Both early-onset and late-onset ventilator-associated pneumonia are caused mainly by potentially multiresistant bacteria

Ventilator-associated pneumonia: pathobiological heterogeneity and diagnostic challenges

Ventilator-associated pneumonia (VAP) affects up to 20% of critically ill patients and induces significant antibiotic prescription pressure, accounting for half of all antibiotic use in the ICU. VAP significantly increases hospital length of stay and healthcare costs yet is also associated with long-term morbidity and mortality. The diagnosis of VAP continues to present challenges and pitfalls for the currently available clinical, radiological and microbiological diagnostic armamentarium. Biomarkers and artificial intelligence offer an innovative potential direction for ongoing future research. In this Review, we summarise the pathobiological heterogeneity and diagnostic challenges associated with VAP.

Using Methicillin-Resistant Staphylococcus aureus Nasal Screens to Rule Out Methicillin-Resistant S aureus Pneumonia in Surgical Intensive Care Units

INTRODUCTION

The methicillin-resistant Staphylococcus aureus (MRSA) polymerase chain reaction (PCR) has a high negative predictive value (NPV). We aimed to understand if there was a difference in the NPV of the MRSA screen in surgical intensive care units (ICUs) and to determine its role in antibiotic de-escalation.

METHODS

We performed a single-center, retrospective cohort study of adults with a positive respiratory culture and MRSA nasal PCR admitted to a surgical ICU from 2016 to 2019. Patients were stratified by surgical ICU: cardiothoracic/cardiovascular intensive care unit (CVICU) or transplant/acute care surgery intensive care unit (ACS-ICU). Our primary outcome was the NPV of MRSA screen. Secondary outcome was the duration of empiric MRSA-targeted therapy.

RESULTS

We analyzed 61 patients: 42.6% (n = 26) ACS-ICU and 57.4% (n = 35) CVICU. There were no differences in age, comorbidities, prior MRSA infection, recent antibiotic use, immunocompromised status, or renal replacement therapy. At pneumonia diagnosis, more patients in the ACS-ICU were hospitalized ≥5 d (65.4% versus 8.6%, P < 0.0001) and more patients in the CVICU were in septic shock (88.6% versus 34.5%, P < 0.0001) and thrombocytopenic (40% versus 11.5%, P = 0.02). NPV of the PCR was similar (ACS-ICU: 0.92 [0.75-0.98], CV-ICU 0.89 [0.73-0.96]). On multivariable linear regression, the CVICU was associated with longer empiric therapy (β 1.5, 95% CI 0.8-2.3, P < 0.0001), as was hospitalization for ≥5 d (β 0.73, 95% CI 0.06-1.39, P = 0.03).

CONCLUSIONS

The MRSA nasal PCR screen has a high NPV for ruling out MRSA pneumonia in critically ill surgical patients. However, patients in the CVICU and patients hospitalized ≥5 d had a longer time to de-escalation of MRSA-targeted therapy, potentially due to higher clinical risk profile.

Early-Onset Ventilator-Associated Pneumonia in Pediatric Severe Traumatic Brain Injury

BACKGROUND

Early-onset ventilator-associated pneumonia (VAP) is associated with poor outcomes in patients with severe traumatic brain injury (TBI). The primary aim of this study was to describe VAP, including the microbiology of VAP and differences in frequency of VAP when various definitions are applied. The secondary aim was to determine the clinical variables associated with the development of VAP in children with severe TBI.

METHODS

This is a retrospective cohort study at a quaternary referral children's hospital with a level I trauma center designation. Inclusion criteria were patients aged 0-18 years admitted to the pediatric intensive care unit between 2015 and 2020 with severe TBI requiring at least 2 days of invasive ventilation. VAP was defined by using Center of Disease Control (CDC) definition or clinical VAP, based on physician diagnosis. We compared general demographics, reviewed trauma and injury data, and outcomes to assess any differences between patients with VAP and non-VAP patients. Associations were tested with regression models.

RESULTS

After applying all inclusion and exclusion criteria, 90 patients were included in the analysis. Patients with VAP were older (8.5 vs. 5.6 years, P = 0.03). Patients with VAP were less likely to have suffered from abusive head trauma (P = 0.01). Patients who received continuous neuromuscular blockade or targeted temperature management did not have different frequencies of VAP. CDC-defined VAP was diagnosed in 27% of patients. Number of patients with VAP increased to 41% for physician-diagnosed or clinical VAP. Methicillin-sensitive Staphylococcus aureus was the most common isolate grown, followed by Hemophilus influenza, with most VAP occurring on days 2-5 of intubation. VAP was not associated with mortality but was associated with worse functional status scale in patients who survived to discharge (8 vs. 7.5, P = 0.048). Over a cumulative period of days, nebulized 3% and albuterol were associated with decreased incidence of VAP.

CONCLUSIONS

Ventilator-associated pneumonia occurs commonly in children with severe TBI, with rates of 27-41%, depending on CDC-defined VAP or clinical VAP. The discrepancy between clinical VAP and CDC-defined VAP further illustrates the need for a standardized definition for VAP. Although most interventions were not associated with VAP, nebulized 3% saline and albuterol were associated with reduced incidence of VAP; future investigation is needed to determine whether mucolytic agents can decrease the rate of VAP in children with severe TBI.

WNT9A Affects Late-Onset Acute Respiratory Distress Syndrome and 28-Day Survival: Evidence from a Three-Step Multiomics Study

Late-onset (more than 48 h after ICU admission) acute respiratory distress syndrome (ARDS) is associated with shorter survival time and higher mortality; however, the underlying molecular targets remain unclear. As the WNT gene family is known to drive inflammation, immunity, and tissue fibrosis, all of which are closely related to the pathogenesis and prognosis of ARDS, we aim to investigate the associations of the WNT family with late-onset ARDS and 28-day survival. Genetic (n = 380), epigenetic (n = 185), transcriptional (n = 160), and protein (n = 300) data of patients with ARDS were extracted from the MEARDS (Molecular Epidemiology of ARDS) cohort. We used sure independence screening to identify late onset-related genetic biomarkers and constructed a genetic score on the basis of eight SNPs, which was associated with risk for late-onset ARDS (odds ratio [OR], 2.72; P = 3.81 × 10-14) and survival (hazard ratio [HR], 1.28; P = 0.008). The associations were further externally validated in the iSPAAR (Identification of SNPs Predisposing to Altered Acute Lung Injury Risk) (ORlate onset, 2.49 [P = 0.006]; HRsurvival, 1.87 [P = 0.045]) and MESSI (Molecular Epidemiology of Severe Sepsis in the ICU) (ORlate onset, 4.12 [P = 0.026]; HRsurvival, 1.45 [P = 0.036]) cohorts. Furthermore, we functionally interrogated the six mapped genes of eight SNPs in the multiomics data and noted associations of WNT9A (WNT family member 9A) in epigenetic (ORlate onset, 2.95 [P = 9.91 × 10-4]; HRsurvival, 1.53 [P = 0.011]) and protein (ORlate onset, 1.42 [P = 0.035]; HRsurvival, 1.38 [P = 0.011]) data. The mediation analysis indicated that the effects of WNT9A on ARDS survival were mediated by late onset (HRindirect, 1.12 [P = 0.014] for genetic data; HRindirect, 1.05 [P = 0.030] for protein data). The essential roles of WNT9A in immunity and fibrosis may explain the different trajectories of recovery and dysfunction between early- and late-onset ARDS, providing clues for ARDS treatment.

Rate of Multidrug-resistance to Antimicrobial Drugs in Patients in Pediatric Neurointensive Care

Background

Multidrug-resistant (MDR) organisms in the critical care unit are a worldwide concern. The vulnerability to MDR infection in pediatric patients admitted in neurocritical care are due to altered mental status, immature immune system, higher risk of aspiration, and more frequent use of invasive devices. We aimed to measure the burden of MDR infection in pediatric neurosurgical intensive care unit (NSICU) patients.

Methods

All pediatric patients between 1 and 18 years for intracranial and spine surgeries admitted for more than 48 hours in NSICU were enrolled in the study. If patients showed a clinical picture of pneumonia, bloodstream infection (BSI), or urinary tract infection (UTI) after receiving mechanical ventilation or an indwelling device for at least 48 hours, samples of tracheal aspirates, urine, blood, and cerebrospinal fluid (CSF) were sent for microbiological culture. We noted the type of organism, MDR infection rate, and associated risk factors. Pearson Chi-squared test and Fisher's test were used for statistical analysis; p < 0.05 was considered statistically significant.

Results

A total of 274 pediatric patients were studied. In 1 year, there was a total of 1,790 patient days. The inclusive MDR infection rate was 17.3/1,000 patient days. Also, Klebsiella pneumoniae (38.7%) was the commonest MDR pathogen. The commonest source of infection was BSI (32.3%). The risk factors associated with MDR infections were the length of stay in NSICU, mechanical ventilation of more than 5 days, emergency surgery, respiratory and cardiac comorbidities, and poor nutrition status (p < 0.05).

Conclusion

The MDR infection rate in our study was 17.3/1,000 patient days in pediatric patients. Also, K. pneumonia e was found to be the commonest MDR pathogen. Bloodstream was the commonest source of infection.

How to cite this article

Patel S, Prabhakar H, Kapoor I. Rate of Multidrug-resistance to Antimicrobial Drugs in Patients in Pediatric Neurointensive Care. Indian J Crit Care Med 2023;27(1):67-72.

A Narrative Review on the Approach to Antimicrobial Use in Ventilated Patients with Multidrug Resistant Organisms in Respiratory Samples—To Treat or Not to Treat? That Is the Question

Multidrug resistant organisms (MDRO) are commonly isolated in respiratory specimens taken from mechanically ventilated patients. The purpose of this narrative review is to discuss the approach to antimicrobial prescription in ventilated patients who have grown a new MDRO isolate in their respiratory specimen. A MEDLINE and PubMed literature search using keywords “multidrug resistant organisms”, “ventilator-associated pneumonia” and “decision making”, “treatment” or “strategy” was used to identify 329 references as background for this review. Lack of universally accepted diagnostic criteria for ventilator-associated pneumonia, or ventilator-associated tracheobronchitis complicates treatment decisions. Consideration of the clinical context including signs of respiratory infection or deterioration in respiratory or other organ function is essential. The higher the quality of respiratory specimens or the presence of bacteremia would suggest the MDRO is a true pathogen, rather than colonization, and warrants antimicrobial therapy. A patient with higher severity of illness has lower safety margins and may require initiation of antimicrobial therapy until an alternative diagnosis is established. A structured approach to the decision to treat with antimicrobial therapy is proposed.

Risk Factors and Algorithms for the Empirical Treatment of Hospital-Acquired Pneumonia and Ventilator-Associated Pneumonia

Hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) continue to be major concerns for morbidity and mortality, especially in patients treated in the intensive care unit. With the rise in multidrug-resistant organisms, HAP and VAP treatment is challenged by the need for early appropriate treatment, with broad-spectrum agents, while still being aware of the principles of antibiotic stewardship. The two major society guidelines proposed a series of risk factors in their most recent guidelines to help identify patients who can most benefit from narrow- or broad-spectrum initial empiric antibiotic therapy. The guidelines reveal differences in the proposed risk factors and treatment approaches, as well as major similarities.

Effects of CNS Injury-Induced Immunosuppression on Pulmonary Immunity

Patients suffering from stroke, traumatic brain injury, or other forms of central nervous system (CNS) injury have an increased risk of nosocomial infections due to CNS injury-induced immunosuppression (CIDS). Immediately after CNS-injury, the response in the brain is pro-inflammatory; however, subsequently, local and systemic immunity is suppressed due to the compensatory release of immunomodulatory neurotransmitters. CIDS makes patients susceptible to contracting infections, among which pneumonia is very common and often lethal. Ventilator-acquired pneumonia has a mortality of 20–50% and poses a significant risk to vulnerable patients such as stroke survivors. The mechanisms involved in CIDS are not well understood. In this review, we consolidate the evidence for cellular processes underlying the pathogenesis of CIDS, the emerging treatments, and speculate further on the immune elements at play.

A comparison of diagnostic algorithms and clinical parameters to diagnose ventilator-associated pneumonia: a prospective observational study

Background

Suspicion and clinical criteria continue to serve as the foundation for ventilator-associated pneumonia (VAP) diagnosis, however the criteria used to diagnose VAP vary widely. Data from head-to-head comparisons of clinical diagnostic algorithms is lacking, thus a prospective observational study was performed to determine the performance characteristics of the Johanson criteria, Clinical Pulmonary Infection Score (CPIS), and Centers for Disease Control and Prevention’s National Healthcare Safety Network (CDC/NHSN) criteria as compared to Hospital in Europe Link for Infection Control through Surveillance (HELICS) reference standard.

Methods

A prospective observational cohort study was performed in three mixed medical-surgical ICUs from one academic medical center from 1 October 2016 to 30 April 2018. VAP diagnostic criteria were applied to each patient including CDC/NHSN, CPIS, HELICS and Johanson criteria. Tracheal aspirate cultures (TAC) and serum procalcitonin values were obtained for each patient.

Results

Eighty-five patients were enrolled (VAP 45, controls 40). Using HELICS as the reference standard, the sensitivity and specificity for each of the assessed diagnostic algorithms were: CDC/NHSN (Sensitivity 54.2%; Specificity 100%), CPIS (Sensitivity 68.75%; Specificity 95.23%), Johanson (Sensitivity 67.69%; Specificity 95%). The positive TAC rate was 81.2%. The sensitivity for positive TAC with the serum procalcitonin level > 0.5 ng/ml was 51.8%.

Conclusion

VAP remains a considerable source of morbidity and mortality in modern intensive care units. The optimal diagnostic method remains unclear. Using HELICS criteria as the reference standard, CPIS had the greatest comparative diagnostic accuracy, whereas the sensitivity of the CDC/NHSN was only marginally better than a positive TAC plus serum procalcitonin > 0.5 ng/ml. Algorithm accuracy was improved by adding serum procalcitonin > 0.5 ng/ml, but not positive quantitative TAC.

Trial Registration: Not indicated for this study type.

Antimicrobial Susceptibility among Pathogens Isolated in Early- versus Late-Onset Ventilator-Associated Pneumonia

Ventilator-associated pneumonia (VAP) is associated with increased hospital stay and high morbidity and mortality in critically ill patients. The aims of this study were to (i) determine the incidence of multidrug-resistant (MDR) pathogens in the first episodes of VAP and to assess potential differences in bacterial profiles of subjects with early- versus late-onset VAP. This was a retrospective cohort study over a period of 18 months including all patients who had a first episode of VAP confirmed by positive bacterial culture. Subjects were distributed into two groups according to the number of intubation days: early-onset VAP (<5 days) or late-onset VAP (≥5 days). The primary endpoint was the nature of causative pathogens and their resistance profiles. Sixty patients were included, 29 men and 31 women, with an average age of 38 ± 16 years. The IGS 2 at admission was 40.5 [32–44] and APACHE was 19 [15–22]. Monomicrobial infections were diagnosed in 77% of patients (n = 46). The most frequently isolated bacteria were A. baumannii, 53% (n = 32); P. aeruginosa in 37% (n = 22); Enterobacterales in 28% (n = 17) and S. aureus in 5% (n = 3). Ninety-seven percent of the bacteria were MDR. The VAP group comprised 36 (60%) episodes of early-onset VAP and 24 (40%) episodes of late-onset VAP. There was no significant difference in the distribution of the bacterial isolates, nor in terms of antibacterial resistances between early- and late-onset VAPs. Our data support recent observations that there is no microbiological difference in the prevalence of potential MDR pathogens or in their resistance profiles associated with early- versus late-onset VAPs, especially in countries with high rates of MDR bacteria.

Microorganisms and clinical outcomes of early- and late-onset ventilator-associated pneumonia at Srinagarind Hospital, a tertiary center in Northeastern Thailand

Background

Ventilator-associated pneumonia (VAP) is a common nocosomial infection in intensive care unit (ICU). Local microbiological surveillance of pathogens and resistance patterns for early-onset VAP (EOVAP) and late-onset VAP (LOVAP) will help to choose appropriate empiric antibiotics.

Objective

To compare the multi-drug resistant (MDR) pathogens, treatment outcomes, and factors associated with hospital mortality of VAP.

Method

A cross-sectional study between 1 January 2015 and 31 December 2017 at Srinagarind hospital, Khon Kaen University was conducted. The demographic data, causative pathogens, hospital length of stay (LOS), ICU LOS, mechanical ventilator (MV) days, and hospital mortality were retrospectively reviewed.

Results

One hundred and ninety patients were enrolled; 42 patients (22%) were EOVAP and 148 patients (78%) were LOVAP. Acinetobacter baumannii was the most common pathogen in both groups (50% EOVAP vs 52.7% LOVAP). MDR pathogens were significant greater in LOVAP (81.8%) than EOVAP (61.9%) (p = 0.007). The EOVAP had a significantly better ICU LOS [median (interquartile range, IQR) 20.0 (11.0, 30.0) vs. 26.5 (17.0, 43.0) days], hospital LOS [median (IQR) 26.5 (15.0, 44.0) vs. 35.5 (24.0, 56.0) days] shorter MV days [median (IQR) 14.0 (10.0, 29.0) vs. 23.0 (14.0, 35.5) days] and lower hospital mortality (16.7% vs 35.1%) than LOVAP (p < 0.05). The factor associated with hospital mortality was having simplified acute physiology (SAP) II score ≥ 40 with an adjusted odds ratio (aOR) of 2.22 [95% confidence interval (CI), 1.08–4.54, p = 0.02].

Conclusion

LOVAP had significantly higher MDR pathogens, MV days, ICU LOS, hospital LOS and hospital mortality than EOVAP. A broad-spectrum antibiotic to cover MDR pathogens should be considered in LOVAP. The factor associated with hospital mortality of VAP was a SAPII score ≥ 40.

Potential Impact of Hospital-acquired Pneumonia Guidelines on Empiric Antibiotics. An Evaluation of 113 Veterans Affairs Medical Centers

Rationale: The 2016 guidelines for hospital-acquired pneumonia (HAP) suggest applying a universal antibiogram resistance threshold in addition to patient criteria to determine empiric coverage. The impact of these recommendations is unknown.Objectives: 1) Describe national antibiotic use and microbiology patterns for HAP among patients with noninfectious admissions, 2) measure the predictive performance of the antibiogram threshold and risk factors, and 3) estimate the change in practice with guideline implementation.Methods: We conducted a retrospective analysis of all hospitalizations without initial infection but with secondary pneumonia diagnoses at Veterans Affairs Medical Centers between October 1, 2012, and September 30, 2015. For each hospitalization we extracted: presence of methicillin-resistant Staphylococcus aureus (MRSA) and resistant gram-negative rods (R-GNR) in cultures, anti-MRSA and antipseudomonal antimicrobial administration, and facility-level prevalence of MRSA and R-GNR. We calculated the percentage of hospitalizations with resistant organisms, broad-spectrum antibiotics, and the predictive performance of patient characteristics and prevalence thresholds for MRSA.Results: Among 3,562 cases, 5.17% were positive for MRSA and 2.30% for R-GNR. The recommended MRSA prevalence threshold was 100.00% sensitive (95% confidence interval [CI], 98.02-100.00%) and 0.03% specific (95% CI, 0.00-0.16%) for MRSA-positive culture, leading to overtreatment of 94.81% (95% CI, 94.02-95.50%) of patients. Pressor order (odds ratio [OR], 3.89; 95% CI, 1.17-12.91) and intravenous antibiotics within the past 90 days (OR, 1.98; 95% CI, 1.03-3.81) were associated with MRSA. Mechanical ventilation was associated with R-GNR (OR, 4.37; 95% CI, 1.52-12.57).Conclusions: The guideline-recommended antibiogram threshold and characteristics did not improve prediction of MRSA or R-GNR and would have led to an increase in MRSA treatment.

The Current Epidemiological Landscape of Ventilator-associated Pneumonia in the Intensive Care Unit: A Multicenter Prospective Observational Study in China

Background

Ventilator-associated pneumonia (VAP) is among the most important hospital-acquired infections in the intensive-care unit setting. However, clinical data regarding the epidemiology of VAP in China are limited.

Methods

A multicenter, longitudinal, observational study was performed from March 2013 to December 2015 to prospectively collect data on patients diagnosed with VAP. Specifically, patients supported by invasive mechanical ventilation for longer than 48 hours were included. Clinical data were recorded for each VAP patient. The exact pathogen distribution and the incidence of VAP were calculated. Risk factors associated with mortality were analyzed using univariate and multivariate regression analyses.

Results

A total of 2492 patients received mechanical ventilation for longer than 48 hours and were enrolled in the study. A total of 129 (5.0%) patients fulfilled the VAP criteria, and 38 (29.5%) patients were diagnosed with early-onset VAP. The incidence of VAP was 4.5 per 1000 ventilation days, with a 28-day mortality rate of 45%. Individual pathogens, including 115 bacteria and 2 fungi, were identified in 117 (90.7%) enrollees, and 87 (75.7%) bacteria were multidrug-resistant organisms. Acinetobacter baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa were the most commonly detected pathogens causing VAP. No difference in the distribution of pathogens was observed between early- and late-onset VAP or between surviving and non-surviving patients. Multivariate regression revealed that older ages and Sequential Organ Failure Assessment Scores were correlated with increased 28-day mortality rates.

Conclusions

High pathogen resistance and mortality were found in both early- and late-onset VAP.

Clinical Trials Registration

NCT01943331.

Emerging trends of nosocomial pneumonia in intensive care unit of a tertiary care public teaching hospital in Western India

BACKGROUND

Nosocomial pneumonia poses great challenge to an intensivist. Detailed information about hospital-acquired pneumonia (HAP) and ventilator-acquired pneumonia (VAP) is crucial for prevention and optimal management, thus improving quality Intensive Care Unit (ICU) care. Hence, we aimed to study the current trend of nosocomial pneumonia in ICU.

MATERIALS AND METHODS

It was a prospective observational cohort study, conducted in the ICU of a tertiary care teaching public hospital over a period of 18 months. We studied clinical profile and outcome of 120 adult patients who developed VAP/HAP during the study period. We also analyzed the causative organisms, antibiotic sensitivity, and resistance pattern in these patients.

RESULTS

Out of 120 patients, 29 patients were HAP and 91 patients were VAP. Mortality was 60% (72), and development of VAP and requirement of mechanical ventilation showed significant association with mortality (P < 0.00001). Most common organism causing HAP was Staphylococcus aureus (43.4%) and VAP was Klebsiella pneumoniae (49%). Maximum antibiotic sensitivity was found to piperacillin + tazobactam (58.8%), followed by imipenem (49.5%) and meropenem (41.8%), whereas maximum antibiotic resistance was found to cefepime (95.1%), followed by ceftazidime and amoxicillin (91.2%).

CONCLUSION

Nosocomial pneumonia showed high incidence (17.44%) and mortality (60%). Common organisms identified were S. aureus and K. pneumoniae. Resistance was high for commonly used antibiotics and high antibiotic sensitivity for piperacillin + tazobactam and carbapenem. Contexte: La pneumonie nosocomiale pose un grand défi à un intensiviste. Des informations détaillées sur la pneumonie acquise dans les hôpitaux (HAP) et la pneumonie acquise par le ventilateur (VAP) sont essentielles pour la prévention et la gestion optimale, améliorant ainsi les soins de soins intensifs de qualité (UTI). Par conséquent, nous avons cherché à étudier la tendance actuelle de la pneumonie nosocomiale en UTI. Matériaux et méthodes: il s'agissait d'une étude de cohorte observationnelle prospective menée dans l'UCI d'un hôpital public d'enseignement tertiaire sur une période de 18 mois. Nous avons étudié le profil clinique et le résultat de 120 patients adultes qui ont développé le VAP / HAP pendant la période d'étude. Nous avons également analysé les organismes responsables, la sensibilité aux antibiotiques et le modèle de résistance chez ces patients. Résultats: Sur 120 patients, 29 patients étaient HAP et 91 patients étaient VAP. La mortalité était de 60% (72), et le développement du VAP et l'exigence de ventilation mécanique ont montré une association significative avec la mortalité (P < 0,00001). L'organisme le plus fréquent causant HAP était Staphylococcus aureus (43,4%) et VAP était Klebsiella pneumoniae (49%). Une sensibilité antibiotique maximale a été observée chez la pipéracilline + tazobactam (58,8%), suivie de l'imipénème (49,5%) et du méropénem (41,8%), alors que la résistance antibiotique maximale a été observée à cefépime (95,1%), suivie de ceftazidime et de l'amoxicilline (91,2%) .

CONCLUSION

la pneumonie nosocomiale a montré une incidence élevée (17,44%) et la mortalité (60%). Les organismes communs identifiés étaient S. aureus et K. pneumoniae. La résistance était élevée pour les antibiotiques couramment utilisés et une forte sensibilité aux antibiotiques pour la pipéracilline + le tazobactam et le carbapénème.

Respective impact of implementation of prevention strategies, colonization with multiresistant bacteria and antimicrobial use on the risk of early- and late-onset VAP: An analysis of the OUTCOMEREA network

Rationale

The impact of prevention strategies and risk factors for early-onset (EOP) versus late-onset (LOP) ventilator-associated pneumonia (VAP) are still debated.

Objectives

To evaluate, in a multicenter cohort, the risk factors for EOP and LOP, as the evolution of prevention strategies.

Methods

7,784 patients with mechanical ventilation (MV) for at least 48 hours were selected into the multicenter prospective OUTCOMEREA database (1997–2016). VAP occurring between the 3^rd and 6^th day of MV defined EOP, while those occurring after defined LOPs. We used a Fine and Gray subdistribution model to take the successful extubation into account as a competing event.

Measurements and main results

Overall, 1,234 included patients developed VAP (EOP: 445 (36%); LOP: 789 (64%)). Male gender was a risk factor for both EOP and LOP. Factors specifically associated with EOP were admission for respiratory distress, previous colonization with multidrug-resistant Pseudomonas aeruginosa, chest tube and enteral feeding within the first 2 days of MV. Antimicrobials administrated within the first 2 days of MV were all protective of EOP. ICU admission for COPD exacerbation or pneumonia were early risk factors for LOP, while imidazole and vancomycin use within the first 2 days of MV were protective factors. Late risk factors (between the 3^rd and the 6^th day of MV) were the intra-hospital transport, PAO2-FIO2<200 mmHg, vasopressor use, and known colonization with methicillin-resistant Staphylococcus aureus. Among the antimicrobials administered between the 3^rd and the 6^th day, fluoroquinolones were the solely protective one.Contrarily to LOP, the risk of EOP decreased across the study time periods, concomitantly with an increase in the compliance with bundle of prevention measures.

Conclusion

VAP risk factors are mostly different according to the pneumonia time of onset, which should lead to differentiated prevention strategies.

Management of mechanical ventilation in patients with hospital-acquired pneumonia: A retrospective, observational study

BACKGROUND

Hospital-acquired pneumonia (HAP) in intensive care patients is a frequent reason for mechanical ventilation (MV). The management of MV and ventilator weaning vary, depending on the type of lung inflammation. This retrospective, observational study screened the data from all patients admitted to the intensive care unit (ICU) of the Department of Anaesthesiology and Intensive Care Medicine, Faculty of Medicine and Dentistry, Palacky University Olomouc between 2011 and 2016. The aims were to determine the parameters of pressure-controlled ventilation, the frequencies of tracheostomy, bronchoscopy, reconnection to MV, the length of ICU and hospital stay and the mortality in subgroups with early-/late-onset HAP compared to a subgroup with community-acquired pneumonia (CAP) and patients with MV without pneumonia. The primary outcome of this study was MV length.

RESULTS

Over the study period, a total of 2672 patients were hospitalised. Excluded were 137 organ donors, 66 patient without MV and 20 patients placed on volume-controlled ventilation. The cohort comprised 2.447 patients requiring MV. A total of 1.927 patients (78.7%) were indicated for MV without signs of pneumonia. CAP was diagnosed in 131 patients (5.4%). The criteria for HAP were met by 389 patients (16.0%). Early-onset and late-onset HAP was diagnosed in 63 (2.6%) and 326 (13.3%) patients, respectively. In the subgroups without pneumonia, with CAP, early- and late-onset HAP, the median MV times were 3, 6, 6 and 12 days, respectively, and the median peak inspiratory pressure (Pinsp) of MV was 20, 25, 25 and 27 cm H₂O, respectively. The median positive end-expiratory pressure (PEEP) was 5, 8, 8 and 11 cm H₂O, respectively. The median inspired oxygen concentrations (FiO₂) were 0.45, 0.7, 0.7 and 0.8, respectively. The median length of hospital stays was 8, 15, 15 and 17 days. The mortality rates were 11.4%, 3.8%, 9.5% and 31.3%, respectively.

CONCLUSIONS

During MV, the late-onset HAP subgroup was shown to have the highest Pinsp, PEEP and FiO₂, the longest MV time, ICU and hospital stay, the highest frequency of tracheostomy, reconnection to MV, pulmonary hygiene bronchoscopy and the highest mortality compared to the early-onset HAP and CAP subgroups. The lowest values were found in the mechanically ventilated patients without pneumonia. The differences were due to the severity of lung damage that is graduated from CAP over early-onset HAP after late-onset HAP.

Controversies and advances in the management of ventilator associated pneumonia

INTRODUCTION

Although national surveillance data suggests that the incidence of ventilator associated pneumonia (VAP) is down-trending, it remains one of the most commonly encountered hospital acquired infections in the United States and worldwide. Its association with increased healthcare costs and worsened patient outcomes warrants continued effort to improve the care of patients with VAP. Areas covered: The increasing prevalence of multi-drug resistant bacteria further drives the need to explore advances in diagnostic and treatment options. In this review, controversies pertaining to the definition and diagnosis of VAP as well as empiric treatment strategies will be discussed along with several developments related to rapid microbiologic testing methods and the use of non-traditional antimicrobial agents. Expert commentary: The application of rapid diagnostic techniques to identify microbial pathogens is perhaps one of the most impactful advancements in the treatment of serious nosocomial infections. This technology has the potential to reduce inappropriate initial antimicrobial therapy, unnecessary antimicrobial exposure, and mortality in patients with VAP. In addition, the anticipated approval of new antimicrobial agents within the next several years will provide a much-needed expansion of available treatment options in an era of growing antimicrobial resistance.

Significant Publications on Infectious Diseases Pharmacotherapy in 2016

PURPOSE

This is a summary of the most important articles on infectious diseases (ID) pharmacotherapy published in peer-reviewed literature in 2016 as selected by clinical pharmacists with ID expertise.

SUMMARY

The Houston Infectious Diseases Network (HIDN) was asked to identify articles published in peer-reviewed literature in 2016 that were believed to contribute significantly to ID pharmacotherapy, including human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS). A list of 46 articles on general ID pharmacotherapy and 8 articles on HIV/AIDS were nominated. Members of the Society of Infectious Diseases Pharmacists (SIDP) were surveyed to select 10 general ID articles believed to have made a significant impact on general ID pharmacotherapy and 1 article most significant to HIV/AIDS pharmacotherapy. Of 445 SIDP members surveyed, 212 (47.6%) and 95 (21.3%) members voted for general ID pharmacotherapy- and HIV/AIDS-related articles, respectively. The 11 highest-ranked papers (10 general ID-related articles and 1 HIV/AIDS-related article) are summarized here.

CONCLUSION

With the large number of ID-related articles published each year, it can be challenging to stay current with the most relevant ID publications. This review of significant publications in 2016 may provide a starting point for that process.

Microbial Etiology of Pneumonia: Epidemiology, Diagnosis and Resistance Patterns

Globally, pneumonia is a serious public health concern and a major cause of mortality and morbidity. Despite advances in antimicrobial therapies, microbiological diagnostic tests and prevention measures, pneumonia remains the main cause of death from infectious disease in the world. An important reason for the increased global mortality is the impact of pneumonia on chronic diseases, along with the increasing age of the population and the virulence factors of the causative microorganism. The increasing number of multidrug-resistant bacteria, difficult-to-treat microorganisms, and the emergence of new pathogens are a major problem for clinicians when deciding antimicrobial therapy. A key factor for managing and effectively guiding appropriate antimicrobial therapy is an understanding of the role of the different causative microorganisms in the etiology of pneumonia, since it has been shown that the adequacy of initial antimicrobial therapy is a key factor for prognosis in pneumonia. Furthermore, broad-spectrum antibiotic therapies are sometimes given until microbiological results are available and de-escalation cannot be performed quickly. This review provides an overview of microbial etiology, resistance patterns, epidemiology and microbial diagnosis of pneumonia.

Management of Adults With Hospital-acquired and Ventilator-associated Pneumonia: 2016 Clinical Practice Guidelines by the Infectious Diseases Society of America and the American Thoracic Society

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.These guidelines are intended for use by healthcare professionals who care for patients at risk for hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP), including specialists in infectious diseases, pulmonary diseases, critical care, and surgeons, anesthesiologists, hospitalists, and any clinicians and healthcare providers caring for hospitalized patients with nosocomial pneumonia. The panel's recommendations for the diagnosis and treatment of HAP and VAP are based upon evidence derived from topic-specific systematic literature reviews.

Case fatality rate related to nosocomial and ventilator-associated pneumonia in an ICU: a single-centre retrospective cohort study

BACKGROUND

Nosocomial pneumonia (NP) and ventilator associated pneumonia (VAP) have been associated with financially significant economic burden and increased case fatality rate in adult intensive care units (ICUs). This study was designed to evaluate case fatality rate among patients with NP and VAP in a respiratory ICU.

METHODS

In 2008-2013, VAP and NP in the ICUs were included in this retrospective single-centre cohort study. Data on demographics, co-morbidities, severity of illness, mechanical ventilation, empirical treatment, length of hospital stay and laboratory findings were recorded in each group, as were case fatality rate during ICU admission and after discharge including short-term (28-day) and long-term (a year) case fatality rate.

RESULTS

A total of 108 patients with VAP (n = 64, median (IQR) age: 70 (61-75) years, 67.2% were men) or NP (n = 44, median (IQR) age: 68 (62-74) years, 68.2% were men) were found. Appropriate empirical antibiotic therapy was identified only in 45.2 and 42.9% of patients with VAP and NP, respectively. Overall case fatality rate in VAP and NP (81.3 vs 84.1), ICU case fatality rate (42.2 vs 45.5%), short-term case fatality rate (15.6 vs 27.3%) and long-term case fatality rate (23.4 vs 11.4%) were similar between VAP and NP groups along with occurrence 50% of case fatality rate cases in the first 2 months and 90% within the first year of discharge. Multivariate analysis showed that chronic obstructive pulmonary disease (COPD) (HR: 3.15, 95% CI: 1.06-9.38; p = 0.039) and presence of septic shock (HR: 3.83, 95% CI: 1.26-11.60; p = 0.018) were independently associated with lower survival.

CONCLUSION

In conclusion, our findings in a retrospective cohort of respiratory ICU patients with VAP or NP revealed high ICU, short- and long-term case fatality rates within 1 year of diagnosis, regardless of the diagnosis of NP after 48 h of initial admission or after induction of ventilator support. COPD and presence of septic shock are associated with high fatality rate and our findings speculate that as increasing compliance with infection control programs and close monitoring especially in 2 months of discharge might reduce high-case fatality rate in patients with VAP and NP.

Empirical antibiotic therapy for pneumonia in intensive care units: a multicentre, retrospective analysis of potentially pathogenic microorganisms identified by endotracheal aspirates cultures

The purpose of this investigation was to explore the presumed relationship between the days of hospitalisation and microorganisms identified by endotracheal aspirate cultures in relation to adequate empirical treatment strategies of pneumonia in the intensive care unit (ICU). All potentially pathogenic microorganisms identified by (surveillance) cultures of endotracheal aspirates obtained in the ICUs of two Dutch teaching hospitals in 2007 and 2012 were retrospectively collected and analysed. Antibiotic susceptibilities to 11 antibiotics were calculated for several time points (days or weeks) after hospital admission and expressed per patient-day. In total, 4184 potentially pathogenic microorganisms identified in 782 patients were analysed. Prevalence of the classic early-onset pneumonia-causing microorganisms decreased from 55 % on the first four days to 34 % on days 4–6 after hospital admission (p < 0.0001). Susceptibility to amoxicillin/clavulanic acid was below 70 % on all days. Except for days 0 and 12, susceptibility to ceftriaxone was below 80 %. The overall susceptibility to piperacillin/tazobactam was 1518/1973 (77 %) in 2007 vs. 727/1008 (67 %) in 2012 (p < 0.0001). After day 8 of hospital admission, susceptibility to piperacillin/tazobactam therapy was below 80 % in 2012. After one week of hospital admission, susceptibilities to antibiotics were lower in the hospital that included that antibiotic in the local empirical treatment protocols as compared to the hospitals in which that antibiotic was not or infrequently included: 90/434 (21 %) vs. 117/398 (29 %); p = 0.004 for amoxicillin/clavulanic acid and 203/433 (47 %) vs. 253/398 (64 %); p < 0.001 for ceftriaxone. No cut-off in the number of days after hospital admission could be identified to distinguish early-onset from late-onset pneumonia. Consequently, the choice of empirical antibiotics should probably not be based on the time of onset.

Risk factors for ventilator-associated pneumonia in patients with severe traumatic brain injury in a Serbian trauma centre

INTRODUCTION

The aims of this study were (1) to assess the incidence of ventilator-associated pneumonia (VAP) in patients with traumatic brain injury (TBI), (2) to identify risk factors for developing VAP, and (3) to assess the prevalence of the pathogens responsible.

PATIENTS AND METHODS

The following data were collected prospectively from patients admitted to a 24-bed intensive care unit (ICU) during 2013/14: the mechanism of injury, trauma distribution by system, the Acute Physiology and Chronic Health Evaluation (APACHE) II score, the Abbreviated Injury Scale (AIS) score, the Injury Severity Score (ISS), underlying diseases, Glasgow Coma Scale (GCS) score, use of vasopressors, need for intubation or cardiopulmonary resuscitation upon admission, and presence of pulmonary contusions. All patients were managed with a standardized protocol if VAP was suspected. The Sequential Organ Failure Assessment (SOFA) score and the Clinical Pulmonary Infection Score (CPIS) were measured on the day of VAP diagnosis.

RESULTS

Of the 144 patients with TBI who underwent mechanical ventilation for >48h, 49.3% did not develop VAP, 24.3% developed early-onset VAP, and 26.4% developed late-onset VAP. Factors independently associated with early-onset VAP included thoracic injury (odds ratio (OR) 8.56, 95% confidence interval (CI) 2.05-35.70; p=0.003), ISS (OR 1.09, 95% CI 1.03-1.15; p=0.002), and coma upon admission (OR 13.40, 95% CI 3.12-57.66; p<0.001). Age (OR 1.04, 95% CI 1.02-1.07; p=0.002), ISS (OR 1.09, 95% CI 1.04-1.13; p<0.001), and coma upon admission (OR 3.84, 95% CI 1.44-10.28; p=0.007) were independently associated with late-onset VAP (Nagelkerke r(2)=0.371, area under the curve (AUC) 0.815, 95% CI 0.733-0.897; p<0.001). The 28-day survival rate was 69% in the non-VAP group, 45.7% in the early-onset VAP group, and 31.6% in the late-onset VAP group. Acinetobacter spp was the most common pathogen in patients with early- and late-onset VAP.

CONCLUSIONS

These results suggest that the extent of TBI and trauma of other organs influences the development of early VAP, while the extent of TBI and age influences the development of late VAP. Patients with early- and late-onset VAP harboured the same pathogens.

Risks for multidrug-resistant pathogens in the ICU

PURPOSE OF REVIEW

The impact of multidrug-resistant organisms (MDROs) is rising and often underestimated. The epidemiology of MDROs is extremely complex and multifactorial. There is increasing antibiotic resistance, mainly related to antibiotic pressure and patients' characteristics.

RECENT FINDINGS

Emphasis on MDRO epidemiology is needed to better understand current strategies of prevention and management. Among them, antibiotic stewardship has been one of the most successful strategies. It is important to note that there is a controversial issue when considering community and healthcare-related infections. In addition, different strategies have been determined to find the impact and optimal use of recently launched antibiotics for MDRO treatment.

SUMMARY

Infections with MDROs can prolong hospital stay, promote antibiotic use and prolong duration of mechanical ventilation. Some points should be further explored in clinical research such as the heterogeneity of healthcare-associated pneumonia and the need of new drug development. Resistance to non fermentative Gram-negative bacilli, rising minimum inhibitory concentration in methicillin-resistant Staphylococcus aureus and spread of MDROs in patients without known risk factors suggest a review of guideline validation, taking into account ecology and severity of patient illness to provide timely and appropriate empiric therapy.

Early-onset pneumonia after out-of-hospital cardiac arrest

Early-onset pneumonia (EOP) is a common complication after successful cardiopulmonary resuscitation. Currently, EOP diagnosis is difficult because usual diagnostic tools are blunted by the features of post-cardiac arrest syndrome and therapeutic hypothermia itself. When the diagnosis of EOP is suspected, empiric antimicrobial therapy should be considered following bronchopulmonary sampling. The onset of EOP increases the length of mechanical ventilation duration and intensive care unit stay, but its influence on survival and neurological outcome seems marginal. Therapeutic hypothermia has been recognized as an independent risk factor for this infectious complication. All together, these observations underline the need for future prospective clinical trials to better delineate pathogens and risk factors associated with EOP. In addition, there is a need for diagnostic approaches serving the accurate diagnosis of EOP.

Pathogens in Early-Onset and Late-Onset Intensive Care Unit–Acquired Pneumonia

Objectives.

To compare the type of pathogens isolated from patients with early-onset intensive care unit (ICU)-acquired pneumonia with those isolated from patients with late-onset ICU-acquired pneumonia and to study risk factors for the isolation of pathogens that are potentially resistant to multiple drugs.

Design.

Prospective cohort study.

Setting.

Patients admitted to the ICU of a 677-bed, university-affiliated teaching hospital in Belgium during 1997-2002.

Methods.

ICU-acquired pneumonia was defined as a case of pneumonia that occurred 2 days or more after admission to the ICU in combination with a positive results of radiologic analysis, clinical signs and symptoms, and a positive culture result. All cases of pneumonia were categorized as either early onset (within 7 days after admission) and late onset (7 days or more after admission), with or without previous antibiotic treatment, and the corresponding pathogens were analyzed. Risk factors for the isolation of pathogens potentially resistant to multiple drugs (ie, Pseudomonas aeruginosa, Serratia marcescens, Enterobacter species, Morganella morganii, methicillin-resistant Stapylococcus aureus, Citrobacter species, Acinetobacter species, Burkholderia species, extended-spectrum β-lactamase–producing pathogens, and Stenotrophomonas maltophilia) were analyzed using logistic regression analysis.

Results.

A total of 4,200 patients stayed at the ICU for 2 or more days, 298 of whom developed ICU-acquired pneumonia, for an overall incidence of 13 cases (95% confidence interval [CI], 11-14 cases) per 1,000 ICU-days. Pathogens potentially resistant to multiple drugs were isolated from 52% of patients with early-onset pneumonia. Risk factors for the isolation of these pathogens were greater age and previous receipt of antibiotic prophylaxis (adjusted odds ratio [aOR], 4.6 [95% CI, 1.6-13.0]) or antibiotic therapy (aOR, 8.2 [95% CI, 2.8-23.8]). The length of ICU admission and hospital stay were weaker risk factors for the isolation of these pathogens.

Conclusions.

Pathogens potentially resistant to multiple drugs were isolated in 52% of cases of early-onset ICU-acquired pneumonia. Previous antibiotic use (both prophylactic and therapeutic) is the main risk factor for the isolation of these pathogens.

Microbiology of Ventilator–Associated Pneumonia Compared With That of Hospital-Acquired Pneumonia

Objective.

Nosocomial pneumonia is the leading cause of mortality attributed to nosocomial infection. Appropriate empirical therapy has been associated with improved survival, but data are limited regarding the etiologic agents of hospital-acquired pneumonia in non-ventilated patients (HAP). This evaluation assessed whether the currently recommended empirical therapy is appropriate for both ventilator-associated pneumonia (VAP) and HAP by evaluating the infecting flora.

Design.

Prospectively collected hospitalwide surveillance data was obtained by infection control professionals using standard Centers for Disease Control and Prevention definitions.

Setting.

A tertiary care academic hospital.

Patients.

All patients admitted from 2000 through 2003.

Results.

A total of 588 episodes of pneumonia were reported in 556 patients: 327 episodes of VAP in 309 patients, and 261 episodes of HAP in 247 Patients. The infecting flora in ventilated patients included gram-positive cocci (32.0% [oxacillin-susceptible Staphylococcus aureus {OSSA}, 9.25%; oxacillin-resistant Staphylococcus aureus {ORSA}, 17.75%]), gram-negative bacilli (59.0% {Pseudomonas aeruginosa, 17.50%; Stenotrophomonas maltophilia, 6.75%; Acinetobacter species, 7.75%), and miscellaneous pathogens (9.0%). The infecting flora in nonventilated patients included gram-positive cocci (42.59% [OSSA, 13.33%; ORSA, 20.37%]), gram-negative bacilli (39.63% [P. aeruginosa, 9.26%; S. maltophilia, 1.11%; Acinetobacter species, 3.33%), and miscellaneous pathogens (17.78%).

Conclusions.

Our data demonstrated that patients with HAP, compared with those with VAP, had a similar frequency of infection with ORSA but less commonly had infections due to P. aeruginosa, Acinetobacter species, and S. maltophilia. However, the overall frequency of infection with these pathogens was sufficiently high to warrant the use of empirical therapy likely to be active against them. Our data supports using the currently recommended empirical therapy for both HAP and VAP.

Ventilator-associated pneumonia: present understanding and ongoing debates

INTRODUCTION

Ventilator-associated pneumonia (VAP) is a common cause of nosocomial infection, and is related to significant utilization of health-care resources. In the past decade, new data have emerged about VAP epidemiology, diagnosis, treatment and prevention.

RESULTS

Classifying VAP strictly based on time since hospitalization (early- and late-onset VAP) can potentially result in undertreatment of drug-resistant organisms in ICUs with a high rate of drug resistance, and overtreatment for patients not infected with resistant pathogens. A combined strategy incorporating diagnostic scoring systems, such as the Clinical Pulmonary Infection Score (CPIS), and either a quantitative or qualitative microbiological specimen, plus serial measurement of biomarkers, leads to responsible antimicrobial stewardship. The newly proposed ventilator-associated events (VAE) surveillance definition, endorsed by the Centers for Disease Control and Prevention, has low sensitivity and specificity for diagnosing VAP and the ability to prevent VAE is uncertain, making it a questionable surrogate for the quality of ICU care. The use of adjunctive aerosolized antibiotic treatment can provide high pulmonary concentrations of the drug and may facilitate shorter durations of therapy for multi-drug-resistant pathogens. A group of preventive strategies grouped as a 'ventilator bundle' can decrease VAP rates, but not to zero, and several recent studies show that there are potential barriers to implementation of these prevention strategies.

CONCLUSION

The morbidity and mortality related to VAP remain high and, in the absence of a gold standard test for diagnosis, suspected VAP patients should be started on antibiotics based on recommendations per the 2005 ATS guidelines and knowledge of local antibiotic susceptibility patterns. Using a combination of clinical severity scores, biomarkers, and cultures might help with reducing the duration of therapy and achieving antibiotic de-escalation.

How to treat VAP due to MDR pathogens in ICU patients

Background

The increasing occurrence of multidrug resistant (MDR) bacteria arises at a time when there is a lack of antibiotics active against these pathogens and few new antimicrobials are in the pipelines of the pharmaceutical industry. Treatment of ventilator-associated pneumonia (VAP) caused especially by MDR Gram-negative bacilli (GNB) represents a real challenge due to the dearth of treatment options.

Methods

We searched the medical literature relevant about management of ventilator-associated pneumonia caused by multi-drug resistant pathogens including GNB and methicillin-resistant S. aureus.

Results

Empirical therapy should be prescribed based on the local pattern of susceptibilities. Colistin and tigecycline are in many cases the unique options for the treatment of many episodes of VAP caused by MDR-GNB. Tigecyline (not licensed for treatment of pneumonia) should be used with an initial bolus of 200 mg followed by 100 mg every 12 h. The need for a loading dose and the administration of high doses of colistin (9 million IU/day in two or three doses) is currently accepted. Vancomycin has been considered the treatment of choice for pneumonia due to MRSA although linezolid may provide higher rate of clinical cure for MRSA VAP with a good safety profile. The initial antibiotic treatment must be reassessed and simplify in accordance of culture results.

Conclusions

Empirical treatment of VAP due to MDR pathogens should be based on knowledge of local ecology. A strategy combining early high doses of effective agents with subsequent simplification in the light of microbiologic information is recommended.

Resistance patterns and outcomes in intensive care unit (ICU)-acquired pneumonia. Validation of European Centre for Disease Prevention and Control (ECDC) and the Centers for Disease Control and Prevention (CDC) classification of multidrug resistant organisms

INTRODUCTION

Bacterial resistance has become a major public health problem.

OBJECTIVE

To validate the definition of multidrug-resistant organisms (MDRO) based on the European Centre for Disease Prevention and Control (ECDC) and the Centers for Disease Control and Prevention (CDC) classification.

MATERIAL

Prospective, observational study in six medical and surgical Intensive-Care-Units (ICU) of a University hospital.

RESULTS

Three-hundred-and-forty-three patients with ICU-acquired pneumonia (ICUAP) were prospectively enrolled, 140 patients had no microbiological confirmation (41%), 82 patients (24%) developed ICUAP for non-MDRO, whereas 121 (35%) were MDROs. Non-MDRO, MDRO and no microbiological confirmation patients did not present either a significant different previous antibiotic use (p 0.18) or previous hospital admission (p 0.17). Appropriate antibiotic therapy was associated with better ICU survival (105 [92.9%] vs. 74 [82.2%]; p = 0.03). An adjusted multivariate regression logistic analysis identified that only MDRO had a higher ICU-mortality than non-MDRO and no microbiological confirmation patients (OR 2.89; p < 0.05; 95% CI for Exp [β]. 1.02-8.21); Patients with MDRO ICUAP remained in ICU for a longer period than MDRO and no microbiological confirmation respectively (p < 0.01) however no microbiological confirmation patients had more often antibiotic consumption than culture positive ones.

CONCLUSIONS

Patients who developed ICUAP due to MDRO showed a higher ICU-mortality than non-MDRO ones and use of ICU resources. No microbiological confirmation patients had more often antibiotic consumption than culture positive patients. Risk factors for MDRO may be important for the selection of initial antimicrobial therapy, in addition to local epidemiology.

Ventilator-associated pneumonia in a tertiary care intensive care unit: Analysis of incidence, risk factors and mortality

Background:

Ventilator-associated pneumonia (VAP) is the most common nosocomial infection diagnosed in the intensive care unit (ICU) and in spite of advances in diagnostic techniques and management it remains a common cause of hospital morbidity and mortality.

Objective:

The primary objective of the following study is to determine the incidence, various risk factors and attributable mortality associated with VAP and secondary objective is to identify the various bacterial pathogens causing VAP in the ICU.

Materials and Methods:

This prospective observational study was carried out over a period of 1 year. VAP was diagnosed using the clinical pulmonary infection score. Endotracheal aspirate (ETA) and bronchoalveolar lavage (BAL) samples of suspected cases of VAP were collected from ICU patients and processed as per standard protocols.

Statistical Analysis:

Fisher's exact test was applied when to compare two or more set of variables were compared.

Results:

The incidence of VAP in our study was 57.14% and the incidence density of VAP was 31.7/1000 ventilator days. Trauma was the commonest underlying condition associated with VAP. The incidence of VAP increased as the duration of mechanical ventilation increased and there was a total agreement in bacteriology between semi-quantitative ETAs and BALs in our study. The overall mortality associated with VAP was observed to be 48.33%.

Conclusions:

The incidence of VAP was 57.14%. Study showed that the incidence of VAP is directly proportional to the duration of mechanical ventilation. The most common pathogens causing VAP were Acinetobacter spp. and Pseudomonas aeruginosa and were associated with a high fatality rate.

Short- vs long-duration antibiotic regimens for ventilator-associated pneumonia: a systematic review and meta-analysis

BACKGROUND

We performed a systematic review and meta-analysis of short- vs long-duration antibiotic regimens for ventilator-associated pneumonia (VAP).

METHODS

We searched PubMed and Cochrane Central Registry of Controlled Trials. Four randomized controlled trials (RCTs) comparing short (7-8 days) with long (10-15 days) regimens were identified. Primary outcomes included mortality, antibiotic-free days, and clinical and microbiologic relapses. Secondary outcomes included mechanical ventilation-free days, duration of mechanical ventilation, and length of ICU stay.

RESULTS

All RCTs included mortality data, whereas data on relapse and antibiotic-free days were provided in three and two out of four RCTs, respectively. No difference in mortality was found between the compared arms (fixed effect model [FEM]: OR = 1.20; 95% CI, 0.84-1.72; P = .32). There was an increase in antibiotic-free days in favor of the short-course treatment with a pooled weighted mean difference of 3.40 days (random effects model: 95% CI, 1.43-5.37; P &lt; .001). There was no difference in relapses between the compared arms, although a strong trend to lower relapses in the long-course treatment was observed (FEM: OR = 1.67; 95% CI, 0.99-2.83; P = .06). No difference was found between the two arms regarding the remaining outcomes. Sensitivity analyses yielded similar results.

CONCLUSIONS

Short-course treatment of VAP was associated with more antibiotic-free days. No difference was found regarding mortality and relapses; however, a strong trend for fewer relapses was observed in favor of the long-course treatment, being mostly driven by one study in which the observed relapses were probably more microbiologic than clinical. Additional research is required to elucidate the issue.

Epidemiology and outcomes of ventilator-associated pneumonia in northern Brazil: an analytical descriptive prospective cohort study

BACKGROUND

Ventilator-associated pneumonia (VAP) is considered the most common nosocomial infection in the intensive care unit (ICU), but its features are not fully known in many hospitals in Brazil. We identified clinical and epidemiological aspects associated with VAP in an intensive care unit (ICU) in a general public hospital in northern Brazil and performed an analytical descriptive prospective cohort study.

METHODS

We analyzed data from thirty-three patients who developed VAP while in the ICU. Clinical and epidemiological data of patients were obtained and tracheal secretions were submitted to culture. Microbial isolates were identified and evaluated for resistance against antimicrobial agents by using the automated Vitek 2 system.

RESULTS

The frequency of VAP was 26.2% in patients submitted to invasive mechanical ventilation for at least 48 hours, and death occurred in 78.8% of cases. Only the presence of comorbidity showed a significant association (P = 0.029) with death. The most commonly found bacteria were Pseudomonas aeruginosa, Acinetobacter spp., and Enterobacteriaceae. We also found a frequency of 54.5% of multiresistant bacteria associated with VAP, and previous antibiotic therapy was used in 97% of patients.

CONCLUSIONS

VAP in our ICU presented with a high frequency and was mainly caused by multiresistant bacteria. Implementation of rational protocols for the use of antibacterial agents and rapid delivery of culture and susceptibility test results are essential. This may help decrease VAP-related mortality rates by multiresistant bacteria in the ICU.

Emergence of methicillin-resistant Staphylococcus aureus USA300 genotype as a major cause of late-onset nosocomial pneumonia in intensive care patients in the USA

OBJECTIVE

To compare demographic and clinical characteristics, and methicillin-resistant Staphylococcus aureus (MRSA) strain characteristics, in patients with early-onset (EO) and late-onset (LO) MRSA nosocomial pneumonia.

METHODS

This was a retrospective analysis of data from a multicenter observational study of nosocomial pneumonia patients admitted between November 2008 and July 2010. Laboratory analyses performed on MRSA isolates included confirmation of antimicrobial susceptibility and heteroresistance to vancomycin, USA typing, staphylococcal cassette chromosome (SCC) mec typing, and detection of Panton-Valentine leukocidin (PVL) genes.

RESULTS

We identified 134 patients; 42 (31%) had EO MRSA pneumonia and 92 (69%) had LO MRSA pneumonia. The patients in the LO group were more likely to have risk factors for multidrug-resistant pathogens (98% vs. 76%, p<0.001). The MRSA USA300 strain was found with equal frequency in the EO and LO groups. Likewise, both groups had similar frequencies of isolates exhibiting PVL and SCCmec type IV.

CONCLUSIONS

Our findings provide further evidence of the continued migration of community-associated MRSA into the healthcare setting in the USA. MRSA USA300 genotype has emerged as a significant cause of LO nosocomial pneumonia in intensive care units. Appropriate anti-MRSA antimicrobial therapy should be considered for both EO and LO hospital-acquired pneumonia and ventilator-associated pneumonia.

Association between systemic corticosteroids and outcomes of intensive care unit-acquired pneumonia

OBJECTIVE

The use of corticosteroids is frequent in critically-ill patients. However, little information is available on their effects in patients with intensive care unit-acquired pneumonia. We assessed patients' characteristics, microbial etiology, inflammatory response, and outcomes of previous corticosteroid use in patients with intensive care unit-acquired pneumonia.

DESIGN

Prospective observational study.

SETTING

Intensive care units of a university teaching hospital.

PATIENTS

Three hundred sixteen patients with intensive care unit-acquired pneumonia. Patients were divided according to previous systemic steroid use at onset of pneumonia.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Survival at 28 days was analyzed using Cox regression, with adjustment for the propensity for receiving steroid therapy. One hundred twenty-five (40%) patients were receiving steroids at onset of pneumonia. Despite similar baseline clinical severity, steroid treatment was associated with decreased 28-day survival (adjusted hazard ratio for propensity score and mortality predictors 2.503; 95% confidence interval 1.176-5.330; p = .017) and decreased systemic inflammatory response. In post hoc analyses, steroid treatment had an impact on survival in patients with nonventilator intensive care unit-acquired pneumonia, those with lower baseline severity and organ dysfunction, and those without etiologic diagnosis or bacteremia. The cumulative dosage of corticosteroids had no significant effect on the risk of death, but bacterial burden upon diagnosis was higher in patients receiving steroid therapy.

CONCLUSIONS

In critically-ill patients, systemic corticosteroids should be used very cautiously because this treatment is strongly associated with increased risk of death in patients with intensive care unit-acquired pneumonia, particularly in the absence of established indications and in patients with lower baseline severity. Decreased inflammatory response may result in delayed clinical suspicion of intensive care unit-acquired pneumonia and higher bacterial count.

Early-onset ventilator-associated pneumonia in adults randomized clinical trial: comparison of 8 versus 15 days of antibiotic treatment

PURPOSE

The optimal treatment duration for ventilator-associated pneumonia is based on one study dealing with late-onset of the condition. Shortening the length of antibiotic treatment remains a major prevention factor for the emergence of multiresistant bacteria.

OBJECTIVE

To demonstrate that 2 different antibiotic treatment durations (8 versus 15 days) are equivalent in terms of clinical cure for early-onset ventilator-associated pneumonia.

METHODS

Randomized, prospective, open, multicenter trial carried out from 1998 to 2002.

MEASUREMENTS

The primary endpoint was the clinical cure rate at day 21. The mortality rate was evaluated on days 21 and 90.

RESULTS

225 patients were included in 13 centers. 191 (84.9%) patients were cured: 92 out of 109 (84.4%) in the 15 day cohort and 99 out of 116 (85.3%) in the 8 day cohort (difference = 0.9%, odds ratio = 0.929). 95% two-sided confidence intervals for difference and odds ratio were [-8.4% to 10.3%] and [0.448 to 1.928] respectively. Taking into account the limits of equivalence (10% for difference and 2.25 for odds ratio), the objective of demonstrative equivalence between the 2 treatment durations was fulfilled. Although the rate of secondary infection was greater in the 8 day than the 15 day cohort, the number of days of antibiotic treatment remained lower in the 8 day cohort. There was no difference in mortality rate between the 2 groups on days 21 and 90.

CONCLUSION

Our results suggest that an 8-day course of antibiotic therapy is safe for early-onset ventilator-associated pneumonia in intubated patients.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01559753.

A European survey of antibiotic management of methicillin-resistant Staphylococcus aureus infection: current clinical opinion and practice

Although the epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) varies across Europe, healthcare-associated MRSA infections are common in many countries. Despite several national guidelines, the approach to treatment of MRSA infections varies across the continent, and there are multiple areas of management uncertainty for which there is little clinical evidence to guide practice. A faculty, convened to explore some of these areas, devised a survey that was used to compare the perspectives of infection specialists from across Europe on the management of MRSA infections with those of the faculty specialists. The survey instrument, a web-based questionnaire, was sent to 3840 registered delegates of the 19th European Congress of Clinical Microbiology and Infectious Diseases, held in April 2009. Of the 501 (13%) respondents to the survey, 84% were infection/microbiology specialists and 80% were from Europe. This article reports the survey results from European respondents, and shows a broad range of opinion and practice on a variety of issues pertaining to the management of minor and serious MRSA infections, such as pneumonia, bacteraemia, and skin and soft tissue infections. The issues include changing epidemiology, when and when not to treat, choice of treatment, and duration and route of treatment. The survey identified areas where practice can be improved and where further research is needed, and also identified areas of pan-European consensus of opinion that could be applied to European guidelines for the management of MRSA infection.

Do guidelines change outcomes in ventilator-associated pneumonia?

PURPOSE OF REVIEW

The purpose of the study is to summarize effects of implementation of current and past guidelines for management and treatment of ventilator-associated pneumonia (VAP) on outcome of intensive care patients, with particular focus on etiology of VAP, pathogens prediction, appropriate empiric antibiotic therapy and mortality.

RECENT FINDINGS

Several studies have shown that in patients with clinical suspicion of VAP, appropriate antibiotic therapy administered in a timely manner can improve survival. Guidelines for management and treatment of VAP have been developed to help physicians to achieve those goals. Implementation of guidelines into clinical practice is difficult to achieve and requires extensive education for healthcare personnel and translation of recommendations into local protocols. Studies have shown that guidelines implementation is associated with better outcome. However, extensive research needs to be undertaken in order to validate efficacy of guidelines in predicting etiology of pneumonia, in particular, to promptly identify multidrug-resistant pathogens. Only one recent report has validated the latest guidelines and called attention for further research to improve microbial prediction.

SUMMARY

Guidelines implementation can improve outcomes. To achieve this goal, guidelines should be adapted to local microbiology, accurately predict VAP pathogens and help physicians to administer the most appropriate empirical antimicrobial therapy.

Early- and late-onset pneumonia: is this still a useful classification?

The choice of empirical treatment of nosocomial pneumonia in the intensive-care unit (ICU) used to rely on the interval after the start of mechanical ventilation. Nowadays, however, the question of whether in fact there is a difference in the distribution of causative pathogens is under debate. Data from 308 ICUs from the German National Nosocomial Infection Surveillance System, including information on relevant pathogens isolated in 11,285 cases of nosocomial pneumonia from 1997 to 2004, were used for our evaluation. Each individual pneumonia case was allocated either to early- or to late-onset pneumonia, with three differentiation criteria: onset on the 4th day, the 5th day, or the 7th day in the ICU. The frequency of pathogens was evaluated according to these categories. A total of 5,066 additional cases of pneumonia were reported from 2005 to 2006, after the CDC criteria had been modified. From 1997 to 2004, the most frequent microorganisms were Staphylococcus aureus (2,718 cases, including 720 with methicillin [meticillin]-resistant S. aureus), followed by Pseudomonas aeruginosa (1,837 cases), Klebsiella pneumoniae (1,305 cases), Escherichia coli (1,137 cases), Enterobacter spp. (937 cases), streptococci (671 cases), Haemophilus influenzae (509 cases), Acinetobacter spp. (493 cases), and Stenotrophomonas maltophilia (308 cases). The order of the four most frequent pathogens (accounting for 53.7% of all pathogens) was the same in both groups and was independent of the cutoff categories applied: S. aureus was first, followed by P. aeruginosa, K. pneumoniae, and E. coli. Thus, the predictabilities of the occurrence of pathogens were similar for the earlier (1997-to-2004) and later (2005-to-2006) time frames. This classification is no longer helpful for empirical antibiotic therapy, since the pathogens are the same for both groups.

[Ventilator-associated pneumonia]

Ventilator-associated pneumonia (VAP) is the most common nosocomial infection in critical care medicine and has been shown to be an independent risk factor for mortality. However, ventilator induced lung injury itself is probably only a minor factor predisposing to VAP. In contrast, invasive ventilation using an endotracheal tube is obviously a more important measure. Thus, microaspiration of potentially infectious secretion from the oropharynx into the trachea along the tube has been suggested to be the most critical pathophysiological event in the process of VAP development. Accordingly, non-invasive ventilation provides a decreased risk of VAP. Therefore, all measures aimed at averting microaspiration or shorten the duration of mechanical ventilation are appropriate to prevent VAP. Moreover, oropharyngeal decontamination may be helpful by reducing bacterial colonisation. Effectiveness of therapy depends on early treatment and therefore requires early diagnosis. With this aim combined clinical, radiologic, and microbiological parameters should be taken into account. Adequate antimicrobial therapy in due consideration for individual risk factors and local antibiotic resistance is the most important therapeutic measure.

Multidrug-resistant Pseudomonas aeruginosa ventilator-associated pneumonia: the role of endotracheal aspirate surveillance cultures

BACKGROUND

Inappropriate antibacterial treatment of ventilator-associated pneumonia (VAP) due to multidrug-resistant (MDR) pathogens is associated with increased mortality. Endotracheal aspirate (ETA) surveillance cultures potentially identify MDR pathogens, particularly MDR Pseudomonas aeruginosa, resulting in improved selection of therapy in patients who subsequently develop VAP.

OBJECTIVE

To investigate the role of ETA surveillance cultures in the identification of MDR P. aeruginosa in newly intubated adults who subsequently develop VAP.

METHODS

Daily ETA surveillance cultures for P. aeruginosa were collected in all adults newly intubated for 48 hours or more. Patients with preexisting lung disease or colonization or infection with P. aeruginosa were excluded. Risk factors and outcomes of patients newly colonized with MDR P. aeruginosa were assessed.

RESULTS

Seventy-five patients newly colonized with P. aeruginosa were identified. Twenty (27%) of these patients were colonized with a P. aeruginosa isolate that was MDR (resistant to > or = 3 classes of antibiotics). Six patients were colonized by an isolate resistant to all tested classes of antibiotics. Forty-five percent of patients colonized with MDR P. aeruginosa subsequently developed VAP. Prior receipt of fluoroquinolones was an independent predictor of colonization with MDR P. aeruginosa (OR 11.82; 95% CI 2.10 to 66.46; p = 0.005).

CONCLUSIONS

Performance of routine surveillance cultures may aid in the early detection of MDR P. aeruginosa, improving the initiation of early and appropriate antibiotic therapy for patients who subsequently develop VAP.

Evidence-based algorithms for diagnosing and treating ventilator-associated pneumonia

BACKGROUND

Ventilator-associated pneumonia (VAP) is widely recognized as a serious and common complication associated with high morbidity and high costs. Given the complexity of caring for heterogeneous populations in the intensive care unit (ICU), however, there is still uncertainty regarding how to diagnose and manage VAP.

OBJECTIVE

We recently conducted a national collaborative aimed at reducing health care-associated infections in ICUs of hospitals operated by the Hospital Corporation of America (HCA). As part of this collaborative, we developed algorithms for diagnosing and treating VAP in mechanically ventilated patients. In the current article, we (1) review the current evidence for diagnosing VAP, (2) describe our approach for developing these algorithms, and (3) illustrate the utility of the diagnostic algorithms using clinical teaching cases.

DESIGN

This was a descriptive study, using data from a national collaborative focused on reducing VAP and catheter-related bloodstream infections.

SETTING

The setting of the study was 110 ICUs at 61 HCA hospitals.

INTERVENTION

None.

MEASUREMENTS AND RESULTS

We assembled an interdisciplinary team that included infectious disease specialists, intensivists, hospitalists, statisticians, critical care nurses, and pharmacists. After reviewing published studies and the Centers for Disease Control and Prevention VAP guidelines, the team iteratively discussed the evidence, achieved consensus, and ultimately developed these practical algorithms. The diagnostic algorithms address infant, pediatric, immunocompromised, and adult ICU patients.

CONCLUSIONS

We present practical algorithms for diagnosing and managing VAP in mechanically ventilated patients. These algorithms may provide evidence-based real-time guidance to clinicians seeking a standardized approach to diagnosing and managing this challenging problem.

Previous endotracheal aspirate allows guiding the initial treatment of ventilator-associated pneumonia

OBJECTIVES

Any delay in adequate antibiotic treatment compromises the outcome of ventilator-associated pneumonia (VAP). However, the diagnosis and optimal treatment of VAP remain a challenge for intensivists. We assessed the potential impact of using results of routine weekly endotracheal aspirate (EA) cultures to guide initial antibiotic treatment for VAP.

DESIGN AND SETTING

Retrospective analysis of prospectively collected data in a medical-surgical intensive care unit (ICU) of a university hospital.

PATIENTS AND METHODS

We studied 113 VAP episodes and evaluated the concordance between the latest EA and the broncho-alveolar lavage (BAL). We stratified patients into three groups: concordant EA-BAL (concordant group), discordant EA-BAL (discordant group) and EA not performed group. We then compared the adequacy of the antibiotic prescribed initially and outcomes between the three groups.

MEASUREMENTS AND MAIN RESULTS

Ninety assessable EA-BAL samples were evaluated. When guided by EA, the initial antibiotic regimen was adequate in 85% of situations, a proportion significantly superior (P < 0.05) to that resulting from application of the ATS guidelines (73%). When clinicians did not have a pre-VAP EA to guide their treatment (EA not performed group), only 61% of treatments were adequate. No significant difference was observed between the three groups for length of mechanical ventilation, length of ICU stay, nonpulmonary nosocomial infections and mortality.

CONCLUSION

Once-a-week routine quantitative EA cultures may help to improve the adequacy of empiric antibiotic therapy for VAP.

Effect of clarithromycin in patients with sepsis and ventilator-associated pneumonia

BACKGROUND

Because clarithromycin provided beneficiary nonantibiotic effects in experimental studies, its efficacy was tested in patients with sepsis and ventilator-associated pneumonia (VAP).

METHODS

Two hundred patients with sepsis and VAP were enrolled in a double-blind, randomized, multicenter trial from June 2004 until November 2005. Clarithromycin (1 g) was administered intravenously once daily for 3 consecutive days in 100 patients; another 100 patients were treated with placebo. Main outcomes were resolution of VAP, duration of mechanical ventilation, and sepsis-related mortality within 28 days.

RESULTS

The groups were well matched with regard to demographic characteristics, disease severity, pathogens, and adequacy of the administered antimicrobials. Analysis comprising 141 patients who survived revealed that the median time for resolution of VAP was 15.5 days and 10.0 days among placebo- and clarithromycin-treated patients, respectively (P = .011); median times for weaning from mechanical ventilation were 22.5 days and 16.0 days, respectively (p = .049). Analysis comprising all enrolled patients showed a more rapid decrease of the clinical pulmonary infection score and a delay for advent of multiple organ dysfunction in clarithromycin-treated patients, compared with those of placebo-treated patients (p = .047). Among the 45 patients who died of sepsis, time to death was significantly prolonged in clarithromycin-treated compared with placebo-treated patients (p = .004). Serious adverse events were observed in 0% and 3% of placebo- and clarithromycin-treated patients, respectively (P = .25).

CONCLUSIONS

Clarithromycin accelerated the resolution of VAP and weaning from mechanical ventilation in surviving patients and delayed death in those who died of sepsis. The mortality rate at day 28 was not altered. Results are encouraging and render new perspectives on the management of sepsis and VAP.