L and K 3.8 (3.5-4.1) mEq/L.

CONCLUSION

IHD for critically ill patients with cancer and AKI offered acceptable hemodynamic stability and provided adequate metabolic control.

Sustained low-efficiency extended dialysis (SLED) with single-pass batch system in critically-ill patients with acute kidney injury (AKI)

BACKGROUND

Single-pass batch dialysis (SBD) is a well-established system for treatment of end-stage renal disease. However, little evidence is available on sustained low-efficiency extended dialysis (SLED) performed with SBD in patients with acute kidney injury (AKI) in the intensive care unit (ICU).

METHODS

All SLED-SBD sessions conducted on AKI patients in nine ICUs between March and June 2010 were retrospectively analyzed regarding the achieved metabolic and fluid control. Logistic regression was performed to identify the risk factors associated with hypotension and clotting during the sessions.

RESULTS

Data from 106 patients and 421 sessions were analyzed. Patients were 54.2 ± 17.0 years old, 51 % males, and the main AKI cause was sepsis (68 %); 80 % of patients needed mechanical ventilation and 55 % vasoactive drugs. Hospital mortality was 62 %. The median session time was 360 min [interquartile range (IQR) 300-360] and prescribed ultrafiltration was 1500 ml (IQR 800-2000). In 272 sessions (65 %) no complications were recorded. No heparin was used in 269/421 procedures (64 %) and system clotting occurred in 63 sessions (15 %). Risk factors for clotting were sepsis [odds ratio (OR) 2.32 (1.31-4.11), p = 0.004], no anticoagulation [OR 2.94 (1.47-5.91), p = 0.002] and the prescribed time (hours) [OR 1.14 (1.05-1.24), p = 0.001]. Hypotension occurred in 25 % of procedures and no independent risk factors were identified by logistic regression. Adequate metabolic and fluid balance was achieved during SLED sessions. Median blood urea decreased from 107 to 63 mg/dl (p < 0.001), potassium from 4.1 to 3.9 mEq/l (p < 0.001), and increased bicarbonate (from 21.4 to 23.5 mEq/l, p < 0.001). Median fluid balance during session days ranged from +1300 to -20 ml/24 h (p < 0.001).

CONCLUSIONS

SLED-SBD was associated with a low incidence of clotting despite frequent use of saline flush, and achieved a satisfactory hemodynamic stability and reasonable metabolic and fluid control in critically-ill AKI patients.