Healthcare-associated bloodstream infections in a neonatal intensive care unit over a 20-year period (1992-2011): trends in incidence, pathogens, and mortality

OBJECTIVE

To analyze trends in the incidence and pathogen distribution of healthcare-associated bloodstream infections (HABSIs) over a 20-year period (1992-2011).

DESIGN

Historical cohort study.

SETTING

Thirty-two-bed neonatal intensive care unit (NICU) in a tertiary referral hospital.

PATIENTS

Neonates with HABSIs defined according to the criteria of the National Institute of Child Health and Development (NICHD).

METHODS

A hospital-based ongoing surveillance program was used to identify HABSI cases in neonates. A distinction between definite or possible HABSI was made according to the NICHD criteria. Incidence, incidence densities (HABSIs per 1,000 hospital-days and HABSIs per 1,000 total parenteral nutrition-days), and case fatality rate were calculated. Logistic regression analysis was used to find time trends. Four periods of 5 years were considered when executing variance analysis.

RESULTS

In total, 682 episodes of HABSIs occurred on 9,934 admissions (6.9%). The median total incidence density rate was 3.1 (interquartile range, 2.2-3.9). A significant increasing time trend in incidence density was observed for the period 1995-2011 (P < .003). A significant decrease in the case fatality rate was found in the last 5-year period (P < .001). No neonate died following possible HABSIs, whereas the case fatality rate among neonates with definite HABSIs was 9.7%. Most HABSIs were caused by coagulase-negative staphylococci (n = 414 [60.7%]). A significant increase in Staphylococcus aureus HABSI was observed in the last 10-year period (P < .001).

CONCLUSIONS

An increase in incidence density rate occurred, while the case fatality rate dropped. Better perinatal care could be responsible for the latter. A decrease in days before infection and a high incidence of coagulase-negative Staphylococcus HABSIs indicate the need for vigorous application of evidence-based prevention initiatives, in particular for catheter care.

Critically ill elderly adults with infection: analysis of the extended prevalence of infection in intensive care study

OBJECTIVES

To determine the effect of age on patterns of infection and on outcomes in individuals with infection.

DESIGN

Analysis of data from an international, observational, point-prevalence study: Extended Prevalence of Infection in Intensive Care (EPIC II).

SETTING

Intensive care units (ICUs; N=1,265) in 75 countries.

PARTICIPANTS

All adults present in a participating ICU on May 8, 2007. Individuals with an infection were included and classified according to age (18–44, 45–64, 65–74, 75–84, ≥85).

MEASUREMENTS

Demographic, physiological, bacteriological, and therapeutic data were collected on the day of the study. Outcome data were collected until hospital discharge or for 60 days.

RESULTS

Of the 13,796 adults enrolled in EPIC II, 7,087 (51.4%) had an infection. Of these, 330 (4.7%) were aged 85 and older, 1,405 (19.8%) were 75 to 84, 1,713 (24.2%) were 65 to 74, 2,358 (33.3%) were 45 to 64, and 1,281 (18.1%) were 18 to 44. Severity of illness did not differ between groups. Those aged 85 and older had fewer bloodstream infections than those younger than 75, fewer central nervous system infections than those who were younger than 65, and more abdominal infections than those who were younger than 45. A microbiological diagnosis was established less frequently in participants aged 85 and older than in younger participants. Gram-negative microorganisms were more frequently isolated in those aged 85 and older than in other groups. ICU and hospital mortality were significantly higher in participants aged 85 and older than in those who were younger than 65.

CONCLUSION

A large proportion of individuals in the ICU with infection are aged 65 and older. Patterns of infection, including site and type of microorganism, vary according to age. Being aged 85 and older was an independent risk factor for mortality in individuals in the ICU with infection.

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.

Insights and advances in multidisciplinary critical care: a review of recent research

The intensive care unit is a work environment where superior dedication is pivotal to optimize patients' outcomes. As this demanding commitment is multidisciplinary in nature, it requires special qualities of health care workers and organizations. Thus research in the field covers a broad spectrum of activities necessary to deliver cutting-edge care. However, given the abundance of research articles and education activities available, it is difficult for modern critical care clinicians to keep up with the latest progress and innovations in the field. This article broadly summarizes new developments in multidisciplinary intensive care, providing elementary information about advanced insights in the field by briefly describing selected articles bundled in specific topics. Issues considered include cardiovascular care, monitoring, mechanical ventilation, infection and sepsis, nutrition, education, patient safety, pain assessment and control, delirium, mental health, ethics, and outcomes research.

Cuff pressure of endotracheal tubes after changes in body position in critically ill patients treated with mechanical ventilation

BACKGROUND

In order to avoid microaspiration and tracheal injury, the target for endotracheal tube cuff pressure is 20 to 30 cm H2O.

OBJECTIVE

To assess the effect of changes in body position on cuff pressure in adult patients.

METHODS

Twelve orally intubated and sedated patients received neuromuscular blockers and were positioned in a neutral starting position (backrest, head-of-bed elevation 30º, head in neutral position) with cuff pressure at 25 cm H2O. Then, 16 changes in position were performed: anteflexion head, hyperextension head, left and right lateral flexion of head, left and right rotation of the head, semirecumbent position (head-of-bed elevation 45°), recumbent position (head-of-bed elevation 10°), horizontal backrest, Trendelenburg position (10°), and left and right lateral positioning over 30°, 45°, and 90°. Once a patient was correctly positioned, cuff pressure was recorded during an end-expiratory ventilatory hold. The pressure observed was compared with the cuff pressure at the starting position. Values outside the target range (20-30 cm H2O) were considered clinically relevant.

RESULTS

A total of 192 measurements were performed (12 subjects × 16 positions). A significant deviation in cuff pressure occurred with all 16 changes (P < .05). No pressures were less than the lower limit (20 cm H2O). Pressures were greater than the upper limit (30 cm H2O) in 40.6% of the measurements. In each position, the upper target limit was exceeded at least once. Within-patient variability was substantial (P = .02).

CONCLUSION

Simple changes in patients' positioning can result in potentially harmful cuff pressures.

Fungal sepsis in the ICU: are we doing better? Trends in incidence, diagnosis, and outcome

Despite the availability of broad-spectrum antifungal agents, fungal sepsis remains an issue in Intensive Care Unit (ICU) patients. In terms of occurrence rates, the most important fungal infections are invasive candidiasis and invasive pulmonary aspergillosis. Early diagnosis is essential to optimize the chances of survival. As clinical rules based on risk factor assessment lack specificity, early initiation of antifungal therapy depends on fast and reliable diagnostics. Blood cultures or histopathologic evidence is the gold standard but blood cultures lack sensitivity and biopsy sampling may include substantial risk in critically ill patients. Non-culture-based diagnosis tools have therefore arisen as a smart way to detect earlier and/or more accurately the patients with on going fungal infection. For diagnosing invasive candidiasis, three assays (beta-D-glucan and mannan antigen detection, and polymerase chain reaction) yield promising predictive values, albeit that specificity remains an issue. In the absence of biopsies, invasive pulmonary aspergillosis can be diagnosed in nonneutropenic ICU patients by galactomannan antigen detection in broncho-alveolar lavage fluid. Aspergillus colonization of the respiratory tract can be discriminated from invasive disease by means of a clinical algorithm with high sensitivity but only moderate specificity. The incidence of invasive candidiasis has been stable over the past decades, but an alarming trend towards more non-albicans Candida species and reduced susceptibility is observed. Given the problematic diagnosis of invasive aspergillosis no reliable trend data are available. Outcome following fungal sepsis remains cumbersome. Given the availability of potent antifungal agents any progress in survival is likely to come from a more timely diagnosis.

Prevention of ventilator-associated pneumonia in intensive care units: an international online survey

Background

On average 7% of patients admitted to intensive-care units (ICUs) suffer from a potentially preventable ventilator-associated pneumonia (VAP). Our objective was to survey attitudes and practices of ICUs doctors in the field of VAP prevention.

Methods

A questionnaire was made available online in 6 languages from April, 1^st to September 1^st, 2012 and disseminated through international and national ICU societies. We investigated reported practices as regards (1) established clinical guidelines for VAP prevention, and (2) measurement of process and outcomes, under the assumption “if you cannot measure it, you cannot improve it”; as well as attitudes towards the implementation of a measurement system. Weighted estimations for Europe were computed based on countries for which at least 10 completed replies were available, using total country population as a weight. Data from other countries were pooled together. Detailed country-specific results are presented in an online additional file.

Results

A total of 1730 replies were received from 77 countries; 1281 from 16 countries were used to compute weighted European estimates, as follows: care for intubated patients, combined with a measure of compliance to this guideline at least once a year, was reported by 57% of the respondents (95% CI: 54–60) for hand hygiene, 28% (95% CI: 24–33) for systematic daily interruption of sedation and weaning protocol, and 27% (95%: 23–30) for oral care with chlorhexidine. Only 20% (95% CI: 17–22) were able to provide an estimation of outcome data (VAP rate) in their ICU, still 93% (95% CI: 91–94) agreed that “Monitoring of VAP-related measures stimulates quality improvement”. Results for 449 respondents from 61 countries not included in the European estimates are broadly comparable.

Conclusions

This study shows a low compliance with VAP prevention practices, as reported by ICU doctors in Europe and elsewhere, and identifies priorities for improvement.

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.

Essentials for selecting antimicrobial therapy for intra-abdominal infections

Intra-abdominal infection (IAI) is a complex disease entity in which different aspects must be balanced in order to select the proper antimicrobial regimen and determine duration of therapy. A current classification indicates different faces of peritonitis. Primary peritonitis implies an intact gastrointestinal tract without overt barrier disruption. Secondary peritonitis refers to localized or diffuse peritoneal inflammation and abscess formation due to disruption of the anatomical barrier. Tertiary peritonitis includes cases that cannot be solved by a single or even sequential surgical intervention, often in combination with sequential courses of antimicrobial therapy. The most frequently used classification distinguishes ‘uncomplicated’ and ‘complicated’ IAI. In uncomplicated IAI, the infectious process is contained within a single organ, without anatomical disruption. In complicated IAI, disease is extended, with either localized or generalized peritonitis. However, there exists more than a single dimension of complexity in IAI, including severity of disease expression through systemic inflammation. As the currently used classifications of IAI often incite confusion by mixing elements of anatomical barrier disruption, severity of disease expression and (the likelihood of) resistance involvement, we propose an alternative for the current widely accepted classification. We suggest abandoning the terms ‘uncomplicated’ and ‘complicated’ IAI, as they merely confuse the issue. Furthermore, the term ‘tertiary peritonitis’ should likewise be discarded, as this simply refers to treatment failure of secondary peritonitis resulting in a state of persistent infection and/or inflammation. Hence, anatomical disruption and disease severity should be separated into different phenotypes for the same disease in combination with either presence or absence of risk factors for involvement of pathogens that are not routinely covered in first-line antimicrobial regimens (Pseudomonas aeruginosa, enterococci, Candida species and resistant pathogens). Generally, these risk factors can be brought back to recent exposure to antimicrobial agents and substantial length of stay in healthcare settings (5–7 days). As such, we developed a grid based on the different components of the classification: (i) anatomical disruption; (ii) severity of disease expression; and (iii) either community-acquired/early-onset healthcare-associated origin or healthcare-associated origin and/or recent antimicrobial exposure. The grid allows physicians to define the index case of IAI in a more unequivocal way and to select the most convenient empirical antimicrobial regimens. The grid advises on the necessity of covering nosocomial Gram-negative bacteria (including P. aeruginosa), enterococci and yeasts. The basis of antimicrobial therapy for IAI is that both Gram-negative and anaerobic bacteria should always be covered.

In recent years, some newer agents such as doripenem, moxifloxacin and tigecycline have been added to the antimicrobial armamentarium for IAI. For patients in whom the source can be adequately controlled, antimicrobial therapy should be restricted to a short course (e.g. 3–7 days in peritonitis).

Alteration of cardiac progenitor cell potency in GRMD dogs

Among the animal models of Duchenne muscular dystrophy (DMD), the Golden Retriever muscular dystrophy (GRMD) dog is considered the best model in terms of size and pathological onset of the disease. As in human patients presenting with DMD or Becker muscular dystrophies (BMD), the GRMD is related to a spontaneous X-linked mutation of dystrophin and is characterized by myocardial lesions. In this respect, GRMD is a useful model to explore cardiac pathogenesis and for the development of therapeutic protocols. To investigate whether cardiac progenitor cells (CPCs) isolated from healthy and GRMD dogs may differentiate into myocardial cell types and to test the feasibility of cell therapy for cardiomyopathies in a preclinical model of DMD, CPCs were isolated from cardiac biopsies of healthy and GRMD dogs. Gene profile analysis revealed an active cardiac transcription network in both healthy and GRMD CPCs. However, GRMD CPCs showed impaired self-renewal and cardiac differentiation. Population doubling and telomerase analyses highlighted earlier senescence and proliferation impairment in progenitors isolated from GRMD cardiac biopsies. Immunofluorescence analysis revealed that only wt CPCs showed efficient although not terminal cardiac differentiation, consistent with the upregulation of cardiac-specific proteins and microRNAs. Thus, the pathological condition adversely influences the cardiomyogenic differentiation potential of cardiac progenitors. Using PiggyBac transposon technology we marked CPCs for nuclear dsRed expression, providing a stable nonviral gene marking method for in vivo tracing of CPCs. Xenotransplantation experiments in neonatal immunodeficient mice revealed a valuable contribution of CPCs to cardiomyogenesis with homing differences between wt and dystrophic progenitors. These results suggest that cardiac degeneration in dystrophinopathies may account for the progressive exhaustion of local cardiac progenitors and shed light on cardiac stemness in physiological and pathological conditions. Furthermore, we provide essential information that canine CPCs may be used to alleviate cardiac involvement in a large preclinical model of DMD.

Direct myocardial implantation of human embryonic stem cells in a dog model of Duchenne cardiomyopathy reveals poor cell survival in dystrophic tissue

Duchenne muscular dystrophy is characterized by progressive muscle weakness and early death resulting from dystrophin deficiency. Spontaneous canine muscular disorders are interesting settings to evaluate the relevance of innovative therapies in human using pre-clinical trials.

Burns, inhalation injury and ventilator-associated pneumonia: value of routine surveillance cultures

PURPOSE

Burn patients with inhalation injury are at particular risk for ventilator-associated pneumonia (VAP). Routine endotracheal surveillance cultures may provide information about the causative pathogen in subsequent VAP, improving antibiotic therapy. Our objective was to assess the incidence of VAP in burn patients with inhalation injury, and the benefit of routine surveillance cultures to predict multidrug resistant (MDR) pathogens.

PROCEDURES

Historical cohort (n=53) including all burn patients with inhalation injury requiring mechanical ventilation, admitted to the Ghent burn unit (2002-2010).

MAIN FINDINGS

Median (interquartile range) age and total burned surface area were 44y (39-55y) and 35% (19-50%). Overall, 70 episodes of VAP occurred in 46 patients (86.8%). Median mechanical ventilation days (MVD) prior to VAP onset were 7d (4-9d). The incidence was 55 episodes/1000 MVD. In 23 episodes (32.9%) at least one MDR causative pathogen was involved, mostly Pseudomonas aeruginosa and Enterobacter spp. The sensitivity and specificity of surveillance cultures to predict MDR etiology in subsequent VAP was respectively 83.0% and 96.2%. The positive and negative predictive value was 87.0% and 95.0%, respectively.

CONCLUSIONS

The incidence of VAP in burn patients with inhalation injury is high. In this cohort routine surveillance cultures had excellent operating characteristics to predict MDR pathogen involvement.