Pneumonia in the surgical intensive care unit: Is every one preventable?

Facts and Fallacy of Benchmark Performance Indicators

Efforts to improve quality in healthcare have arisen from the recognition that the quality of care delivered and resulting outcomes are highly variable. Performance benchmarking using high-quality data to compare risk-adjusted outcomes between hospitals and surgeons has been widely adopted as one means for addressing this problem. In this article we discuss the history, current state, methodologies, and potential pitfalls of benchmarking efforts to improve quality of healthcare in the United States.

Inadequacy of Algorithmic Ventilator-Associated Pneumonia Diagnosis in Acute Care Surgery

Clinical utility of algorithms to diagnose ventilator-associated pneumonia (VAP) in surgical patients has not been established. We aimed to test the diagnostic accuracy of two established methods to reliably diagnose VAP in acutely ill and injured surgical patients. After institutional review board approval, we prospectively collected data on 508 mechanically ventilated acute care surgery patients. Microbiologic samples were taken daily from all patients. Demographics, clinical, laboratory, and radiographic data were collected. The Johanson Criteria (JC) and Clinical Pulmonary Infection Score (CPIS) were calculated and analyzed. Sensitivity, specificity, and positive predictive values (PPV) and negative predictive value (NPV) were calculated in comparison to positive respiratory cultures. Of the 508 patients, 312 (61.4%) were acutely injured; emergent general surgery was performed in 141 (27.8%) patients, and 54 (10.6%) underwent elective operation. Positive respiratory cultures were identified in 198 (39%) of the 508 patients. JC diagnosed VAP in 291 (57.3%) patients (sensitivity 82.8%, specificity 59%, PPV 56.4%, NPV 84.3%, accuracy 68.3%). The CPIS resulted in 189 (37.2%) VAP diagnoses (sensitivity 61.1%, specificity 78.1%, PPV 64%, NPV 75.9%, and accuracy 71.5%). To address the inaccuracy of the algorithms, concordance testing was performed on the data to evaluate correlation between the algorithmic VAP diagnosis criteria and respiratory culture data. Nonconcordance with culture data diagnosis was identified with both JC (rho 0.41) and CPIS (rho 0.41). Sensitivity, specificity, PPV and NPV, and accuracy of both established clinical formulas was unacceptably low in acute care surgery patients.

Early bronchoalveolar lavage for intubated trauma patients with TBI or chest trauma

PURPOSE

To evaluate the efficacy of an early bronchoalveolar lavage (E-BAL) protocol. BAL was performed within 48 h for intubated patients with traumatic brain injury or chest trauma. We hypothesized that E-BAL would decrease antibiotic use and improve outcomes compared to late BAL (L-BAL) triggered by clinical signs of pneumonia.

METHODS

Retrospective cohort analysis of 132 patients with quantitative BAL and ≥1 risk factor: head Abbreviated Injury Score ≥2, ≥3 rib fractures, or radiographic signs of aspiration or pulmonary contusion. E-BAL (n=71) was compared to L-BAL (n=61). Pneumonia was defined as ≥10⁴ organisms on BAL or Clinical Pulmonary Infection Score >6.

RESULTS

There were no significant differences in age, injury severity, initial Pao₂:Fio₂, or smoking status between E-BAL and L-BAL groups. 52% and 61% of the E-BAL and L-BAL cultures were positive, respectively. E-BAL patients had fewer antibiotic days (7.3 vs 9.2, P=.034), ventilator days (11 vs 15, P=.002), tracheostomies (49% vs 75%, P=.002), and shorter intensive care unit and hospital length of stay (13 vs 17 days (P=.007), 18 vs 22 days (P=.041)).

CONCLUSIONS

More than half of all E-BAL patients had pneumonia present early after admission. E-BAL was associated with fewer days on antibiotics and better outcomes than L-BAL.

Ventilator-Associated Pneumonia in Trauma Patients: Different Criteria, Different Rates

BACKGROUND

No consensus exists regarding the definition of ventilator-associated pneumonia (VAP). Even within a single institution, inconsistent diagnostic criteria result in conflicting rates of VAP. As a Level 1 trauma center participating in the Trauma Quality Improvement Project (TQIP) and the National Healthcare Safety Network (NHSN), our institution showed inconsistencies in VAP rates depending on which criteria was applied. The purpose of this study was to compare VAP definitions, defined by culture-based criteria, National Trauma Data Bank (NTDB) and NHSN, using incidence in trauma patients.

METHODS

A retrospective chart review of consecutive trauma patients who were diagnosed with VAP and met pre-determined inclusion and exclusion criteria admitted to our rural, 861-bed, Level 1 trauma and tertiary care center between January 2008 and December 2011 was performed. These patients were identified from the National Trauma Registry of the American College of Surgeons (NTRACS) database and an in-house infection control database. Ventilator-associated pneumonia diagnosis criteria defined by the U.S. Center for Disease Control and Prevention (used by the NHSN), the NTDB, and our institutional, culture-based criteria gold standard were compared among patients.

RESULTS

Two hundred seventy-nine patients were diagnosed with VAP (25.4% met NHSN criteria, 88.2% met NTDB, and 76.3% met culture-based criteria). Only 58 (20.1%) patients met all three criteria. When NHSN criteria were compared with culture-based criteria, NHSN showed a high specificity (92.5%) and low sensitivity (28.2%). The positive predictive value (PPV) was 84.5%, but the negative predictive value (NPV) was 47.1%. The agreement between the NHSN and the culture-based criteria was poor (κ = 0.18). Conversely, the NTDB showed a lower specificity (57.8%), but greater sensitivity (86.4%) compared with culture-based criteria. The PPV and NPV were both 74% and the two criteria showed fair agreement (κ = 0.41).

CONCLUSIONS

The lack of standard diagnostic criteria for VAP resulted in variable reporting to different agencies. Emphasis on establishing a consensus VAP definition should be undertaken.

International multidisciplinary consensus conference on multimodality monitoring: ICU processes of care

There is an increased focus on evaluating processes of care, particularly in the high acuity and cost environment of intensive care. Evaluation of neurocritical-specific care and evidence-based protocol implementation are needed to effectively determine optimal processes of care and effect on patient outcomes. General quality measures to evaluate intensive care unit (ICU) processes of care have been proposed; however, applicability of these measures in neurocritical care populations has not been established. A comprehensive literature search was conducted for English language articles from 1990 to August 2013. A total of 1,061 articles were reviewed, with 145 meeting criteria for inclusion in this review. Care in specialized neurocritical care units or by neurocritical teams can have a positive impact on mortality, length of stay, and in some cases, functional outcome. Similarly, implementation of evidence-based protocol-directed care can enhance outcome in the neurocritical care population. There is significant evidence to support suggested quality indicators for the general ICU population, but limited research regarding specific use in neurocritical care. Quality indices for neurocritical care have been proposed; however, additional research is needed to further validate measures.

Analogues of the frog skin peptide alyteserin-2a with enhanced antimicrobial activities against Gram-negative bacteria

The emergence of strains of multidrug-resistant Gram-negative bacteria mandates a search for new types of antimicrobial agents. Alyteserin-2a (ILGKLLSTAAGLLSNL.NH₂) is a cationic, α-helical peptide, first isolated from skin secretions of the midwife toad, Alytes obstetricans, which displays relatively weak antimicrobial and haemolytic activities. Increasing the cationicity of alyteserin-2a while maintaining amphipathicity by the substitution Gly¹¹ → Lys enhanced the potency against both Gram-negative and Gram-positive bacteria by between fourfold and 16-fold but concomitantly increased cytotoxic activity against human erythrocytes by sixfold (mean concentration of peptide producing 50% cell death; LC₅₀=24 µM). Antimicrobial potency was increased further by the additional substitution Ser⁷ →Lys, but the resulting analogue remained cytotoxic to erythrocytes (LC₅₀=38 µM). However, the peptide containing D-lysine at positions 7 and 11 showed high potency against a range of Gram-negative bacteria, including multidrug-resistant strains of Acinetobacter baumannii and Stenotrophomonas maltophilia (minimum inhibitory concentration = 8 µM) but appreciably lower haemolytic activity (LC₅₀=185 µM) and cytotoxicity against A549 human alveolar basal epithelial cells (LC₅₀=65 µM). The analogue shows potential for treatment of nosocomial pulmonary infections caused by bacteria that have developed resistance to commonly used antibiotics.