Adjunctive therapy with intravenous human immunoglobulin G improves survival of patients with acute renal failure

Reducing mortality in acute kidney injury patients: systematic review and international web-based survey

OBJECTIVE

To identify all interventions that increase or reduce mortality in patients with acute kidney injury (AKI) and to establish the agreement between stated beliefs and actual practice in this setting.

DESIGN AND SETTING

Systematic literature review and international web-based survey.

PARTICIPANTS

More than 300 physicians from 62 countries.

INTERVENTIONS

Several databases, including MEDLINE/PubMed, were searched with no time limits (updated February 14, 2012) to identify all the drugs/techniques/strategies that fulfilled all the following criteria: (a) published in a peer-reviewed journal, (b) dealing with critically ill adult patients with or at risk for acute kidney injury, and (c) reporting a statistically significant reduction or increase in mortality.

MEASUREMENTS AND MAIN RESULTS

Of the 18 identified interventions, 15 reduced mortality and 3 increased mortality. Perioperative hemodynamic optimization, albumin in cirrhotic patients, terlipressin for hepatorenal syndrome type 1, human immunoglobulin, peri-angiography hemofiltration, fenoldopam, plasma exchange in multiple-myeloma-associated AKI, increased intensity of renal replacement therapy (RRT), CVVH in severely burned patients, vasopressin in septic shock, furosemide by continuous infusion, citrate in continuous RRT, N-acetylcysteine, continuous and early RRT might reduce mortality in critically ill patients with or at risk for AKI; positive fluid balance, hydroxyethyl starch and loop diuretics might increase mortality in critically ill patients with or at risk for AKI. Web-based opinion differed from consensus opinion for 30% of interventions and self-reported practice for 3 interventions.

CONCLUSION

The authors identified all interventions with at least 1 study suggesting a significant effect on mortality in patients with or at risk of AKI and found that there is discordance between participant stated beliefs and actual practice regarding these topics.

Acute kidney injury clinical trial design: old problems, new strategies

Apart from supportive dialysis there are no universally accepted interventions in acute kidney injury (AKI). We have summarized the outcomes of all published randomized, placebo-controlled studies of non-dialysis treatment of AKI. Forty-nine trials were identified, only one of which was in a paediatric population. Sixteen trials had positive outcomes; these trials are not comparable in terms of methodology used or outcomes assessed, and they share many of the problems of the negative trials. We discuss the flaws in clinical trial design that have contributed to poor or uncertain outcomes and propose minimum requirements for future trials. In particular, future trials should incorporate biomarkers specific to the etiology of the AKI, and treatment should match the phase of injury.

A novel IL-18BP ELISA shows elevated serum IL-18BP in sepsis and extensive decrease of free IL-18

IL-18 binding protein (IL-18BP) is a circulating antagonist of the proinflammatory Th1 cytokine IL-18. It effectively blocks IL-18 by forming a 1:1 high affinity (Kd=400 pM) complex, exhibiting a very low dissociation rate. We have developed a sandwich ELISA for IL-18BPa and determined its limit of detection (62 pg/ml). Interference by IL-18 and related cytokines, as well as cross reactivity with other IL-18BP isoforms (b, c, and d) were determined. Using this ELISA, we measured serum IL-18BPa in large cohorts of healthy individuals and in septic patients. Serum IL-18BPa in healthy individuals was 2.15+/-0.15 ng/ml (range 0.5-7 ng/ml). In sepsis, the level rose to 21.9+/-1.44 ng/ml (range 4-132 ng/ml). Total IL-18 was measured in the same sera by an electrochemiluminescence assay and free IL-18 was calculated based on the mass action law. Total IL-18 was low in healthy individuals (64+/-17 pg/ml) and most of it ( approximately 85%) was in its free form. Total IL-18 and IL-18BPa were both elevated in sepsis patients upon admission (1.5+/-0.4 ng/ml and 28.6+/-4.5 ng/ml, respectively). At these levels, most of the IL-18 is bound to IL-18BPa, however the remaining free IL-18 is still higher than in healthy individuals. We conclude that IL-18BPa considerably inhibits circulating IL-18 in sepsis. Yet, exogenous administration of IL-18BPa may further reduce circulating IL-18 activity.

The Presence of Superantigens and Complex Host Responses in Severe Sepsis May Need a Broad Therapeutic Approach

Patients with sepsis can progress into septic shock, disseminated intravascular coagulation, and multiorgan dysfunction syndrome. Various materials secreted by or released from microorganisms such as bacteria initiate these processes. In some bacteria, certain antigens and toxins may cause a 100-fold greater or supernormal activation of monocytes and T lymphocytes, leading to activation of the cascade systems in the host. This can explain the extremely rapid progress of the sepsis into septic shock seen in some patients. In Group A streptococci, more than 100 different toxins have been identified, about 5 of which (superantigens) cause an extremely fast immunological response. Because the toxins and antigens can activate so many different cascade systems in the host, the clinical picture is extremely complex, and little benefit is derived from therapy, which interferes with only 1 or 2 of the parameters in the patient with sepsis. Instead, reversal of the septic shock requires the removal or inhibition of several toxins or substances activating the cascade systems. A broader therapeutic approach may be the use of apheresis (plasma exchange).

Apheresis as Therapy for Patients with Severe Sepsis and Multiorgan Dysfunction Syndrome

Progressive multiorgan dysfunction syndrome may occur in the course of sepsis and septic shock as well as after various intoxications, pancreatitis, crush injuries, and major surgery. Despite conventional intensive care therapies, the prognosis in these patients is still poor. Apheresis, which uses more selective adsorption techniques, can lower the extent of toxins and cytokines in blood. This is achieved in clinical practice by, e.g., using polymyxin B as adsorbent. Although significantly lowered, the mortality is still about 50% with this technique. By unselective plasma exchange, the mortality is reduced down to 20 to 40%. A controlled and randomized study has shown a significant benefit. The centrifugation technique may be favorable over plasma filtration. Not only removal but also replacement with plasma seems important. In the future, probably selective techniques will be used in the early stages of sepsis while unselective plasma exchange may be useful in a disseminated situation.

Multicenter clinical trial of recombinant human insulin-like growth factor I in patients with acute renal failure

BACKGROUND

Patients with acute renal failure (ARF) have high morbidity and mortality rates, particularly if they have serious comorbid conditions. Several studies indicate that in rats with ARF caused by ischemia or certain nephrotoxins, insulin-like growth factor-I (IGF-I) enhances the recovery of renal function and suppresses protein catabolism.

METHODS

Our objective was to determine whether injections of recombinant human IGF-I (rhIGF-I) would enhance the recovery of renal function and is safe in patients with ARF. The study was designed as a randomized, double-blind, placebo-controlled trial in intensive care units in 20 teaching hospitals. Seventy-two patients with ARF were randomized to receive rhIGF-I (35 patients) or placebo (37 patients). The most common causes of ARF in the rhIGF-I and placebo groups were, respectively, sepsis (37 and 35% of patients) and hypotension or hemodynamic shock (42 and 27% of patients). At baseline, the mean (+/- SD) APACHE II scores in the rhIGF-I and placebo-treated groups were 24 +/- 5 and 25 +/- 8, respectively. In the rhIGF-I and placebo groups, the mean (median) urine volume and urinary iothalamate clearances (glomerular filtration rate) were 1116 +/- 1037 (887) and 1402 +/- 1183 (1430) ml/24 hr and 6.4 +/- 5.9 (4.3) and 8.7 +/- 7.2 (4.4) ml/min and did not differ between the two groups. Patients were injected subcutaneously every 12 hours with rhIGF-I, 100 microgram/kg desirable body weight, or placebo for up to 14 days. Injections were started within six days of the onset of ARF. The primary end-point was a change in glomerular filtration rate from baseline. Other end points included changes from baseline in urine volume, creatinine clearance and serum urea, creatinine, albumin and transferrin, frequency of hemodialysis or ultrafiltration, and mortality rate.

RESULTS

During the treatment period, which averaged 10.7 +/- 4.1 and 10.6 +/- 4.5 days in the rhIGF-I and placebo groups, there were no differences in the changes from baseline values of the glomerular filtration rate, creatinine clearance, daily urine volume, or serum urea nitrogen, creatinine, albumin or transferrin. In patients who did not receive renal replacement therapy, there was also no significant difference in serum creatinine and urea between the two groups. Twenty patients in the rhIGF-I group and 17 placebo-treated patients underwent dialysis or ultrafiltration. Twelve rhIGF-I-treated patients and 12 placebo-treated patients died during the 28 days after the onset of treatment.

CONCLUSIONS

rhIGF-I does not accelerate the recovery of renal function in ARF patients with substantial comorbidity.

Apheresis of plasma compounds as a therapeutic principle in severe sepsis and multiorgan dysfunction syndrome

During sepsis there is an increase in the plasma content of several compounds, e.g., bacterial toxins, cytokines, cell debris, free hemoglobin and myoglobin. In blood, these compounds activate various cascade systems, which in large amounts or in more vulnerable patients lead to a disseminated intra-vascular coagulopathy (DIC) with multiorgan dysfunction syndrome (MODS) and death, despite conventional intensive care unit therapy. Therapeutic attempts to reverse these conditions have so far been of limited benefit. These effects have mainly been focused on lowering the blood concentration of single substances such as tumor necrosis factor. By the use of low-and high-flux hemodialysis filters, usually only small amounts of these substances are removed. By the use of plasmapheresis or plasma exchange, the extent of removal is considerably increased. The efficacy varies between the techniques (centrifugation vs. filtration or adsorption) and has also different influences on e.g. the complement system. This report describes these techniques and the therapeutical possibilities given by them. In small trials, blood or plasma exchange has been used as rescue therapy in critically ill patients with a progressive MODS and DIC. A survival of about 80% of the patients has been reported in these studies and the use of combined therapy will be discussed. Controlled trials are required in this field.

Comparison of early IgM-enriched immunoglobulin vs polyvalent IgG administration in score-identified postcardiac surgical patients at high risk for sepsis

STUDY OBJECTIVE

To address the relevance of the IgM component in polyvalent immunoglobulins in sepsis treatment by comparison of the clinical course under polyvalent IgG vs IgGMA therapy in postcardiac surgical patients at high risk for sepsis and to reassess the prognostic validity of sequential changes in acute physiology and chronic health evaluation (APACHE II) scores during treatment.

DESIGN

Prospective, randomized clinical trial.

SETTING

Cardiac surgical ICU in a university hospital.

PATIENTS

Among 870 consecutive patients after elective open-heart surgery, 29 (3.3%) met the previously validated high-risk criterion (APACHE II score > or = 24 on the first postoperative day) with a mean APACHE II score-predicted mortality risk of 63%.

INTERVENTIONS

In addition to standard therapy, 27 of these patients were randomized to receive commercially available IV IgG (Polyglobin N, n = 14, total dosage: 18 mL/kg) or IgGMA (Pentaglobin, n = 13, total dosage: 15 mL/kg).

MEASUREMENTS AND RESULTS

The two groups were comparable in baseline disease severity and concurrent therapy. The extent of score-quantified improvement in disease severity during treatment was similar in both groups (mean fall in APACHE II scores within 4 days; IgG, -6.9; IgGMA, -5.2), as were score-defined improvement rates (rate of patients with score decrease > or = 7 within 4 days: IgG, 57%; IgGMA, 54%) and in-hospital mortality (IgG, 29%; IgGMA, 31%) (all p = NS). There was a strong association between the decrease over time in APACHE II scores during therapy and prognosis (mortality rates in patients with vs without score-assessed improvement: 0% vs 67%, p = 0.0002).

CONCLUSIONS

IgG and IgGMA were associated with a comparable improvement in disease severity in score-identified postcardiac surgical patients at high risk for sepsis. Given the design as an efficacy rather than an equivalence study, this hypothesis derived from our results needs independent validation in larger trials. Sequential APACHE II score changes were reconfirmed as a prognostically valid quantitative measure of disease progress during sepsis therapy.

Use of APACHE II classification to evaluate outcome and response to therapy in acute renal failure patients in a surgical intensive care unit

The study objective was to determine the applicability of the acute physiology and chronic health evaluation (APACHE) II score in surgical patients with acute renal failure (ARF) requiring dialytic support, and to assess its utility in evaluating data from this specific disease group. This was a retrospective, partly prospective follow-up study of patients who developed ARF during their course of stay on the surgical intensive care unit (ICU) of a Dutch university hospital from January 1, 1986, to January 31, 1994. A total of 111 patients were identified, of whom 104 patients were considered eligible for this study. Data for the individual APACHE II scores were calculated from the most deranged values during the initial 24 h of ICU admission (APACHE II1) and on the day dialytic support was instituted (APACHE II2). The ratio between the two APACHE II scores was also calculated for each patient (AP2/AP1 ratio). Receiver operating characteristic curves (ROC) were constructed. Other variables evaluated included age, sex, serum creatinine, diagnostic category, time from ICU admission to start of dialytic support, and the type of dialytic support. Of these 104 patients (median age 64; range 23-85 years), 51 (50%) survived to leave the ICU, of whom 47 (46%) survived to leave hospital. The APACHE II2 score (27.0 +/- 4.4 vs. 22.4 +/- 3.5; p < 0.001) and AP2/AP1 ratio (1.12 +/- 0.09 vs. 0.97 +/- 0.06; p < 0.001) were significantly higher for nonsurvivors as compared to survivors. The ROC curve was most discriminative for the AP2/AP1 ratio (area under the curve 0.92) and to a lesser extent for the APACHE II2 score (area under the curve 0.78). Estimated risk of death with the APACHE II equation did not improve predictive power. Multivariate analysis of various variables revealed the AP2/AP1 ratio as the single most important factor predicting death (odds ratio 13.8, p < 0.001). Adjusting for the AP2/AP1 ratio, no impact on outcome was observed for age, diagnostic category, time from ICU admission to start of dialytic support, and the type of dialytic support. Above a value of 1.0 of the AP2/AP1 ratio, logistic regression revealed a sharp increase in death probability with increasing AP2/AP1 ratio. APACHE II, when used at the time of initiation of dialytic support, proved to be a valid way in our surgical ICU to stratify ARF patients by the severity of their illness. Moreover, use of the AP2/AP1 ratio further improved the usefulness of this severity index and may help to identify patients who have little chance of survival. Predicting death with the APACHE II equation did not improve predictive power.