Clinical and economic consequences of ventilator-associated pneumonia: a systematic review

Attributable cost of methicillin resistance: an issue that is difficult to evaluate

Estimating the consequences and the cost of methicillin resistance is a difficult challenge. Patients who develop methicillin-resistant ventilator-associated pneumonia (VAP) are very different from those who develop methicillin-sensitive VAP, and biased estimates are frequent. We reviewed some important confounding factors of which the reader should be aware.

Nosocomial infections in neurocritical care

Development of nosocomial infections is a commonly encountered problem for critically ill patients. Approximately half of all nosocomial pneumonias in the neurointensive care unit (NICU) are associated with ventilator-associated pneumonia. Prompt diagnosis with appropriate specimen analysis is required in order to prevent increased morbidity. Catheter-related blood stream infection imposes financial as well as medical implications. Multifaceted interventions are helpful to ensure adherence with evidence-based infection control guidelines. Urosepsis occurs in approximately 16% of patients. Colonized patients without evidence of infection do not require treatment, but the indwelling catheter should be changed. NICU patients have increased risk of developing cerebrospinal fluid infection due to frequent placement of external ventricular drains. The incidence of ventriculostomy-related meningitis or ventriculitis is approximately 8%. It is unclear whether the duration of ventricular catheter has any relationship with the risk of infection. Patients often receive multiple antibiotics, leading to an increased risk of developing Clostridium difficile colitis, which needs prompt diagnosis and appropriate antimicrobial therapy.

Nursing care of the mechanically ventilated patient: what does the evidence say? Part one

The care of the mechanically ventilated patient is at the core of a nurse's clinical practice in the Intensive Care Unit (ICU). Published work relating to the numerous nursing issues of the care of the mechanically ventilated patient in the ICU is growing significantly. Literature focuses on patient assessment and management strategies for patient stressors, pain and sedation. Yet this literature is fragmentary by nature. The purpose of this paper is to provide a single comprehensive examination of the evidence related to the care of the mechanically ventilated patient. In part one of this two-part paper, the evidence on nursing care of the mechanically ventilated patient is explored with specific focus on patient safety: particularly patient and equipment assessment. Part two of the paper examines the evidence related to the mechanically ventilated patient's comfort, the patient/family unit, patient position, hygiene, management of stressors, pain management and sedation.

Understanding economic outcomes in critical care

PURPOSE OF REVIEW

The high costs of critical illness make economic outcomes important adjuncts to clinical outcomes in intensive care unit research. Costs are markedly different than other clinical outcomes, both in their measurement and their interpretation.

RECENT FINDINGS

Although not necessarily patient-centered, economic outcomes are important to society. Costs are also useful summary measures of less-meaningful surrogates such as organ failures and lengths of stay. Limitations of economic outcomes, however, are numerous. Accurate measurement of costs in the ICU requires a thorough consideration of both direct and indirect costs, an understanding of the fixed and variable components of critical care expenditures, and knowledge that reducing resource use saves only the marginal, versus average, cost of ICU resources. Costs must also be interpreted alongside measures of effectiveness using proper modeling techniques. Interpretation can vary based on choice of effectiveness measure, perspective of the analysis, and societal and cultural norms.

SUMMARY

When correctly measured and interpreted alongside measures of effectiveness, costs are a useful and important outcome in critical care research.

Update in ventilator-associated pneumonia

PURPOSE OF REVIEW

Ventilator-associated pneumonia remains an important topic (or subject) in the care of the critically ill. Issues related to ventilator-associated pneumonia are now particularly acute given the continued increase in rates of antimicrobial resistance seen in intensive care units. This review examines the latest literature in this area, including promising approaches to infection prevention and recently developed guidelines to aid clinicians in limiting, identifying and treating ventilator-associated pneumonia.

RECENT FINDINGS

Increasingly rigorous and robust studies have shown the enormous cost, morbidity and mortality of infections acquired in the intensive care unit in general and of ventilator-associated pneumonia in particular, and offered potential management options. Specific areas of promise include advances in means of diagnosis, such as appropriate use of bronchoscopy and inflammatory markers, and treatment methods, including short-course treatment regimens and the use of 'de-escalation' as a strategy for antibiotic prescribing.

SUMMARY

Recent studies have started to illuminate the full magnitude of the impact of ventilator-associated pneumonia in the intensive care unit and suggest potential measures for intervention. Hopefully, additional work will aid in eventual development of effective preventive, diagnostic and therapeutic strategies that can reliably improve patient outcomes.

Nosocomial pneumonia

PURPOSE OF REVIEW

This review describes the most recent advances in the management and prevention of nosocomial pneumonia. The new ATS guidelines in particular are most likely to affect clinical practice outside the USA.

RECENT FINDINGS

The problem of multidrug-resistant bacteria causing nosocomial pneumonia seems to be increasing. This is particularly true for methicillin-resistant Staphylococcus aureus. While the diagnosis of ventilator associated pneumonia remains a conflictive issue, serial tracheobronchial aspirates may improve the selection of adequate antimicrobial treatment. Combined beta-lactam and aminoglycoside therapy is inferior to beta-lactam monotherapy, both in terms of clinical outcome and in the prevention of resistance during treatment; in addition, it carries an increased risk of nephrotoxicity.

SUMMARY

The updated ATS guidelines will considerably impact clinical approaches to nosocomial and healthcare-related pneumonia. Serial tracheobronchial aspirates can be used to guide selection of antimicrobial treatment in ventilator associated pneumonia. The combination of beta-lactams and aminoglycosides is likely to be abandoned in the future. New potent treatment options for pneumonia due to nonfermenters are urgently needed.

Diagnosis and Treatment of Ventilator-Associated Pneumonia

Ventilator-associated pneumonia (VAP) is the most common nosocomial infection in the ICU. Patients who acquire VAP have higher mortality rates and longer ICU and hospital stays. Because there are other potential causes of fever, leukocytosis, and pulmonary infiltrates, clinical diagnostic criteria are overly sensitive in the diagnosis of VAP. Employing quantitative cultures of bronchopulmonary secretions in the diagnostic algorithm leads to less antibiotic use and probably to lower mortality. With respect to microbiologic diagnosis, it is not clear that the use of a particular sampling method (bronchoscopic or nonbronchoscopic), when quantitatively cultured, is associated with better outcomes. Delayed administration of adequate antibiotic therapy is linked to an increased mortality rate. Hence, the focus of initial antibiotic therapy should be to rapidly provide antibiotic coverage for all likely pathogens and to then narrow or focus the antibiotic spectrum based on the results of quantitative cultures. Eight days of antibiotic therapy appears equivalent to 15 days of therapy except when treating nonlactose-fermenting Gram-negative organisms. In this latter situation, longer treatment durations appear to reduce the risk of recrudescence after discontinuation of antibiotic therapy. A guideline-based approach using the local hospital or ICU antibiogram can increase the likelihood that adequate initial antibiotic therapy is used and reduce the overall use of antibiotics and the associated selection pressure for multidrug-resistant organisms.

Morbidity and cost burden of methicillin-resistant Staphylococcus aureus in early onset ventilator-associated pneumonia

Introduction

To gain a better understanding of the clinical and economic outcomes associated with methicillin-resistant Staphylococcus aureus (MRSA) infection in patients with early onset ventilator-associated pneumonia (VAP), we retrospectively analyzed a multihospital US database to identify patients with VAP over a 24 month period (2002–2003).

Method

Data recorded included physiologic, laboratory, culture, and other clinical variables from 59 institutions. VAP was defined as new positive respiratory culture after at least 24 hours of mechanical ventilation (MV) and the presence of primary or secondary ICD-9-CM diagnosis codes of pneumonia. Outcomes measures included in-hospital morbidity and mortality for the population overall and after onset of VAP (duration of MV, intensive care unit [ICU] stay, in-hospital stay, and case mix and severity-adjusted operating cost). The overall cost was calculated at the hospital level using the Center for Medicare and Medicaid Services Cost/Charge Index for each calendar year.

Results

A total of 499 patients were identified as having VAP. S. aureus was the leading organism (31% of isolates). Patients with MRSA were significantly older than patients with methicillin-sensitive Staphylococcus aureus (MSSA; median age 74 versus 67 years, P < 0.05) and more likely to be medical patients. Compared with MSSA patients, MRSA patients on average consumed excess resources of 4.4 (95% confidence interval 0.6–8.2) overall MV days, 3.8 (-0.5 to +8.0) days of inpatient length of stay (LOS), 5.3 (1.0–9.7) ICU days, and US$7731 (-US$8393 to +US$23,856) total cost after controlling for case mix and other factors. Furthermore, MRSA patients needed excess resources after the onset of VAP (4.5 [95% confidence interval 1.0–8.1] MV days, 3.7 [-0.5 to +8.0] inpatient days, and 4.4 [0.4–8.4] ICU days) after controlling for the same case mix and admission severity covariates.

Conclusion

S. aureus remains a common cause of VAP. VAP due to MRSA was associated with increased overall LOS, ICU LOS, and attributable ICU LOS compared with MSSA-related VAP. Although not statistically significant because of small sample size and large variation, the attributable excess costs of MRSA amounted to approximately US$8000 per case after controlling for case mix and severity.

Impact of the suctioning system (open vs. closed) on the incidence of ventilation-associated pneumonia: Meta-analysis of randomized controlled trials

OBJECTIVE

Ventilation-associated pneumonia (VAP) is a serious complication of patients in intensive care units (ICU) who require mechanical ventilation. The choice of suctioning system (open vs. closed) remains unresolved in evidence-based guidelines. This meta-analysis was carried out to analyze the effect of the type of suctioning system on the incidence of VAP.

DESIGN

A search of the literature was used to identify randomized controlled trials addressing this question. A meta-analysis was then performed to calculate the relative risk of ventilation-associated pneumonia acquisition with the two suctioning systems.

RESULTS

Nine trials were included, with 648 patients in the open suctioning group and 644 in the closed suctioning group. VAP occurred in 128 (20%) of the open suctioning group and in 120 (19%) in the closed suctioning group (relative risk 0.95).

CONCLUSIONS

At a given pneumonia prevalence of 20% in ICU patients there was no significant advantage for the use of either suctioning system in this meta-analysis. The choice of suctioning system should therefore be based on handling, cost, and individual patient's disease until more data are available.

Toward a zero VAP rate: personal and team approaches in the ICU

In a fast-paced setting like the intensive care unit (ICU), nurses must have appropriate tools and resources in order to implement appropriate and timely interventions. Ventilator-associated pneumonia (VAP) is a costly and potentially fatal outcome for ICU patients that requires timely interventions. Even with established guidelines and care protocols, nurses do not always incorporate best practice interventions into their daily plan of care. Despite the plethora of information and guidelines about how to apply interventions in order to save lives, managers of ICUs are challenged to involve the bedside nurse and other ICU team members to apply these bundles of interventions in a proactive, rather than reactive, manner in order to prevent complications of care. The purpose of this article is to illustrate the success of 2 different methods utilized to improve patient care in the ICU. The first method is a personal process improvement model, and the second method is a team approach model. Both methods were utilized in order to implement interventions in a timely and complete manner to prevent VAP and its related problem, hospital-associated pneumonia, in the ICU setting. Success with these 2 methods has spurred an interest in other patient care initiatives.

Acute Physiology and Chronic Health Evaluation (APACHE) IV: hospital mortality assessment for today's critically ill patients

OBJECTIVE

To improve the accuracy of the Acute Physiology and Chronic Health Evaluation (APACHE) method for predicting hospital mortality among critically ill adults and to evaluate changes in the accuracy of earlier APACHE models.

DESIGN

: Observational cohort study.

SETTING

A total of 104 intensive care units (ICUs) in 45 U.S. hospitals.

PATIENTS

A total of 131,618 consecutive ICU admissions during 2002 and 2003, of which 110,558 met inclusion criteria and had complete data.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We developed APACHE IV using ICU day 1 information and a multivariate logistic regression procedure to estimate the probability of hospital death for randomly selected patients who comprised 60% of the database. Predictor variables were similar to those in APACHE III, but new variables were added and different statistical modeling used. We assessed the accuracy of APACHE IV predictions by comparing observed and predicted hospital mortality for the excluded patients (validation set). We tested discrimination and used multiple tests of calibration in aggregate and for patient subgroups. APACHE IV had good discrimination (area under the receiver operating characteristic curve = 0.88) and calibration (Hosmer-Lemeshow C statistic = 16.9, p = .08). For 90% of 116 ICU admission diagnoses, the ratio of observed to predicted mortality was not significantly different from 1.0. We also used the validation data set to compare the accuracy of APACHE IV predictions to those using APACHE III versions developed 7 and 14 yrs previously. There was little change in discrimination, but aggregate mortality was systematically overestimated as model age increased. When examined across disease, predictive accuracy was maintained for some diagnoses but for others seemed to reflect changes in practice or therapy.

CONCLUSIONS

APACHE IV predictions of hospital mortality have good discrimination and calibration and should be useful for benchmarking performance in U.S. ICUs. The accuracy of predictive models is dynamic and should be periodically retested. When accuracy deteriorates they should be revised and updated.

Kinetic bed therapy to prevent nosocomial pneumonia in mechanically ventilated patients: a systematic review and meta-analysis

INTRODUCTION

Nosocomial pneumonia is the most important infectious complication in patients admitted to intensive care units. Kinetic bed therapy may reduce the incidence of nosocomial pneumonia in mechanically ventilated patients. The objective of this study was to investigate whether kinetic bed therapy reduces the incidence of nosocomial pneumonia and improves outcomes in critically ill mechanically ventilated patients.

METHODS

We searched Medline, EMBASE, CINAHL, CENTRAL, and AMED for studies, as well as reviewed abstracts of conference proceedings, bibliographies of included studies and review articles and contacted the manufacturers of medical beds. Studies included were randomized or pseudo-randomized clinical trials of kinetic bed therapy compared to standard manual turning in critically ill mechanically ventilated adult patients. Two reviewers independently applied the study selection criteria and extracted data regarding study validity, type of bed used, intensity of kinetic therapy, and population under investigation. Outcomes assessed included the incidence of nosocomial pneumonia, mortality, duration of ventilation, and intensive care unit and hospital length of stay.

RESULTS

Fifteen prospective clinical trials were identified, which included a total of 1,169 participants. No trial met all the validity criteria. There was a significant reduction in the incidence of nosocomial pneumonia (pooled odds ratio (OR) 0.38, 95% confidence interval (CI) 0.28 to 0.53), but no reduction in mortality (pooled OR 0.96, 95%CI 0.66 to 1.14), duration of mechanical ventilation (pooled standardized mean difference (SMD) -0.14 days, 95%CI, -0.29 to 0.02), duration of intensive care unit stay (pooled SMD -0.064 days, 95% CI, -0.21 to 0.086) or duration of hospital stay (pooled SMD 0.05 days, 95% CI -0.18 to 0.27).

CONCLUSION

While kinetic bed therapy has been purported to reduce the incidence of nosocomial pneumonia in mechanically ventilated patients, the overall body of evidence is insufficient to support this conclusion. There appears to be a reduction in the incidence of nosocomial pneumonia, but no effect on mortality, duration of mechanical ventilation, or intensive care or hospital length of stay. Given the lack of consistent benefit and the poor methodological quality of the trials included in this analysis, definitive recommendations regarding the use of this therapy cannot be made at this time.