Continuous hemofiltration in the treatment of acute renal failure

Risk Assessment of Venous Thromboembolism among Septic Shock Patients: Single versus Concurrent Insertion of Central Venous Catheters

Background and Objectives: Thrombosis is a serious complication experienced by some hospitalized patients. While concurrent placement of two catheters (CVCs) in the same central vein offers several benefits in clinical settings, we aimed to investigate the role of this procedure in relation to the risk of thrombosis. Materials and Methods: Over a two-year retrospective analysis, we examined 114 patients with septic shock caused by a pulmonary infection, who underwent the insertion of one or more central lines into a central vein during their ICU stay. Logistic regression models were employed to assess the correlation between the Caprini risk score, the placement of two CVCs in the same vein, COVID-19 infection and the risk of venous thromboembolism (VTE). Results: In total, 53% of the patients underwent the concurrent insertion of two CVCs. The placement of two CVCs in the same vein appears to elevate the VTE risk by 2.5 times (95% CI: 1.03-6.12). Logistic regression analysis indicated that hemodialysis catheters amplify the VTE risk by nearly five times, even when accounting for a series of factors (95% CI: 1.86-12.31). Conclusions: Our study suggests that the elevated risk of VTE is likely associated with the insertion of the hemodialysis catheters rather than solely the presence of two concurrent catheters.

Dialysis and Extracorporeal Therapies for Enhanced Elimination of Toxic Ingestions and Poisoning

Poisoning and toxic ingestions cause significant morbidity and mortality worldwide. Extracorporeal therapies such as dialysis, haemoperfusion and plasma exchange are selectively applied to patients with severe intoxications unresponsive to standard interventions and can be lifesaving. Extracorporeal therapies are a complex but fundamental aspect of the practice of nephrology. Without high-quality evidence to guide implementation, an understanding of toxicokinetics and the physiochemical principles of the enhanced elimination techniques is especially important. This review provides a comphrensive, user-friendly outline of the application of extracorporeal therapy in the poisoned patient.

Small Extracellular Vesicles Propagate the Inflammatory Response After Trauma

Trauma is the leading cause of death in individuals under 44 years of age. Thorax trauma (TxT) is strongly associated with trauma-related death, an unbalanced innate immune response, sepsis, acute respiratory distress syndrome, and multiple organ dysfunction. It is shown that different in vivo traumata, such as TxT or an in vitro polytrauma cytokine cocktail trigger secretion of small extracellular nanovesicles (sEVs) from endothelial cells with pro-inflammatory cargo. These sEVs transfer transcripts for ICAM-1, VCAM-1, E-selectin, and cytokines to systemically activate the endothelium, facilitate neutrophil-endothelium interactions, and destabilize barrier integrity. Inhibition of sEV-release after TxT in mice ameliorates local as well as systemic inflammation, neutrophil infiltration, and distant organ damage in kidneys (acute kidney injury, AKI). Vice versa, injection of TxT-plasma-sEVs into healthy animals is sufficient to trigger pulmonary and systemic inflammation as well as AKI. Accordingly, increased sEV concentrations and transfer of similar cargos are observed in polytrauma patients, suggesting a fundamental pathophysiological mechanism.

Peritoneal Dialysis for Management of Pediatric Acute Renal Failure

Background

While the use of continuous renal replacement therapies in the management of children with acute renal failure (ARF) has increased, the role of peritoneal dialysis (PD) in the treatment of pediatric ARF has received less attention.

Design

Retrospective database review of children requiring PD for ARF over a 10-year period.

Setting

Pediatric intensive care unit at a tertiary-care referral center.

Patients

Sixty-three children without previously known underlying renal disease who required PD for treatment of ARF.

Results

Causes of ARF were congestive heart failure (27), hemolytic-uremic syndrome ( 13 ), sepsis ( 10 ), nonrenal organ transplant ( 7 ), malignancy ( 3 ), and other ( 3 ). Mean duration of PD was 11 ± 13 days. Children with ARF were younger (30 ± 48 months vs 88 ± 68 months old, p < 0.0001) and smaller (11.9 ± 15.9 kg vs 28 ± 22 kg, p < 0.0001) than children with known underlying renal disease who began PD during the same time period. Percutaneously placed PD catheters were used in 62% of children with ARF, compared to 4% of children with known renal disease ( p < 0.0001). Hypotension was common in patients with ARF (46%), which correlated with a high frequency of vasopressor use (78%) at the time of initiation of PD. Complications of PD occurred in 25% of patients, the most common being catheter malfunction. Recovery of renal function occurred in 38% of patients; patient survival was 51%.

Conclusions

Peritoneal dialysis remains an appropriate therapy for pediatric ARF from many causes, even in severely ill children requiring vasopressor support. Such children can be cared for without the use of more expensive and technology-dependent forms of renal replacement therapies.

Fibrin Glue Used Successfully in Peritoneal Dialysis Catheter Leakage in Children

Background

Acute renal failure in infants and small children is generally treated with peritoneal dialysis (PD). Dialysis has to be started immediately after catheter implantation. Early dialysate leakage can complicate the effectiveness of dialysis. Fibrin glue applied to the external part of the tunnel may stop dialysate leakage and eliminate the need for surgical intervention. The use of fibrin glue in the treatment of PD catheter leakage in children was studied.

Methods

Fibrin glue was used in 8 children (age 0.8 – 57 months) on PD in whom dialysate leakage was seen during the first 24 to 48 hours after catheter insertion. The dialysis volume initially administered was 20 mL/kg body weight. Fibrin glue (1 mL) was applied to the external part of the subcutaneous catheter tunnel through the exit site, as close to the cuff as possible. The occurrence of dialysate leakage and complications such as exit-site or tunnel infection and peritonitis were evaluated.

Results

Nine single-cuff straight Tenckhoff catheters were implanted in 8 children. In 5 cases, no subcutaneous tunnel was created. One child had catheter replacement due to obstruction of the catheter; on both occasions, catheter leakage was seen and treated with fibrin glue. In all 8 patients, no relapse of dialysate leakage was seen after application of the fibrin glue. During the time of PD, exit-site infections, tunnel infections, and peritonitis did not occur.

Conclusion

Fibrin glue is a successful, simple, and safe substance for the treatment of peritoneal dialysate leakage in infants and small children with acute renal failure treated with PD.

Blood Glutamate Reducing Effect of Hemofiltration in Critically Ill Patients

Glutamate toxicity plays a well-established role in secondary brain damage following acute and chronic brain insults. Previous studies have demonstrated the efficacy of hemodialysis and peritoneal dialysis in reducing blood glutamate levels. However, these methods are not viable options for hemodynamically unstable patients. Given more favorable hemodynamics, longer treatment, and less needed anticoagulation, we investigated whether hemofiltration could be effective in lowering blood glutamate levels. Blood samples were taken from 10 critically ill patients immediately before initiation of hemofiltration and after 1, 2, 4, 6, and 12 h, for a total of 6 blood samples. Samples were sent for determination of glutamate, glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), hemoglobin, hematocrit, urea, creatinine, glucose, sodium, potassium, platelet, and white blood cell (WBC) levels. There was a statistically significant reduction in blood glutamate levels at all time points compared to baseline levels. There was no difference in levels of GOT or GPT. Hemofiltration can be a promising method of reducing blood glutamate levels, especially in critically ill patients where hemodialysis and peritoneal dialysis may be contraindicated.

AN69ST membranes adsorb nafamostat mesylate and affect the management of anticoagulant therapy: a retrospective study

BACKGROUND

In Japan, nafamostat mesylate (NM) is frequently used as an anticoagulant during continuous renal replacement therapy (CRRT). The dialyzer membrane AN69ST has been reported to adsorb NM and affect the management of anticoagulant therapy. However, the adsorbed amount has not yet been quantitatively assessed. Therefore, in this study, we evaluated the pre- and post-hemofilter prolongation of the activated clotting time (ACT) in patients with AN69ST and PS membranes. We also measured the adsorption of NM in three types of CRRT membranes using an experimental model.

METHODS

In a study of patients who underwent CRRT using AN69ST or PS membranes in 2015 at the Advanced Emergency and Critical Care Center, Okayama University Hospital, pre- and post-hemofilter ACT measurements were extracted retrospectively, and the difference was calculated. In addition, AN69ST (sepXiris100), PS (HEMOFEEL SHG-1.0), and PMMA membranes (HEMOFEEL CH-1.0N) were used in an in vitro model of a dialysis circuit, and the concentrations of NM were measured in pre- and post-hemofilter membranes and filtrates.

RESULTS

The ACT difference was significantly lower in the group using AN69ST membranes (p < 0.01). In the in vitro model (n = 4) with adsorption and filtration, the post-hemofilter and filtrate concentrations of NM in AN69ST membranes were significantly lower than those in the PS and PMMA membranes (p < 0.01). The NM adsorption clearance of the AN69ST membrane was significantly higher than that of the PS and PMMA membranes.

CONCLUSIONS

The AN69ST membrane had higher NM adsorption than the PS and PMMA membranes. This may have resulted in the lower ACT difference in patients undergoing CRRT using the AN69ST membrane than in patients undergoing CRRT using PS or PMMA membranes.

Acute abrin poisoning treated with continuous renal replacement therapy and hemoperfusion successfully: A case report

RATIONALE

Abrin is a highly toxic protein obtained from the seeds of Abrus precatorius, but poisoning due to ingestion of A precatorius is extremely rare in China.

PATIENT CONCERNS

A 16-year-old girl, perfectly healthy before, was admitted to the department of gastroenterology owing to intentional ingestion of 10 crushed A precatorius seeds, with multiple episodes of somnolent and anxious mental status, vomiting, abdominal pain, diarrhea, hematochezia, and hematuria.

DIAGNOSIS

Acute abrin poisoning.

INTERVENTIONS

We immediately took effective measures including gastric lavage, purgation, gastric acid suppression by proton pump inhibitor (PPI), liver protection, hemostasis, blood volume and electrolytes resuscitation, continuous renal replacement therapy (CRRT), and hemoperfusion (HP).

OUTCOMES

Her unwell mental status was improved to the point at which she became conscious and relaxed. The symptoms of vomiting, abdominal pain, diarrhea, hematochezia, and hematuria disappeared gradually. The girl eventually made an excellent recovery with no complications at her 3-month follow-up.

LESSONS

The combination of CRRT and HP is an efficient measure in the treatment of abrin poisoning for which there is no specific antidote. This is the first reported case of an abrin poisoning patient successfully treated by CRRT plus HP. Our experience will be useful to other physicians in managing patients of acute abrin poisoning in the future.

Delta neutrophil index is an independent predictor of mortality in septic acute kidney injury patients treated with continuous renal replacement therapy

Background

Delta neutrophil index (DNI), representing an elevated fraction of circulating immature granulocytes in acute infection, has been reported as a useful marker for predicting mortality in patients with sepsis. The aim of this study was to evaluate the prognostic value of DNI in predicting mortality in septic acute kidney injury (S-AKI) patients treated with continuous renal replacement therapy (CRRT).

Method

This is a retrospective analysis of consecutively CRRT treated patients. We enrolled 286 S-AKI patients who underwent CRRT and divided them into three groups based on the tertiles of DNI at CRRT initiation (high, DNI > 12.0%; intermediate, 3.6–12.0%; low, < 3.6%). Patient survival was estimated with the Kaplan-Meier method and Cox proportional hazards models to determine the effect of DNI on the mortality of S-AKI patients.

Results

Patients in the highest tertile of DNI showed higher Acute Physiology and Chronic Health Evaluation II score (highest tertile, 27.9 ± 7.0; lowest tertile, 24.6 ± 8.3; P = 0.003) and Sequential Organ Failure Assessment score (highest tertile, 14.1 ± 3.0; lowest tertile, 12.1 ± 4.0; P = 0.001). The 28-day mortality rate was significantly higher in the highest tertile group than in the lower two tertile groups (P < 0.001). In the multiple Cox proportional hazard model, DNI was an independent predictor for mortality after adjusting multiple confounding factors (hazard ratio, 1.010; 95% confidence interval, 1.001–1.019; P = 0.036).

Conclusion

This study suggests that DNI is independently associated with mortality of S-AKI patients on CRRT.

Continuous Renal Replacement Therapy (CRRT) in the Intensive Care Unit

This review is specifically designed to address the topic of CRRT based on the needs and interests of intensivists. Some of the materials, concepts, and formulas presented in this review have been drawn from a previous chapter authored by myself and intended for individuals whose primary interest is specifically dialysis[1]. Since this previous chapter was authored in 1994, similar material presented in this review has been updated in order to present the most current information.

The Role of Renal Replacement Therapy in the Management of Pharmacologic Poisonings

Pharmacologic toxicities are common and range from mild to life-threatening. The aim of this study is to review and update the data on the role of renal replacement therapy (RRT) in the management of various pharmacologic poisonings. We aim to provide a focused review on the role of RRT in the management of pharmacological toxicities. Relevant publications were searched in MEDLINE with the following search terms alone or in combination: pharmacologic toxicity, hemodialysis, hemofiltration, renal replacement therapy, toxicology, poisonings, critical illness, and intensive care. The studies showed that a pharmacologic substance should meet several prerequisites to be deemed dialyzable. These variables include having a low molecular weight (<500 Da) and low degree of protein binding (<80%), being water-soluble, and having a low volume of distribution (<1 L/kg). RRT should be strongly considered in critically ill patients presenting with toxic alcohol ingestion, salicylate overdose, severe valproic acid toxicity, metformin overdose, and lithium poisoning. The role of RRT in other pharmacologic toxicities is less certain and should be considered on a case-by-case basis.

Evaluation of nucleoside reverse transcriptase inhibitor dosing during continuous veno-venous hemofiltration

Background Unpredictable drug concentrations may lead to suboptimal exposure to nucleoside reverse transcriptase inhibitors (NRTIs) due to inadequate doses administered during continuous veno-venous hemofiltration (CVVH), which in turn may lead to decreased antiretroviral efficacy and possibly further HIV disease progression. Objective To compare administered doses of NRTIs to calculated doses of NRTIs to evaluate if patients were expected to have a favorable pharmacokinetic exposure profile while receiving CVVH. Methods The NRTI dose was compared to a table of recommendations based on a mathematical formula that estimates the amount of drug expected to be removed during CVVH. Results Twelve patients were on 27 NRTIs. Eleven (41%) NRTI doses were expected to provide a favorable pharmacokinetic profile based on pharmacokinetic mathematical calculations. Conclusion The majority of NRTIs were potentially not optimally dosed based on proposed pharmacokinetic calculations.

Dosing nucleoside reverse transcriptase inhibitors in adults receiving continuous veno-venous hemofiltration

BACKGROUND AND OBJECTIVE

Characteristics of nucleoside reverse transcriptase inhibitors (NRTIs) make the drug class susceptible to elimination via continuous veno-venous hemofiltration (CVVH), potentially leading to suboptimal drug concentrations if given at the recommended anephric doses during CVVH. The objective of this study was to formulate NRTI dosing recommendations for adults receiving CVVH.

METHODS

A mathematical formula that estimates the amount of drug likely to be removed during CVVH at various flow rates was used to calculate the supplemental NRTI dose required during CVVH.

RESULTS

A proposed table of dosing recommendations for NRTIs during CVVH is presented.

CONCLUSION

Clinicians should utilize these recommendations in the context of each individual patient, taking into consideration patient-specific factors and severity of illness. Future pharmacokinetic research correlating plasma and intracellular concentrations of NRTIs during CVVH is warranted to elucidate appropriate dosing.

Can we predict poor hemodynamic tolerance of intermittent hemodialysis with echocardiography in intensive care patients?

OBJECTIVES

Tolerance of intermittent hemodialysis is potentially poor for patients hospitalized in the intensive care unit, particularly those in shock. The aim of this study was to determine whether an evaluation of the hemodynamic state by echocardiography before an intermittent hemodialysis session could predict tolerance during the session.

METHODS

Before an intermittent hemodialysis session, transesophageal echocardiography was performed on sedated patients, and transthoracic echocardiography was performed on nonsedated patients. Poor tolerance during intermittent hemodialysis was defined by the following criteria: greater than 20% decrease in mean arterial pressure, need for fluid loading (≥500 mL), a 15% increase in catecholamine if the dose was stable before the session or doubling the speed of catecholamine infusion if necessary, arrhythmia, and the necessity to stop the session before its prescribed end.

RESULTS

A total of 54 patients were included: 20 (37%) were intubated under controlled mechanical ventilation (group 1) and underwent transesophageal echocardiography; 14 (26%) were intubated under pressure support ventilation (group 2) and underwent transthoracic echocardiography; and 20 (37%) had no ventilation support (group 3). Twenty-four patients (46%) had poor tolerance criteria. A comparison of groups showed no significant difference in tolerance. Similarly, there was no difference with and without ultrafiltration. Increased respiratory variation of the vena cava was not predictive of poor tolerance in groups 1 and 2. In group 3, there was greater variation in patients with poor tolerance. In patients receiving mechanical ventilation, greater respiratory variability of the maximum velocity measured in the pulmonary artery was predictive of poor tolerance.

CONCLUSIONS

The hemodynamic profile of patients receiving mechanical ventilation was unable to predict tolerance of an intermittent hemodialysis session. In patients without mechanical ventilation, hypovolemia before the session appeared to be predictive of poor tolerance.

Device-Based Therapy in the Prevention of Contrast-Induced Nephropathy

Contrast-induced nephropathy (CIN) is a common condition that is associated with short- and, likely, long-term adverse outcomes. Although periprocedural intravenous hydration is the simplest and most widely used technique to prevent CIN, the limited ability of this approach to mitigate the CIN risk in high-risk populations has provided an impetus to develop new preventive strategies. A range of potentially useful device-based approaches offers new preventive techniques. Well-designed and adequately powered randomized studies of these device-based therapies are urgently needed to determine the expanding role they will play in future clinical practice.

A stepwise approach for the management of poisoning with extracorporeal treatments

The use of an extracorporeal treatment (ECTR) in a poisoned patient may be life-saving in a limited number of scenarios. The decision-processes surrounding the use of ECTR in poisoning is complex: most nephrologists are not trained to assess a poisoned patient while clinical toxicologists rarely prescribe ECTRs. Deciding on which ECTR is most appropriate for a poison requires a good understanding of the poison's physicochemical and pharmacokinetic properties. Further, a detailed understanding of the capabilities and limitations of the different ECTRs can be useful to select the most appropriate ECTR for a given clinical situation. This manuscript provides a stepwise approach to assess the usefulness of ECTRs in poisoning.

Treatment with echinocandins during continuous renal replacement therapy

Echinocandins are indicated as first-line treatment for invasive candidiasis in moderate to severe illness. As sepsis is the main cause of acute kidney injury, the combination of echinocandin treatment and continuous renal replacement therapy (CRRT) is common. Optimizing antibiotic dosage in critically ill patients receiving CRRT is challenging. The pharmacokinetics of echinocandins have been studied under various clinical conditions; however, data for CRRT patients are scarce. Classically, drugs like echinocandins with high protein binding and predominantly non-renal elimination are not removed by CRRT, indicating that no dosage adjustment is required. However, recent studies report different proportions of echinocandins lost by filter adsorption. Nevertheless, the clinical significance of these findings remains unclear.

Outcome of acute kidney injury in Sudanese children - an experience from a sub-Saharan African unit

♦

BACKGROUND

Acute Kidney Injury (AKI) is an important cause of morbidity and mortality in developing countries. Although continuous renal replacement therapy is gaining more popularity worldwide, peritoneal dialysis (PD) in children remains an appropriate therapy for AKI in children for all age groups including neonates. ♦

METHODOLOGY

We retrospectively reviewed all children who have been admitted with AKI at the pediatric nephrology unit, Soba University Hospital, Khartoum, during the period from January 2005 to December 2011. ♦

RESULTS

Over 7 years we recorded 659 children of whom 362 (54.9%) were male. The spectrum of age was variable with the majority being neonates, 178 (27.1%). The average patient admission rate was 94 patients per year, with an estimated incidence of 9.8 patients/million population/year. Common causes of AKI were sepsis 202 (30.8%), acute glomerulonephritis 75 (11.5%) and obstructive uropathy due to stones 56 (8.5%). The most common dialysis modality used was PD, 343 (52.4%), and peritonitis was reported in 53 (15.4%) patients. Recovery from AKI was achieved in 450 (68.9%) children, 37 (5.7%) went into chronic kidney disease (CKD), 33 (5.1%) referred to the pediatric surgery and 194 (29.7%) died. ♦

CONCLUSION

In the setting of developing countries where AKI is a common cause of morbidity and mortality, reasonably equipped renal units with adequately trained medical staff may save many lives. International funding programs for communicable diseases and charity organizations should include AKI management in their programs. Acute PD remains the treatment modality of choice for AKI in developing countries.

Use of peripheral ultrafiltration in the postoperative cardiac surgery patient

BACKGROUND

: After cardiac surgery, most patients have development of third-space fluid retention, commonly treated with diuretics. In some patients diuretics are ineffective. In this subset, a simplified system for ultrafiltration was used for fluid extraction.

METHODS

: After obtaining permission from the institutional review board, the hospital charts of the first 30 patients having ultrafiltration were retrospectively reviewed to abstract data on fluid extraction and patient outcomes. Data are expressed as mean ± standard deviation.

RESULTS

: From April 2004 through January 2006, 30 patients were selected for ultrafiltration. In one patient, adequate intravenous access could not be obtained. There were 11 female and 18 male (age, 69 ± 12 years) postoperative cardiac surgery patients. The mean ultrafiltration run was 10.5 ± 9 hours, resulting in fluid extraction of 3528 ± 2111 mL per run and 5596 ± 3870 mL per patient (11 patients had more than 1 run). Hospital stay was 9.4 ± 4.4 days. Three patients died unrelated to ultrafiltration.

CONCLUSIONS

: Ultrafiltration as an alternative means of fluid extraction in postoperative cardiac surgery patients was effective and well tolerated.

Analyzing Chinese patients with post-operative acute kidney injury

BACKGROUND

To investigate clinical characteristics and risk factors of Chinese patients with post-operative acute kidney injury (PO-AKI).

METHODS

Patients with PO-AKI in Ruijin Hospital from December 1997 to December 2005 were retrospectively studied.

RESULTS

Patients' mean age was 62.2 ± 18.1 years. There were 111 males and 57 females. The mean serum creatinine at diagnosis was 370.41 ± 320.92 μmol/L and the mean estimated glomerular filtration rate was 33.56 ± 24.24 mL/min. For the outcome of the patients, 38 died and the mortality rate was 22.6%. There were 17 patients (10.1%) with Acute Dialysis Quality Initiative-RIFLE (risk-injury-failure-loss-end classification) phase R, 21 (12.5%) with phase I, and 130 (77.4%) with phase F. There was no significant difference in mortality regarding patients who underwent different types of surgeries. For the risk factors related to PO-AKI, acute tubular necrosis (ATN) increased relative risk of mortality PO-AKI (odds ratio = 7.089, 95% confidence interval = 2.069-24.288, p < 0.001). Multivariate regression models showed that ATN had a positive correlation with mortality of PO-AKI.

CONCLUSIONS

PO-AKI is one of the most common causes of AKI in patients who underwent operations. Special attention should be paid to risk factors related to PO-AKI in order to improve prognosis.

Blood cleaner on-chip design for artificial human kidney manipulation

A novel design of a blood cleaner on-chip using an optical waveguide known as a PANDA ring resonator is proposed. By controlling some suitable parameters, the optical vortices (gradient optical fields/wells) can be generated and used to form the trapping tools in the same way as optical tweezers. In operation, the trapping force is formed by the combination between the gradient field and scattering photons by using the intense optical vortices generated within the PANDA ring resonator. This can be used for blood waste trapping and moves dynamically within the blood cleaner on-chip system (artificial kidney), and is performed within the wavelength routers. Finally, the blood quality test is exploited by the external probe before sending to the destination. The advantage of the proposed kidney on-chip system is that the unwanted substances can be trapped and filtered from the artificial kidney, which can be available for blood cleaning applications.

Ultrafiltration in the management of acute decompensated heart failure

PURPOSE OF REVIEW

Admissions to hospital for acute decompensated heart failure continue to increase and represent a significant burden on both patients' and healthcare resources. The majority of these admissions are for the control of volume overload; however, standard treatment with intravenous diuretics is not always effective and can lead to increased renal morbidity. One alternative to standard therapy is mechanical fluid removal with ultrafiltration, this review will highlight the current evidence and efficacy regarding ultrafiltration use in acute heart failure.

RECENT FINDINGS

Multiple recent clinical trials have demonstrated the safety and feasibility of ultrafiltration in the management of acute heart failure. Ultrafiltration may be more effective at removing fluid than standard diuretic therapy and has been associated with beneficial long-term results. However, it remains to be determined whether ultrafiltration is truly nephroprotective and when and how this therapy is best utilized.

SUMMARY

Ultrafiltration is an attractive alternative to standard diuretic therapy in the management of volume overload from acute heart failure. Further research is needed to confirm the cost-effectiveness and to determine long-term impacts on morbidity and mortality.

[Ascites, hepatorenal syndrome and spontaneous bacterial peritonitis in patients with portal hypertension]

Ascites, hepatic encephalopathy and variceal hemorrhage are three major complications of portal hypertension. The diagnostic evaluation of ascites involves an assessment of its etiology by determining the serum-ascites albumin gradient and the exclusion of spontaneous bacterial peritonitis. Ascites is primarily related to an inability to excrete an adequate amount of sodium into urine, leading to a positive sodium balance. Sodium restriction and diuretic therapy are keys of ascites control. But, with the case of refractory ascites, large volume paracentesis and transjugular portosystemic shunts are required. In hepatorenal syndrome, splanchnic vasodilatation with reduction in effective arterial volume causes intense renal vasoconstriction. Splanchnic and/or peripheral vasoconstrictors with albumin infusion, and renal replacement therapy are only bridging therapy. Liver transplantation is the only definitive modality of improving the long term prognosis.

Extracorporeal Removal Techniques for the Poisoned Patient: A Review for the Intensivist

The kidney is able to rapidly eliminate many water-soluble xenobiotics (exogenous chemicals). However, in the face of extraordinary serum concentrations of these xenobiotics or renal dysfunction, alternative elimination techniques often become necessary. Extracorporeal removal (ECR) techniques are used to increase the clearance of xenobiotics. These techniques include hemodialysis (HD), charcoal hemoperfusion (HP), and modalities grouped under the heading of continuous renal replacement therapy (CRRT): continuous venovenous hemofiltration (CVVH) and continuous venovenous hemodiafiltration (CVVHDF). Extracorporeal removal is limited to patients with significant or potentially significant clinical poisoning because the resources required to perform ECR are great. Therefore, most patients who are treated with these techniques are being cared for in intensive care units (ICUs). Our goal in this review is to discuss the properties that make xenobiotics amenable to removal by ECR and the advantages and disadvantages of the individual techniques. We discuss xenobiotics that constitute clear indications for ECR, including the toxic alcohols, salicylates, and lithium. We review the use of CRRT, a modality for which clear indications for treatment of poisonings are currently lacking.

The impact of continuous renal replacement therapy on drug therapy

Critically ill patients with multisystem organ failure often require daily administration of large volumes of fluid to provide electrolyte and nutrition support, medications, and blood products. This often results in fluid overload, which has historically been managed with intermittent hemodialysis (IHD). Unfortunately, IHD entails a high rate of fluid and solute removal that often exacerbates hemodynamic instability. Accordingly, continuous renal replacement therapy (CRRT), involving slow and continuous removal of water and solutes from the plasma, is currently preferred for managing these patients.

Rhabdomyolysis Following Recent Severe Coxsackie Virus Infection in Patient with Chronic Renal Failure: One Case Report and a Review of the Literature

Coxsackie virus infection may be life-threatening, although in most cases, it is asymptomatic. Coxsackie virus infection can cause rhabdomyolysis. This study reports a 39-year-old female patient with chronic renal failure who presented with fever, myalgia, anuria, edema, vomiting, diarrhea, exacerbation of renal function, elevation of serum CK, CK-MB, CK-MM, myoglobin, and liver function abnormality. Serology for Coxsackie virus IgM antibody was positive at first, and IgG antibody became positive 4 weeks later. Muscle biopsy showed skeletal muscle denaturalization and necrosis. She underwent hemodialysis three times per week and then kidney transplantation. No evidence suggests relapse of Coxsackie virus infection 5 months after transplantation. As illustrated with the present case, serological testing may reveal an early, quick, and simple diagnosis in a case of rhabdomyolysis after a viral illness.

Dialysis and pediatric acute kidney injury: choice of renal support modality

Dialytic intervention for infants and children with acute kidney injury (AKI) can take many forms. Whether patients are treated by intermittent hemodialysis, peritoneal dialysis or continuous renal replacement therapy depends on specific patient characteristics. Modality choice is also determined by a variety of factors, including provider preference, available institutional resources, dialytic goals and the specific advantages or disadvantages of each modality. Our approach to AKI has benefited from the derivation and generally accepted defining criteria put forth by the Acute Dialysis Quality Initiative (ADQI) group. These are known as the risk, injury, failure, loss, and end-stage renal disease (RIFLE) criteria. A modified pediatrics RIFLE (pRIFLE) criteria has recently been validated. Common defining criteria will allow comparative investigation into therapeutic benefits of different dialytic interventions. While this is an extremely important development in our approach to AKI, several fundamental questions remain. Of these, arguably, the most important are "When and what type of dialytic modality should be used in the treatment of pediatric AKI?" This review will provide an overview of the limited data with the aim of providing objective guidelines regarding modality choice for pediatric AKI. Comparisons in terms of cost, availability, safety and target group will be reviewed.

Novel potential therapies for septic shock

Sepsis is the systemic inflammatory response syndrome secondary to a local infection. Septic shock, the severe complication of sepsis associated with refractory hypotension, is frequently a near-fatal condition requiring prompt diagnosis and management. Although the recent years have been associated with considerable improvements in the knowledge of the pathophysiology of the disease and remarkable advances have been achieved in sepsis treatment, the morbidity and mortality of this disease are still unacceptably high. In this review, we will briefly discuss the ongoing standard treatment of septic shock and describe novel potential therapies, aiming to improve hemodynamic support and/or control inflammatory response in sepsis. These therapies were associated with benefits in experimental studies and have been tested or are currently under testing in randomized controlled studies with septic patients.

Intermittent hemodialysis versus continuous renal replacement therapy for acute renal failure in the intensive care unit: an observational outcomes analysis

BACKGROUND

Studies have failed to show a survival difference between intermittent hemodialysis (IHD) and continuous renal replacement therapy (CRRT). Comparative cost analyses are limited and fail to control for differences in patient disease severity and comorbid conditions. The authors retrospectively estimated clinical and economic outcomes associated with CRRT and IHD among critically ill patients experiencing acute renal failure (ARF) in 2 tertiary care hospitals in Rochester, Minnesota, between January 1, 2000, and December 12, 2001.

METHODS

161 critically ill patients requiring dialysis for ARF were analyzed. Patient demographics, comorbid conditions, ARF etiology, mode of renal replacement therapy (RRT), renal recovery, and survival were abstracted from medical chart. APACHE II scores at dialysis initiation were calculated. Administrative data tracked length of stay (LOS) and direct medical costs from initiation of RRT to death or intensive care unit (ICU) and hospital discharge. Multivariate modeling was used to adjust outcomes for baseline differences.

RESULTS

84 (52%) of the patients received CRRT and 77 (48%) received IHD. CRRT-treated patients were younger (58 vs 65 years), less likely male (58% vs 77%), had higher APACHE II scores (32 vs 27) with a higher incidence of sepsis (46% vs 30%) and respiratory disease (56% vs 39%), and were less likely to have chronic renal insufficiency (32% vs 49%). With adjustment for differences in baseline patient characteristics, the RRT method did not affect the likelihood of renal recovery, in-hospital survival, or survival during follow-up. Mean adjusted ICU LOS was 9.5 days shorter for IHD-treated than CRRT-treated patients (P< .001), and the adjusted mean difference in hospital and total costs associated with ICU stay was $56,564 and $60 827, in favor of IHD (P< .001). Mean adjusted total costs through hospital discharge were $93 611 and $140,733 among IHD-treated and CRRT-treated patients, respectively (P< .001).

CONCLUSIONS

This observational study suggests that costs may significantly differ by mode of RRT despite similar severity-adjusted patient outcomes. Future prospective comparisons of renal replacement modalities will need to include both clinical and economic outcomes.

Partial blood recirculation: a new trial for prolonging filter life during continuous hemodiafiltration

Although continuous hemodiafiltration (CHDF) has been widely accepted in the management of complicated acute renal failure, the requirement for prolonged continuous systemic anticoagulation appears to be a major drawback. We herein describe the case of a patient who developed postoperative multiple organ failure and received CHDF therapy with partial blood recirculation (PBR). PBR is a mode of extracorporeal circulation used as an anticoagulation modality. The technique accelerates the blood flow rate with the goal of extending filter life, and it was performed because the filter life had been significantly shortened (10.5 +/- 5.1 h) during the CHDF process in this case. Despite increasing the dose of the anticoagulant, changing the hemofilter and changing the mode from postdilution to predilution, we did not obtain amelioration of filter life. The filter life was significantly improved (41.5 +/- 1.4 h) when we performed PBR. It is difficult to minimize the bleeding risk and maintain filter life during CHDF. Our success in prolonging the filter life during this case therefore suggests that PBR might resolve one of the main problems related to CHDF, although more study is needed to clarify the advantages of this system.

Tracheobronchiale Nekrose

Mediastinitis is a bacterial or non-bacterial infection of the mediastinum. Descending necrotizing mediastinitis (DNM) is a rare but life-threatening complication. The mostly feared form of mediastinitis very often has a fatal outcome. We report on a patient with tracheobronchial necrosis following DNM and emphasize the paramount importance of early and complex surgical therapy combined with immediate intensive care treatment. This case describes the intensive medicine and anaesthetic management, which was complicated by the tracheobronchial-pleural fistula and in particular by the respiratory therapy.

Impact of glucose levels on advanced glycation end products in hemodialysis

The current obesity epidemic throughout the western world has resulted in a considerable increase in the condition Type II diabetes mellitus. Recently, the World Health Organization has predicted that the global prevalence of Type II will increase from 175 million patients in 2003 to over 350 million by 2030. One of the major consequences of this disorder is renal failure, which presents itself as chronic kidney disease, and can progress to end-stage renal disease. Once diagnosed, patients are generally treated using dialysis due to a shortage of kidney donors. The fundamental process of dialysis still requires improvement because the survival rate of these patients is relatively poor. This has resulted in considerable research into improvements in hemodialysis membranes, and the challenge to find more suitable marker(s) in assessing the efficacy of the dialysis process. A class of compounds highlighted as a possible accumulative toxin is advanced glycation end products or AGEs. This is an article regarding the impact of hemodialysis and hemodiafiltration on glucose and AGE levels within the body and the consequences of a chronic hyperglycemic condition. It also highlights the negative aspects of using dextrose in conventional dialysis solutions (an area that has already been identified by peritoneal dialysis clinicians as problematic). The review concludes by suggesting several possible topics of future research.

Renal disease: the anesthesiologist's perspective

The kidney is a remarkable organ whose functions include maintaining fluid and electrolyte balance, excreting metabolic waste products, and controlling vascular tone. Blood flow within the kidney is very heterogeneous, which places the metabolically active medulla at high risk for ischemic injury. A number of mediators play a role in the modulation of renal blood flow, including angiotensin II, dopamine, vasopressin, prostaglandins, atrial natriuretic peptide, endothelin, and nitric oxide. Early markers of renal injury elicit strong interest, although currently there is no reliable marker available. Surgery causes the release of catecholamines, renin, angiotensin, and AVP that lead to a redistribution of renal blood flow and a decrease in GFR. Additionally, general anesthesia often results in some degree of hypotension and depressed cardiac output, which further reduces renal perfusion and potentially jeopardizes renal function. A careful anesthetic plan is imperative in the patient with renal insufficiency or failure because acute renal failure in the perioperative period is associated with a high morbidity and mortality. Factors including advanced age, diabetes, underlying renal insufficiency, and heart failure place a patient at high risk for developing acute renal failure. It is imperative to maintain euvolemia, normotension, and cardiac output, and to avoid nephrotoxic agents to optimize renal blood flow and renal perfusion as the best prevention of renal dysfunction. Further studies are needed to establish if any therapies exist to prevent or treat renal dysfunction effectively.

The role of continuous renal replacement therapy in the treatment of poisoning

Extracorporeal elimination of drugs and toxins is a critical component in the management of poisonings, though specific techniques and indications remain a matter of debate. Conventional hemodialysis is frequently the treatment of choice because of its widespread availability and proven effectiveness for certain drugs and toxins. With the increased availability of continuous renal replacement therapy (CRRT) modalities, there is yet another therapeutic option, but one that has yet to find a definitive role in this field. The continuous nature of these therapies is attractive for the management of acute renal failure, but the relatively slower clearance rates as compared to conventional hemodialysis is a distinct drawback in patients with acute xenobiotic-induced toxicity. There are abundant case reports as well as a few small case series in the medical literature documenting the use of CRRT, but specific techniques and the clinical outcomes vary considerably. Therefore one cannot draw definitive conclusions regarding benefit. Some patients, particularly those who are hemodynamically unstable and are not candidates for conventional hemodialysis, may warrant a trial of CRRT. However, at the present time, routine use for the treatment of poisoning is not supported. Controlled trials to better clarify its role would be beneficial, though such studies would be extremely difficult to conduct in this field. We believe that the intelligent application of extracorporeal modalities requires a thorough knowledge of drug pharmacokinetics, of the techniques utilized, and a skeptical analysis of the available literature.