Automated surveillance of non-ventilator-associated hospital-acquired pneumonia (nvHAP): a systematic literature review

BACKGROUND

Hospital-acquired pneumonia (HAP) and its specific subset, non-ventilator hospital-acquired pneumonia (nvHAP) are significant contributors to patient morbidity and mortality. Automated surveillance systems for these healthcare-associated infections have emerged as a potentially beneficial replacement for manual surveillance. This systematic review aims to synthesise the existing literature on the characteristics and performance of automated nvHAP and HAP surveillance systems.

METHODS

We conducted a systematic search of publications describing automated surveillance of nvHAP and HAP. Our inclusion criteria covered articles that described fully and semi-automated systems without limitations on patient demographics or healthcare settings. We detailed the algorithms in each study and reported the performance characteristics of automated systems that were validated against specific reference methods. Two published metrics were employed to assess the quality of the included studies.

RESULTS

Our review identified 12 eligible studies that collectively describe 24 distinct candidate definitions, 23 for fully automated systems and one for a semi-automated system. These systems were employed exclusively in high-income countries and the majority were published after 2018. The algorithms commonly included radiology, leukocyte counts, temperature, antibiotic administration, and microbiology results. Validated surveillance systems' performance varied, with sensitivities for fully automated systems ranging from 40 to 99%, specificities from 58 and 98%, and positive predictive values from 8 to 71%. Validation was often carried out on small, pre-selected patient populations.

CONCLUSIONS

Recent years have seen a steep increase in publications on automated surveillance systems for nvHAP and HAP, which increase efficiency and reduce manual workload. However, the performance of fully automated surveillance remains moderate when compared to manual surveillance. The considerable heterogeneity in candidate surveillance definitions and reference standards, as well as validation on small or pre-selected samples, limits the generalisability of the findings. Further research, involving larger and broader patient populations is required to better understand the performance and applicability of automated nvHAP surveillance.

[Diagnosis and antibiotic therapy of nosocomial pneumonia in adults: from recommendations to real practice. A review]

Nosocomial pneumonia is a healthcare-associated infection with significant consequences for the patient and the healthcare system. The efficacy of treatment significantly depends on the timeliness and adequacy of the antibiotic therapy regimen. The growth of resistance of gram-negative pathogens of nosocomial pneumonia to antimicrobial agents increases the risk of prescribing inadequate empirical therapy, which worsens the results of patient treatment. Identification of risk factors for infection with multidrug-resistant microorganisms, careful local microbiological monitoring with detection of resistance mechanisms, implementation of antimicrobial therapy control strategy and use of rational combinations of antibacterial drugs are of great importance. In addition, the importance of using new drugs with activity against carbapenem-resistant strains, including ceftazidime/aviabactam, must be understood. This review outlines the current data on the etiology, features of diagnosis and antibacterial therapy of nosocomial pneumonia.

Identifying patients at increased risk of non-ventilator-associated pneumonia on admission to hospital: a pragmatic prognostic screening tool to trigger preventative action

BACKGROUND

Non-ventilator healthcare-associated pneumonia (NV-HAP) is an important healthcare-associated infection. This study tested the feasibility of using routine admission data to identify those patients at high risk of NV-HAP who could benefit from targeted, preventive interventions.

METHODS

Patients aged ≥64 years who developed NV-HAP five days or more after admission to elderly-care wards, were identified by retrospective case note review together with matched controls. Data on potential predictors of NV-HAP were captured from admission records. Multi-variate analysis was used to build a prognostic screening tool (PRHAPs); acceptability and feasibility of the tool was evaluated.

RESULTS

A total of 382 cases/381 control patients were included in the analysis. Ten predictors were included in the final model; nine increased the risk of NV-HAP (OR between 1.68 and 2.42) and one (independent mobility) was protective (OR 0.48; 95% CI 0.30-0.75). The model correctly predicted 68% of the patients with and without NV-HAP; sensitivity 77%; specificity 61%. The PRHAPs tool risk score was 60% or more if two predictors were present and over 70% if three were present. An expert consensus group supported incorporating the PRHAPs tool into electronic logic systems as an efficient mechanism to identify patients at risk of NV-HAP and target preventative strategies.

CONCLUSIONS

This prognostic screening (PRHAPs) tool, applied to data routinely collected when a patient is admitted to hospital, could enable staff to identify patients at greatest risk of NV-HAP, target scarce resources in implementing a prevention care bundle, and reduce the use of antimicrobial agents.

Including Organ Dysfunctions in a Predictive Score for Nosocomial Pneumonia After Cardiothoracic Surgery

BACKGROUND

Clinical diagnosis of ICU-acquired pneumonia after cardiothoracic surgery is challenging. Johanson criteria (chest radiograph infiltrate, purulent tracheal secretions, fever, and leukocytosis) fail in half the cases. A high Clinical Pulmonary Infection Score (CPIS) and ≥ 2-point increase in Sequential Organ Failure Assessment (SOFA) score (SOFA↑ ≥ 2) may improve diagnosis. The aim of the study was to evaluate whether CPIS or SOFA↑ ≥ 2 contributes to predict ICU-acquired pneumonia in subjects after cardiothoracic surgery.

METHODS

We used a prospective observational design. Spiegelhalter-Knill-Jones scoring systems including CPIS or SOFA↑ ≥ 2, together with other clinical and laboratory variables, were developed in a derivation cohort. A positive quantitative pulmonary sample culture was required to confirm ICU-acquired pneumonia. Area under the receiver operating characteristic curve (AUROC) was computed for each of the 2 scoring systems. The best system was evaluated in a validation cohort.

RESULTS

Derivation and validation cohorts included 172 and 108 subjects, with 410 and 216 suspected ICU-acquired pneumonia episodes, respectively. AUROC was 0.53 ± 0.03 for CPIS (P = .29) and 0.54 ± 0.03 for SOFA↑ ≥ 2 (P = .29). Adding purulent tracheal secretions and leukocytosis to SOFA↑ ≥ 2 (SOFA model) increased AUROC to 0.65 ± 0.03 (P < .001). Adding catecholamine use to CPIS (CPIS model) increased AUROC only slightly, to 0.57 ± 0.03. The probabilities predicted by the SOFA model were reliable, especially when high or low.

CONCLUSIONS

A clinical scoring system including at least SOFA↑ ≥ 2 increase barely improved ICU-acquired pneumonia prediction in subjects after cardiothoracic surgery.

A multiplex pneumonia panel for diagnosis of hospital-acquired and ventilator-associated pneumonia in the era of emerging antimicrobial resistance

Background

Antimicrobial resistance (AMR), including multidrug (MDR) and extensively drug-resistant (XDR) bacteria, is an essential consideration in the prevention and management of hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP). In the AMR era, the clinical utility of the BioFire FilmArray Pneumonia Panel Plus (BFPP) to diagnose HAP/VAP has not been thoroughly evaluated.

Methods

We enrolled adult hospitalized patients with HAP or VAP at Siriraj Hospital and Saraburi Hospital from July 2019–October 2021. Respiratory samples were collected for standard microbiological assays, antimicrobial susceptibility testing (AST), and the BFPP analysis.

Results

Of 40 subjects, 21 were men. The median duration of HAP/VAP diagnoses was 10.5 (5, 21.5) days, and 36 endotracheal aspirate and 4 sputum samples were collected. Standard cultures isolated 54 organisms—A. baumannii (37.0%), P. aeruginosa (29.6%), and S. maltophilia (16.7%). 68.6% of Gram Negatives showed an MDR or XDR profile. BFPP detected 77 bacterial targets—A. baumannii 32.5%, P. aeruginosa 26.3%, and K. pneumoniae 17.5%. Of 28 detected AMR gene targets, CTX-M (42.5%), OXA-48-like (25%), and NDM (14.3%) were the most common. Compared with standard testing, the BFPP had an overall sensitivity of 98% (88-100%), specificity of 81% (74-87%), positive predictive value of 60% (47-71%), negative predictive value of 99% (96-100%), and kappa (κ) coefficient of 0.64 (0.53-0.75). The concordance between phenotypic AST and detected AMR genes in Enterobacterales was 0.57. There was no concordance among A. baumannii, P. aeruginosa, and S. aureus

Conclusions

The BFPP has excellent diagnostic sensitivity to detect HAP/VAP etiology. The absence of S. maltophilia and discordance of AMR gene results limit the test performance.

Extra-pulmonary complications of 45 critically ill patients with COVID-19 in Yichang, Hubei province, China: A single-centered, retrospective, observation study

Mortality of critically ill patients with coronavirus disease 2019 (COVID-19) was high. Aims to examine whether time from symptoms onset to intensive care unit (ICU) admission affects incidence of extra-pulmonary complications and prognosis in order to provide a new insight for reducing the mortality. A single-centered, retrospective, observational study investigated 45 critically ill patients with COVID-19 hospitalized in ICU of The Third People's Hospital of Yichang from January 17 to March 29, 2020. Patients were divided into 2 groups according to time from symptoms onset to ICU admission (>7 and ≤7 days) and into 2 groups according to prognosis (survivors and non-survivors). Epidemiological, clinical, laboratory, radiological characteristics and treatment data were studied. Compared with patients who admitted to the ICU since symptoms onset ≤7 days (55.6%), patients who admitted to the ICU since symptoms onset >7 days (44.4%) were more likely to have extra-pulmonary complications (19 [95.0%] vs 16 [64.0%], P = .034), including acute kidney injury, cardiac injury, acute heart failure, liver dysfunction, gastrointestinal hemorrhage, hyperamylasemia, and hypernatremia. The incidence rates of acute respiratory distress syndrome, pneumothorax, and hospital-acquired pneumonia had no difference between the 2 groups. Except activated partial thromboplastin and Na+ concentration, the laboratory findings were worse in group of time from symptoms onset to ICU admission >7 days. There was no difference in mortality between the 2 groups. Of the 45 cases in the ICU, 19 (42.2%) were non-survivors, and 16 (35.6%) were with hospital-acquired pneumonia. Among these non-survivors, hospital-acquired pneumonia was up to 12 (63.2%) besides higher incidence of extra-pulmonary complications. However, hospital-acquired pneumonia occurred in only 4 (15.4%) survivors. Critically ill patients with COVID-19 who admitted to ICU at once might get benefit from intensive care via lower rate of extra-pulmonary complications.

Fatal fulminant community-acquired pneumonia caused by hypervirulent Klebsiella pneumoniae K2-ST86: Case report

RATIONALE

Invasive community-acquired infections, including pyogenic liver abscesses, caused by hypervirulent Klebsiella pneumoniae (hvKp) strains have been well recognized worldwide. Among these, sporadic hvKp-related community-acquired pneumonia (CAP) is an acute-onset, rapidly progressing disease that can likely turn fatal, if left untreated. However, the clinical diagnosis of hvKp infection remains challenging due to its non-specific symptoms, lack of awareness regarding this disease, and no consensus definition of hvKp.

PATIENT CONCERNS

A 39-year-old man presented with high-grade fever and sudden-onset chest pain. Laboratory testing revealed an elevated white blood cell count of 11,600 cells/μl and C-reactive protein level (>32 mg/dl). A chest X-ray and computed tomography revealed a focal consolidation in the left lower lung field.

DIAGNOSIS

Diagnosis of fulminant CAP caused by a hvKp K2-ST86 strain was made based upon multilocus sequencing typing (MLST).

INTERVENTIONS

The patient was treated with ampicillin/sulbactam.

OUTCOMES

The pneumonia became fulminant. Despite intensive care and treatment, he eventually died 15.5 hours after admission.

LESSONS

This is the first case of fatal fulminant CAP caused by a hvKp K2-ST86 strain reported in Japan. MLST was extremely useful for providing a definitive diagnosis for this infection. Thus, we propose that a biomarker-based approach should be considered even for an exploratory diagnosis of CAP related to hvKp infection.

Rapid syndromic molecular testing in pneumonia: The current landscape and future potential

Community acquired pneumonia (CAP), hospital-acquired pneumonia (HAP) and ventilator associated pneumonia (VAP) are all associated with significant mortality and cause huge expense to health care services around the world. Early, appropriate antimicrobial therapy is crucial for effective treatment. Syndromic diagnostic testing using novel, rapid multiplexed molecular platforms represents a new opportunity for rapidly targeted antimicrobial therapy to improve patient outcomes and facilitate antibiotic stewardship. In this article we review the currently available testing platforms and discuss the potential benefits and pitfalls of rapid testing in pneumonia.

Pneumonic Plague in a Dog and Widespread Potential Human Exposure in a Veterinary Hospital, United States

In December 2017, a dog that had pneumonic plague was brought to a veterinary teaching hospital in northern Colorado, USA. Several factors, including signalment, season, imaging, and laboratory findings, contributed to delayed diagnosis and resulted in potential exposure of >116 persons and 46 concurrently hospitalized animals to Yersinia pestis.

Development and Assessment of Objective Surveillance Definitions for Nonventilator Hospital-Acquired Pneumonia

IMPORTANCE

Hospital-acquired pneumonia is the most common health care-associated infection in the United States. Most cases occur in nonventilated patients, but many hospitals track hospital-acquired pneumonia only in ventilated patients because of the complexity and subjectivity of conducting surveillance for large numbers of nonventilated patients.

OBJECTIVE

To propose and assess potentially objective, efficient, and reproducible surveillance definitions for nonventilator hospital-acquired pneumonia (NV-HAP) using routine clinical data stored in electronic health record systems.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study was conducted in 2 tertiary referral and 2 community hospitals in Massachusetts between May 31, 2015, and July 1, 2018. All nonventilated patients aged 18 years or older who were admitted to these hospitals were included (N = 310 651).

EXPOSURES

Ten candidate definitions for NV-HAP based on clinically meaningful combinations of 6 potential surveillance criteria were proposed: worsening oxygenation, temperature higher than 38 °C (fever), abnormal white blood cell count of less than 4000/μL or more than 12 000/μL, performance of chest imaging, submission of respiratory specimen for culture, and 3 or more days of new antibiotics.

MAIN OUTCOMES AND MEASURES

Incidence rates, lengths of stay, hospital mortality rates, and odds ratios (ORs) for time to discharge and mortality compared with those of matched controls were calculated for each candidate definition. The ORs were adjusted for demographics, clinical service, comorbidities, and severity of illness.

RESULTS

The study analyzed 310 651 patients with 489 519 admissions, including 205 054 patients with 311 484 admissions of 3 or more days. Among the patients with 311 484 admissions, the mean (SD) patient age was 58.3 (19.3) years and 176 936 (56.8%) were of women. Incidence rates for candidate definitions per 100 admissions ranged from 3.4 events for worsening oxygenation alone to 0.9 event for worsening oxygenation and at least 3 days of new antibiotics to 0.6 event for worsening oxygenation, at least 3 days of new antibiotics, fever, abnormal white blood cell count, and performance of chest imaging. Crude mortality rates ranged from 16.1% (n = 2643) for patients with worsening oxygen alone to 27.7% (n = 868) for patients with worsening oxygenation, at least 3 days of antibiotics, fever or abnormal white blood cell count, and chest imaging. Patients who met NV-HAP candidate definitions remained in the hospital for twice as long as their matched controls (adjusted ORs ranged from 1.8 [95% CI, 1.7-1.8] to 2.1 [95% CI, 2.0-2.1]) and were 4 to 6 times as likely to die in the hospital (adjusted ORs ranged from 3.8 [95% CI, 3.5-4.0] to 6.5 [95% CI, 5.2-8.2]). Agreement between candidate definitions and clinical diagnoses was fair (κ = 0.33).

CONCLUSIONS AND RELEVANCE

These findings suggest that objective surveillance for NV-HAP using electronically computable definitions that incorporate common clinical criteria is feasible and generates incidence, mortality, and adjusted ORs for hospital mortality similar to estimates from manual surveillance. These definitions have the potential to facilitate widespread, automated surveillance for NV-HAP and thus inform the development and evaluation of prevention programs.

Health Care-Associated Pneumonia: Is It Still a Useful Concept?

"Health care-associated pneumonia (HCAP) was introduced into guidelines because of concerns about the increasing prevalence of drug-resistant pathogens (DRPs) not covered by standard empirical therapy. We now know that DRPs are very localized phenomena with low rates in most sites. Although HCAP risk factors are associated with a higher mortality, this is driven by comorbidities rather than the pathogens. Empirical coverage of DRPs has generally not resulted in better patient outcomes. A far more nuanced approach must be taken for patients with risk factors for DRPs taking into account the local cause and severity of disease.

Community-acquired Pneumonia and Hospital-acquired Pneumonia

Pneumonia is among the leading causes of morbidity and mortality worldwide. Although Streptococcus pneumoniae is the most likely cause in most cases, the variety of potential pathogens can make choosing a management strategy a complex endeavor. The setting in which pneumonia is acquired heavily influences diagnostic and therapeutic choices. Because the causative organism is typically unknown early on, timely administration of empiric antibiotics is a cornerstone of pneumonia management. Disease severity and rates of antibiotic resistance should be carefully considered when choosing an empiric regimen. When complications arise, further work-up and consultation with a pulmonary specialist may be necessary.

Use of an innovative and non-invasive device for virologic sampling of cough aerosols in patients with community and hospital acquired pneumonia: a pilot study

BACKGROUND

The aetiology of lower respiratory tract infections is challenging to investigate. Despite the wide array of diagnostic tools, invasive techniques, such as bronchoalveolar lavage (BAL), are often required to obtain adequate specimens. PneumoniaCheckTM is a new device that collects aerosol particles from cough, allowing microbiological analyses. Up to now it has been tested only for bacteria detection, but no study has investigated its usefulness for virus identification.

METHODS

In this pilot study we included 12 consecutive patients with pneumonia. After testing cough adequacy via a peak flow meter, a sampling with PneumoniaCheckTM was collected and a BAL was performed in each patient. Microbiological analyses for virus identification were performed on each sample and concordance between the two techniques was tested (sensitivity, specificity and positive/negative predictive values), taking BAL results as reference.

RESULTS

BAL was considered adequate in 10 patients. Among them, a viral pathogen was identified by PneumoniaCheckTM 6 times, each on different samples, whereas BAL allowed to detect the presence of a virus on 7 patients (14 positivities). Overall, the specificity for PneumoniaCheckTM to detect a virus was 100%, whereas the sensitivity was 66%. When considering only herpes viruses, PneumoniaCheckTM showed a lower sensitivity, detecting a virus in 1/4 of infected patients (25%).

CONCLUSIONS

In this pilot study PneumoniaCheckTM showed a good correlation with BAL for non-herpes virologic identification in pneumonia patients, providing excellent specificity. Further studies on larger population are needed to confirm these results and define its place in the panorama of rapid diagnostic tests for lower respiratory tract infections.

High heterogeneity in community-acquired pneumonia inclusion criteria: does this impact on the validity of the results of randomized controlled trials?

BACKGROUND

There is no consensus on the most accurate combination of diagnostic criteria to define community acquired pneumonia (CAP). We describe inclusion criteria in randomized controlled trials (RCT) of CAP and assess their performance for the diagnosis of formally identified CAP.

METHODS

RCTs related to CAP recorded on ClinicalTrials.gov were analysed. Due to high heterogeneity, we divided close CAP inclusion criteria into patterns (i.e. combinations of inclusion criteria). To assess their diagnostic performances, these CAP definition patterns were applied to a reference population of 319 suspected CAP patients, in whom the CAP diagnosis had been confirmed (n = 163) or excluded (n = 156) by an adjudication committee after a systematic thoracic CT-scan and a 28-day follow-up period.

RESULTS

In the 47 RCTs included in the analysis, 42 different CAP inclusion criteria combinations were identified and 8 patterns created. This heterogeneity was not explained either by the trials' methodology or by their objectives. When applied to the reference population, the performance ranges of the 8 definition patterns were 9.8-56.4% for sensitivities, 56.4 97.4% for specificities, 63.6 83.6% for positive predictive values and 50.8-66.7% for negative predictive values. None of the CAP definitions had both sensitivity and specificity superior to 65%. Depending on the CAP definition, the rate of included patients without CAP ("false positives") ranged from 1 to 21%.

CONCLUSIONS

CAP diagnostic criteria within RCTs are heterogeneous, which may have far-reaching consequences on validity of RCT results.

The Diagnostic Yield of Noninvasive Microbiologic Sputum Sampling in a Cohort of Patients with Clinically Diagnosed Hospital-Acquired Pneumonia

The clinical predictors of positive sputum culture have not been previously reported in hospital-acquired pneumonia (HAP), and data on yield of sputum culture in this setting are scant. Current Infectious Disease Society of America guidelines for HAP recommend noninvasive sputum sampling, though the data for this practice are limited. We assessed the yield of sputum culture in HAP cases at an academic medical center from January 2007 to July 2013. HAP cases were identifi ed by International Classifi cation of Diseases, Ninth Revision-Clinical Modifi cation codes for bacterial pneumonia and all cases were validated by chart review. Our cohort had 1172 hospitalizations with a HAP diagnosis. At least 1 sputum specimen was collected noninvasively and sent for bacterial culture after hospital day 2 and within 7 days of HAP diagnosis in 344 of these hospitalizations (29.4%), with a total of 478 sputum specimens, yielding 63 (13.2%) positive, 109 (22.8%) negative, and 306 (64.0%) contaminated cultures (>10 epithelial cells per high power fi eld). Signifi cant predictors of a positive sputum culture were chronic lung disease (relative risk [RR] = 2.0; 95% confi dence interval [CI], 1.2-3.4) and steroid use (RR = 1.8; 95% CI, 1.1-3.2). The most commonly identifi ed organisms were Gram-negative rods not further speciated (25.9%), Staphylococcus aureus (21.0%), and Pseudomonas aeruginosa (14.8%). Because of the ease of obtaining a sputum sample combined with the prevalence of commonly drug-resistant organisms, we suggest that sputum culture in HAP is a potentially useful noninvasive diagnostic technique.

Performance of the PSI and CURB-65 scoring systems in predicting 30-day mortality in healthcare-associated pneumonia

INTRODUCTION

Healthcare-associated pneumonia (HCAP) is the leading cause of infection in a hospital setting and is associated with a high mortality rate. This study aimed to evaluate the performance of the pneumonia severity index (PSI) and confusion, urea, respiratory rate, blood pressure, age≥65 (CURB-65) systems in predicting 30-day mortality in HCAP in adult patients.

PATIENTS AND METHODS

A cross-sectional study took place and data from 109 non-immunocompromised individuals aged>18 years were analyzed. The clinical diagnosis of HCAP included the presence of radiographic infiltrates in patients≥48hours after hospital admission. The PSI and CURB-65 scores were calculated and performance measures were estimated. Summary statistics were used to describe the study sample. The PSI and CURB-65 scores were calculated based on 20 and 5 criteria, respectively, and the performance indicators of the screening tools were estimated.

RESULTS

The overall 30-day mortality was 59.6%. At every given threshold, PSI sensitivity was higher, but showed a lower specificity than the CURB-65, and the highest Youden index (0.392) was observed at cut-off V in the PSI. The area under the ROC curve was 0.737 (95% CI: 0.646-0.827) and 0.698 (95% CI: 0.600-0.797) using the PSI and CURB-65 systems, respectively (P=.323).

CONCLUSION

Our findings suggest that the performance of the PSI and CURB-65 is reasonable for predicting 30-day mortality in adult HCAP patients and may be used in healthcare settings.

Particularities of community- acquired pneumonia in the elderly

BACKGROUND

Acute community-acquiredpneumonia in olderadults has averysevereprognosiswith a mortality rate whichcanreach 10%. Knowing the clinical, etiological, therapeutic and progressive features of thisdiseasecan help to establish management rulesthatcanimprove the prognosis. The aim of ourstudywas to compare the community-acquiredpneumonia profile in olderadults and youngerthem.

METHODS

Retrospective comparative studyincluding patients hospitalized for community-acquiredpneumonia. Two groups of patients weredefined: group 1 subjectsagedbetween 18 and 64 years and group 2 subjectsaged 65 years and older.

RESULTS

The meanage of elderlywas 76±6,18. COPD was five times more common in group 2 (p = 0.0001). Symptomsweredifferent in the two groups withpredominance of dyspnea in the group of elderly. Prognosisfactors scores (PSI and CURB_65) in elderlywerehighercompared to youngersubjects. Sputum culture wascontributory in third cases in both groups. Pseudomonas aeruginosawas the mostcommonpathogenidentified in the elderly. Empiricaltreatmentwas the mostprescribed in both groups. Evolution was more favorable in group 1 (p = 0.006). Complications, hospitalization in ICU and delay of recoveryweremostcommon in the group 2.

CONCLUSION

Our studyconfirmedsomecharacteristics of community-acquiredpneumonia in elderly; it has mostlyrevealed the importance of microbiological tests in this population.