Episodes Of Ventilator-associated Pneumonia Research Articles

Implementation of ventilator associated pneumonia prevention bundle in the neonatal intinsive care unit at Alexandria University Children’s Hospital, Egypt

Introduction Ventilator-associated pneumonia (VAP) is a nosocomial lung infection that develops at or later than 48 h after mechanical ventilation (MV). It is the second most frequent hospital-acquired infection in neonatal intensive care units (NICUs). It results in high morbidity, mortality, prolonged NICU length of stay, and increased cost of hospitalization. Egypt and other developing countries report higher VAP rates compared with developed countries. Furthermore, studies monitoring VAP rates and success of intervention strategies in Egyptian NICUs are few. Aim The aim of the present study was to estimate the incidence of VAP during the implementation of the prevention bundle and also to identify the causative agents and significant risk factors in the NICU at Alexandria University Children’s Hospital. Patients and methods A nonrandomized clinical trial with historical control was conducted. All neonates admitted to the NICU in the period from July 2015 till March 2016, who spent more than 48 h on MV, were subjected to a VAP prevention bundle. Eligible neonates who spent more than 48 h on MV were monitored closely for VAP development. A thorough assessment of history, clinical examination, routine investigations, and chest radiography were carried out on all enrolled infants. Neonates who developed clinically suspected VAP were further subjected to nonbronchoscopic bronchoalveolar lavage for bacteriological confirmation of the clinical diagnosis. A review of records was performed to determine the incidence of VAP in the 9 months before intervention. Oral swabs were taken to study the pattern of oral colonization in ventilated neonates to trace its role in VAP development. Also, cultures of residual gastric volume and water traps inserted into the ventilator circuits were studied. Results A total of 108 episodes of VAP were diagnosed, with a cumulative incidence of clinically diagnosed VAP equal to 37.6% (34.2 VAP cases/1000 ventilation days). The incidence of bacteriological-confirmed VAP in this study was 19.97/1000 ventilation days. The most important risk factors for the occurrence of VAP were prematurity, low birth weight, prolonged duration of ventilation, re-intubations, and enteral feeding. Gram-negative bacteria were the predominating cause of VAP in the NICU and Klebsiella was the most common pathogen isolated from nonbronchoscopic bronchoalveolar lavage cultures. Conclusion VAP is a severe complication of MV as it significantly increases neonatal mortality. The VAP preventive bundle implemented in the present work was associated with a reduction in the VAP rate in the NICU.

Current Epidemiology of Ventilator-associated Pneumonia in an Intensive Care Unit in Vietnam

BackgroundThe increase of multi-drug-resistant Gram-negative bacteria as a cause of ventilator-associated pneumonia (VAP) is a global concern. The epidemiology of VAP in Southeast Asia remains largely unknown.MethodsThis prospective cohort study was conducted at the Intensive Care Unit (ICU) of Bach Mai Hospital in Hanoi. Patients who received mechanical ventilation for >48 hours, and were diagnosed with VAP, in November 2015–May 2016 were included. Patients with no positive respiratory culture for a causative organism were excluded. Those with multiple VAP episodes >7 days apart with a different causative organism were counted separately.ResultsFifty-six patients (67 episodes) with VAP in 992 admissions were identified. Ten had ≥2 episodes. In 11 episodes, ≥2 isolates were found from a respiratory sample; 78 isolates were identified in total. The cohort median age was 61 (interquartile range [IQR]: 48–70) years, with 43 (76.8%) males. Fourteen (24.6%) patients had diabetes, 10 (17.5%) had chronic kidney diseases, 17 (29.8%) had congestive heart disease, 9 (15.8%) had COPD, and 5 (8.8%) had malignancy. Among isolated bacteria, Acinetobacter baumannii (ACB) was highly resistant to meropenem, levofloxacin, and amikacin (Table). The 7-day mortality was 13% (n = 7) and 31-day mortality was 43.8% (n = 21). ACB cases had higher 31-day mortality (18 [56.2%] vs. 4 [25%]; P = 0.041) and longer ICU stay (16 days [IQR: 10–27] vs. 9 [3–15]; P = 0.024; deceased excluded) than non-ACB. Colistin was used in 23 (41.1%) cases as empiric therapy and 25 (44.6%) as definitive therapy.ConclusionHigh resistance rates and worse clinical outcomes were found in VAP cases due to ACB in ICU in Vietnam. Further study is warranted for appropriate treatment and infection control measures.TableAntimicrobial resistance of bacterial isolates* in ventilator-associated pneumonia, n (%) Acinetobacter baumannii (n = 37) Klebsiella pneumoniae (n = 11) Pseudomonas aeruginosa (n = 15)Meropenem37 (100)7 (63.6)11 (73.3)Ceftazidime37 (100)11 (100)10 (66.7)Levofloxacin37 (100)11 (100)11 (73.3)Amikacin35 (94.6)3 (27.3)10 (66.7)Colistin000*Include Stenotrophomonas maltophilia (n = 6), Serratia marcescens (n = 3), Enterobacter cloacae (n = 2), Elizabethkingia meningoseptica (n = 2).Disclosures All authors: No reported disclosures.

Molecular quantification of bacteria from respiratory samples in patients with suspected ventilator-associated pneumonia

Ventilator-associated pneumonia (VAP) is the most common infection in critically ill patients. Initial antibiotic therapy is often broad spectrum, which promotes antibiotic resistance so new techniques are under investigation to obtain early microbiological identification and quantification. This trial compares the performance of a new real-time quantitative molecular-based method with conventional culture in patients with suspected VAP. Patients with suspected VAP who were ventilated for at least 48 h were eligible. An endotracheal aspirate (ETA) and a bronchoalveolar lavage (BAL) were performed at each suspected VAP episode. Both samples were analysed by conventional culture and molecular analysis. For the latter, bacterial DNA was extracted from each sample and real-time PCR were run. In all, 120 patients were finally included; 76% (91) were men; median age was 65 years, and clinical pulmonary infection score was ≥6 for 73.5% (86) of patients. A total of 120 BAL and 103 ETA could be processed and culture results above the agreed threshold were obtained for 75.0% (90/120) of BAL and 60.2% (62/103) of ETA. The main isolated bacteria were Staphylococcus aureus, Pseudomonas aeruginosa and Haemophilus influenzae. Performance was 89.2% (83.2%–93.6%) sensitivity and 97.1% (96.1%–97.9%) specificity for BAL samples and 71.8% (61.0%–81.0%) sensitivity and 96.6% (95.4%–97.5%) specificity for ETA samples when the molecular biology method was compared with conventional culture method (chosen as reference standard). This new molecular method can provide reliable quantitative microbiological data and is highly specific with good sensitivity for common pathogens involved in VAP.

Prospective observational study to compare oral topical metronidazole versus 0.2% chlorhexidine gluconate to prevent nosocomial pneumonia

Nosocomial pneumonia is one of the most common health care-associated infections in intensive care units (ICUs) worldwide, attributing to high morbidity and mortality. Our study aim is to investigate the effectiveness of oral hygiene with 0.2% chlorhexidine gluconate (CHX) and 0.08% metronidazole (MDE) influencing the microbiologic epidemiology and incidence of nonintubation pneumonia (NIP) and ventilator-associated pneumonia (VAP). Patients who stayed >48 hours in the emergency ICU between 2008 and 2012 were enrolled and provided oral hygiene by swabbing with 0.08% MDE twice daily until discharge or death during the first year (period M), whereas CHX was applied during the following 3 years (period C). The incidence and microbiologic epidemiology of NIP and VAP were studied. There were 873 patients enrolled. There were 44 episodes of NIP and 25 episodes of VAP that occurred among 212 patients in period M, and 84 episodes of NIP and 49 episodes of VAP occurred among 661 patients in period C. Overall, the rate of NIP and VAP decreased year by year. Acinetobacter baumannii was the most frequently identified bacteria for NIP (22.9%) and VAP (25.3%), with an annual ascent. Few changes were observed on bacteria distribution for NIP and VAP. Oral hygiene with CHX, having reduced the incidence of nosocomial pneumonia among critical ill patients, suggests a benefit of oral hygiene in decreasing the incidence of nosocomial pneumonia, including VAP in ICUs, but not bacterial epidemiology.

Clinical predictors and microbiology of ventilator-associated pneumonia in the intensive care unit: a retrospective analysis in six Italian hospitals.

The purpose of this study was to assess the main clinical predictors and microbiological features of ventilator-associated pneumonia (VAP) in the Intensive Care Unit (ICU) environment. This work is a retrospective analysis over one year from September 2010 to September 2011. Patients' risk factors, causes of admission, comorbidities and respiratory specimens collected in six Italian ICUs were reviewed. Incidence and case fatality rate of VAP were evaluated. After stratification for VAP development, univariate and multivariate analyses were performed to assess the impact of patients' conditions on the onset of this infection. A total of 1,647 ICU patients (pts) were considered. Overall, 115 patients (6.9%) experienced at least one episode of VAP. The incidence rate for VAP was 5.82/1,000 pts-days, with a case fatality rate of 44.3%. Multivariate analysis showed that admission for neurological disorders (aIRR 4.12, CI 1.24-13.68, p = 0.02) and emergency referral to ICU from other hospitals (aIRR 2.11, CI 1.03-4.31, p = 0.04) were associated with higher risk of VAP, whereas a tendency to a higher risk of infection was detected for admission due to respiratory disease, cardiac disease, trauma and for having obesity or renal failure. A total of 372 microbiological isolates from respiratory specimens were collected in VAP patients. The most common species were Klebsiella pneumoniae, Acinetobacter baumannii and Pseudomonas aeruginosa, showing high resistance rates to carbapenems. Neurological disorders and emergency referral at the admission into the ICU are significantly associated with the onset of VAP. A high incidence of multi-drug resistant Gram-species was detected in the respiratory specimens.

The impact of implementing multifaceted interventions on the prevention of ventilator-associated pneumonia

Ventilator-associated pneumonia (VAP) is a frequent hospital acquired infections among intensive care unit patients. The Institute for Healthcare Improvement has suggested a "care bundle" approach for the prevention of VAP. This report describes the effects of implementing this strategy on VAP rates. All mechanically ventilated patients admitted to the intensive care unit between 2008 and 2013 were prospectively followed for VAP development according to the National Healthcare Safety Network criteria. In 2011, a 7-element care bundle was implemented, including head-of-bed elevation 30°-45°, daily sedation vacation and assessment for extubation, peptic ulcer disease prophylaxis, deep vein thrombosis prophylaxis, oral care with chlorhexidine, endotracheal intubation with in-line suction and subglottic suctioning, and maintenance of endotracheal tube cuff pressure at 20-30 mmHg. The bundle compliance and VAP rates were then followed. A total of 3665 patients received mechanical ventilation, and there were 9445 monitored observations for bundle compliance. The total bundle compliance before and after initiation of the VAP team was 90.7% and 94.2%, respectively (P < .001). The number of VAP episodes decreased from 144 during 2008-2010 to only 14 during 2011-2013 (P < .0001). The rate of VAP decreased from 8.6 per 1000 ventilator-days to 2.0 per 1000 ventilator-days (P < .0001) after implementation of the care bundle. This study suggests that systematic implementation of a multidisciplinary team approach can reduce the incidence of VAP. Further sustained improvement requires persistent vigilant inspections.

Staphylococcus aureus bacteremic pneumonia.

Staphylococcus aureus bacteremic pneumonia is an uncommon cause of hospitalization, with a high mortality rate. However, published reports are scarce and have included a small number of cases. All patients with S. aureus bacteremic pneumonia were prospectively collected in our institution from 2000 to 2014, and a retrospective revision was performed to identify risk factors associated with methicillin resistance and to update the mortality of this entity. A total of 98 patients were admitted: 57.1% were due to methicillin-susceptible S. aureus (MSSA) and 42.8% due to methicillin-resistant S. aureus (MRSA). In 40 patients (40.8%), the infection was community acquired. Thirteen were ventilator-associated pneumonia episodes. The most frequent comorbidities were chronic lung disease (34.7%), chronic renal failure (31.6%), diabetes mellitus (29.6%), and cardiovascular disease (31.6%). Septic shock was present in 46 patients (46.9%). The 30-day mortality was 46.9%. MRSA infections occurred in older patients, more frequently with cardiovascular diseases, and they had received antibiotic treatment in the previous month more often than MSSA-infected patients. Patients with infection due to MSSA presented more frequently with septic shock, but they received more frequently appropriate empirical antibiotic therapy than patients with MRSA pneumonia (96% vs. 38.1%), and no differences in mortality were observed between both groups. In conclusion, S. aureus bacteremic pneumonia is a severe infection that, nowadays, affects people with comorbidities and the mortality is still high.

Continuous control of tracheal cuff pressure for VAP prevention: a collaborative meta-analysis of individual participant data

BackgroundUnderinflation of tracheal cuff is a risk factor for microaspiration of contaminated secretions and subsequent ventilator-associated pneumonia (VAP). The aim of this collaborative meta-analysis of individual participant data is to determine the impact of continuous control of Pcuff on the incidence of VAP.MethodsStudies were identified by searching PubMed and references of relevant articles. Data from 3 prospective controlled trials (two randomized and one quasi-randomized), which evaluated the impact of continuous control of Pcuff on the incidence of VAP, were obtained and pooled together. Three different devices were used to continuously control Pcuff. VAP was diagnosed using clinical, radiologic, and quantitative microbiological criteria. The impact of continuous control of Pcuff on VAP was assessed by Cox regression analysis, stratified on trial.Results263 (48.4 %) patients received continuous control of Pcuff, and 280 (51.5 %) patients received routine control of Pcuff using a manometer. 36 (13.6 %) VAP were diagnosed in continuous control group, and 72 (25.7 %) in routine care group (HR 0.47, 95 % CI 0.31–0.71, p < 0.001). However, heterogeneity was apparent in continuous control effect size across trials (I2 = 58 %, p = 0.085). The number of patients needed to treat to prevent one VAP episode was 8. No significant impact of continuous control of Pcuff was found on duration of mechanical ventilation, ICU length of stay, or mortality.ConclusionContinuous control of Pcuff might be beneficial in reducing the risk for VAP. However, no significant impact of continuous control of Pcuff was found on duration of mechanical ventilation, ICU length of stay, or mortality.

The impact of onset time on the isolated pathogens and outcomes in ventilator associated pneumonia.

Several guidelines base the empirical therapy of ventilator-associated pneumonia (VAP) on the time of onset. However, there is emerging evidence that the isolated microorganisms may be similar regardless of onset time. This study evaluated the characteristics and outcomes of VAP with different onset times. All of the mechanically ventilated patients admitted to the ICU of a 900-bed tertiary-care hospital between 01/08/2003 and 31/12/2010 were prospectively followed for VAP development according to the National Healthcare Safety Network criteria. The patients were categorized into four groups: EO if VAP occurred within 4 days of intubation and hospital admission; LO if VAP occurred after 4 days of admission; EL if VAP occurred within 4 days of intubation, but after the fourth hospitalization day; and LL if VAP occurred after the fourth day of intubation and hospitalization. Out of the 394 VAP episodes, 63 (16%) were EO episodes, 331 (84.0%) were LO episodes, 40 (10.1%) were EL episodes and 291 (73.1%) were LL episodes. The isolated microorganisms were comparable among the four groups, with a similar rate of potentially multidrug resistant organisms in the EO-VAP (31.7%), LO-VAP (40.8%), EL-VAP (37.5%) and LL-VAP (43.3%) samples. The hospital mortality was 24% for EO-VAP cases, 28% for LO-VAP cases, 40% for EL-VAP cases and 49% for LL-VAP cases. However, in the adjusted multivariate analysis, neither LO-VAP, EL-VAP nor LL-VAP was associated with an increased risk of hospital mortality compared with EO-VAP (OR, 0.86 95% CI, 0.34-2.19; 1.22; 95% CI, 0.41-3.68, and 0.95; 95% CI, 0.43-2.10, respectively). In this study, the occurrence of potential multidrug resistant pathogens and the mortality risk were similar regardless of VAP timing from hospital admission and intubation. The bacterial isolates obtained from the VAP cases did not follow an early vs. late-onset pattern, and thus, these terms may not be clinically helpful.

Intervention to Reduce Ventilator-Associated Pneumonia in Individuals on Long-Term Ventilation by Introducing a Customized Bundle.

To evaluate the effectiveness of a modified bundle of preventative measures to decrease ventilator-associated pneumonia (VAP) in chronically ventilated long-term care facility (LTCF) residents. Cohort before-and-after study. Geriatric hospital ward. LTCF residents on long-term ventilation. The modified bundle included hand hygiene before patient care, elevation of the head of the bed to more than 30° for individuals who are supine, chlorhexidine oral care at the beginning of each nursing shift, keeping tracheostomy cannula balloon pressure at 20 to 30 cm H2 O, and measuring nasogastric food remnants before every meal for individuals fed through a nasogastric tube. Number of VAP episodes was determined prospectively, and rates were calculated as episodes per 1,000 ventilation days. VAP rate decreased from 5.97 before the intervention to 2.34 after the intervention (P < .001). The use of broad-spectrum antibiotics decreased from 1,788 defined daily doses before the intervention to 1,093 after (P = .04). A modified bundle successfully decreased VAP rates in chronically ventilated elderly LTCF residents.

Five-year trends for ventilator-associated pneumonia: Correlation between microbiological findings and antimicrobial drug consumption

The epidemiology of multidrug-resistant bacteria (MDRB) has changed significantly in European healthcare settings, with a decrease in frequency of meticillin-resistant Staphylococcus aureus and an increase in extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae. Little is known about the effects of these changes on ventilator-associated pneumonia (VAP). A retrospective 5-year trend analysis of ICU antibiotic consumption and resistance in bacteria causing VAP was undertaken. Poisson regression analysis between complete microbiological data and antibiotic consumption was performed. In total, 252 episodes of VAP in 184 patients were identified between 2007 and 2011, from which 364 causal bacteria were isolated. Enterobacteriaceae isolation rates increased significantly over this period [from 6.64 to 10.52 isolates/1000 patient-days; P=0.006], mostly due to an increase in AmpC-producing Enterobacteriaceae (APE) (2.85–4.51 isolates/1000 patient-days; P=0.013), whereas the number of episodes due to S. aureus and Pseudomonas aeruginosa remained stable. A positive association was found between the increase in APE infections and an increase in past-year antibiotic consumption: amoxicillin/clavulanic acid (P=0.003), ceftazidime and cefepime (P=0.007), carbapenems (P=0.002), fluoroquinolones (P=0.012), macrolides (P=0.002) and imidazoles (P=0.004). No such association was found for the emergence of resistance in P. aeruginosa. These results indicate a change in the epidemiology of VAP, with Enterobacteriaceae exceeding P. aeruginosa and S. aureus. Moreover, a positive correlation was observed between antibiotic consumption and the incidence of potentially MDRB such as APE. No such correlation was found for ESBL-producing Escherichia coli and antibiotic-resistant P. aeruginosa.

Screening for Ventilator-Associated Pneumonia in the Surgical Intensive Care Unit: A Single-Institution Analysis of 1,013 Lower Respiratory Tract Cultures.

Refinement of criteria for both screening and initiation of empiric therapy in ventilator-associated pneumonia (VAP) will minimize antibiotic overuse. We hypothesized that variables within the commonly used Clinical Pulmonary Infection Score (CPIS) have unfavorable test performance characteristics. Consecutive bronchoalveolar lavage (BAL) cultures obtained from surgical intensive care unit patients were abstracted (2009-2012). Ventilator-associated pneumonia was defined as ≥10(5) cfu/mL. The CPIS both without (CPISclinical) and with (CPISclinical+GS) the result of gram stain (GS) was calculated. Test performance characteristics for the sample, as well as several subgroups, were compared. One thousand thirteen lower respiratory tract cultures from 492 patients were analyzed; 438 (43.2%) of cultures were classified as VAP, and 310 of 492 patients (62.4%) had ≥1 episode of VAP. Both CPISclinical and CPISclinical+GS had poor discrimination for VAP (Receiver-operating characteristic area under the curve=0.55 and 0.66, respectively). Sensitivity of CPISclinical using a threshold of >6 was 21%; the lowest threshold for CPISclinical for which the sensitivity was at least 85% was 3. The highest sensitivity among the individual CPIS components was new CXR infiltrate (91.1%). Among the subset of cultures sent during the early VAP window (days intubated 2-5), organisms on GS had a sensitivity of 93.3%. The CPISclinical, CPISclinical+GS, organisms, and neutrophils on GS parameters all became less accurate in both the late VAP window and when screening for recurrent VAP. Every case of VAP had at least one of the following: 1) fever; 2) new CXR infiltrate, or 3) organisms on GS. In this series of BALs, traditional screening tools for VAP missed the majority of microbiological confirmed cases. Screening based on either new CXR infiltrate or fever yielded an acceptably high sensitivity. The only scenario identified in which empiric antibiotics could be withheld safely was the absence of organisms on GS in the early VAP window.

A Prospective Evaluation of Ventilator-Associated Conditions and Infection-Related Ventilator-Associated Conditions

The Centers for Disease Control and Prevention has shifted policy away from using ventilator-associated pneumonia (VAP) and toward using ventilator-associated conditions (VACs) as a marker of ICU quality. To date, limited prospective data regarding the incidence of VAC among medical and surgical ICU patients, the ability of VAC criteria to capture patients with VAP, and the potential clinical preventability of VACs are available. This study was a prospective 12-month cohort study (January 2013 to December 2013). We prospectively surveyed 1,209 patients ventilated for ≥ 2 calendar days. Sixty-seven VACs were identified (5.5%), of which 34 (50.7%) were classified as an infection-related VAC (IVAC) with corresponding rates of 7.0 and 3.6 per 1,000 ventilator days, respectively. The mortality rate of patients having a VAC was significantly greater than that of patients without a VAC (65.7% vs 14.4%, P < .001). The most common causes of VACs included IVACs (50.7%), ARDS (16.4%), pulmonary edema (14.9%), and atelectasis (9.0%). Among IVACs, 44.1% were probable VAP and 17.6% were possible VAP. Twenty-five VACs (37.3%) were adjudicated to represent potentially preventable events. Eighty-six episodes of VAP occurred in 84 patients (10.0 of 1,000 ventilator days) during the study period. The sensitivity of the VAC criteria for the detection of VAP was 25.9% (95% CI, 16.7%-34.5%). Although relatively uncommon, VACs are associated with greater mortality and morbidity when they occur. Most VACs represent nonpreventable events, and the VAC criteria capture a minority of VAP episodes.

Impact of Pathogen-Directed Antimicrobial Therapy for Ventilator-Associated Pneumonia in Trauma Patients on Charges and Recurrence

Ventilator-associated pneumonia (VAP) represents one of the driving forces behind antibiotic use in the ICU. In a previous study, we established a defined algorithm for treatment of hospital-acquired VAP dictated by the causative pathogen. The purpose of the current study was to evaluate the impact of this algorithm for hospital-acquired VAP on recurrence and charges in trauma patients. Patients with VAP secondary to MRSA, Acinetobacter baumannii, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, or Enterobacteriaceae during 5 years subsequent to the previous study were evaluated. All VAP were diagnosed using quantitative cultures of the bronchoalveolar lavage effluent. Duration of antimicrobial therapy was dictated by the causative pathogen. If microbiologic resolution, defined as <10(3) colony-forming units/mL, was achieved, therapy was stopped by day 10. The remainder received 14 days of therapy. Recurrence was defined as >10(5) colony-forming units/mL on subsequent bronchoalveolar lavage performed within 2 weeks after completion of appropriate therapy. Five hundred and twenty-nine VAP episodes were identified in 381 patients. Overall recurrence was unchanged compared with the previous study (1.5% vs 2%; p = 0.3). There was a decrease in the number of bronchoalveolar lavages performed per patient compared with the previous study (1.6 vs 2.3; p = 0.24) and a reduction of 4.8 antibiotic days per VAP episode compared with the previous study. Both changes resulted in a cumulative reduction of $3,535.04 per patient, for a savings of $1.35 million during the study period. Hospital-acquired VAP can be managed effectively by a defined course of therapy dictated by the causative pathogen. Adherence to an established algorithm simplified the management of VAP and contributed to a cumulative reduction in patient charges without impacting recurrence.

Differences between novel and conventional surveillance paradigms of ventilator-associated pneumonia

To investigate the concordance between novel and conventional surveillance paradigms for ventilator-associated pneumonia (VAP). This study was conducted at a regional teaching hospital in southern Taiwan with 5 acute intensive care units. To assess the validity of novel ventilator-associated event (VAE) surveillance, we retrospectively applied the VAE algorithm to analyze all VAP cases that were identified using conventional definitions between April 2010 and February 2014. Patient outcomes, including ventilator days, hospital stay lengths, and in-hospital mortality were recorded. Among 165 episodes of conventional VAP, 55 (33.3%), 40 (24.2%), 20 (12.1%), and 2 (1.2%) episodes were classified as a ventilator-associated condition, an infection-related ventilator-associated complication, possible VAP, and probable VAP, respectively, according to the new VAE algorithm. Changes in positive end-expiratory pressure and inspired oxygen fraction levels during the development of VAP were significant higher among each VAE category than for conventional VAP (all P < .001). In-hospital mortality was significantly higher among patients with ventilator-associated condition than for patients with conventional VAP (P = .0185). In our study population, novel VAE surveillance only detected one-third of conventional VAP cases. Thus, more studies are needed to further validate VAE surveillance compared with conventional VAP by using strong microbiologic criteria, particularly bronchoalveolar lavage with a protected specimen brush for diagnosing VAP.

Gastropulmonary Route of Infection and the Prevalence of Microaspiration in the Elderly Patients with Ventilator-Associated Pneumonia Verified by Molecular Microbiology-GM-PFGE.

Gastropulmonary route of infection was considered to be an important mechanism of ventilator-associated pneumonia (VAP). However there is little evidence to support this assumption. Moreover, the prevalence of microaspiration in elderly ventilated patients was not well understood. To confirm gastropulmonary infection route and investigate the prevalence of microaspiration in elderly ventilated patients using genome macrorestriction-pulsed field gel electrophoresis (GM-PFGE). Patients over 60 years old, expected to receive mechanical ventilation longer than 48 h, were prospectively enrolled from October 2009 to January 2012. Clinical data were collected and recorded until they died, developed pneumonia, or were extubated. Samples from gastric fluid, subglottic secretion and lower respiratory tract (LRT) were collected during the follow-up for microbiological examination. To evaluate the homogeneity, GM-PFGE was performed on strains responsible for VAP that had the same biochemical phenotype as those isolated from gastric juice and subglottic secretions sequentially. Among 44 VAP patients, 76 strains were isolated from LRT and considered responsible for VAP. Twenty-two isolates had the same biochemical phenotype with the corresponding gastric isolates. The homology was further confirmed using GM-PFGE in 12 episodes of VAP. Nearly 30% of VAPs were caused by microaspiration based on the analysis of bacterial phenotype or GM-PFGE. In addition, 58.3% patients with gastric colonization developed VAP, especially late-onset VAP (LOP). Gastropulmonary infection route exists in VAP especially LOP in elderly ventilated patients. It is one of the important mechanisms in the development of VAP.

How to treat VAP due to MDR pathogens in ICU patients.

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

Description and microbiology of endotracheal tube biofilm in mechanically ventilated subjects.

A biofilm is found on the inner side of endotracheal tubes (ETT) in mechanically ventilated patients, but its features and role in pneumonia remain unclear. This prospective, observational, monocentric study included critically ill ventilated subjects. Measurement of the ETT inner volume was first performed before extubation using the acoustic reflection method. After extubation, the biofilm was studied by means of optical and atomic force microscopy. Bacteriological analysis was then performed and compared with clinical documentation. Twenty-four subjects were included. Duration of intubation lasted from 2 to 79 d (mean ± SD: 11 ± 15 d). The mean percentage of ETT volume loss evaluated in situ (n = 21) was 7.1% and was not linked with the duration of intubation. Analyses with atomic force microscopy (n = 6) showed a full coverage of the inner part of the tube with biofilm, even after saline rinse. Its thickness ranged from 0.8 to 5 μm. Bacteriological cultures of the biofilm (n = 22) often showed the same bacteria as in tracheal secretions, especially for pathogenic organisms. Pseudomonas aeruginosa and Candida albicans were among the most frequent microorganisms. In subjects who had experienced a successfully treated episode of ventilator-associated pneumonia (n = 5), the responsible bacteria were still present in the biofilm. ETT biofilm is always present in intubated patients whatever the duration of intubation and appears quickly after intubation. Even after soft rinse, a small but measurable part of biofilm remains always present, and seems strongly adherent to the ETT lumen. It contains potentially pathogenic bacteria for the lung.

Ventilator-associated respiratory infection following lung transplantation

The medical records of 170 adult patients who underwent lung transplantation between January 2010 and December 2012 were reviewed to assess the incidence, causative organisms, risk factors and outcomes of post-operative pneumonia and tracheobronchitis. 20 (12%) patients suffered 24 episodes of ventilator-associated pneumonia. The condition was associated with mean increases of 43 days in mechanical ventilation and of 35 days in hospital stay, and significantly higher hospital mortality (OR 9.0, 95% CI 3.2-25.1). Pseudomonas aeruginosa (eight out of 12 patients were multidrug-resistant) was the most common pathogen, followed by Enterobacteriaceae (one out of five patients produced extended-spectrum β-lactamases). Gastroparesis occurred in 55 (32%) patients and was significantly associated with pneumonia (OR 6.2, 95% CI 2.2-17.2). Ventilator-associated tracheobronchitis was associated with a mean increase of 28 days in mechanical ventilation and 30.5 days in hospital stay, but was not associated with higher mortality (OR 1.2, 95% CI 0.4-3.2). Pseudomonas aeruginosa (six out of 16 patients were multidrug resistant) was the most common pathogen, followed by Enterobacteriaceae (three out of 14 patients produced extended-spectrum β-lactamase). Patients with gastroparesis also had more episodes of ventilator-associated tracheobronchitis (40% versus 12%, p<0.001). In conclusion, ventilator-associated pneumonia following lung transplantation increased mortality. Preventing gastroparesis probably decreases the risk of pneumonia and tracheobronchitis. Multidrug-resistant bacteria frequently cause post-lung-transplantation pneumonia and tracheobronchitis.

The accuracy of Gram stain of respiratory specimens in excluding Staphylococcus aureus in ventilator-associated pneumonia

ObjectiveTo evaluate the Gram stain of deep tracheal aspirate as a tool to direct empiric antibiotic therapy, and more specifically as a tool to exclude the need for empiric antibiotic coverage against Staphylococcus aureus in ventilator-associated pneumonia (VAP). DesignA prospective, single-center, observational, cohort study. SettingAll wards at a community hospital. PatientsAdult patients requiring mechanical ventilation, identified as having VAP in a 54-month prospective surveillance database. InterventionsSampling of lower airway secretions by deep endotracheal aspiration was taken from each patient who developed VAP. Samples were sent immediately for Gram stain and qualitative bacterial cultures. Demographic and relevant clinical data were collected; Gram stain, culture, and antibiotic susceptibility results were documented; and outcome was followed prospectively. Measurements and Main ResultsThe analysis included 114 consecutive patients with 115 episodes of VAP from June 2007 to January 2012. Sensitivity of Gram stain compared with culture was 90.47% for gram-positive cocci, 69.6% for gram-negative rods, and 50% for sterile cultures. Specificity was 82.5%, 77.8%, and 79%, respectively. Negative predictive value was high for gram-positive cocci (97%) and sterile cultures (96%) but low for gram-negative rods (20%). Acinetobacter baumanii (45%) and Pseudomonas aeruginosa (38 %) were the prevailing isolates. S aureus was found in 18.3% of the patients. Most isolates were multiresistant. ConclusionsAbsence of gram-positive bacteria on Gram stain had a high negative predictive value. These data can be used to narrow the initial empiric antibiotic regimen and to avoid unnecessary exposure of patients to vancomycin and other antistaphyloccocal agents.