Predictors of 7- and 30-day mortality in pediatric intensive care unit patients with cancer and hematologic malignancy infected with Gram-negative bacteria

Background

Infection with Gram-negative bacteria is associated with increased morbidity and mortality. The aim of this study was to evaluate the predictors of 7- and 30-day mortality in pediatric patients in an intensive care unit with cancer and/or hematologic diseases and Gram-negative bacteria infection.

Methods

Data were collected relating to all episodes of Gram-negative bacteria infection that occurred in a pediatric intensive care unit between January 2009 and December 2012, and these cases were divided into two groups: those who were deceased seven and 30 days after the date of a positive culture and those who survived the same time frames. Variables of interest included age, gender, presence of solid tumor or hematologic disease, cancer status, central venous catheter use, previous Pseudomonas aeruginosa infection, infection by multidrug resistant-Gram-negative bacteria, colonization by multidrug resistant-Gram-negative bacteria, neutropenia in the preceding seven days, neutropenia duration ≥3 days, healthcare-associated infection, length of stay before intensive care unit admission, length of intensive care unit stay >3 days, appropriate empirical antimicrobial treatment, definitive inadequate antimicrobial treatment, time to initiate adequate antibiotic therapy, appropriate antibiotic duration ≤3 days, and shock. In addition, use of antimicrobial agents, corticosteroids, chemotherapy, or radiation therapy in the previous 30 days was noted.

Results

Multivariate logistic regression analysis resulted in significant relationship between shock and both 7-day mortality (odds ratio 12.397; 95% confidence interval 1.291–119.016; p = 0.029) and 30-day mortality (odds ratio 6.174; 95% confidence interval 1.760–21.664; p = 0.004), between antibiotic duration ≤3 days and 7-day mortality (odds ratio 21.328; 95% confidence interval 2.834-160.536; p = 0.003), and between colonization by multidrug resistant-Gram-negative bacteria and 30-day mortality (odds ratio 12.002; 95% confidence interval 1.578–91.286; p = 0.016).

Conclusions

Shock was a predictor of 7- and 30-day mortality, and colonization by multidrug resistant-Gram-negative bacteria was an important risk factor for 30-day mortality.

Weighted-incidence syndromic combination antibiograms to guide empiric treatment of critical care infections: a retrospective cohort study

Introduction

Empiric antimicrobial selection for critical care infections must balance the need for timely adequate coverage with the resistance pressure exerted by broadspectrum agents. We estimated the potential of weighted incidence syndromic combination antibiograms (WISCAs) to improve time to adequate coverage for critical care infections. In contrast to traditional antibiograms, WISCAs display the likelihood of coverage for a specific infectious syndrome (rather than individual pathogens), and also take into account the potential for poly-microbial infections and the use of multi-drug regimens.

Methods

Cases of ventilator-associated pneumonia (VAP) and catheter-related bloodstream infection (CRBSI) were identified over three years using stringent surveillance criteria. Based on the susceptibility profile of the culprit pathogens, we calculated the WISCA percentages of infections that would have been adequately covered by common antimicrobial(s). We then computed the excess percentage coverage offered by WISCA regimens compared to the actual antimicrobials administered to patients by 12 h, 24 h, and 48 h from culture collection.

Results

Among 163 patients with critical care infection, standard practice only resulted in adequate coverage of 35% of patients by 12 h, 52% by 24 h, and 75% by 48 h. No WISCA mono-therapy regimen offered greater than 85% adequate overall coverage for VAP and CRBSI. A wide range of dual therapy regimens would have conferred greater than 90% adequate coverage, with excess coverage estimated to be as high as +56%, +42% and +18% at 12 h, 24 h and 48 h, respectively. We did not detect a decrease in mortality associated with early adequate treatment, and so could not estimate potential downstream benefits.

Conclusions

WISCA-derived empiric antimicrobial regimens can be calculated for patients with intensive care unit (ICU)-acquired infections, and have the potential to reduce time to adequate treatment. Prospective research must confirm whether implementation of WISCA prescribing aids facilitate timely adequate treatment and improved ICU outcomes.

Long-term adherence to a 5 day antibiotic course guideline for treatment of intensive care unit (ICU)-associated Gram-negative infections

OBJECTIVES

To determine long-term adherence to a 5 day antibiotic course guideline for treating intensive care unit (ICU)-acquired Gram-negative bacteria (GNB) infections.

METHODS

Descriptive analysis of patient-level data on all GNB-active antibiotics prescribed from day 3 and all GNB identified in clinical samples in 5350 patients admitted to a 30 bed general ICU between 2002 and 2009.

RESULTS

Four thousand five hundred and eleven of 5350 (84%) patients were treated with one or more antibiotics active against GNB commenced from day 3. Gentamicin was the most frequently prescribed antibiotic (92.2 days of therapy/1000 patient-days). Only 6% of courses spanned >6 days of therapy and 89% of antibiotic therapy days were with a single antibiotic active against GNB. There was no significant difference between gentamicin and meropenem in the number of first courses in which a resistant GNB was identified in blood cultures [11/1177 (0.9%) versus 5/351 (1.4%); P = 0.43] or respiratory tract specimens [59/951 (6.2%) versus 17/246 (6.9%); P = 0.68] at the time of starting therapy.

CONCLUSIONS

This study demonstrates long-term adherence to a 5 day course antibiotic guideline for treatment of ICU-associated GNB infections. This guideline is a potential antibiotic-sparing alternative to currently recommended dual empirical courses extending to ≥7 days.

Duration of antibiotic therapy for critically ill patients with bloodstream infections: A retrospective cohort study

BACKGROUND

The optimal duration of antibiotic treatment for bloodstream infections is unknown and understudied.

METHODS

A retrospective cohort study of critically ill patients with bloodstream infections diagnosed in a tertiary care hospital between March 1, 2010 and March 31, 2011 was undertaken. The impact of patient, pathogen and infectious syndrome characteristics on selection of shorter (≤10 days) or longer (>10 days) treatment duration, and on the number of antibiotic-free days, was examined. The time profile of clinical response was evaluated over the first 14 days of treatment. Relapse, secondary infection and mortality rates were compared between those receiving shorter or longer treatment.

RESULTS

Among 100 critically ill patients with bloodstream infection, the median duration of antibiotic treatment was 11 days, but was highly variable (interquartile range 4.5 to 17 days). Predictors of longer treatment (fewer antibiotic-free days) included foci with established requirements for prolonged treatment, underlying respiratory tract focus, and infection with Staphylococcus aureus or Pseudomonas species. Predictors of shorter treatment (more antibiotic-free days) included vascular catheter source and bacteremia with coagulase-negative staphylococci. Temperature improvements plateaued after the first week; white blood cell counts, multiple organ dysfunction scores and vasopressor dependence continued to decline into the second week. Among 72 patients who survived to 10 days, clinical outcomes were similar between those receiving shorter and longer treatment.

CONCLUSION

Antibiotic treatment durations for patients with bloodstream infection are highly variable and often prolonged. A randomized trial is needed to determine the duration of treatment that will maximize cure while minimizing adverse consequences of antibiotics.

An alternate pathophysiologic paradigm of sepsis and septic shock: implications for optimizing antimicrobial therapy

The advent of modern antimicrobial therapy following the discovery of penicillin during the 1940s yielded remarkable improvements in case fatality rate of serious infections including septic shock. Since then, pathogens have continuously evolved under selective antimicrobial pressure resulting in a lack of significant improvement in clinical effectiveness in the antimicrobial therapy of septic shock despite ever more broad-spectrum and potent drugs. In addition, although substantial effort and money has been expended on the development novel non-antimicrobial therapies of sepsis in the past 30 years, clinical progress in this regard has been limited. This review explores the possibility that the current pathophysiologic paradigm of septic shock fails to appropriately consider the primacy of the microbial burden of infection as the primary driver of septic organ dysfunction. An alternate paradigm is offered that suggests that has substantial implications for optimizing antimicrobial therapy in septic shock. This model of disease progression suggests the key to significant improvement in the outcome of septic shock may lie, in great part, with improvements in delivery of existing antimicrobials and other anti-infectious strategies. Recognition of the role of delays in administration of antimicrobial therapy in the poor outcomes of septic shock is central to this effort. However, therapeutic strategies that improve the degree of antimicrobial cidality likely also have a crucial role.

Immune response in severe infection: could life-saving drugs be potentially harmful?

Critically ill patients suffer a high rate of nosocomial infection with secondary sepsis being a common cause of death. Usage of antibiotics and catecholamines is often necessary, but it can compromise complex immune response to infection. This review explores influence of these life-saving drugs on host immune response to severe infection.

Update on bloodstream infections in ICUs

PURPOSE OF REVIEW

To describe new developments in the epidemiology and outcomes associated with bloodstream infections (BSIs) in ICUs.

RECENT FINDINGS

The incidence and outcomes associated with BSI among patients admitted to ICUs have been changing as a result of increasing numbers of older patients with comorbid medical illnesses suffering critical illness. Community-onset healthcare-associated BSIs are recognized as important causes of BSIs in ICUs and are distinct from community-acquired and nosocomial BSIs. Electronic surveillance systems are evolving that provide efficient information about the occurrence of BSIs and for tracking the emergence of resistance.

SUMMARY

The incidence of healthcare-associated BSIs increases and is associated with bacteria resistant to antimicrobials used in community-acquired infections. The recent years have witnessed the emergence of extensively resistant bacteria in many regions worldwide, and this is associated with major implications for failure of antimicrobial therapies. Enhanced preventive efforts and optimization of therapy are needed in order to reduce the major burden of BSIs in critically ill patients and to minimize the further emergence of resistance.

Characteristics and determinants of outcome of hospital-acquired bloodstream infections in intensive care units: the EUROBACT International Cohort Study

PURPOSE

The recent increase in drug-resistant micro-organisms complicates the management of hospital-acquired bloodstream infections (HA-BSIs). We investigated the epidemiology of HA-BSI and evaluated the impact of drug resistance on outcomes of critically ill patients, controlling for patient characteristics and infection management.

METHODS

A prospective, multicentre non-representative cohort study was conducted in 162 intensive care units (ICUs) in 24 countries.

RESULTS

We included 1,156 patients [mean ± standard deviation (SD) age, 59.5 ± 17.7 years; 65 % males; mean ± SD Simplified Acute Physiology Score (SAPS) II score, 50 ± 17] with HA-BSIs, of which 76 % were ICU-acquired. Median time to diagnosis was 14 [interquartile range (IQR), 7-26] days after hospital admission. Polymicrobial infections accounted for 12 % of cases. Among monomicrobial infections, 58.3 % were gram-negative, 32.8 % gram-positive, 7.8 % fungal and 1.2 % due to strict anaerobes. Overall, 629 (47.8 %) isolates were multidrug-resistant (MDR), including 270 (20.5 %) extensively resistant (XDR), and 5 (0.4 %) pan-drug-resistant (PDR). Micro-organism distribution and MDR occurrence varied significantly (p < 0.001) by country. The 28-day all-cause fatality rate was 36 %. In the multivariable model including micro-organism, patient and centre variables, independent predictors of 28-day mortality included MDR isolate [odds ratio (OR), 1.49; 95 % confidence interval (95 %CI), 1.07-2.06], uncontrolled infection source (OR, 5.86; 95 %CI, 2.5-13.9) and timing to adequate treatment (before day 6 since blood culture collection versus never, OR, 0.38; 95 %CI, 0.23-0.63; since day 6 versus never, OR, 0.20; 95 %CI, 0.08-0.47).

CONCLUSIONS

MDR and XDR bacteria (especially gram-negative) are common in HA-BSIs in critically ill patients and are associated with increased 28-day mortality. Intensified efforts to prevent HA-BSIs and to optimize their management through adequate source control and antibiotic therapy are needed to improve outcomes.

Characteristics and determinants of outcome of hospital-acquired bloodstream infections in intensive care units: the EUROBACT International Cohort Study

PURPOSE

The recent increase in drug-resistant micro-organisms complicates the management of hospital-acquired bloodstream infections (HA-BSIs). We investigated the epidemiology of HA-BSI and evaluated the impact of drug resistance on outcomes of critically ill patients, controlling for patient characteristics and infection management.

METHODS

A prospective, multicentre non-representative cohort study was conducted in 162 intensive care units (ICUs) in 24 countries.

RESULTS

We included 1,156 patients [mean ± standard deviation (SD) age, 59.5 ± 17.7 years; 65 % males; mean ± SD Simplified Acute Physiology Score (SAPS) II score, 50 ± 17] with HA-BSIs, of which 76 % were ICU-acquired. Median time to diagnosis was 14 [interquartile range (IQR), 7-26] days after hospital admission. Polymicrobial infections accounted for 12 % of cases. Among monomicrobial infections, 58.3 % were gram-negative, 32.8 % gram-positive, 7.8 % fungal and 1.2 % due to strict anaerobes. Overall, 629 (47.8 %) isolates were multidrug-resistant (MDR), including 270 (20.5 %) extensively resistant (XDR), and 5 (0.4 %) pan-drug-resistant (PDR). Micro-organism distribution and MDR occurrence varied significantly (p < 0.001) by country. The 28-day all-cause fatality rate was 36 %. In the multivariable model including micro-organism, patient and centre variables, independent predictors of 28-day mortality included MDR isolate [odds ratio (OR), 1.49; 95 % confidence interval (95 %CI), 1.07-2.06], uncontrolled infection source (OR, 5.86; 95 %CI, 2.5-13.9) and timing to adequate treatment (before day 6 since blood culture collection versus never, OR, 0.38; 95 %CI, 0.23-0.63; since day 6 versus never, OR, 0.20; 95 %CI, 0.08-0.47).

CONCLUSIONS

MDR and XDR bacteria (especially gram-negative) are common in HA-BSIs in critically ill patients and are associated with increased 28-day mortality. Intensified efforts to prevent HA-BSIs and to optimize their management through adequate source control and antibiotic therapy are needed to improve outcomes.

Impact of inappropriate empiric antimicrobial therapy on mortality of septic patients with bacteremia: a retrospective study

Background. Inappropriate empiric antimicrobials could be a major cause of unfavorable mortality rates in co-morbid patients. This study aimed to assess the prevalence and impact of first-dose and 24-hour inappropriate antimicrobials on mortality rates of bacteremic septic patients. Methods. A retrospective cohort study was employed. Case record forms of patients diagnosed as sepsis, severe sepsis, or septic shock with positive hemoculture during 2009 were retrieved from the medical wards, Siriraj Hospital. Demographic data, antimicrobial use, types of bacteria isolated from blood and susceptibilities, patients' comorbidities, 28-day and overall mortality rates were collected and analyzed. Results. There were 229 cases, mean age (SD) of 63.5 (17.2) years and mean (SD) APACHE II score of 24.7 (6.8). The prevalence of first-dose and 24-hour inappropriate antimicrobials was 29.7% and 25.3%, respectively. The 28-day and overall mortality rates between first-dose inappropriate and appropriate antimicrobial were 67.6% versus 60.2% (P = 0.301) and 75.0% versus 68.3% (P = 0.345), consequently. Patients with septic shock and inappropriate first-dose antimicrobials significantly had higher 28-day mortality rate (61.6% versus 41.9%; P = 0.017). Conclusion. Higher mortality rates in bacteremic septic patients were substantially associated with inappropriate first-dose antimicrobials and 3-hour delayed antimicrobial administration after sepsis diagnosis.

Impact of combination therapy with aminoglycosides on the outcome of ICU-acquired bacteraemias

Pharmacodynamic studies report on the rapid bactericidal activity of aminoglycosides, conferring them as being of theoretical interest for bacteraemia treatment. We assessed this issue in a retrospective study of patients with intensive care unit (ICU)-acquired bacteraemias. To determine the impact of aminoglycosides in antimicrobial combination on the outcome of patients with bacteraemia, we performed a monovariate analysis and a logistic regression analysis comparing patients treated with or without aminoglycosides. Forty-eight bacteraemias in 48 patients were included. Eighteen patients received aminoglycosides. Baseline characteristics as well as adaptation and adequation of antibiotherapy did not differ in patients who did or did not receive aminoglycosides. Patients who received aminoglycosides had longer time alive away from the ICU (11.3 ± 8.9 (10 [0–20]) vs. 3.2 ± 6.6 (0 [0–2] days; p = 0.002) and free from mechanical ventilation (12.5 ± 9.3 (14 [0–21] vs. 5.5 ± 9.2 (0 [0–10] days; p = 0.02) on day 28. The ICU mortality was 16% in the aminoglycoside group versus 46% (p = 0.03). In the multivariate analysis, patients treated with aminoglycosides were 6 times less likely to die than those treated without aminoglycosides (confidence interval [CI] = [1.3–28.9]; p = 0.02). Our study supports the hypothesis that combination short-term antibiotherapy with an aminoglycoside for ICU-acquired bacteraemias could increase survival.

Predictors of in-hospital mortality in elderly patients with bacteraemia admitted to an Internal Medicine ward

BACKGROUND

Infectious diseases are a common cause of increased morbidity and mortality in elderly patients. Bacteraemia in the elderly is a difficult diagnosis and a therapeutic challenge due to age-related vicissitudes and to their comorbidities. The main purpose of the study was to assess independent risk factors for in-hospital mortality among the elderly with bacteraemia admitted to an Internal Medicine Ward.

METHODS

Overall, a cohort of 135 patients, 65 years of age and older, with bacteraemia were retrospectively studied. Data related to demographic information, comorbidities, clinical parameters on admission, source and type of infection, microorganism isolated in the blood culture, laboratory data and empirical antibiotic treatment was recorded from each patient. Multivariate logistic regression was performed to identify independent predictors of all-cause in-hospital mortality.

RESULTS

Of these 135 patients, 45.9% were women. The most common infections in this group of patients were urinary tract infections (46.7%). The main microorganisms isolated in the blood cultures were Escherichia coli (14.9%), Methicillin-resistant Staphylococcus aureus (MRSA) (12.0%), non-MRSA (11.4%), Klebsiella pneumoniae (9.1%) and Enterococcus faecalis (8.0%). The in-hospital mortality was 22.2%. Independent prognostic factors associated with in-hospital mortality were age ≥ 85 years, chronic renal disease, bacteraemia of unknown focus and cognitive impairment at admission (OR, 2.812 [95% CI, 1.039-7.611; p = 0.042]; OR, 6.179 [95% CI, 1.840-20.748; p = 0.003]; OR, 8.673 [95% CI, 1.557-48.311; p = 0.014] and OR, 3.621 [95% CI, 1.226-10.695; p = 0.020], respectively). By multivariate analysis appropriate antibiotic therapy was not associated with lower odds of mortality.

CONCLUSION

Bacteraemia in the elderly has a high mortality rate. There are no set of signs or clinical features that can predict bacteraemia in the elderly. However, older age (≥ 85 years), chronic renal disease, bacteraemia of unknown focus and severe cognitive impairment adversely affects the outcome of elderly patients with bacteraemia admitted to an Internal Medicine ward.

Infection in the critically ill--questions we should be asking

Best practice in infection control and management in the critically ill continues to generate considerable debate. The wide variation in current practice is witness to this continuing uncertainty. In large part this is due to the lack of a decent evidence base and to an over-reliance on deep-set dogma. Data that go against the grain are often conveniently overlooked and political imperatives frequently supervene. This article highlights some of these discrepancies and argues for a more balanced, scientific approach. In this time of financial restraint, we need to identify true priorities from both health and economic perspectives, and to see what practices can safely and effectively be modified or abandoned.

How I manage haematology patients with septic shock

Patients with a variety of haematological conditions are at risk of infection and its most serious complication: septic shock. Mortality for septic shock remains high and especially so in patients with haematological malignancy and following bone marrow transplantation. However, advances in the treatment of severe sepsis have improved mortality rates even though evidence for the management of severe sepsis in haematology patients is limited. Wherever possible this review will concentrate on evidence directly applicable to haematology patients but inevitably will have to extrapolate evidence from other patient groups. The Surviving Sepsis Guidelines 2008 provide information on best practice in the management of patients with severe sepsis and septic shock and are broadly applicable though not specific to haematology patients. This review summarizes a practical approach to the management of severe sepsis in haematology patients and highlights areas of research which may bring new treatments in the future. The review is limited to the management and initial resuscitation of septic shock in adult haematology patients and will not address the detailed intensive care management of these patients or the management of severe sepsis in children.