Common Ventilator-associated Pneumonia Research Articles

Ventilator-Associated Pneumonia in Paediatric Intensive Care Unit Patients: Microbiological Profile, Risk Factors, and Outcome.

Introduction Ventilator-associated pneumonia (VAP) is one of the dreaded events in sick children who are ventilated in the paediatric intensive care unit (PICU) and has a high mortality rate. So, there is a need to know the causative organisms, risk factors, and possible predictors in a particular PICU for prevention, early identification, and treatment to decrease morbidity and mortality. This study was planned with the objectives to determine the microbiological profile, associated risk factors, and outcome of VAP in children. Methods In this observational cross-sectional study conducted at Dr.B C Roy Post Graduate Instituteof Paediatric Science, Kolkata, India, 37 VAP cases were diagnosed using clinical pulmonary infection score >6 and confirmed by tracheal culture and X-ray. Results The number of paediatric patients suffering from VAP was 37 (36.2%).The commonest age group involvement was one to five years. The microbiological profile included Pseudomonas aeruginosa (29.8%) and Klebsiellapneumoniae (21.6%) as the commonest organisms followed by Staphylococcus aureus (18.9%) and Acinetobacter (13.5%). The factors significantly associated with the increased frequency of VAP were the use of steroids, sedation, and reintubation. The mean duration of mechanical ventilation (MV) in VAP was 15 days compared to non-VAP (seven days), and the longer duration of ventilation was significantly associated with VAP (p=0.00001). Mortality in VAP was 48.54% compared to non-VAP (55.84%) with no significant association (p=0.0843) of VAP with death occurrence. Conclusion The present study showed that VAP occurrence isassociated with prolonged duration of MV, PICU stay, and hospital stay but is not significantly associated with mortality. It also indicated that gram-negative bacteria were the most common VAP causative organisms in this cohort.

PCR coupled to electrospray ionization mass spectrometry for microbiological diagnosis and surveillance of ventilator-associated pneumonia.

Etiological diagnosis is essential for anti-infective therapy in patients with ventilator-associated pneumonia (VAP). The present study aimed to evaluate the capacity of sequential PCR coupled to electrospray ionization mass spectrometry (PCR/ESI-MS) tests as a rapid diagnostic technique for patients with VAP. A total of 12 patients diagnosed with VAP were enrolled at the intensive care unit in Zhongshan Hospital, Fudan University. Mini-bronchoalveolar lavage fluid specimens were prospectively collected on VAP 0, 5 and 10 days following the beginning of mechanical ventilation. Routine clinical culture and PCR/ESI-MS were compared for identification of microorganisms in the specimens. A total of 51 bacterial species were detected by either of the two methods. The positive rates of routine clinical culture and PCR/ESI-MS were 38.2 and 88.2%, respectively. Out of the 16 specimens positive in routine cultures, 15 were also positive on PCR/ESI-MS, except for one, from which a mix of three distinct bacterial isolates were reported by culture. Among the 50 bacterial species identified by PCR/ESI-MS, 15 (35.7%) of the common VAP pathogens were confirmed by paired culture. Furthermore, of the 16 bacterial isolates that were finally confirmed to be responsible for VAP, 14 were identified by a sequential PCR/ESI-MS test concurrently when the culture results were obtained. PCR/ESI-MS identified pathogens that may cause VAP in 8 subjects prior to the occurrence of associated clinical manifestations. To conclude, PCR/ESI-MS was a potential rapid technique for diagnosis of VAP within 6 h. Regular respiratory specimen monitoring using PCR/ESI-MS provides information for selecting appropriate and adequate antibiotic therapies in ventilated patients.

Biofilm formation on three different endotracheal tubes: a prospective clinical trial

BackgroundBiofilm formation on endotracheal tubes (ETTs) is an early and frequent event in mechanically ventilated patients. The biofilm is believed to act as a reservoir for infecting microorganisms and thereby contribute to development and relapses of ventilator-associated pneumonia (VAP). Once a biofilm has formed on an ETT surface, it is difficult to eradicate. This clinical study aimed to compare biofilm formation on three widely used ETTs with different surface properties and to explore factors potentially predictive of biofilm formation.MethodsWe compared the grade of biofilm formation on ETTs made of uncoated polyvinyl chloride (PVC), silicone-coated PVC, and PVC coated with noble metals after > 24 h of mechanical ventilation in critically ill patients. The comparison was based on scanning electron microscopy of ETT surfaces, biofilm grading, surveillance and biofilm cultures, and occurrence of VAP.ResultsHigh-grade (score ≥ 7) biofilm formation on the ETTs was associated with development of VAP (OR 4.17 [95% CI 1.14–15.3], p = 0.031). Compared to uncoated PVC ETTs, the silicone-coated and noble-metal-coated PVC ETTs were independently associated with reduced high-grade biofilm formation (OR 0.18 [95% CI 0.06–0.59], p = 0.005, and OR 0.34 [95% CI 0.13–0.93], p = 0.036, respectively). No significant difference was observed between silicon-coated ETTs and noble-metal-coated ETTs (OR 0.54 [95% CI 0.17–1.65], p = 0.278). In 60% of the oropharyngeal cultures and 58% of the endotracheal cultures collected at intubation, the same microorganism was found in the ETT biofilm at extubation. In patients who developed VAP, the causative microbe remained in the biofilm in 56% of cases, despite appropriate antibiotic therapy. High-grade biofilm formation on ETTs was not predicted by either colonization with common VAP pathogens in surveillance cultures or duration of invasive ventilation.ConclusionHigh-grade biofilm formation on ETTs was associated with development of VAP. Compared to the uncoated PVC ETTs, the silicone-coated and noble-metal-coated PVC ETTs were independently associated with reduced high-grade biofilm formation. Further research on methods to prevent, monitor, and manage biofilm occurrence is needed.Trial registrationClinicalTrials.gov NCT02284438. Retrospectively registered on 21 October 2014.

World-Wide Variation in Incidence of Staphylococcus aureus Associated Ventilator-Associated Pneumonia: A Meta-Regression.

Staphylococcus aureus (S. aureus) is a common Ventilator-Associated Pneumonia (VAP) isolate. The objective here is to define the extent and possible reasons for geographic variation in the incidences of S. aureus-associated VAP, MRSA-VAP and overall VAP. A meta-regression model of S. aureus-associated VAP incidence per 1000 Mechanical Ventilation Days (MVD) was undertaken using random effects methods among publications obtained from a search of the English language literature. This model incorporated group level factors such as admission to a trauma ICU, year of publication and use of bronchoscopic sampling towards VAP diagnosis. The search identified 133 publications from seven worldwide regions published over three decades. The summary S. aureus-associated VAP incidence was 4.5 (3.9–5.3) per 1000 MVD. The highest S. aureus-associated VAP incidence is amongst reports from the Mediterranean (mean; 95% confidence interval; 6.1; 4.1–8.5) versus that from Asian ICUs (2.1; 1.5–3.0). The incidence of S. aureus-associated VAP varies by up to three-fold (for the lowest versus highest incidence) among seven geographic regions worldwide, whereas the incidence of VAP varies by less than two-fold. Admission to a trauma unit is the most important group level correlate for S. aureus-associated VAP.

Ventilator‐associated pneumonia in a paediatric intensive care unit in a developing country with high HIV prevalence

To obtain preliminary prevalence, aetiological and outcome data on South African paediatric patients with ventilator-associated pneumonia (VAP). Non-bronchoscopic bronchoalveolar lavage (BAL) specimens taken between January 2004 and September 2005 were prospectively recorded and related clinical data were retrospectively reviewed. VAP was defined as a new isolate on BAL and a modified Clinical Pulmonary Infection Score > or =5. A total of 230 patients aged 3.9 (2.2-9.1) months (median interquartile range (IQR) ) underwent 309 BALs during 244 paediatric intensive care unit (PICU) admissions. Most patients (84%) were admitted with acute infectious diseases, with a 70% incidence of comorbidity. Thirty-three patients (14.3%) were HIV-exposed but uninfected and 58 (25.2%) were HIV-infected. Of 172 BALs taken > or =48 h after intubation, 63 specimens from 55 patients fulfilled VAP criteria. Acinetobacter baumannii was the most common VAP pathogen, followed by Klebsiella pneumoniae, viruses, yeasts and Staphylococcus aureus. Patients who developed VAP had a higher proportion of comorbid conditions (76% vs. 55%, P= 0.01) and reintubations (39% vs. 12%, P < 0.0001) when compared with non-VAP patients. Median (IQR) length of PICU stay was 12.5 (5-21) days versus 8 (5-14) days (P= 0.03); and the risk adjusted PICU mortality was 1.38 versus 0.79 (P= 0.002) in VAP versus non-VAP patients, respectively. VAP is associated with significant morbidity and mortality and may relate to the high incidence of comorbid conditions in this population. Primary VAP pathogens differ from developed countries.