A comparison of ventilator-associated pneumonia rates determined by different scoring systems in four intensive care units in the North West of England

Risk factors and outcomes associated with ventilator associated pneumonia amongst intubated trauma patients admitted to the general intensive care unit of a major trauma centre

Background

Despite the use of care bundles, ventilator associated pneumonia (VAP) remains a frequently occurring health care-associated infection, increasing costs, length of stay (LOS) and mortality. The incidence is higher amongst trauma patients, although due to variable definitions and study populations risk factors for developing VAP are disputed, with few reports from the UK.

Methods

This 6-year review of intubated trauma patients admitted to the general Intensive Care Unit (ICU) of a UK major trauma centre, collected data on suspected risk factors for VAP, as well as demographic information, outcomes and microbiology. Ninety-nine patients who developed VAP within the first 7 days of admission were compared with 191 patient who did not, with multivariable logistic regression used to control for confounding variables.

Results

Univariable analysis suggested that injury severity score (ISS) (34 v 29), head injury (66.7% v 50.8%), polytrauma (79.8% v 68.1%) and ventilator days (10 v 5) were associated with increased risk of VAP, but after adjustment only ventilator days remained significant (OR 1.04, 95% CI 1.01–1.06). Antibiotics within 24 h of admission were associated with reduced odds of developing VAP, whether this was for pulmonary prophylaxis (OR 0.43, 95% CI 0.22–0.83, p = 0.013) or non-pulmonary reasons (OR 0.27, 95% CI 0.15–0.51, p < 0.001).

Conclusions

Only increasing ventilator days was associated with increased odds of developing VAP. The use of early antimicrobials was associated strongly with a reduction in the odds of developing VAP; this could be explained by unmeasured confounding or a prophylactic effect against aspiration.

Ventilator-associated pneumonia surveillance using two methods

BACKGROUND

Ventilator-associated pneumonia surveillance is used as a quality indicator due to concerns that some cases may be preventable and may contribute to mortality. Various surveillance criteria exist for the purposes of national reporting, but a large-scale direct comparison has not been conducted.

METHODS

A prospective cohort study applied two routinely used surveillance criteria for ventilator-associated pneumonia from the European Centre for Disease Control and the American Centers for Disease Control to all patients admitted to two large general intensive care units. Diagnostic rates and concordance amongst diagnostic events were compared.

FINDINGS

A total of 713 at-risk patients were identified during the study period. The European surveillance algorithm returned a rate of 4.6 cases of ventilator-associated pneumonia per 1000 ventilation days (95% confidence interval 3.1-6.6) and the American surveillance system a rate of 5.4 (3.8-7.5). The concordance between diagnostic events was poor (Cohen's Kappa 0.127 (-0.003 to 0.256)).

CONCLUSIONS

The algorithms yield similar rates, but the lack of event concordance reveals the absence of inter-algorithm agreement for diagnosing ventilator-associated pneumonia, potentially undermining surveillance as an indicator of care quality.

The Incidence and Characteristics of Venous Thromboembolism in Neurocritical Care Patients: A Prospective Observational Study

Risk of venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), is presumed to be high for neurologic intensive care unit (NICU) patients. However, exact incidences of VTE have yet to be reported. In this prospective observational study, we consecutively enrolled 126 neurocritical care patients who had an NICU stay ≥1 week with paralysis and/or unconsciousness. All patients received DVT prevention strategies. Patients were screened for VTE after 1 week of hospitalization, using venous ultrasonography and computed tomography pulmonary angiography. Following 1 week of NICU hospitalization, DVT incidence was 35.7% and PE incidence was 17.5%. Of the DVTs, 75.6% were in the muscular calf vein. Of the PEs, 22.7% were in main pulmonary arteries, while 77.3% were in branches. Approximately 96% of the DVTs and 86% of the PEs were asymptomatic. Approximately 24% of patients with DVT had a concurrent PE, while 50% of PE patients had a DVT. Paralysis, raised d-dimer on admission, and pulmonary infection were found to be independent risk factors for DVT. Paraplegia, femoral vein thrombosis, and pulmonary infection were found to be independent risk factors for PE. Despite active preventive measures, incidences of VTE in NICU patients were high. Most VTEs were asymptomatic, meaning they could have led to a missed diagnosis. Attention should be paid to the VTE events of critically ill neurological patients.

The prevalence of suspected ventilator-associated pneumonia in Scottish intensive care units

Ventilator-associated pneumonia is the most common healthcare-associated infection in mechanically ventilated patients. Despite this, accurate diagnosis of ventilator-associated pneumonia is difficult owing to the variety of criteria that exist. In this prospective national audit, we aim to quantify the existence of patients with suspected ventilator-associated pneumonia that would not be detected by our standard healthcare-associated infection screening process. Furthermore, we aim to assess the impact of tracheostomy insertion, subglottic drainage endotracheal tubes and chlorhexidine gel on ventilator-associated pneumonia rate. Of the 227 patients recruited, suspected ventilator-associated pneumonia occurred in 32 of these patients. Using the HELICS definition, 13/32 (40.6%) patients were diagnosed with ventilator-associated pneumonia (H-posVAP). Suspected ventilator-associated pneumonia rate was increased in our tracheostomy population, decreased in the subglottic drainage endotracheal tube group and unchanged in the chlorhexidine group. The diagnosis of ventilator-associated pneumonia remains a contentious issue. The formalisation of the HELICS criteria by the European CDC should allow standardised data collection throughout Europe, which will enable more consistent data collection and meaningful data comparison in the future. Our data add weight to the argument against routine oral chlorhexidine. The use of subglottic drainage endotracheal tubes in preventing ventilator-associated pneumonia is interesting and requires further investigation.

Preventing ventilator-associated pneumonia-a mixed-method study to find behavioral leverage for better protocol adherence

OBJECTIVE

Preventing ventilator-associated pneumonia (VAP) is an important goal for intensive care units (ICUs). We aimed to identify the optimal behavior leverage to improve VAP prevention protocol adherence.

DESIGN

Mixed-method study using adherence measurements to assess 4 VAP prevention measures and qualitative analysis of semi-structured focus group interviews with frontline healthcare practitioners (HCPs).

SETTING

The 6 ICUs in the 900-bed University Hospital Zurich in Zurich, Switzerland.Patients and participantsAdherence to VAP prevention measures were assessed in patients with a device for invasive ventilation (ie, endotracheal tube, tracheostomy tube). Participants in focus group interviews included a convenience samples of ICU nurses and physicians.

RESULTS

Between February 2015 and July 2017, we measured adherence to 4 protocols: bed elevation showed adherence at 27% (95% confidence intervals [CI], 23%-31%); oral care at 41% (95% CI, 36%-45%); sedation interruption at 81% (95% CI, 74%-85%); and subglottic suctioning at 88% (95% CI, 83%-92%). Interviews were analyzed first inductively according a grounded theory approach then deductively against the behavior change wheel (BCW) framework. Main behavioral facilitators belonged to the BCW component 'reflective motivation' (ie, perceived seriousness of VAP and self-efficacy to prevent VAP). The main barriers belonged to 'physical capability' (ie, lack of equipment and staffing and side-effects of prevention measures). Furthermore, 2 primarily technical approaches (ie, 'restructuring environment' and 'enabling HCP') emerged as means to overcome these barriers.

CONCLUSIONS

Our findings suggest that technical, rather than education-based, solutions should be promoted to improve VAP prevention. This theory-informed mixed-method approach is an effective means of guiding infection prevention efforts.

Evaluating the Cost-Effectiveness of Proportional-Assist Ventilation Plus vs. Pressure Support Ventilation in the Intensive Care Unit in Two Countries

Background: Mechanical ventilation is an integral, but expensive, part of the intensive care unit (ICU). Optimal use of mechanical ventilation could save costs and improve patient outcomes. Here, the cost effectiveness of proportional assist ventilation (PAV™ ventilation by Medtronic) is estimated relative to pressure support ventilation (PSV).

Methods: A cohort-level, clinical model was built using data from clinical trials. The model estimates patient-ventilator asynchrony >10%, tracheostomy, ventilator-associated pneumonia, other nosocomial infections, spontaneous breathing trial success, hypoxemia, and death. Cost and quality of life are associated with all events, with cost effectiveness defined as the cost per quality-adjusted life year (QALY) gained in the US and UK.

Results: The mean cost of ICU care was lower with PAV™ than with PSV in the US and UK, but the total cost of care over 40 years was higher due to more patients surviving and incurring future care costs. Reduced time on mechanical ventilation, fewer nosocomial infections, and extended life expectancy with PAV™ drove QALY improvement. The cost per QALY gained with PAV™ was $8,628 and £2,985.

Conclusion: PAV™ improves quality of life and reduces short-term costs. PAV™ is likely to be considered cost-effective over 40-years in the US and UK.

The effects of oral rinse with 0.2% and 2% chlorhexidine on oropharyngeal colonization and ventilator associated pneumonia in adults' intensive care units

BACKGROUND

Ventilator Associated Pneumonia (VAP) is the most common nosocomial infection in Intensive Care Units (ICUs) which increases the length of ICU stay, duration of mechanical ventilation, and mortality. The present study used an oral care protocol and compared the effects of two different concentrations of chlorhexidine on reduction of oropharyngeal colonization and VAP.

MATERIALS AND METHODS

This study was performed on 114 patients from trauma, surgery, neurosurgery, and general ICUs randomly allocated to two groups under oral care with 0.2% and 2% chlorhexidine solution. A multidisciplinary team approved the oral care protocol. Data was collected using a demographic information form, APACHE IV form, Beck oral assessment scale, mucosal-plaque assessment scale, and oropharyngeal swab culture.

RESULTS

The results showed a significant reduction in VAP (p=0.007) and oropharyngeal colonization (p=0.007) in the group under oral care with 2% chlorhexidine solution compared with the other group. However, no significant difference was found between the two groups in terms of oropharyngeal adverse effects (p=0.361).

CONCLUSION

Oral decontamination with 2% compared to 0.2% chlorhexidine is a more effective method in the prevention of VAP and reduction of oropharyngeal colonization (especially gram-positive).

Contamination of single-use bronchoscopes in critically ill patients

Disposable bronchoscopes such as the Ambu aScope^TM 3 are marketed as 'single use' The risks of contamination from prolonged device storage before possible re-use are unknown. Following clinical bronchoscopy in patients whose lungs were mechanically ventilated, 20 aScope^TM 3's bronchoscopes received a standard 'social clean' and were then stored. Subsequent paired saline flush and swab samples were taken at time zero, and at 24 h and 48 h. Positive microbiological cultures were obtained from at least one time point from 16 of the 20 bronchoscopes. Pathogens considered at high risk of causing pneumonia were isolated from seven bronchoscopes, with significant quantities from six of them. Our study demonstrates that aScope^TM 3's should not be re-used on the same patient, as clinically significant growth of micro-organisms occurs frequently, despite adequate social cleaning. Culture of bronchoscopes themselves may be a potentially useful diagnostic tool in the context of pulmonary infection. Our data make it clear that these devices are single use and not single patient use.