Cause Of Ventilator-associated Pneumonia Research Articles

Protective effect of procysteine on Acinetobacter pneumonia in hyperoxic conditions

Ventilator-associated pneumonia (VAP) is an important cause of morbidity and mortality in critical care settings. Acinetobacter has become a leading cause of VAP. In particular, the appearance and spread of multidrug-resistant Acinetobacter is of great concern. In this study, we examined the effect of the antioxidant procysteine on Acinetobacter murine pneumonia in hyperoxic conditions in order to simulate VAP. Acinetobacter was administered intranasally to BALB/c mice kept in hyperoxic conditions. At designated timepoints, bacterial number, cytokine production and histopathological findings in the lungs were examined. The effects of procysteine on survival rates, lung bacterial burdens and the phagocytic activities of alveolar macrophages were evaluated. Drastic decreases in survival were observed when the infected mice were kept in hyperoxic conditions (P < 0.001). Significant differences in pulmonary bacterial number and neutrophil accumulation were observed between mice kept in hyperoxic or normoxic conditions on day 3. Although all mice infected with Acinetobacter spp. and kept in hyperoxic conditions died by day 3, procysteine treatment significantly improved survival (60% survival on day 7, P < 0.01). Procysteine treatment decreased the lung bacterial burden on days 2 and 3. Finally, improved uptake of FITC-labelled beads by alveolar macrophages from mice treated with procysteine and kept in hyperoxic conditions was noted. These results suggest that hyperoxia increases mortality in mice with Acinetobacter pneumonia and that procysteine improves survival by increasing the phagocytic activity of alveolar macrophages in mice kept in hyperoxic conditions.

Endotracheal tube with tapered-type cuff for preventing ventilator-associated pneumonia: a randomized clinical trial

The most common cause of ventilator-associated pneumonia (VAP) is aspiration of oral secretion through the endotracheal tube (ET). Subglottic suction drainage (SSD) has been recommended as a safety measure against aspiration due to its high effectiveness. Currently, two types of cuff shape - spindle and tapered - are predominant in high-volume, low-pressure (HVLP) ETs with SSD. However, the shape most suitable for preventing dripping onto the subglottis has not been determined. The purpose of this study was to determine whether an ET with tapered-type cuff can reduce the incidence of VAP.

Acinetobacter is the most common pathogen associated with late-onset and recurrent ventilator-associated pneumonia in an adult intensive care unit in Saudi Arabia

The guidelines for initial empiric antimicrobial therapy for ventilator-associated pneumonia (VAP) are highly dependent on the type of causative pathogen and the time of diagnosis. The objective of this study was to examine the microbial causes of VAP and describe any variability by the timing of VAP onset and over time. A prospective surveillance study was conducted in the adult general intensive care unit of a tertiary care hospital in Riyadh, Saudi Arabia. Microbial isolates obtained from blood and different respiratory specimens of patients diagnosed with VAP (using the US Centers for Disease Control and Prevention definition) between August 2003 and June 2009 were included. A total of 457 pathogens were identified during the study; 380 (83.2%) were associated with primary VAP and 77 (16.8%) were associated with recurrent VAP. Of primary VAP pathogens, 159 (41.8%) were associated with early-onset (<5 days) and 221 (58.2%) were associated with late-onset (≥5 days) VAP. The most common pathogen identified was Acinetobacter spp (26.5%), followed by Pseudomonas aeruginosa (21.7%), Staphylococcus aureus including methicillin-resistant S. aureus (MRSA) (15.3%), Klebsiella spp (6.8%), Haemophilus spp (6.1%), and Enterobacter spp (5.0%). Acinetobacter spp and MRSA were significantly associated with late-onset VAP while Haemophilus spp and Streptococcus pneumoniae were significantly associated with early-onset VAP. Acinetobacter spp was the only pathogen associated with recurrent VAP and its incidence showed a significant increasing trend during the study period. Acinetobacter spp was significantly associated with prolonged ventilation, sedation, and nasogastric intubation. Acinetobacter baumannii is the most common and increasingly important pathogen associated with VAP in our patients, especially late-onset and recurrent VAP.

P069: Drug-resistant acinetobacter ventilator-associated pneumonia: a time for desperate measures!

There is a wide geographic and temporal variability of bacterial resistance among microbial causes of ventilator-associated pneumonia (VAP). The contribution of multi-drug resistant (MDR) pathogens to the VAP etiology in Saudi Arabia was never studied.

Midkine Is Expressed and Differentially Processed during Chronic Obstructive Pulmonary Disease Exacerbations and Ventilator-Associated Pneumonia Associated with Staphylococcus aureus Infection

Staphylococcus aureus is sometimes isolated from the airways during acute exacerbations of chronic obstructive pulmonary disease (COPD) but more commonly recognized as a cause of ventilator-associated pneumonia (VAP). Antimicrobial proteins, among them midkine (MK), are an important part of innate immunity in the airways. In this study, the levels and possible processing of MK in relation to S. aureus infection of the airways were investigated, comparing COPD and VAP, thus comparing a state of disease with preceding chronic inflammation and remodeling (COPD) with acute inflammation (that is, VAP). MK was detected in the small airways and alveoli of COPD lung tissue but less so in normal lung tissue. MK at below micromolar concentrations killed S. aureus in vitro. Proteolytic processing of MK by the staphylococcal metalloprotease aureolysin (AL), but not cysteine protease staphopain A (SA), resulted in impaired bactericidal activity. Degradation was seen foremost in the COOH-terminal portion of the molecule that harbors high bactericidal activity. In addition, MK was detected in sputum from patients suffering from VAP caused by S. aureus but less so in sputum from COPD exacerbations associated with the same bacterium. Recombinant MK was degraded more rapidly in sputum from the COPD patients than from the VAP patients and a greater proteolytic activity in COPD sputum was confirmed by zymography. Taken together, proteases of both bacteria and the host contribute to degradation of the antibacterial protein MK, resulting in an impaired defense of the airways, in particular, in COPD where the state of chronic inflammation could be of importance.

Active surveillance cultures of methicillin-resistant Staphylococcus aureus as a tool to predict methicillin-resistant S. aureus ventilator-associated pneumonia*

Ventilator-associated pneumonia is one of the most common infections in the intensive care unit and methicillin-resistant Staphylococcus aureus has emerged as a common cause of ventilator-associated pneumonia. We sought to study the performance characteristics of once weekly active surveillance culture of methicillin-resistant S. aureus colonization in predicting the development of methicillin-resistant S. aureus ventilator-associated pneumonia. Prospective observational study. Eighty-nine-bed surgical and medical intensive care units in a university-affiliated urban teaching hospital and level I trauma and burn center. All patients≥16 yrs old admitted to the intensive care unit on mechanical ventilation≥48 hrs who met diagnostic criteria for ventilator-associated pneumonia by quantitative lower respiratory tract cultures obtained through bronchoscopic alveolar lavage or brush specimen between January 2008 and October 2010 were included. None. Nine hundred twenty-four episodes of suspected ventilator-associated pneumonia were evaluated, and 388 patients with bronchoalveolar lavage-confirmed ventilator-associated pneumonia were included. Surveillance cultures were taken from the nares, oropharynx or trachea, and any open wound routinely on admission to the intensive care unit, every 7 days afterward, and at intensive care unit discharge. Of the 388 patients, 37 (9.5%) had methicillin-resistant S. aureus ventilator-associated pneumonia and 54 (13.9%) had methicillin-resistant S. aureus colonization documented by active surveillance culture before the development of ventilator-associated pneumonia. The sensitivity and specificity of prior methicillin-resistant S. aureus colonization as a predictor for methicillin-resistant S. aureus ventilator-associated pneumonia are 70.3% (95% confidence interval [CI] 52.8-83.6) and 92.0% (95% CI 88.5-94.5), respectively. The positive and negative predictive values are 48.1% (95% CI 34.5- 62.0) and 96.7% (95% CI 94.0-98.3). In our study, prior methicillin-resistant S. aureus colonization as ascertained by once-weekly active surveillance culture yielded high specificity and negative predictive value, suggesting that negative active surveillance culture can accurately exclude methicillin-resistant S. aureus as an etiology in most patients with ventilator-associated pneumonia and may decrease the need for empirical methicillin-resistant S. aureus coverage in patients with suspected ventilator-associated pneumonia.

Ventilator-associated pneumonia due to meticillin-resistant Staphylococcus aureus: risk factors and outcome in a large general hospital

Data about risk factors and impact on outcome of methicillin-resistant S. aureus (MRSA) in unselected patients with ventilator-associated pneumonia (VAP) are limited. To assess predisposing factors and outcome of VAP due to MRSA in a large teaching institution. Prospective study carried out over four years in the three adult ICUs of our hospital. Patients with MRSA-VAP were compared with those with bacterial VAP due to other microorganisms. Overall, 474 episodes of bacterial VAP were collected. Significant differences between MRSA-VAP (111) and VAP due to other microorganisms (363) were found for median age (68 vs. 62 years), median APACHE II score (12 vs. 11), neurosurgery (5.4% vs. 13.8%), abdominal surgery (35% vs. 19%), prior treatment with any antibiotic (82.9% vs. 64.5%) and with imipenem (24% vs. 11%) at present admission before VAP, and pleural effusion (12% vs. 5%). Multivariate analysis adjusted for confounding factors showed that higher APACHE II score, prior treatment with any antibiotic and pleural effusion were independent risk factors for MRSA. As for treatment and outcome, the differences between MRSA-VAP and other VAP were inadequate empiric treatment (70% vs. 53%), median cost of antibiotics per episode (€974 vs. €726), and in-hospital mortality (60% vs. 47%). At multivariate analysis, however, MRSA was not found to be an independent risk factor for mortality. MRSA is a common cause of VAP. Underlying conditions predispose to its high mortality.

Prevalence and clinical outcomes of episodes of ventilator-associated pneumonia caused by SPM-1-producing and non-producing imipenem-resistant Pseudomonas aeruginosa

Pseudomonas aeruginosa is a leading cause of ventilator-associated pneumonia (VAP) and exhibits high rates of resistance to several antimicrobial drugs. The carbapenens are usually the drugs of choice against this microorganism. However, the carbapenem resistance has increased among these strains worldwide. The presence of metallo-β-lactamases (MBL) has been pointed out as a major mechanism of resistance among these strains. No previous study addressed outcomes of respiratory infections caused by these strains. Our group sought to analyze the epidemiology and clinical outcomes of patients with VAP caused by imipenem-resistant P. aeruginosa. A total of 29 clinical isolates of carbapenem-resistant Pseudomonas aeruginosa were screened for metallo-β-lactamase (MBL) genes. Demographic and clinical variables were similar between the SPM-1-producing and non-SPM-1-producing group. Five (17.2%) isolates were positive for blaSPM-1. No other MBL gene was found. All patients were treated with polymyxin B. The infection-related mortality was 40% and 54.2% for SPM-1-producing and -non-producing isolates, respectively. There were no differences in epidemiological and clinical outcomes between the two groups.

Subglottic secretion drainage for the prevention of ventilator-associated pneumonia: A systematic review and meta-analysis*

Aspiration of secretions containing bacterial pathogens into the lower respiratory tract is the main cause of ventilator-associated pneumonia. Endotracheal tubes with subglottic secretion drainage can potentially reduce this and, therefore, the incidence of ventilator-associated pneumonia. New evidence on subglottic secretion drainage as a preventive measure for ventilator-associated pneumonia has been recently published and to consider the evidence in totality, we conducted an updated systematic review and meta-analysis. We searched computerized databases, reference lists, and personal files. We included randomized clinical trials of mechanically ventilated patients comparing standard endotracheal tubes to those with subglottic secretion drainage and reporting on the occurrence of ventilator-associated pneumonia. Studies were meta-analyzed for the primary outcome of ventilator-associated pneumonia and secondary clinical outcomes. We identified 13 randomized clinical trials that met the inclusion criteria with a total of 2442 randomized patients. Of the 13 studies, 12 reported a reduction in ventilator-associated pneumonia rates in the subglottic secretion drainage arm; in meta-analysis, the overall risk ratio for ventilator-associated pneumonia was 0.55 (95% confidence interval, 0.46-0.66; p < .00001) with no heterogeneity (I = 0%). The use of subglottic secretion drainage was associated with reduced intensive care unit length of stay (-1.52 days; 95% confidence interval, -2.94 to -0.11; p = .03); decreased duration of mechanically ventilated (-1.08 days; 95% confidence interval, -2.04 to -0.12; p = .03), and increased time to first episode of ventilator-associated pneumonia (2.66 days; 95% confidence interval, 1.06-4.26; p = .001). There was no effect on adverse events or on hospital or intensive care unit mortality. In those at risk for ventilator-associated pneumonia, the use of endotracheal tubes with subglottic secretion drainage is effective for the prevention of ventilator-associated pneumonia and may be associated with reduced duration of mechanical ventilation and intensive care unit length of stay.

Molecular Laboratory Tests for the Diagnosis of Respiratory Tract Infection Due to Staphylococcus aureus

When Staphylococcus aureus is the cause of ventilator-associated pneumonia or a bacterial infection following influenza, the infections are devastating if not treated promptly. Disease due to methicillin-resistant S. aureus (MRSA) continues to be of concern throughout most of the United States. Currently, the U.S. Food and Drug Administration (FDA) has cleared polymerase chain reaction tests for detection of MRSA in nasal swab specimens; however, there are no FDA-cleared tests for identifying S. aureus in purulent respiratory secretions. The real-time polymerase chain reaction tests for S. aureus (primarily MRSA) in nares provide results in <2 h and have sensitivities ranging from 95% to 100%, with specificities of 96%-99%; these results are comparable to that of standard cultures, which can take up to 3-4 days for final results. The FDA is encouraged to work closely with industry providers to expedite the evaluation and clearance process for molecular diagnostic devices detecting S. aureus (including MRSA) in the diagnosis of respiratory tract infection.

Incidence, risk stratification, antibiogram of pathogens isolated and clinical outcome of ventilator associated pneumonia

Background:The initial empirical therapy of Ventilator Associated Pneumonia (VAP) modified based on the knowledge of local microbiological data is associated with decreased morbidity and mortality. The objective was to find the incidence and risk factors associated with VAP, the implicated pathogens and their susceptibility pattern as well as to assess the final clinical outcome in VAP.Materials and Methods:This was a prospective cohort study of 107 patients taken on ventilatory support for two or more days and those not suffering from pneumonia prior were to be taken on ventilator. The study was done over a period of one year. VAP was diagnosed using clinical pulmonary infection score of >6. The mortality, incidence of VAP, frequency of different pathogens isolated, their antibiotic sensitivity pattern, duration of mechanical ventilation and duration of hospital stay were assessed.Statistical Analysis:Univariate analysis, χ2 test and paired t-test.Results:The incidence of VAP was 28.04%. Mortality in VAP group was 46.67%, while in the non-VAP group was 27.28%. High APACHE II score was associated with a high mortality rate as well as increased incidence of VAP. The most common organisms isolated from endotracheal aspirate of patients who developed VAP were Pseudomonas aeruginosa, Methicillin-resistant Staphylococcus aureus (MRSA), Klebsiella pneumoniae and Acinetobacter baumannii. Most strains of Pseudomonas (55.56%) were resistant to commonly used beta-lactam antibiotics known to be effective against Pseudomonas. All strains of Staphylococcus aureus were MRSA and most isolates of K. pneumoniae (85.71%) were extended-spectrum beta-lactamase producing. About 50% isolates of Acinetobacter were resistant to carbapenems. Mortality was highest for infections caused by A. baumannii (83.33%) and K. pneumoniae (71.42%).Conclusions:APACHE II score can be used to stratify the risk of development of VAP and overall risk of mortality. Drug-resistant strains of various organisms are an important cause of VAP in our setting.

Viral-reactivated pneumonia during mechanical ventilation: is there need for antiviral treatment?

Respiratory viruses are not a common cause of ventilator-associated pneumonia (VAP). Herpesviridae [Herpes simplex virus (HSV) and cytomegalovirus (CMV)] are detected frequently in the lower respiratory tract of ventilated patients. HSV is detected between days 7 and 14 of invasive mechanical ventilation (IMV); presence of the virus does not necessarily imply pathogenicity, but the association with adverse clinical outcomes supports the hypothesis of a pathogenic role in a variable percentage of patients. Bronchopneumonitis associated with HSV should be considered in patients with prolonged IMV, reactivation with herpetic mucocutaneous lesions and those belonging to a risk population with burn injuries or acute lung injury. Reactivation of CMV is common in critically ill patients and usually occurs between days 14 and 21 in patients with defined risk factors. The potential pathogenic role of CMV seems clear in patients with acute lung injury and persistent respiratory failure in whom there is no isolation of bacterial agent as a cause of VAP. The best diagnostic test is not defined although lung biopsies should be considered in addition to the usual methods before starting specific treatment. The role of mimivirus is uncertain and is yet to be defined, but the serologic evidence of this new virus in the context of VAP appears to be associated with adverse clinical outcomes.

Fluid leakage across tracheal tube cuff, effect of different cuff material, shape, and positive expiratory pressure: a bench-top study

Standard polyvinylchloride (PVC) endotracheal tube (ETT) cuffs do not protect from aspiration across the cuff, a leading cause of ventilator-associated pneumonia (VAP). In a long-lasting in vitro study we compared the effect of different cuff materials (PVC, polyurethane, and guayule latex), shapes (cylindrical, conical), and positive end expiratory pressures (PEEP) in reducing fluid leakage across the cuff. We compared fluid leakage across a cylindrical double-layer guayule latex prototype cuff, three cylindrical PVC cuffs (Mallinckrodt Hi-Lo, Mallinckrodt HighContour, Portex Ivory), one conical PVC cuff (Mallinckrodt TaperGuard), and two polyurethane cuffs (Mallinckrodt SealGuard, conical; Microcuff, cylindrical). Ten centimeters of dyed water was poured above the cuffs inflated (pressure 30 cmH(2)O) in a vertical cylinder (diameter 20 mm). A respiratory circuit connected the bottom of the cylinder to a breathing bag inflated at four pressures (PEEP = 0, 5, 10, 15 cmH(2)O). Pictures were taken every 60 s for 24 h to measure leakage as a reduction in the water column above the cuff. Five new ETTs of each type were tested. The guayule latex cuffs showed no leakage at all the PEEP levels. Both the cylindrical and conical polyurethane cuffs showed limited leakage (2.1 ± 1.8 cm of water) only for PEEP zero. The PVC cuffs showed reduced leakage with increasing PEEP: 8.4 ± 1.5, 7.8 ± 2.2, 2.2 ± 1.0, and 0 cm of water at 0, 5, 10, and 15 cmH(2)O, respectively. Among all the PVC cuffs, the conical shape ensured higher sealing properties. The guayule latex cuffs always prevented fluid leakage; the polyurethane and PVC cuffs required incremental levels of PEEP to prevent fluid leakage ever-present at zero PEEP.

Treatment of Recurrent Stenotrophomonas maltophilia Ventilator-Associated Pneumonia with Doxycycline and Aerosolized Colistin

Objective: To report a case of recurrent Stenotrophomonas maltophilia ventilator-associated pneumonia (VAP) that was successfully treated with doxycycline and aerosolized colistin. Case Summary: A 28-year-old male was admitted with a severe head injury and required mechanical ventilation. The patient developed S. maltophilia VAP on hospital day 17, which was cured after 7 days of treatment with high-dose intravenous trimethoprim/sulfamethoxazole (TMP/SMX). However, on day 34, the patient developed recurrent S. maltophilia VAP that did not respond clinically or demonstrate eradication on follow-up culture after 10 days of TMP/SMX. At that time, TMP/SMX was discontinued and treatment was initiated with intravenous doxycycline and aerosolized colistin. The VAP episode was cured after 14 days of treatment with doxycycline/aerosolized colistin. Discussion: S. maltophilia is an emerging cause of VAP in some centers. This organism is associated with high mortality rates and has few treatment options because it is intrinsically resistant to most drug classes. Recent data suggest that doxycycline and aerosolized colistin each are effective in treatment of other multidrug-resistant organisms, such as Pseudomonas aeruginosa and Acinetobacter baumannii. However, this is the first report describing the use of this antibiotic regimen for S. maltophilia. High-dose TMP/SMX is considered to be the drug of choice primarily based on excellent in vitro activity. Few data exist on how to treat patients who fail therapy with TMP/SMX or cannot receive that drug because of resistance, allergy, or adverse events. Thus, it is important to report alternative methods for treating this infection. Conclusions: The positive clinical response to doxycycline and aerosolized colistin seen in the patient described here suggests that this combination may be an alternative treatment in patients who fail initial treatment or cannot receive standard therapies.

Treatment of Recurrent Stenotrophomonas maltophilia Ventilator-Associated Pneumonia with Doxycycline and Aerosolized Colistin

To report a case of recurrent Stenotrophomonas maltophilia ventilator-associated pneumonia (VAP) that was successfully treated with doxycycline and aerosolized colistin. A 28-year-old male was admitted with a severe head injury and required mechanical ventilation. The patient developed S. maltophilia VAP on hospital day 17, which was cured after 7 days of treatment with high-dose intravenous trimethoprim/sulfamethoxazole (TMP/SMX). However, on day 34, the patient developed recurrent S. maltophilia VAP that did not respond clinically or demonstrate eradication on follow-up culture after 10 days of TMP/SMX. At that time, TMP/SMX was discontinued and treatment was initiated with intravenous doxycycline and aerosolized colistin. The VAP episode was cured after 14 days of treatment with doxycycline/aerosolized colistin. S. maltophilia is an emerging cause of VAP in some centers. This organism is associated with high mortality rates and has few treatment options because it is intrinsically resistant to most drug classes. Recent data suggest that doxycycline and aerosolized colistin each are effective in treatment of other multidrug-resistant organisms, such as Pseudomonas aeruginosa and Acinetobacter baumannii. However, this is the first report describing the use of this antibiotic regimen for S. maltophilia. High-dose TMP/SMX is considered to be the drug of choice primarily based on excellent in vitro activity. Few data exist on how to treat patients who fail therapy with TMP/SMX or cannot receive that drug because of resistance, allergy, or adverse events. Thus, it is important to report alternative methods for treating this infection. The positive clinical response to doxycycline and aerosolized colistin seen in the patient described here suggests that this combination may be an alternative treatment in patients who fail initial treatment or cannot receive standard therapies.

Mini-bronchoalveolar lavage quantitative polymerase chain reaction for diagnosis of methicillin-resistant Staphylococcus aureus pneumonia*

Methicillin-resistant Staphylococcus aureus is a common cause of ventilator-associated pneumonia and can be identified by the mecA gene that confers resistance. The objective was to develop a polymerase chain reaction assay for mecA using mini-bronchoalveolar lavage to allow rapid diagnosis of ventilator associated pneumonia attributable to methicillin-resistant Staphylococcus aureus. Real-time quantitative polymerase chain reaction was developed using serial dilution of plasmids containing known amounts of mecA gene fragments. Specificity of molecular identification was based on the presence of the mecA gene and S. aureus-specific femA-SA gene, with absence of Staphylococcus epidermidis specific femA-SE. To validate the polymerase chain reaction, we compared it to mini-bronchoalveolar lavage quantitative cultures in 100 mechanically ventilated patients with suspected pneumonia. We derived a threshold value for defining a positive polymerase chain reaction based on a priori criteria of 100% sensitivity. We then tested the polymerase chain reaction using this threshold value on a separate cohort of 50 patients. Polymerase chain reaction was able to detect mecA down to a copy number of three, with a high degree of correlation (r=.999). The area under the receiver-operating characteristic curve for polymerase chain reaction was 0.98 (95% confidence interval, 0.93-0.99). Using a cut-point of >or=421 for the polymerase chain reaction resulted in sensitivity of 100%, specificity of 87% (95% confidence interval 81%-94%), positive predictive value of 39% (95% confidence interval, 29%-49%), negative predictive value of 100%, and an overall correct classification rate of 89%. Applying the polymerase chain reaction with a cut-point of >or=421 to the second cohort resulted in a sensitivity of 100% and a specificity of 80%. Quantitative polymerase chain reaction of mecA combined with femA-SA and femA-SE detection was able to rapidly and accurately diagnose methicillin-resistant S. aureus.

How I Learned My ABCs: Action, Back to Basics, Collaboration, Discovery

Research is essential to generate the scientific evidence for critical care nursing practice, but it is challenging to conduct research in the busy critical care environment. The challenges are even greater in a setting with limited resources for research and where nurses have not typically conducted independent clinical studies. To detail a successful research trajectory for studying the ABCs of patient care in the critically ill: airway, breathing, and circulation. After initial studies on circulation were conducted, the research was narrowed to focus on airway management. Airway management may be a key factor in preventing ventilator-associated pneumonia because aspiration of colonized oral, gastric, and tracheal secretions is the primary cause of ventilator-associated pneumonia. Multiple descriptive, pilot, and interventional studies have been conducted; findings from each have contributed to future studies. Other ABCs were critical to this research success: action, back to basics, collaboration, and discovery. It is important for researchers to be self-motivated and to take initiative to develop skills and resources for conducting clinical studies. Several guiding principles help to promote success in research: (1) generate research ideas grounded in observation and clinical practice, (2) collaborate with others, and (3) establish affiliations and partnerships. Discovery occurs in many ways: new findings to guide practice and research, resources to conduct the study, and self-discovery. Nursing research is not easy. However, determination and resources help nursing researchers achieve success.

Effect of linezolid in ventilator-associated pneumonia caused by MRSA

Evaluation of: Wunderink RG, Mendelson MH, Somero MS et al. Early microbiological response to linezolid vs vancomycin in ventilator-associated pneumonia due to methicillin-resistant Staphylococcus aureus. Chest 134, 1200–1207 (2008).Methicillin-resistant Staphylococcus aureus (MRSA) is an important cause of ventilator-associated pneumonia (VAP), especially in patients who develop VAP late in their hospital course. Clinical failure in MRSA VAP is unacceptably high. Linezolid is an oxazolidinone antimicrobial agent that demonstrates bacteriostatic activity against MRSA and has been demonstrated to be equivalent to vancomycin in the treatment of nosocomial pneumonia. Retrospective analysis of two randomized, double-blind, studies suggests that linezolid therapy may confer clinical benefit over vancomycin in patients with MRSA VAP. Linezolid demonstrates excellent penetration into the epithelial-lining fluid and this feature has been postulated to be integral to its therapeutic benefit in MRSA VAP. This article evaluates the findings of a recently published prospective, randomized, open-label, comparator-controlled, multicenter trial that aims to compare the early microbiological efficacy of linezolid with vancomycin in the treatment of VAP caused by MRSA.

The risk factors and spread of multidrug-resistant Acinetobacter baumannii in intubated patients in a medical intensive care unit

Aim: Acinetobacter baumannii is one of the most common causes of ventilator-associated pneumonia in intensive care units. The aim of this study was to determine the risk factors for colonization in the respiratory tract and infection with A. baumannii in a medical intensive care unit (MICU), and to examine the genetic link between strains and the spread of isolates. Materials and methods: This study was conducted prospectively between 1 December 2004 and 31 January 2006 in the MICU. Patients (> 16 years old) admitted to the MICU that were mechanically ventilated and/or intubated were enrolled in the study. Results: Ninety-eight patients were evaluated for A. baumannii colonization during or at the end of their intubation; 44 (45%) of these patients were colonized by A. baumannii. The length of intubation (OR: 1.032, P = 0.014) and diabetes mellitus (OR: 4.140, P = 0.008) were the major risk factors for colonization of the respiratory tract by A. baumannii. During the study period A. baumannii infection developed in 35 (80%) of the 44 colonized patients. The important risk factors for A. baumannii infection were colonization (OR: 3.962, P = 0.006) and tracheostomy (OR: 4.857, P = 0.001). Genotyping analysis was performed for 59 isolates. Overall, 3 clones (clone A, B, and C) were identified in patients; 88% were clone A (52 isolates), 7% were clone B (4 isolates), and 5% were clone C (3 isolates). Conclusion: Length of intubation and diabetes mellitus were significant risk factors for A. baumannii colonization in intubated patients. Moreover, colonization and tracheostomy predisposed patients to infection. Additionally, this study documented the spread of multi-drug resistant A. baumannii in intubated patients in an MICU with limited resources.

Early Microbiological Response to Linezolid vs Vancomycin in Ventilator-Associated Pneumonia Due to Methicillin-Resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of ventilator-associated pneumonia (VAP). This prospective, open-label, multicenter clinical trial compared the early microbiological efficacy of linezolid (LZD) therapy with that of vancomycin (VAN) therapy in patients with MRSA VAP. A total of 149 patients with suspected MRSA VAP were randomized to receive either LZD, 600 mg, or VAN, 1 g every 12 h. Patients with baseline bronchoscopic BAL (BBAL) fluid quantitative culture findings that were positive for MRSA (>or= 10(4) cfu/mL) comprised the study population. The primary outcome was microbiological response (<or= 10(2) cfu/mL) in a second BBAL performed 72 to 96 h following the start of treatment. Thirty LZD-treated patients and 20 VAN-treated patients had microbiologically confirmed MRSA at baseline; 23 and 19 patients, respectively, underwent repeat BBAL. While a greater number of LZD-treated patients than VAN-treated patients achieved a microbiological cure (56.5% vs 47.4%, respectively; p = 0.757; 95% confidence interval, -21.1 to 39.4), this difference was not statistically significant. Nonstatistically significant differences were also seen for LZD-treated patients vs VAN-treated patients in terms of clinical cure (66.7% vs 52.9%, respectively), survival rate (86.7% vs 70.0%, respectively), and the mean duration of ventilation (10.4 vs 14.3 d, respectively), hospitalization (18.8 vs 20.1 d, respectively), ICU stay (12.2 vs 16.2 d, respectively), and time spent alive and not receiving mechanical ventilation (15.5 vs 11.1 d, respectively). Three patients who had been extubated prior to undergoing repeat BBAL had been randomized to receive LZD therapy. Early microbiological cure rates were not statistically significantly higher with LZD therapy than with VAN therapy despite trends in all secondary clinical outcomes favoring LZD therapy. These results suggest that any beneficial effect of LZD therapy may be due to factors other than increased bacterial clearance. Clinicaltrials.gov Identifier: NCT00572559.