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Non-ventilator health care-associated pneumonia (NV-HAP): The infection preventionist's role in identifying NV-HAP

      Abstract

      One of the fundamental challenges in nonventilator health care-associated pneumonia (NV-HAP) surveillance is identifying cases and standardizing surveillance protocols. This section highlights clinical pneumonia definitions and current surveillance definitions, as well as the difficulty in case finding methodologies. In addition, we review current microbiology and molecular testing methods. Further, we explore future opportunities to leverage the electronic health care record in attempt to identify a reliable less burdensome data identification and collection methodology. Finally, we highlight the importance of a collaborative approach to prevention of NV- HAP, as well as strategies to assist the IP with facilitating interdisciplinary communication and uptake of evidence-based implementation strategies.

      Key Words

      One of the fundamental challenges in nonventilator health care-associated pneumonia (NV-HAP) surveillance is identifying cases and standardizing surveillance protocols. This section highlights clinical pneumonia definitions, current surveillance definitions, and potential opportunities for electronic data capture. The IP (IP) plays an important role in interdisciplinary team collaborations and communication of key surveillance findings.

      Pneumonia definitions

      The following are clinical definitions of pneumonia found in current literature. See Table 1 for a comparison of selected types of pneumonia based on onset.
      Table 1Onset of selected types of pneumonia
      TypeOnset
      CAP≤48 hours of admission to the hospital
      HAP>48 hours (2 days) following admission to the hospital
      HCAP≤48 hours of admission to the hospital in a patient with recent health care exposure (no longer included in ATS/IDSA pneumonia classification scheme
      • Kalil AC
      • Metersky ML
      • Klompas M
      • et al.
      Management of adults with hospital-acquired and ventilator-associated pneumonia: 2016 clinical practice guidelines by the infectious diseases Society of America and the American Thoracic Society.
      )
      VAP≥48 hours (2 days) following initiation of mechanical ventilation
      CAP, community-acquired pneumonia; HCAP, health care-associated pneumonia, HAP, hospital-acquired pneumonia; VAP, ventilator-associated pneumonia.
      Pneumonia: Levison defines pneumonia as an infection of the pulmonary parenchyma caused by various organisms; it is not a single disease but a group of specific infections, each with its own epidemiology, pathogenesis, presentation, and clinical course.
      • Levison ME
      • et al.
      Pneumonia, including necrotizing pulmonary infections (lung abscess).
      According to the American Thoracic Society (ATS) and Infectious Diseases Society of America (IDSA), pneumonia is defined as the presence of new lung infiltrate and clinical evidence that the infiltrate is of an infectious origin, such as the new onset of fever, purulent sputum leukocytosis, and decline in oxygenation.
      American Thoracic Society; Infectious Diseases Society of America
      Guidelines for the management of adults with hospital-acquired, ventilator-associated, and healthcare-associated pneumonia.
      Community-acquired pneumonia (CAP): CAP is pneumonia acquired in the community or diagnosis of pneumonia within 48 hours of admission to the hospital.
      • Farah R
      • Bleier J
      • Gilbey P
      • Khamisy-Farah R
      Common laboratory parameters for differentiating between community-acquired and healthcare-associated pneumonia.
      Hospital-acquired pneumonia (HAP): HAP is pneumonia that develops more than 48 hours after hospital admission and was not incubating at the time of admission.
      • Stenlund M
      • Sjodahl R
      • Yngman-Uhlin RP
      Incidence and potential risk factors for hospital-acquired pneumonia in an emergency department of surgery.
      Health care-associated pneumonia (HCAP): HCAP was defined as pneumonia acquired by an individual with a specific type of health care contact in the recent past, including hospitalization for 2 or more days within the preceding 90 days, residence in a long-term care or extended care facility, receipt of home infusion therapy, chronic dialysis treatment within 30 days, or wound care. These individuals were once thought to be at increased risk of infection caused by multidrug-resistant organisms.
      • Chalmers JD
      • Rother C
      • Salih W
      • Ewig S
      Healthcare-associated pneumonia does not accurately identify potentially resistant pathogens: a systematic review and meta-analysis.
      However, HCAP was eliminated from the 2016 ATS/IDSA pneumonia management guidelines because multiple studies demonstrated that many patients with HCAP were not at risk for developing multidrug-resistant organisms.
      • Kalil AC
      • Metersky ML
      • Klompas M
      • et al.
      Management of adults with hospital-acquired and ventilator-associated pneumonia: 2016 clinical practice guidelines by the infectious diseases Society of America and the American Thoracic Society.
      Ventilator-associated pneumonia (VAP): VAP is a pneumonia occurring in a patient who is on mechanical ventilation for more than 2 calendar days on the event date with day of mechanical ventilation onset defined as Day 1.
      Centers for Disease Control and Prevention
      Pneumonia (ventilator-associated [VAP] and non-ventilator-associated pneumonia [PNEU]) event.
      It is important to distinguish VAP from HAP that compromises the patient's respiratory status to the point that mechanical ventilation is required.
      Aspiration pneumonia: Aspiration pneumonia develops due to misdirection of oropharyngeal or gastric contents into the larynx and lower respiratory tract.
      • Marik PE
      • Kaplan D
      Aspiration pneumonia and dysphagia in the elderly.
      Long-term care facility–associated pneumonia: In long-term care residents, this type of pneumonia is defined as chest radiographic evidence of pneumonia, probable pneumonia, or presence of an infiltrate plus 2 of the following: new or increased cough; new or increased sputum production; fever; pleuritic chest pain; new or increased findings on chest examination; or one of the following indications of change in status or breathing difficulty: new/increased dyspnea or respiratory rate greater than 25 breaths per minute or worsening mental or functional status.
      • Stone ND
      • Ashraf MS
      • Calder J
      • et al.
      Surveillance definitions of infections in long-term care facilities: revisiting the McGeer criteria.

      Clinical diagnosis

      The diagnosis of pneumonia can be challenging, especially in critically ill patients or patients with other concurrent acute or chronic respiratory conditions. Clinicians frequently assess clinical signs, microbiological findings, and radiologic findings when determining the presence or absence of pneumonia.

      Microbiologic/molecular testing

      Currently, there is no gold standard test to definitively diagnose pneumonia in mechanically ventilated or nonventilated patients. The 2016 IDSA/ATS guidelines
      • Kalil AC
      • Metersky ML
      • Klompas M
      • et al.
      Management of adults with hospital-acquired and ventilator-associated pneumonia: 2016 clinical practice guidelines by the infectious diseases Society of America and the American Thoracic Society.
      provide the following recommendations related to the microbiologic component of pneumonia diagnosis:
      Collection of microbiologic specimens: Noninvasive sampling with semi-quantitative cultures is recommended rather than invasive sampling with quantitative cultures or noninvasive sampling with quantitative cultures (weak recommendation, low-quality evidence). This recommendation was based on the speed with which noninvasive specimens can be collected, decreased incidence of complications, reduced use of resources, and lack of evidence that invasively collected specimens and quantitative cultures lead to improved patient outcomes.
      Clinical criteria vs use of biomarkers: Clinical criteria should be used alone to diagnose VAP and HAP (strong recommendation, moderate-quality evidence). Use of biomarkers in addition to clinical criteria was not recommended because sensitivity and specificity of serum procalcitonin testing and soluble triggering receptor expressed on myeloid cells-1 did not reach predetermined thresholds, and the tests may cloud the diagnosis, resulting in nonidentification of the true infection source or unnecessary antimicrobial therapy.
      • Kalil AC
      • Metersky ML
      • Klompas M
      • et al.
      Management of adults with hospital-acquired and ventilator-associated pneumonia: 2016 clinical practice guidelines by the infectious diseases Society of America and the American Thoracic Society.
      Alby and Mitchell describe the use of molecular tests for the identification of lower respiratory tract infections. Multiplex molecular panels are used to conduct a version of syndromic surveillance related to a particular set of symptoms related to a body site (commonly blood, stool, or the upper respiratory tract).
      • Alby K
      • Mitchell SL
      Lower respiratory multiplex panels for the detection of bacterial and viral infections.
      Recently, 2 molecular tests have been approved by the US Food and Drug Administration for detection of lower respiratory tract infection:
      • Alby K
      • Mitchell SL
      Lower respiratory multiplex panels for the detection of bacterial and viral infections.
      The FilmArray Pneumonia Panel (BioFire Diagnostics) can detect common bacterial and viral pathogens and selected antibiotic resistance markers. It can be used to evaluate both sputum and bronchoalveolar lavage (BAL) samples.The Unyvero molecular test system (Curetis) can detect 19 bacterial targets and 10 resistance markers from endotracheal aspirates.
      Although molecular testing has the potential to improve diagnosis and treatment of pneumonia, the sensitivities of some targets may be a concern. Also, because both hospital and community pathogens can be present, it may be challenging to identify when to perform the test and which patient populations would benefit most.
      • Alby K
      • Mitchell SL
      Lower respiratory multiplex panels for the detection of bacterial and viral infections.
      Microbiological testing is further discussed in Section 2 of this guide.

      Clinical signs and symptoms

      Clinical signs that are frequently considered to be “clues” of infection or, in certain combinations, indicative of a respiratory tract infection include:
      Centers for Disease Control and Prevention
      Pneumonia (ventilator-associated [VAP] and non-ventilator-associated pneumonia [PNEU]) event.
      • Fever
      • Leukopenia or leukocytosis
      • Increased oxygen need
      • Altered mental status in patients older than age 70 years
      • New onset or change in sputum, cough, or lung sounds

      Radiological studies

      Upon identification of clinical signs and symptoms indicative of lower respiratory tract infection, radiological studies can provide supporting evidence of pneumonia (see Table 2).
      Centers for Disease Control and Prevention
      Pneumonia (ventilator-associated [VAP] and non-ventilator-associated pneumonia [PNEU]) event.
      The radiographic patterns of HAP and VAP can be variable and even confusing. X-ray findings may also indicate atelectasis, pulmonary infarction, pulmonary edema, or acute respiratory distress syndrome. Chest X-ray is most valuable when used to rule out pneumonia.
      • Vilar J
      • Domingo ML
      • Soto C
      • Cogollos J
      Radiology of bacterial pneumonia.
      Table 2NHSN categories of hospital-acquired pneumonia
      CategoryDefinition
      PNU1Clinically defined pneumonia
      PNU2Common bacterial or filamentous fungal pathogens

      Viral, Legionella, and other bacterial pneumonias
      PNU3Pneumonia in immunocompromised patients
      NHSN, The National Health care Safety Network.
      Because chest X-ray results may be inconclusive in establishing a diagnosis of pneumonia, supplemental studies such as computerized tomography (CT) may provide additional clarification. Esayag et al described the challenges associated with obtaining chest radiographs in bedbound patients and compared X-ray and CT scan results. They determined that when a chest radiograph was interpreted as normal, a noncontrast-enhanced high-resolution chest CT scan improved pneumonia diagnostic accuracy by 30%.
      • Esayag Y
      • Nikitin I
      • Bar-Ziv J
      • et al.
      Diagnostic value of chest radiographs in bedridden patients suspected of having pneumonia.
      Two studies that evaluated the use of chest CT scan in patients with suspected CAP demonstrated that this test modality increased accuracy of diagnosis when combined with chest X-ray.
      • Hayden GE
      • Wrenn KW
      Chest radiograph vs. computed tomography scan in the evaluation for pneumonia.
      ,
      • Claessens YE
      • Debray MP
      • Tubach F
      • et al.
      Early chest computed tomography scan to assist diagnosis and guide treatment decision for suspected community-acquired pneumonia.
      It is important to note that chest CT scan has disadvantages, including cost and increased radiation exposure for the patient.
      Lung ultrasound has been shown to be effective in the assessment of lung conditions, including pneumonia, and may be useful in bedside diagnosis of that infection. A recent meta-analysis of 5 studies demonstrated that lung ultrasound had high sensitivity and specificity for pneumonia diagnosis, exclusive of interstitial pneumonia (which was not studied).
      • Chavez MA
      • Shams N
      • Ellington LE
      • et al.
      Lung ultrasound for the diagnosis of pneumonia in adults: a systematic review and meta-analysis.
      Advantages of ultrasound as a diagnostic tool include rapid turnaround time, usefulness in resource-poor settings, and elimination of the requirement for patient transport.

      Surveillance

      Surveillance definitions vs clinical diagnoses

      Surveillance definitions are designed to study and identify trends in a population. The consistent application of standardized criteria allows confidence in aggregation and analysis of data. In contrast, clinical diagnoses are patient-specific. Unlike surveillance definitions, all available diagnostic data are considered in a clinical diagnosis, including clinical, epidemiological, and laboratory data that are outside of the scope of a surveillance definition. Therefore, a clinical diagnosis may be made even when a surveillance definition may not be met.
      Centers for Disease Control and Prevention
      PSC Protocol FAQs.
      Subsequently, a surveillance definition may be met even when a clinical diagnosis has been ruled-out due to the utilization of additional data and information. Failure to meet one type of definition should not override a conclusion for the second. Clinical diagnoses may be easier to define than surveillance definitions; however, because they are not standardized, patient-specific diagnoses omit important information used to identify to trends, risk factors, or potential opportunities for improvement in a given population.

      National Healthcare Safety Network and pneumonia surveillance

      The National Healthcare Safety Network (NHSN) health care-associated infection (HAI) surveillance definitions are familiar to many IPs in varied care settings. NHSN describes 3 categories of HAP, as described in Table 2; refer to the NHSN Patient Safety Manual
      Centers for Disease Control and Prevention
      Pneumonia (ventilator-associated [VAP] and non-ventilator-associated pneumonia [PNEU]) event.
      for specific algorithms.
      All site-specific algorithms commence with radiological findings and provide inclusion signs and symptoms, as well as laboratory findings as components of surveillance definitions. In some instances, the surveillance definitions include variations based on the age of the patient. Two helpful tools provided by NHSN in the Patient Safety Manual are a pneumonia flow diagram for patients of any age and an alternative criteria algorithm for infants and children.
      Centers for Disease Control and Prevention
      Pneumonia (ventilator-associated [VAP] and non-ventilator-associated pneumonia [PNEU]) event.

      Pneumonia surveillance and the infection prevention program

      Infection surveillance is a basic component of an infection prevention program.
      • Pottinger JM
      • Herald LA
      • Perl TM
      Basics of surveillance—an overview.
      Multiple studies have demonstrated the positive impact of surveillance for infections on the incidence of HAIs.
      • Gastmeier P
      • Geffers C
      • Brandt C
      • et al.
      Effectiveness of a nationwide nosocomial infection surveillance system for reducing nosocomial infections.
      Conducting surveillance has multiple aims, including:
      • Establishment of baseline metrics
      • Identification of infection clusters and outbreaks
      • Identification of opportunities to prevent or manage HAIs
      • Measurement of the efficacy of improvement initiatives and strategies
      The surveillance plan should be based on epidemiological evidence, focus on the assessment of infection risk factors, and align with current recommended practices and guidelines. Surveillance related to process measures implemented to improve patient safety is also a significant component of the infection prevention program. Implementation of the plan should include mitigation of risk and progress metrics.
      As described in the Pneumonia Definitions at the start of this section, identification of pneumonia is challenging for clinicians. This in turn makes it challenging to identify cases for surveillance purposes.
      For the IP performing surveillance for HAP, the choice of the marker or markers that would suggest a potential reportable case of pneumonia is an important decision. Ideally, the marker should be easily identified and obtained from the electronic medical record, and have high predictive power for pneumonia diagnosis. Selected potential triggers are listed in Table 3.
      Table 3Selected information sources in pneumonia surveillance
      Surveillance elementPotential sources of information
      RadiographicPositive chest X-ray reports

      Positive chest CT scans
      LaboratoryPositive respiratory culture results

      Positive blood culture results

      Molecular test results

      Positive urine test for Legionella pneumophila serogroup 1 antigens

      Serological evidence
      AdministrativeRadiographic test orders with indication related to pneumonia or consolidation

      Antimicrobial treatment orders with indication related to pneumonia

      ICD-10-CM discharge codes associated with pneumonia, not described as present on admission
      An exciting development in NV-HAP surveillance is described by Ji et al.
      • Ji W
      • McKenna C
      • Ochoa A
      • et al.
      Development and assessment of objective surveillance definitions for nonventilator hospital-acquired pneumonia.
      The authors conducted a cohort study in acute care hospitals that assessed multiple surveillance strategies using various combinations of easily abstracted clinical parameters for outcome measures and NV-HAP diagnosis. The authors proposed a surveillance definition that includes worsening oxygenation, administration of a new antibiotic for a minimum of 3 days, fever or abnormal white blood cell count (less than 4,000/mcL or more than 12,000/mcL), and chest imaging order. Application of this surveillance definition in the study population of more than 300,000 patients admitted to acute care yielded a pneumonia incidence rate of 0.6 events per 100 admissions (similar to incidence rates reported by other investigators) and aligned with incidence rates identified during multistate point prevalence surveys conducted by the Centers for Disease Control and Prevention.
      Although the authors concluded that additional validation studies are needed,
      • Ji W
      • McKenna C
      • Ochoa A
      • et al.
      Development and assessment of objective surveillance definitions for nonventilator hospital-acquired pneumonia.
      their work suggests the real possibility of concurrent pneumonia surveillance based on clinical parameters that are readily available as discrete fields in the electronic medical record, eliminating reliance on interpretation of radiological studies or collection of respiratory specimens for microbiological testing. The ability to identify NV-HAP cases in real time would allow the IP to quickly provide HAI metrics to stakeholders, identify clusters of infections, inform and participate in multidisciplinary prevention efforts, and assess the effectiveness of improvement strategies. Challenges with discrepancies between clinical and surveillance definitions encumber interdisciplinary improvement plans.

      Interdisciplinary collaboration

      Collaboration between IPs and their clinical partners can expedite the identification of potential NV-HAP cases. Health care workers who participate in the patient's care are in a great position to provide input about patients who may have developed NVHAP. These collaborative partners may include:
      • Respiratory and other therapists
      • Pharmacists
      • Nursing staff
      • Medical and surgical providers
      • Case managers
      • Laboratory personnel
      Research demonstrates the value of collaboration in improving patient care.
      • Bitter J
      • van Veen-Berkx E
      • Gooszen HG
      • van Amelsvoort P
      Multidisciplinary teamwork is an important issue to healthcare professionals.

      The Joint Commission. Sentinel Event Statistics Released for 2015. Available at:https://bit.ly/2Ro8ovq. Accessed September 22, 2019.

      • Fewster-Thuente L
      • Velsor-Friedrich B
      Interdisciplinary collaboration for healthcare professionals.
      In a study conducted in the Netherlands, investigators concluded that cross-functional teams were better able to improve quality of care and that there is a need to improve collaboration efforts among health care professionals.
      • Bitter J
      • van Veen-Berkx E
      • Gooszen HG
      • van Amelsvoort P
      Multidisciplinary teamwork is an important issue to healthcare professionals.
      The Joint Commission has published data indicating that communication was the third most-frequent root cause for sentinel events during calendar year 2015.

      The Joint Commission. Sentinel Event Statistics Released for 2015. Available at:https://bit.ly/2Ro8ovq. Accessed September 22, 2019.

      Thus, establishment of a collaborative relationship with colleagues to identify potential pneumonia cases is an important first step toward the creation of a performance improvement team that can ultimately plan and implement HAP prevention strategies.
      Key Points
      • Using current definitions, surveillance for NV-HAP is time- and labor-intensive.
      • Due to surveillance challenges, comparison of NV-HAP rates between hospitals is almost impossible currently.
      • Criteria for clinical diagnosis and case definition of pneumonia are not identical.
      • Ideally, markers used for NV-HAP case definition should be easily identified and obtained from the electronic medical record and have high predictive power for pneumonia diagnosis.
      • IPs should develop collaborative, interdisciplinary relationships to further identification of NV-HAP cases and plan and implement prevention strategies.

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