Epidemiology of infection in critically ill patients with acute renal failure

Peritoneal dialysis in acute kidney injury: twenty years of experience at a single center in a developing country

BACKGROUND

This study aimed to explore the role of peritoneal dialysis (PD) in patients with acute kidney injury (AKI) in relation to metabolic and fluid control, outcome and risk factors for death.

METHODS

We performed a retrospective cohort study collecting data from a large reference Center in Brazil on patient characteristics, hospitalization, PD prescription and delivery, clinical outcomes and laboratory exams. We evaluated all patients who had been consecutively treated by PD between January 2004 and January 2024.

RESULTS

Four hundred eighty-seven patients were included. Median age was 64.02 ± 15 years, most of the patients were hospitalized in the intensive care unit (ICU) and needed vasoactive drugs and mechanical ventilation. Sepsis was the main cause of AKI followed by cardiorenal syndrome type 1. Uremia was the main indication for dialysis, followed by the need to meet metabolic and fluid demands. Blood urea nitrogen and creatinine levels stabilized after a median of four dialysis sessions. Fluid removal increased progressively and stabilized at around 2.320 ± 0.91 ml after four sessions. Mechanical complications occurred in 9.2% and peritonitis in 6.2% of patients. Regarding AKI outcome, 34.9% recovered renal function, 6.8% remained on dialysis for over 30 days, and 55.8% died. Technique failure occurred in 19.9% of the cases and the main cause was a mechanical complication. Age, hepatorenal syndrome, APACHE score and dropout from PD due to insufficient fluid control were identified as risk factors for death, while cardiorenal syndrome, need to meet metabolic and fluid demand as indication of dialysis, and negative fluid balance after 4 sessions of PD were identified as protective factors.

CONCLUSION

PD may be an effective solution for AKI patients, allowing adequate metabolic and fluid control. Age, APACHE score, hepatorenal syndrome and dropout from PD were associated with death, while cardiorenal syndrome, need to meet metabolic and fluid demands as indication of dialysis, and negative fluid balance were positive prognostic factors.

Pharmacokinetic variability and significance of therapeutic drug monitoring for broad-spectrum antimicrobials in critically ill patients

Critically ill patients are susceptible to serious infections due to their compromised conditions and extensive use of medical devices, often requiring empiric broad-spectrum antimicrobial therapy. Failure of antimicrobial therapy in this vulnerable population has a direct impact on the patient's survival; hence, selecting the optimal dosage is critical. This population, however, exhibits complex and diverse disease-related physiological changes that can markedly alter antimicrobial disposition. Inflammatory cytokines overexpressed in the systemic inflammatory response syndrome increase vascular permeability, leading to higher volume of distribution for hydrophilic antimicrobials. These cytokines also downregulate metabolic enzyme activities, reducing the clearance of their substrates. Hypoalbuminemia can increase the volume of distribution and clearance of highly protein-bound antimicrobials. Acute kidney injury decreases, while augmented renal clearance increases the clearance of antimicrobials primarily excreted by the kidneys. Furthermore, continuous renal replacement therapy and extracorporeal membrane oxygenation used in critical illness substantially affect antimicrobial pharmacokinetics. The complex interplay of multiple factors observed in critically ill patients poses a significant challenge in predicting the pharmacokinetics of antimicrobials. Therapeutic drug monitoring is the most effective tool to address this issue, and is proactively recommended for vancomycin, teicoplanin, aminoglycosides, voriconazole, β-lactams, and linezolid in critically ill patients. To streamline this process, model-informed precision dosing is expected to promote personalized medicine for this population.

Risk factors for surgical site infection following cardiac surgery in a region endemic for multidrug resistant organisms

OBJECTIVES

To identify risk factors for surgical site infections following cardiosurgery in an area endemic for multidrug resistant organisms.

DESIGN

Single-center, historical cohort study including patients who underwent cardiosurgery during a 6-year period (2014-2020).

SETTING

Joint Commission International accredited, multiorgan transplant center in Palermo, Italy.

MAIN OUTCOME MEASURES

Surgical site infection was the main outcome.

RESULTS

On a total of 3609 cardiosurgery patients, 184 developed surgical site infection (5.1 %). Intestinal colonization with multidrug resistant organisms was more frequent in patients with surgical site infections (69.6 % vs. 33.3 %; p < 0.001). About half of surgical site infections were caused by Gram-negative bacteria (n = 97; 52.7 %). Fifty surgical site infections were caused by multidrug resistant organisms (27.1 %), with extended-spectrum Beta-lactamase-producing Enterobacterales (n = 16; 8.7 %) and carbapenem-resistant Enterobacterales (n = 26; 14.1 %) being the predominant resistance problem. However, in only 24 of surgical site infections caused by multidrug resistant organisms (48 %), mostly carbapenem-resistant Enterobacterales (n = 22), a pathogen match between the rectal surveillance culture and surgical site infections clinical culture was demonstrated. Nevertheless, multivariate logistic regression analysis identified a rectal swab culture positive for multidrug resistant organisms as an independent risk factor for SSI (odds ratio 3.95, 95 % confidence interval 2.79-5.60). Other independent risk factors were female sex, chronic dialysis, diabetes mellitus, previous cardiosurgery, previous myocardial infarction, being overweight/obese, and longer intubation time.

CONCLUSION

In an area endemic for carbapenem-resistant Enterobacterales, intestinal colonization with multidrug resistant organisms was recognized as independent risk factor for surgical site infections.

IMPLICATIONS FOR CLINICAL PRACTICE

No causal relationship between colonization with resistant pathogens and subsequent infection could be demonstrated. However, from a broader epidemiological perspective, having a positive multidrug resistant organisms colonization status appeared a risk factor for surgical site infections. Therefore, strict infection control measures to prevent cross-transmission remain pivotal (e.g., nasal decolonization, hand hygiene, and skin antisepsis).

Prevalence and risk factors for colonisation and infection with carbapenem-resistant Enterobacterales in intensive care units: A prospective multicentre study

OBJECTIVES

This study aimed to investigate the prevalence and risk factors for carbapenem-resistant Enterobacterales colonisation/infection at admission and acquisition among patients admitted to the intensive care unit.

RESEARCH METHODOLOGY/DESIGN

A prospective and multicentre study.

SETTING

This study was conducted in 24 intensive care units in Anhui, China.

MAIN OUTCOME MEASURES

Demographic and clinical data were collected, and rectal carbapenem-resistant Enterobacterales colonisation was detected by active screening. Multivariate logistic regression models were used to analyse factors associated with colonisation/infection with carbapenem-resistant Enterobacterales at admission and acquisition during the intensive care unit stay.

RESULTS

There were 1133 intensive care unit patients included in this study. In total, 5.9% of patients with carbapenem-resistant Enterobacterales colonisation/infection at admission, and of which 56.7% were colonisations. Besides, 8.5% of patients acquired carbapenem-resistant Enterobacterales colonisation/infection during the intensive care stay, and of which 67.6% were colonisations. At admission, transfer from another hospital, admission to an intensive care unit within one year, colonisation/infection/epidemiological link with carbapenem-resistant Enterobacterales within one year, and exposure to any antibiotics within three months were risk factors for colonisation/infection with carbapenem-resistant Enterobacterales. During the intensive care stay, renal disease, an epidemiological link with carbapenem-resistant Enterobacterales, exposure to carbapenems and beta-lactams/beta-lactamase inhibitors, and intensive care stay of three weeks or longer were associated with acquisition.

CONCLUSION

The prevalence of colonisation/infection with carbapenem-resistant Enterobacterales in intensive care units is of great concern and should be monitored systematically. Particularly for the 8.5% prevalence of carbapenem-resistant Enterobacterales acquisition during the intensive care stay needs enhanced infection prevention and control measures in these setting. Surveillance of colonisation/infection with carbapenem-resistant Enterobacterales at admission and during the patient's stay represents an early identification tool to prevent further transmission of carbapenem-resistant Enterobacterales.

IMPLICATIONS FOR CLINICAL PRACTICE

Carbapenem-resistant Enterobacterales colonization screening at admission and during the patient's stay is an important tool to control carbapenem-resistant Enterobacterales spread in intensive care units.

Piperacillin Population Pharmacokinetics and Dosing Regimen Optimization in Critically Ill Children Receiving Continuous Renal Replacement Therapy

We aimed to develop a piperacillin population pharmacokinetic (PK) model in critically ill children receiving continuous renal replacement therapy (CRRT) and to optimize dosing regimens. The piperacillin plasma concentration was quantified by high-performance liquid chromatography. Piperacillin PK was investigated using a nonlinear mixed-effect modeling approach. Monte Carlo simulations were performed to compute the optimal scheme of administration according to the target of 100% interdose interval time in which concentration is one to four times above the MIC (100% fT > 1 to 4× MIC). A total of 32 children with a median (interquartile range [IQR]) postnatal age of 2 years (0 to 11), body weight (BW) of 15 kg (6 to 38), and receiving CRRT were included. Concentration-time courses were best described by a one-compartment model with first-order elimination. BW and residual diuresis (Q_u) explained some between-subject variabilities on volume of distribution (V), where [Formula: see text], and clearance (CL), where [Formula: see text], where CL_pop and V_pop are 6.78 L/h and 55.0 L, respectively, normalized to a 70-kg subject and median residual diuresis of 0.06 mL/kg/h. Simulations with intermittent and continuous administrations for 4 typical patients with different rates of residual diuresis (0, 0.1, 0.25, and 0.5 mL/kg/h) showed that continuous infusions were appropriate to attain the PK target for patients with residual diuresis higher than 0.1 mL/kg/h according to BW and MIC, while for anuric patients, less frequent intermittent doses were mandatory to avoid accumulation. Optimal exposure to piperacillin in critically ill children on CRRT should be achieved by using continuous infusions with escalating doses for high-MIC bacteria, except for anuric patients who require less frequent intermittent doses.

Sepsis and Acute Kidney Injury: A Review Focusing on the Bidirectional Interplay

Although sepsis and acute kidney injury (AKI) have a bidirectional interplay, the pathophysiological mechanisms between AKI and sepsis are not clarified and worthy of a comprehensive and updated review. The primary pathophysiology of sepsis-associated AKI (SA-AKI) includes inflammatory cascade, macrovascular and microvascular dysfunction, cell cycle arrest, and apoptosis. The pathophysiology of sepsis following AKI contains fluid overload, hyperinflammatory state, immunosuppression, and infection associated with kidney replacement therapy and catheter cannulation. The preventive strategies for SA-AKI are non-specific, mainly focusing on infection control and preventing further kidney insults. On the other hand, the preventive strategies for sepsis following AKI might focus on decreasing some metabolites, cytokines, or molecules harmful to our immunity, supplementing vitamin D3 for its immunomodulation effect, and avoiding fluid overload and unnecessary catheter cannulation. To date, several limitations persistently prohibit the understanding of the bidirectional pathophysiologies. Conducting studies, such as the Kidney Precision Medicine Project, to investigate human kidney tissue and establishing parameters or scores better to determine the occurrence timing of sepsis and AKI and the definition of SA-AKI might be the prospects to unveil the mystery and improve the prognoses of AKI patients.

Accelerated versus watchful waiting strategy of kidney replacement therapy for acute kidney injury: a systematic review and meta-analysis of randomized clinical trials

Background

Critically ill patients with severe acute kidney injury (AKI) requiring kidney replacement therapy (KRT) have a grim prognosis. Recently, multiple studies focused on the impact of KRT initiation time [i.e., accelerated versus watchful waiting KRT initiation (WWS-KRT)] on patient outcomes. We aim to review the results of all related clinical trials.

Methods

In this systematic review, we searched all relevant randomized clinical trials from January 2000 to April 2021. We assessed the impacts of accelerated versus WWS-KRT on KRT dependence, KRT-free days, mortality and adverse events, including hypotension, infection, arrhythmia and bleeding. We rated the certainty of evidence according to Cochrane methods and the GRADE approach.

Results

A total of 4932 critically ill patients with AKI from 10 randomized clinical trials were included in this analysis. The overall 28-day mortality rate was 38.5%. The 28-day KRT-dependence rate was 13.0%. The overall incident of KRT in the accelerated group was 97.4% and 62.8% in the WWS-KRT group. KRT in the accelerated group started 36.7 h earlier than the WWS-KRT group. The two groups had similar risks of 28-day [pooled log odds ratio (OR) 1.001, P = 0.982] and 90-day (OR 0.999, P = 0.991) mortality rates. The accelerated group had a significantly higher risk of 90-day KRT dependence (OR 1.589, P = 0.007), hypotension (OR 1.687, P < 0.001) and infection (OR 1.38, P = 0.04) compared with the WWS-KRT group.

Conclusions

This meta-analysis revealed that accelerated KRT leads to a higher probability of 90-day KRT dependence and dialysis-related complications without any impact on mortality rate when compared with WWS-KRT. Therefore, we suggest the WWS-KRT strategy for critically ill patients.

The incidence, mortality and renal outcomes of acute kidney injury in patients with suspected infection at the emergency department

Background

Acute kidney injury (AKI) is a major health problem associated with considerable mortality and morbidity. Studies on clinical outcomes and mortality of AKI in the emergency department are scarce. The aim of this study is to assess incidence, mortality and renal outcomes after AKI in patients with suspected infection at the emergency department.

Methods

We used data from the SPACE-cohort (SePsis in the ACutely ill patients in the Emergency department), which included consecutive patients that presented to the emergency department of the internal medicine with suspected infection. Hazard ratios (HR) were assessed using Cox regression to investigate the association between AKI, 30-days mortality and renal function decline up to 1 year after AKI. Survival in patients with and without AKI was assessed using Kaplan-Meier analyses.

Results

Of the 3105 patients in the SPACE-cohort, we included 1716 patients who fulfilled the inclusion criteria. Of these patients, 10.8% had an AKI episode. Mortality was 12.4% for the AKI group and 4.2% for the non-AKI patients. The adjusted HR for all-cause mortality at 30-days in AKI patients was 2.8 (95% CI 1.7–4.8). Moreover, the cumulative incidence of renal function decline was 69.8% for AKI patients and 39.3% for non-AKI patients. Patients with an episode of AKI had higher risk of developing renal function decline (adjusted HR 3.3, 95% CI 2.4–4.5) at one year after initial AKI-episode at the emergency department.

Conclusion

Acute kidney injury is common in patients with suspected infection in the emergency department and is significantly associated with 30-days mortality and renal function decline one year after AKI.

Correlation of antimicrobial fraction unbound and sieving coefficient in critically ill patients on continuous renal replacement therapy: a systematic review

Background

Fraction unbound has been used as a surrogate for antimicrobial sieving coefficient (SC) to predict extracorporeal clearance in critically ill patients on continuous renal replacement therapy (CRRT), but this is based largely on expert opinion.

Objectives

To examine relationships between package insert-derived fraction unbound (Fu-P), study-specific fraction unbound (Fu-S), and SC in critically ill patients receiving CRRT.

Methods

English-language studies containing patient-specific in vivo pharmacokinetic parameters for antimicrobials in critically ill patients requiring CRRT were included. The primary outcome included correlations between Fu-S, Fu-P, and SC. Secondary outcomes included correlations across protein binding quartiles, serum albumin, and predicted in-hospital mortality, and identification of predictors for SC through multivariable analysis.

Results

Eighty-nine studies including 32 antimicrobials were included for analysis. SC was moderately correlated to Fu-S (R2 = 0.55, P &lt; 0.001) and Fu-P (R2 = 0.41, P &lt; 0.001). SC was best correlated to Fu-S in first (&lt;69%) and fourth (&gt;92%) quartiles of fraction unbound and above median albumin concentrations of 24.5 g/L (R2 = 0.71, P = 0.07). Conversely, correlation was weaker in patients with mortality estimates greater than the median of 55% (R2 = 0.06, P = 0.84). SC and Fu-P were also best correlated in the first quartile of antimicrobial fraction unbound (R2 = 0.66, P &lt; 0.001). Increasing Fu-P, flow rate, membrane surface area, and serum albumin, and decreasing physiologic charge significantly predicted increasing SC.

Conclusions

Fu-S and Fu-P were both reasonably correlated to SC. Caution should be taken when using Fu-S to calculate extracorporeal clearance in antimicrobials with 69%–92% fraction unbound or with &gt;55% estimated in-hospital patient mortality. Fu-P may serve as a rudimentary surrogate for SC when Fu-S is unavailable.

Timing of renal replacement therapy initiation for acute kidney injury in critically ill patients: a systematic review of randomized clinical trials with meta-analysis and trial sequential analysis

Background

Acute kidney injury (AKI) is a common serious complication in critically ill patients. AKI occurs in up to 50% patients in intensive care unit (ICU), with poor clinical prognosis. Renal replacement therapy (RRT) has been widely used in critically ill patients with AKI. However, in patients without urgent indications such as acute pulmonary edema, severe acidosis, and severe hyperkalemia, the optimal timing of RRT initiation is still under debate. We conducted this systematic review of randomized clinical trials (RCTs) with meta-analysis and trial sequential analysis (TSA) to compare the effects of early RRT initiation versus delayed RRT initiation.

Methods

We searched databases (PubMed, EMBASE and Cochrane Library) from inception through to July 20, 2020, to identify eligible RCTs. The primary outcome was 28-day mortality. Two authors extracted the data independently. When the I² values < 25%, we used fixed-effect mode. Otherwise, the random effects model was used as appropriate. TSA was performed to control the risk of random errors and assess whether the results in our meta-analysis were conclusive.

Results

Eleven studies involving 5086 patients were identified. Two studies included patients with sepsis, one study included patients with shock after cardiac surgery, and eight others included mixed populations. The criteria for the initiation of RRT, the definition of AKI, and RRT modalities existed great variations among the studies. The median time of RRT initiation across studies ranged from 2 to 7.6 h in the early RRT group and 21 to 57 h in the delayed RRT group. The pooled results showed that early initiation of RRT could not decrease 28-day all-cause mortality compared with delayed RRT (RR 1.01; 95% CI 0.94–1.09; P = 0.77; I² = 0%). TSA result showed that the required information size was 2949. The cumulative Z curve crossed the futility boundary and reached the required information size. In addition, early initiation of RRT could lead to unnecessary RRT exposure in some patients and was associated with a higher incidence of hypotension (RR 1.42; 95% CI 1.23–1.63; P < 0.00001; I² = 8%) and RRT-associated infection events (RR 1.34; 95% CI 1.01–1.78; P = 0.04; I² = 0%).

Conclusions

This meta-analysis suggested that early initiation of RRT was not associated with survival benefit in critically ill patients with AKI. In addition, early initiation of RRT could lead to unnecessary RRT exposure in some patients, resulting in a waste of health resources and a higher incidence of RRT-associated adverse events. Maybe, only critically ill patients with a clear and hard indication, such as severe acidosis, pulmonary edema, and hyperkalemia, could benefit from early initiation of RRT.

Long-term outcomes of acute kidney injury and strategies for improved care

Acute kidney injury (AKI), once viewed predominantly as a self-limited and reversible condition, is now recognized as a growing problem associated with significant risks of adverse long-term health outcomes. Many cohort studies have established important relationships between AKI and subsequent risks of recurrent AKI, hospital re-admission, morbidity and mortality from cardiovascular disease and cancer, as well as the development of chronic kidney disease and end-stage kidney disease. In both high-income countries (HICs) and low-income or middle-income countries (LMICs), several challenges exist in providing high-quality, patient-centered care following AKI. Despite advances in our understanding about the long-term risks following AKI, large gaps in knowledge remain about effective interventions that can improve the outcomes of patients. Therapies for high blood pressure, glycaemic control (for patients with diabetes), renin-angiotensin inhibition and statins might be important in improving long-term cardiovascular and kidney outcomes after AKI. Novel strategies that incorporate risk stratification approaches, educational interventions and new models of ambulatory care following AKI have been described, and some of these are now being implemented and evaluated in clinical studies in HICs. Care for AKI in LMICs must overcome additional barriers due to limited resources for diagnosis and management.

Risk stratification for early bacteremia after living donor liver transplantation: a retrospective observational cohort study

BACKGROUND

This study investigated perioperative clinical risk factors for early post-transplant bacteremia in patients undergoing living donor liver transplantation (LDLT). Additionally, postoperative outcomes were compared between patients with and without early post-transplant bacteremia.

METHODS

Clinical data of 610 adult patients who underwent elective LDLT between January 2009 and December 2018 at Seoul St. Mary's Hospital were retrospectively collected. The exclusion criteria included overt signs of infection within 1 month before surgery. A total of 596 adult patients were enrolled in this study. Based on the occurrence of a systemic bacterial infection after surgery, patients were classified into non-infected and infected groups.

RESULTS

The incidence of bacteremia at 1 month after LDLT was 9.7% (57 patients) and Enterococcus faecium (31.6%) was the most commonly cultured bacterium in the blood samples. Univariate analysis showed that preoperative psoas muscle index (PMI), model for end-stage disease score, utility of continuous renal replacement therapy (CRRT), ascites, C-reactive protein to albumin ratio, neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio, and sodium level, as well as intraoperative post-reperfusion syndrome, mean central venous pressure, requirement for packed red blood cells and fresh frozen plasma, hourly fluid infusion and urine output, and short-term postoperative early allograft dysfunction (EAD) were associated with the risk of early post-transplant bacteremia. Multivariate analysis revealed that PMI, the CRRT requirement, the NLR, and EAD were independently associated with the risk of early post-transplant bacteremia (area under the curve: 0.707; 95% confidence interval: 0.667-0.745; p < 0.001). The overall survival rate was better in the non-infected patient group. Among patients with bacteremia, anti-bacterial treatment was unable to resolve infection in 34 patients, resulting in an increased risk of patient mortality. Among the factors included in the model, EAD was significantly correlated with non-resolving infection.

CONCLUSIONS

We propose a prognostic model to identify patients at high risk for a bloodstream bacterial infection; furthermore, our findings support the notion that skeletal muscle depletion, CRRT requirement, systemic inflammatory response, and delayed liver graft function are associated with a pathogenic vulnerability in cirrhotic patients who undergo LDLT.

Incident infection following acute kidney injury with recovery to baseline creatinine: A propensity score matched analysis

Background

Severe acute kidney injury (AKI) is associated with subsequent infection. Whether AKI followed by a return to baseline creatinine is associated with incident infection is unknown.

Objective

We hypothesized that risk of both short and long term infection would be higher among patients with AKI and return to baseline creatinine than in propensity score matched peers without AKI in the year following a non-infectious hospital admission.

Design

Retrospective, propensity score matched cohort study.

Participants

We identified 494 patients who were hospitalized between January 1, 1999 and December 31, 2009 and had AKI followed by return to baseline creatinine. These were propensity score matched to controls without AKI.

Main Measures

The predictor variable was AKI defined by International Classification of Diseases, Ninth Revision (ICD-9) codes and by the Kidney Disease Improving Global Outcomes definition, with return to baseline creatinine defined as a decrease in serum creatinine level to within 10% of the baseline value within 7 days of hospital discharge. The outcome variable was incident infection defined by ICD-9 code within 1 year of hospital discharge.

Results

AKI followed by return to baseline creatinine was associated with a 4.5-fold increased odds ratio for infection (odds ratio 4.53 [95% CI, 2.43–8.45]; p<0.0001) within 30 days following discharge. The association between AKI and subsequent infection remained significant at 31–60 days and 91 to 365 days but not during 61–90 days following discharge.

Conclusion

Among patients from an integrated health care delivery system, non-infectious AKI followed by return to baseline creatinine was associated with an increased odds ratio for infection in the year following discharge.

Risk of de novo infection following acute kidney injury: A retrospective cohort study

PURPOSE

Recent studies suggest that acute kidney injury (AKI) can affect distant organ function and increase non-renal complications. We determined whether AKI is associated with an increased risk of incident infections.

MATERIAL AND METHODS

We conducted a one-year single-center retrospective cohort study, excluding patients readmitted to the ICU or for <24 h, on chronic dialysis, and kidney transplant recipients. The primary outcome was the development of incident infections analyzed by multivariate time-dependent Cox models.

RESULTS

Of the 1001 included patients, infections were more frequent in those with AKI (62% vs. 37% without AKI; p < .001). To characterize predictors of incident infections, we excluded patients with an infection until ICU admission (n = 244). Patients with AKI presented infections more often than without AKI (44% vs. 20%; p < .001). AKI, chronic obstructive pulmonary disease, and mechanical ventilation (MV) were associated with incident infections (HR 1.62, 95%CI:1.15-2.30, HR 1.51, 95%CI 1.04-2.18 and HR 2.14, 95%CI:1.48-3.09, respectively) while age, MV, higher fluid balance, and AKI were independent predictors of mortality.

CONCLUSIONS

AKI was associated with incident in-hospital infections. However, newly occurring infections were not associated with an increased risk of mortality. Further studies are needed to understand how AKI affects distant organ function and associated clinical outcomes.

Acute kidney injury is associated with subsequent infection in neonates after the Norwood procedure: a retrospective chart review

BACKGROUND

Acute kidney injury (AKI) and infection are common complications after pediatric cardiac surgery. No pediatric study has evaluated for an association between postoperative AKI and infection. The objective of this study was to determine if AKI in neonates after cardiopulmonary bypass was associated with the development of a postoperative infection.

METHODS

We performed a single center retrospective chart review from January 2009 to December 2015 of neonates (age ≤ 30 days) undergoing the Norwood procedure. AKI was defined by the modified neonatal Kidney Disease Improving Global outcomes serum creatinine criteria using (1) measured serum creatinine and (2) creatinine corrected for fluid balance on postoperative days 1-4. Infection, (culture positive or presumed), must have occurred after a diagnosis of AKI and within 60 days of surgery.

RESULTS

Ninety-five patients were included, of which postoperative infection occurred in 42 (44%). AKI occurred in 38 (40%) and 42 (44%) patients by measured serum creatinine and fluid overload corrected creatinine, respectively, and was most commonly diagnosed on postoperative day 2. The median time to infection from the time of surgery and AKI was 7 days (IQR 5-14 days) and 6 days (IQR 3-13 days), respectively. After adjusting for confounders, the odds of a postoperative infection were 3.64 times greater in patients with fluid corrected AKI (95% CI, 1.36-9.75; p = 0.01).

CONCLUSIONS

Fluid corrected AKI was independently associated with the development of a postoperative infection. These findings support the notion that AKI is an immunosuppressed state that increases the risk of infection.

Effect of an acrylic terpolymer barrier film beneath transparent catheter dressings on skin integrity, risk of dressing disruption, catheter colonisation and infection

OBJECTIVES

We assessed the effect of a skin-protective terpolymer barrier film around the catheter insertion site on frequency of dressing disruptions and skin integrity issues (hyperaemia, skin irritation, residues of adhesives and moisture under the dressing). Secondary outcomes included colonisation of the central venous catheter (CVC) and rates of central line-associated bloodstream infection.

RESEARCH METHODOLOGY

A monocentric, open-label, randomised controlled trial was performed comparing a control group receiving standard transparent catheter dressings without the skin-protecting barrier film and an intervention group receiving a transparent chlorhexidine-impregnated dressing with use of the skin-protective acrylic terpolymer barrier film (3M™ Cavilon™ No - Sting Barrier Film, 3 M Health Care, St. Paul, MN, USA).

RESULTS

Sixty patients were enrolled and randomised in the study accounting for 60 central venous catheters and a total of 533 catheter days. Dressing disruptions occurred more frequently and at sooner time point in the control group. Skin integrity issues were significantly less observed in the intervention group. No differences in CVC colonisation or central line-associated bloodstream infection were observed.

CONCLUSIONS

The application of a barrier film creating a skin-protective polymer layer beneath transparent catheter dressings is associated with less dressing disruptions and skin integrity issues without altering the risk of infectious complications if used in combination with a chlorhexidine-impregnated catheter dressing.

Reversal of Acute Kidney Injury-Induced Neutrophil Dysfunction: A Critical Role for Resistin

OBJECTIVES

To assess the reversibility of acute kidney injury-induced neutrophil dysfunction and to identify involved mechanisms.

DESIGN

Controlled laboratory experiment and prospective observational clinical study.

SETTING

University laboratory and hospital.

SUBJECTS

C57BL/6 wild-type mice.

PATIENTS

Patients with septic shock with or without acute kidney injury.

INTERVENTIONS

Murine acute kidney injury was induced by intraperitoneal injections of folic acid (nephrotoxic acute kidney injury) or by IM injections of glycerol (rhabdomyolysis-induced acute kidney injury). After 24 hours, we incubated isolated neutrophils for 3 hours in normal mouse serum or minimum essential medium buffer. We further studied the effects of plasma samples from 13 patients with septic shock (with or without severe acute kidney injury) on neutrophilic-differentiated NB4 cells.

MEASUREMENTS AND MAIN RESULTS

Experimental acute kidney injury significantly inhibited neutrophil migration and intracellular actin polymerization. Plasma levels of resistin, a proinflammatory cytokine and uremic toxin, were significantly elevated during both forms of acute kidney injury. Incubation in serum or minimum essential medium buffer restored normal neutrophil function. Resistin by itself was able to induce acute kidney injury-like neutrophil dysfunction in vitro. Plasma resistin was significantly higher in patients with septic shock with acute kidney injury compared with patients with septic shock alone. Compared with plasma from patients with septic shock, plasma from patients with septic shock and acute kidney injury inhibited neutrophilic-differentiated NB4 cell migration. Even after 4 days of renal replacement therapy, plasma from patients with septic shock plus acute kidney injury still showed elevated resistin levels and inhibited neutrophilic-differentiated NB4 cell migration. Resistin inhibited neutrophilic-differentiated NB4 cell migration and intracellular actin polymerization at concentrations seen during acute kidney injury, but not at normal physiologic concentrations.

CONCLUSIONS

Acute kidney injury-induced neutrophil dysfunction is reversible in vitro. However, standard renal replacement therapy does not correct this defect in patients with septic shock and acute kidney injury. Resistin is greatly elevated during acute kidney injury, even with ongoing renal replacement therapy, and is sufficient to cause acute kidney injury-like neutrophil dysfunction by itself.

Infection in critically ill pediatric patients on continuous renal replacement therapy

INTRODUCTION

Continuous renal replacement therapies (CRRT) are frequently used in critically ill children and may increase the risk of infection. However, the incidence, characteristics and prognosis of infection in critically ill children on CRRT have not been studied.

METHODS

Data from a prospective, single-center register of critically ill children treated with CRRT was analyzed.

RESULTS

55 children (40% under 1 year of age) were treated with CRRT between June 2008 and January 2012; 43 patients (78.2%) presented 1 or more infections. The most common condition of patients requiring CRRT was heart disease (69%). Infection occurred a median of 11 days after the initiation of CRRT (IQ range: 4 to 21 days). A total of 21 patients (48.8 %) developed 1 infection, 7 (16.2%) developed 2 infections and 15 (34.9%) developed 3 or more infections. The most frequent infection was catheter-related bacteremia, with no differences in catheter location. CRRT duration longer than 4.5 days was the only risk factor for infection. Patients with infection had a longer length of stay (LOS) in the Pediatric Intensive Care Unit (PICU) than patients without it (37.8 vs. 17.6, p = 0.019), but there were no differences in mortality (30.2% vs. 33.3%; p = 0.84).

CONCLUSIONS

Infection rate is high in critically ill children treated with CRRT. More than 4 days of CRRT increases the risk of infection. Infection in these patients entails a longer stay in the PICU but did not increase mortality.

Long-term outcome in ICU patients with acute kidney injury treated with renal replacement therapy: a prospective cohort study

Background

In intensive care unit (ICU) patients, acute kidney injury treated with renal replacement therapy (AKI-RRT) is associated with adverse outcomes. The aim of this study was to evaluate variables associated with long-term survival and kidney outcome and to assess the composite endpoint major adverse kidney events (MAKE; defined as death, incomplete kidney recovery, or development of end-stage renal disease treated with RRT) in a cohort of ICU patients with AKI-RRT.

Methods

We conducted a single-center, prospective observational study in a 50-bed ICU tertiary care hospital. During the study period from August 2004 through December 2012, all consecutive adult patients with AKI-RRT were included. Data were prospectively recorded during the patients’ hospital stay and were retrieved from the hospital databases. Data on long-term follow-up were gathered during follow-up consultation or, in the absence of this, by consulting the general physician.

Results

AKI-RRT was reported in 1292 of 23,665 first ICU admissions (5.5 %). Mortality increased from 59.7 % at hospital discharge to 72.1 % at 3 years. A Cox proportional hazards model demonstrated an association of increasing age, severity of illness, and continuous RRT with long-term mortality. Among hospital survivors with reference creatinine measurements, 1-year renal recovery was complete in 48.4 % and incomplete in 32.6 %. Dialysis dependence was reported in 19.0 % and was associated with age, diabetes, chronic kidney disease (CKD), and oliguria at the time of initiation of RRT. MAKE increased from 83.1 % at hospital discharge to 93.7 % at 3 years. Multivariate regression analysis showed no association of classical determinants of outcome (preexisting CKD, timing of initiation of RRT, and RRT modality) with MAKE at 1 year.

Conclusions

Our study demonstrates poor long-term survival after AKI-RRT that was determined mainly by severity of illness and RRT modality at initiation of RRT. Renal recovery is limited, especially in patients with acute-on-chronic kidney disease, making nephrological follow-up imperative. MAKE is associated mainly with variables determining mortality.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-016-1409-z) contains supplementary material, which is available to authorized users.

Usefulness of serum procalcitonin as a diagnostic biomarker of infection in children with chronic kidney disease

INTRODUCTION

Serum procalcitonin (PCT) levels are known to be low in healthy individuals in healthy subjects but are increased in patients with a severe bacterial infection. It has not been extensively studied in children with chronic kidney disease (CKD), treated either with hemodialysis (HD) or with renal transplantation.

MATERIAL AND METHODS

During a 6-month period, blood samples were taken from 102 (55 HD children and 47 renal transplant recipients) children with a strong clinical suspicion of infection. Procalcitonin levels were measured by ELISA.

RESULTS

Thirty-four/102 cases had proven infections as defined previously. Children with proven infections had a significantly higher PCT (0.920 ±0.24 ng/ml) than those without (0.456 ±0.53 ng/ml), p = 0.04. The ideal cutoff value derived for serum PCT was 0.5 ng/ml. This threshold value established a sensitivity of 94.1% and a specificity of 87.9%.

CONCLUSIONS

This study indicates that significantly increased PCT concentration is a promising predictor of systemic bacterial infection in children with CKD, with good sensitivity and specificity. This study proposes that serum PCT is a convenient index of infection in CKD children at a cutoff value of 0.5 ng/ml.

Short-term Effects of Acute Kidney Injury

Acute kidney injury (AKI) is associated with significant short-term morbidity and mortality, which cannot solely be explained by loss of organ function. Renal replacement therapy allows rapid correction of most acute changes associated with AKI, indicating that additional pathogenetic factors play a major role in AKI. Evidence suggests that reduced renal cytokine clearance as well as increased cytokine production by the acutely injured kidney contribute to a systemic inflammation state, which results in significant effects on other organs. AKI seems to compromise the function of the innate immune system. AKI is an acute systemic disease with serious distant organ effects.

Epidemiology of acute kidney injury in critically ill patients: the multinational AKI-EPI study

PURPOSE

Current reports on acute kidney injury (AKI) in the intensive care unit (ICU) show wide variation in occurrence rate and are limited by study biases such as use of incomplete AKI definition, selected cohorts, or retrospective design. Our aim was to prospectively investigate the occurrence and outcomes of AKI in ICU patients.

METHODS

The Acute Kidney Injury-Epidemiologic Prospective Investigation (AKI-EPI) study was an international cross-sectional study performed in 97 centers on patients during the first week of ICU admission. We measured AKI by Kidney Disease: Improving Global Outcomes (KDIGO) criteria, and outcomes at hospital discharge.

RESULTS

A total of 1032 ICU patients out of 1802 [57.3%; 95% confidence interval (CI) 55.0-59.6] had AKI. Increasing AKI severity was associated with hospital mortality when adjusted for other variables; odds ratio of stage 1 = 1.679 (95% CI 0.890-3.169; p = 0.109), stage 2 = 2.945 (95% CI 1.382-6.276; p = 0.005), and stage 3 = 6.884 (95% CI 3.876-12.228; p < 0.001). Risk-adjusted rates of AKI and mortality were similar across the world. Patients developing AKI had worse kidney function at hospital discharge with estimated glomerular filtration rate less than 60 mL/min/1.73 m(2) in 47.7% (95% CI 43.6-51.7) versus 14.8% (95% CI 11.9-18.2) in those without AKI, p < 0.001.

CONCLUSIONS

This is the first multinational cross-sectional study on the epidemiology of AKI in ICU patients using the complete KDIGO criteria. We found that AKI occurred in more than half of ICU patients. Increasing AKI severity was associated with increased mortality, and AKI patients had worse renal function at the time of hospital discharge. Adjusted risks for AKI and mortality were similar across different continents and regions.

Sepsis and Acute Kidney Injury

Acute kindney injury (AKI) is a clinical syndrome which is generally defined as an abrupt decline in glomerular filtration rate, causing accumulation of nitrogenous products and rapid development of fluid, electrolyte and acid base disorders. In intensive care unit sepsis and septic shock are leading causes of AKI. Sepsis-induced AKI literally acts as a biologic indicator of clinical deterioration. AKI triggers variety of immune, inflammatory, metabolic and humoral patways; ultimately leading distant organ dysfunction and increases morbidity and mortality. Serial mesurements of creatinine and urine volume do not make it possible to diagnose AKI at early stages. Serum creatinine influenced by age, weight, hydration status and become apparent only when the kidneys have lost 50% of their function. For that reason we need new markers, and many biomarkers in the diagnosis of early AKI activity is assessed. Historically "Risk-Injury-Failure-Loss-Endstage" (RIFLE), "Acute Kidney Injury Netwok" (AKIN) and "The Kidney Disease/ Improving Global Outcomes" (KDIGO) classification systems are used for diagnosing easily in clinical practice and research and grading disease. Classifications including diagnostic criteria are formed for the identification of AKI. Neutrophil gelatinase associated lipocalin (NGAL), cystatin-C (Cys-C), kidney injury molecule-1 (KIM-1) and also "cell cycle arrest" molecules has been concerned for clinical use. In this review the pathophysiology of AKI, with the relationship of sepsis and the importance of early diagnosis of AKI is evaluated.

The effect of pathophysiology on pharmacokinetics in the critically ill patient--concepts appraised by the example of antimicrobial agents

Critically ill patients are at high risk for development of life-threatening infection leading to sepsis and multiple organ failure. Adequate antimicrobial therapy is pivotal for optimizing the chances of survival. However, efficient dosing is problematic because pathophysiological changes associated with critical illness impact on pharmacokinetics of mainly hydrophilic antimicrobials. Concentrations of hydrophilic antimicrobials may be increased because of decreased renal clearance due to acute kidney injury. Alternatively, antimicrobial concentrations may be decreased because of increased volume of distribution and augmented renal clearance provoked by systemic inflammatory response syndrome, capillary leak, decreased protein binding and administration of intravenous fluids and inotropes. Often multiple conditions that may influence pharmacokinetics are present at the same time thereby excessively complicating the prediction of adequate concentrations. In general, conditions leading to underdosing are predominant. Yet, since prediction of serum concentrations remains difficult, therapeutic drug monitoring for individual fine-tuning of antimicrobial therapy seems the way forward.

Initial and extended use of femoral versus nonfemoral double-lumen vascular catheters and catheter-related infection during continuous renal replacement therapy

BACKGROUND

The risk of catheter-related infection or bacteremia, with initial and extended use of femoral versus nonfemoral sites for double-lumen vascular catheters (DLVCs) during continuous renal replacement therapy (CRRT), is unclear.

STUDY DESIGN

Retrospective observational cohort study.

SETTING & PARTICIPANTS

Critically ill patients on CRRT in a combined intensive care unit of a tertiary institution.

FACTOR

Femoral versus nonfemoral venous DLVC placement.

OUTCOMES

Catheter-related colonization (CRCOL) and bloodstream infection (CRBSI).

MEASUREMENTS

CRCOL/CRBSI rates expressed per 1,000 catheter-days.

RESULTS

We studied 458 patients (median age, 65 years; 60% males) and 647 DLVCs. Of 405 single-site only DLVC users, 82% versus 18% received exclusively 419 femoral versus 82 jugular or subclavian DLVCs, respectively. The corresponding DLVC indwelling duration was 6±4 versus 7±5 days (P=0.03). Corresponding CRCOL and CRBSI rates (per 1,000 catheter-days) were 9.7 versus 8.8 events (P=0.8) and 1.2 versus 3.5 events (P=0.3), respectively. Overall, 96 patients with extended CRRT received femoral-site insertion first with subsequent site change, including 53 femoral guidewire exchanges, 53 new femoral venipunctures, and 47 new jugular/subclavian sites. CRCOL and CRBSI rates were similar for all such approaches (P=0.7 and P=0.9, respectively). On multivariate analysis, CRCOL risk was higher in patients older than 65 years and weighing >90kg (ORs of 2.1 and 2.2, respectively; P<0.05). This association between higher weight and greater CRCOL risk was significant for femoral DLVCs, but not for nonfemoral sites. Other covariates, including initial or specific DLVC site, guidewire exchange versus new venipuncture, and primary versus secondary DLVC placement, did not significantly affect CRCOL rates.

LIMITATIONS

Nonrandomized retrospective design and single-center evaluation.

CONCLUSIONS

CRCOL and CRBSI rates in patients on CRRT are low and not influenced significantly by initial or serial femoral catheterizations with guidewire exchange or new venipuncture. CRCOL risk is higher in older and heavier patients, the latter especially so with femoral sites.

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.

Severe lactic acidosis in critically ill patients with acute kidney injury treated with renal replacement therapy

PURPOSE

Severe lactic acidosis (SLA) is frequent in intensive care unit (ICU) patients with acute kidney injury (AKI) treated with renal replacement therapy (RRT). The aim of the study is to describe the epidemiology of SLA in this setting.

MATERIALS AND METHODS

An observational single-center cohort analysis was performed on AKI patients treated with RRT. At initiation of RRT, SLA patients (serum lactate concentration>5 mmol/L and pH<7.35) were compared with non-SLA patients.

RESULTS

Of the 454 patients dialyzed during the study period, 342 patients matched inclusion criteria (116 with and 226 patients without SLA). In SLA patients, lactate stabilized/decreased in 69.7% at 4 hours (P=.001) and in 81.8% during the period of 4 to 24 hours (P<.001) after initiation of RRT. Mortality during this 24-hour period was 31.0%. Intensive care unit mortality was 83.6% compared with 47.3% in non-SLA patients. Initial lactate concentration was not related to ICU mortality in SLA patients.

CONCLUSIONS

Severe lactic acidosis was frequent in AKI patients treated with RRT. Severe lactic acidosis patients were more severely ill and had higher mortality compared with patients without. During the first 24 hours of RRT, a correction of lactate concentration and acidosis was observed. In SLA patients, lactate concentration at initiation of RRT was not able to discriminate between survivors and nonsurvivors.

Long-term risk of sepsis among survivors of acute kidney injury

Many prior studies have shown that, in critically ill patients, acute kidney injury (AKI) commonly occurs in association with sepsis and its presence portends an increased likelihood of poor outcomes. In contrast, few studies have focused specifically on the influence of AKI on the long-term risk of developing sepsis. In a previous issue of Critical Care, a population-based cohort study by Lai and colleagues reported a long-term increased risk of severe sepsis for patients surviving beyond 90 days following hospitalization with an episode of AKI requiring renal replacement therapy. While the pathophysiologic mechanisms that underpin this finding remain to be elucidated and causality cannot be proven, this study suggests that severe AKI confers long-term susceptibility to infection and focuses further attention on the critical importance of long-term surveillance for survivors of severe AKI. Further mechanistic and clinical studies are required to more precisely define the extent and duration of any increased risk of severe sepsis beyond which a need for ongoing renal replacement therapy following AKI might be associated. Nonetheless, this novel study by Lai and colleagues could lead to a number of important new avenues for clinical inquiry, such as whether it might be possible to identify those most susceptible to severe sepsis after AKI and, ultimately, whether such episodes might be preventable.

The influence of acute kidney injury on antimicrobial dosing in critically ill patients: are dose reductions always necessary?

Optimal dosing of antimicrobial therapy is pivotal to increase the likelihood of survival in critically ill patients with sepsis. Drug exposure that maximizes bacterial killing, minimizes the development of antimicrobial resistance, and avoids concentration-related toxicities should be considered the target of therapy. However, antimicrobial dosing is problematic as pathophysiological factors inherent to sepsis that alter may result in reduced concentrations. Alternatively, sepsis may evolve to multiple-organ dysfunction including acute kidney injury (AKI). In this case, decreased clearance of renally cleared drugs is possible, which may lead to increased concentrations that may cause drug toxicities. Consequently, when dosing antibiotics in septic patients with AKI, one should consider factors that may lead to underdosing and overdosing. Drug-specific pharmacokinetic and pharmacodynamic data may be helpful to guide dosing in these circumstances. Yet, because of the high interpatient variability in pharmacokinetics of antibiotics during sepsis, this issue remains a significant challenge.

Severity of acute kidney injury and two-year outcomes in critically ill patients

BACKGROUND

The association between levels of acute kidney injury (AKI) during ICU admission and long-term mortality are not well defined.

METHODS

We examined medical records of adult patients admitted to a large tertiary medical center with no history of end-stage renal disease who survived 60 days from ICU admission between 2001 and 2007. Demographic, clinical, physiologic, and date of death data were extracted.

RESULTS

Among 15,048 patients, 12,399 (82.4%) survived 60 days from ICU admission and comprised the study population. AKI did not develop in 5,663 (45.7%) during ICU admission, whereas progressively severe levels of AKI as defined by Acute Kidney Injury Network (AKIN) criteria AKIN 1, AKIN 2, and AKIN 3 developed in 4,589 (37.0%), 1,613 (13.0%), and 534 (4.3%), respectively. Only 42.5% of patients with AKIN 3 survived 2 years from ICU admission. Patients with AKIN 3 had a 61% higher mortality risk 2 years from ICU discharge compared with patients in whom AKI did not develop. Patients with AKIN 1 and AKIN 2 had similar increased mortality risk 2 years from ICU admission (hazard ratio, 1.26 and 1.28, respectively). The level of estimated glomerular filtration rate on ICU discharge and chronic kidney disease were associated with long-term mortality.

CONCLUSIONS

Patients in whom AKI develops during ICU admission have significantly increased risks of death that extend beyond their high ICU mortality rates. These increased risks of death continue for at least 2 years after the index ICU admission.

Risk of developing severe sepsis after acute kidney injury: a population-based cohort study

INTRODUCTION

Sepsis has been a factor of acute kidney injury (AKI); however, little is known about dialysis-requiring AKI and the risk of severe sepsis after survival to discharge.

METHODS

We conducted a population-based cohort study based on the Taiwan National Health Insurance Research Database from 1999 to 2009. We identified patients with AKI requiring dialysis during hospitalization and survived for at least 90 days after discharge, and matched them with those without AKI according to age, sex, and concurrent diabetes. The primary outcome was severe sepsis, defined as sepsis with a diagnosis of acute organ dysfunction. Individuals who recovered enough to survive without acute dialysis were further analyzed.

RESULTS

We identified 2983 individuals (mean age, 62 years; median follow-up, 3.96 years) with dialysis-requiring AKI and 11,932 matched controls. The incidence rate of severe sepsis was 6.84 and 2.32 per 100 person-years among individuals with dialysis-requiring AKI and without AKI in the index hospitalization, respectively. Dialysis-requiring AKI patients had a higher risk of developing de novo severe sepsis than the non-AKI group. In subgroup analysis, even individuals with recovery from dialysis-requiring AKI were at high risk of developing severe sepsis.

CONCLUSIONS

AKI is an independent risk factor for severe sepsis. Even patients who recovered from AKI had a high risk of long-term severe sepsis.

Infection prevention and control strategies in the era of limited resources and quality improvement: a perspective paper

This paper aims to describe, using an evidence-based approach, the importance of and the resources necessary for implementing effective infection prevention and control (IPC) programmes. The intrinsic and explicit values of such strategies are presented from a clinical, health-economic and patient safety perspective. Policy makers and hospital managers are committed to providing comprehensive, accessible, and affordable healthcare of high quality. Changes in the healthcare system over time accompanied with variations in demographics and case-mix have considerably affected the availability, quality and ultimately the safety of healthcare. The main goal of an IPC programme is to prevent and control healthcare-associated infections (HAI). Many patient-, healthcare provider-, and organizational factors are associated with an increased risk for acquiring HAIs and may impact both the quality and outcome of patient care. Evidence has been published in support of having an effective IPC programme. It has been estimated that about one-third of HAIs could be prevented if key elements of the evidence-based recommendations for IPC are adequately introduced and followed. However, several healthcare agencies from over the world have reported deficits in the essential resources and components of current IPC programmes. To meet its main goal, staffing, training, and infrastructure requirements are needed. Nevertheless, and given the economic crisis, policy makers and hospital managers may be tempted to not increase or even to reduce the budget as it consumes resources and does not generate sufficient visible revenue. IPC is a critical issue in patient safety, as HAIs are by far the most common complication affecting admitted patients. The significant clinical and health-economic burden HAIs place on the healthcare system speak to the importance of getting introduced effective IPC programmes.

The effects of preoperative renin-angiotensin system inhibitors on outcomes in patients undergoing cardiac surgery

OBJECTIVE

The effects of preoperative (pre-op) renin-angiotensin system (RAS) inhibitors on outcomes in patients undergoing cardiac surgery remain uncertain. The aim of this study was to evaluate whether the use of pre-op RAS inhibitors affected major outcomes of cardiac surgery.

DESIGN

A retrospective cohort study.

SETTING

A university teaching hospital.

PARTICIPANTS

Patients undergoing cardiac surgery between January 1, 2001 and December 31, 2011.

INTERVENTIONS

One thousand two hundred thirty-nine patients who received pre-op RAS inhibitors were compared with those who did not (control group, n = 1,083).

MEASUREMENTS AND MAIN RESULTS

Acute kidney injury (AKI) was defined using Acute Kidney Injury Network classification. Patients in the RAS inhibitors group presented with higher comorbidities. Pre-op RAS inhibitors therapy was associated with the reduction in the incidence of AKI (27.2% v 34.0%, p<0.001), septicemia (1.9% v 3.5%, p = 0.019), and operative mortality (2.99% v 4.62%, p = 0.039). After adjusted propensity scores and multivariate logistic regression, the pre-op RAS inhibitors were found to have protective effects against AKI (odds ratio [OR]: 0.764, 95% confidence interval [CI]: 0.670-0.873, p<0.001), septicemia (OR: 0.515, 95% CI: 0.348-0.761, p>0.001), and operative mortality (OR: 0.539, 95% CI: 0.348-0.758, p<0.001).

CONCLUSION

The results suggested that pre-op RAS inhibitor therapy was associated with significant reductions in the risk of AKI, operative mortality, and septicemia.

Diagnostic value of serum procalcitonin in patients with chronic renal insufficiency: a systematic review and meta-analysis

BACKGROUND

The diagnostic value of procalcitonin (PCT) for patients with renal impairment is unclear.

METHODS

We searched multiple databases for studies published through December 2011 that evaluated the diagnostic performance of PCT among patients with renal impairment and suspected systemic bacterial infection. We summarized test performance characteristics with the use of forest plots, hierarchical summary receiver operating characteristic (HSROC) curves, and bivariate random effects models.

RESULTS

Our search identified 201 citations, of which seven diagnostic studies evaluated 803 patients and 255 bacterial infection episodes. HSROC-bivariate pooled sensitivity estimates were 73% [95% confidence interval (95% CI) 54-86%] for PCT tests and 78% (95% CI 52-92%) for CRP tests. Pooled specificity estimates were higher for both PCT and CRP tests [PCT, 88% (95% CI 79-93%); CRP, 84% (95% CI, 52-96%)]. The positive likelihood ratio for PCT [likelihood (LR)+ 6.02, 95% CI 3.16-11.47] was sufficiently high to be qualified as a rule-in diagnostic tool, while the negative likelihood ratio was not low enough to be used as a rule-out diagnostic tool (LR- 0.31, 95% CI 0.17-0.57). There was no consistent evidence that PCT was more accurate than CRP test for the diagnosis of systemic infection among patients with renal impairment.

CONCLUSIONS

Both PCT and CRP tests have poor sensitivity but acceptable specificity in diagnosing bacterial infection among patients with renal impairment. Given the poor negative likelihood ratio, its role as a rule-out test is questionable.

Defective neutrophil rolling and transmigration in acute uremia

Circulating neutrophils are essential for innate immunity and undergo rapid, stepwise adhesion to and transmigration through the endothelium following tissue injury and microbial invasion. Neutrophil dysfunction may contribute to morbidity and mortality in acute kidney injury but has not frequently been studied at a mechanistic level. Rossaint et al. provide experimental evidence in mice and humans that acute uremia causes discrete intracellular signaling abnormalities that interfere with specific stages of neutrophil trafficking during inflammation.

Epidemiology of contrast-associated acute kidney injury in ICU patients: a retrospective cohort analysis

PURPOSE

Intensive care unit (ICU) patients frequently undergo contrast-enhanced radiographic examinations, which carries a risk for development of contrast-associated acute kidney injury (CA-AKI). Data on this in ICU patients are scarce. The aim of this study was therefore to evaluate the epidemiology and short- and long-term outcomes of CA-AKI in ICU patients.

METHODS

A retrospective single-centre cohort study covering the period 1 March 2004 to 31 December 2008 on ICU patients who underwent a radiography examination with parenteral administration of iodinated radio contrast media was conducted. Data analysis included univariate and multivariate analyses of patients with and without CA-AKI.

RESULTS

A total of 787 ICU patients were included in the study. CA-AKI occurred in 128 (16.3%) and was associated with higher need for RRT [30 (4.6%) vs. 21 (16.4%), p < 0.001], worse kidney function at discharge, longer length of ICU and hospital stay, and higher 28-day and 1-year mortality [28-day: 86 (13.1%) vs. 46 (35.9%), p < 0.001, and 1-year: 158 (24.0%) vs. 71 (55.5%), p < 0.001]. Higher serum creatinine, lower mean arterial pressure, and administration of diuretics and vasoactive therapy were associated with development of CA-AKI in multivariate analysis. After correction for confounders we found that CA-AKI was associated with 28-day mortality in this cohort of ICU patients (odds ratio = 2.742, 95% confidence interval 1.374-5.471).

CONCLUSIONS

CA-AKI occurred in one out of six ICU patients who underwent a contrast-enhanced radiography examination and was associated with both short-and long-term worse outcomes such as need for RRT, worse kidney function at discharge, increased length of stay in the ICU and hospital, and mortality.

Clinical Experience with Aminoglycosides in Dialysis-Dependent Patients: Risk Factors for Mortality and Reassessment of Current Dosing Practices

Background::

A resurgence of aminoglycoside use has followed the recent increase of multidrug-resistant gram-negative pathogens and is often needed even in the treatment of dialysis-dependent patients; however, studies evaluating the treatment of gram-negative infections with aminoglycosides, including the optimal dose, in the setting of dialysis are limited.

Objective:

To evaluate the current patterns of aminoglycoside use, including microbiologic and clinical indications, and identify risk factors associated with mortality in dialysis-dependent patients receiving aminoglycosides.

Methods:

Utilization, clinical, and microbiologic data were collected retrospectively over a 2-year period (July 2008-June 2010) for adults with a diagnosis of renal failure requiring dialysis and aminoglycoside therapy. Binary logistic and multivariate regression analyses were performed to identify risk factors for alt-cause 30-day mortality.

Results:

Ninety-five consecutive aminoglycoside courses in 88 patients met inclusion criteria for evaluation. A wide variety of clinical and microbiologic indications were documented. The average duration of aminoglycoside therapy was 5.2 days (range 1-42), the average duration of antimicrobial therapy was 13.5 days (1-60), and the all-cause 30-day mortality rate was 36.5%. Factors associated with all-cause 30-day mortality were gram-negative rod (GNR) bacteremia (OR 28.6; p = 0.035), advanced age (OR 8.5; p = 0.030), recent admission (OR 33.4; p = 0.038). and inadequate empiric therapy (OR 14.9; p = 0.024). Intravenous catheter removal was protective of all-cause 30-day mortality (OR 0.01; p = 0.005). A first pre-dialysis plasma concentration relative to the minimum inhibitory concentration (Cp:MIC) <6 mg/L (gentamicin/tobramycin) was associated with an increased risk of mortality (p = 0.026) upon subgroup analysis of dialysis-dependent patients with GNR bloodstream infections.

Conclusions:

Outcomes among dialysis-dependent patients who received aminoglycosides were below expectations. Various risk factors for mortality were identified, including retention of the catheter, inadequate empiric therapy, and a Cp:MIC <6 mg/L. Improved approaches to dosing of aminoglycosides in dialysis-dependent patients, including more aggressive dosing practices, should be urgently explored in attempts to maximize favorable patient outcomes.

[Acute kidney injury]

Acute kidney injury (AKI) is defined as an abrupt decline in the glomerular filtration rate with accumulation of nitrogenous waste products and the inability to maintain fluid and electrolyte homeostasis. Occurring in 7% of all hospitalized patients and 28% to 35% of those in intensive care units, AKI increases hospital mortality. Early evaluation should include differentiating prerenal and postrenal components from intrinsic renal disease. Biological markers can give early warning of AKI and assist with differential diagnosis and assessment of prognosis. The most effective preventive measure is to maintain adequate circulation and cardiac output, avoiding ischemia- or nephrotoxin-induced injury. To that end, patients and situations of risk must be identified, hemodynamics and diuresis monitored, hypovolemia reversed, and nephrotoxins avoided. Protective agents such as sodium bicarbonate, mannitol, prostagiandins, calcium channel blockers, N-acetyl-L-cysteine, sodium deoxycholate, allopurinol, and pentoxifylline should be used. Treatment includes the elimination of prerenal and postrenal causes of AKI; adjustment of doses according to renal function; avoidance of both overhydration and low arterial pressure; maintenance of electrolytic balance, avoiding hyperkalemia and correcting hyperglycemia; and nutritional support, assuring adequate protein intake. For severe AKI, several modalities of renal replacement therapy, differentiated by mechanism and duration, are available. Timing--neither the best moment to start dialysis nor the optimal duration--has been not established. Early detection of AKI is necessary for preventing progression and starting renal replacement therapy at adjusted doses that reflect metabolic requirements.

Hyponatremia in patients with infectious diseases

Hyponatremia is a common electrolyte disturbance associated with considerable morbidity and mortality. Hyponatremia may not infrequently be present during the course of an infection, does not cause specific symptoms and may be overlooked by clinicians. Nonetheless, it may reflect the severity of the underlying process. This review focuses on the clinical and pathophysiological aspects of hyponatremia associated with infectious diseases. In the majority of cases, the fall in serum sodium concentration is of multifactorial origin owing to increased secretion of the anti-diuretic hormone either appropriately or inappropriately. Inadvertent administration of fluids may worsen hyponatremia and prolong morbidity.

Cardiac resynchronization therapy for critically ill patients with left ventricular systolic dysfunction

BACKGROUND

The experience of cardiac resynchronization therapy (CRT) in critically ill patients with cardiogenic shock or advanced heart failure is limited and inadequately described in literature.

METHODS

CRT implants performed in patients on the cardiothoracic intensive care unit (ICU) at a tertiary cardiac centre during 2007-2010 were retrospectively studied.

RESULTS

We identified 24 patients, 17 male, of median age 76 years (IQR 11) treated with a CRT pacemaker (n=10) or CRT defibrillator (n=14). Prior to implantation median left ventricular ejection fraction (LVEF) was 26% (IQR 13) and median QRS duration 146 ms (IQR 29). Eleven (46%) patients were post elective cardiac surgery and 8 (33%) post emergency cardiac surgery or intervention with high prevalence of co-morbidities. Nineteen patients required inotropic support pre-implantation, 8 patients were on mechanical circulatory support and 18 were on mechanical ventilation. Post CRT LVEF improved from 26% to 39% (p=0.027) and the estimated glomerular filtration rate increased from 42 ml/min/1.73 m(2) (IQR 26) to 63 ml/min/1.73 m(2) (IQR 48, p=0.001). All but one patient were successfully weaned from inotropic support within a median of 4 days (IQR 5) post CRT and 22/24 (92%) survived to hospital discharge. After a median follow up of 392 days (IQR 538), 7 (33%) patients died. In-hospital and one year mortality rates were 8.3% and 29.4% respectively. Ten out of 12 patients (83%) were alive at long-term (22 ± 9 months) follow up.

CONCLUSIONS

CRT may assist weaning from circulatory and respiratory support in critically ill patients with left ventricular systolic dysfunction.

Acute renal failure requiring renal replacement therapy in the intensive care unit: impact on prognostic assessment for shared decision making

A 69-year-old female was receiving renal replacement therapy (RRT) for acute renal failure (ARF) in an intensive care unit (ICU). Consultation was requested from the palliative medicine service to facilitate a shared decision-making process regarding goals of care. Clinician responsibility in shared decision making includes the formulation and expression of a prognostic assessment providing the necessary perspective for a spokesperson to match patient values with treatment options. For this patient, ARF requiring RRT in the ICU was used as a focal point for preparing a prognostic assessment. A prognostic assessment should include the outcomes of most importance to a discussion of goals of care: mortality risk and survivor functional status, in this case including renal recovery. A systematic review of the literature was conducted to document published data regarding these outcomes for adult patients receiving RRT for ARF in the ICU. Forty-one studies met the inclusion criteria. The combined mean values for short-term mortality, long-term mortality, renal-function recovery of short-term survivors, and renal-function recovery of long-term survivors were 51.7%, 68.6%, 82.0%, and 88.4%, respectively. This case example illustrates a process for formulating and expressing a prognostic assessment for an ICU patient requiring RRT for ARF. Data from the literature review provide baseline information that requires adjustment to reflect specific patient circumstances. The nature of the acute primary process, comorbidities, and severity of illness are key modifiers. Finally, the prognostic assessment is expressed during a family meeting using recommended principles of communication.

Serum urea concentration is probably not related to outcome in ICU patients with AKI and renal replacement therapy

BACKGROUND

Acute kidney injury (AKI) is a common complication in patients admitted to the intensive care unit (ICU). Among other variables, serum urea concentrations are recommended for timing of initiation of renal replacement therapy (RRT). The aim of this study was to evaluate whether serum urea concentration or different serum urea concentration cutoffs as recommended in the literature were associated with in-hospital mortality at time of initiation of RRT for AKI.

METHODS

This is a retrospective single- centre study during a 3-year period (2004-07), in a 44-bed tertiary care centre ICU of adult AKI patients who were treated with RRT.

RESULTS

Three hundred and two patients were included: 68.9% male, median age 65 years and an APACHE II score of 21. The overall in-hospital mortality was 57.9%. Non-survivors were older (67 versus 64 years, P = 0.016) and had a higher APACHE II score (22 versus 20, P < 0.001). At time of initiation of RRT, they were more severely ill and had a lower serum urea concentration compared to survivors (130 versus 141 mg/dL, P = 0.038). Serum urea concentration, as well as the different historical serum urea concentration cut-offs had low area under the curves for the receiver operating characteristic curve for prediction of mortality. In multivariate analysis, age, and at time of initiation of RRT, potassium, SOFA score with exclusion of points for AKI and RIFLE class were associated with mortality, but serum urea concentration and the different cut-offs were not.

CONCLUSIONS

This retrospective study suggests that serum urea concentration and serum urea concentration cut-offs at time of initiation of RRT have no predictive value for in-hospital mortality in ICU patients with AKI.

Antibiotic optimization in the difficult-to-treat patient with complicated intra-abdominal or complicated skin and skin structure infections: focus on tigecycline

Complicated intra-abdominal and skin and skin structure infections are widely varied in presentation. These infections very often lead to an increase in length of hospital stay, with a resulting increase in costs and mortality. In addition, these infections may be caused by a wide variety of bacteria and are often polymicrobial with the possibility of the presence of antimicrobial-resistant strains, such as methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, extended-spectrum β-lactamase strains (Escherichia coli, Klebsiella pneumoniae), and K. pneumoniae carbapenemase-producing strains. In combination with patients’ immunosuppression or comorbidities, the treatment and management options for initial therapy success are few. Tigecycline, a new glycylcyline antimicrobial from the tetracycline drug class, represents a viable option for the successful treatment of these infections. It has been shown to have activity against a wide variety of bacteria, including the antimicrobial-resistant strains. As with all tetracycline drugs, it is not recommended for pregnant or nursing women. The potential side effects are those typical of tetracycline drugs: nausea, vomiting, and headaches. Drug–drug interactions are not expected, and renal function monitoring is not necessary.

Continuous renal replacement therapy may increase the risk of catheter infection

BACKGROUND AND OBJECTIVES

Little is known about the risks of catheter-related infections in patients undergoing intermittent hemodialysis (IHD) as compared with continuous renal replacement therapy (CRRT) techniques. We compared the two modalities among critically ill adults requiring acute renal replacement therapy (RRT).

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We used the multicenter Cathedia study cohort of 736 critically ill adults requiring RRT. Cox marginal structural models were used to compare time to catheter-tip colonization at removal (intent-to-treat, primary endpoint) among patients who started IHD (n = 470) versus CRRT (n = 266). On-treatment analysis was also conducted to take into account changes in prescription of RRT modality.

RESULTS

Hazard rate of catheter-tip colonization did not increase within the first 10 days of catheter use. Predictors of catheter-tip colonization were higher lactate levels and hypertension, while systemic antibiotics, antiseptics-impregnated catheters, and mechanical ventilation were associated with decreased risk. The incidence of catheter-tip colonization per 1000 catheter-days was 42.7 in the IHD group and 27.7 in the CRRT group (P < 0.01). This association was no longer significant after correction for channeling bias (weighted HR, 0.96; 95% CI: 0.77 to 1.20, P = 0.73). On-treatment analysis revealed an increased risk of primary endpoint during CRRT exposure as compared with IHD exposure (weighted HR, 0.71; 95% CI: 0.56 to 0.92, P < 0.009).

CONCLUSIONS

Our results do not support the use of CRRT when IHD could be an alternative to reduce the risk of catheter-related infection.