Hospital-acquired pneumonia: risk factors, microbiology, and treatment

Ventilator-associated pneumonia: pathobiological heterogeneity and diagnostic challenges

Ventilator-associated pneumonia (VAP) affects up to 20% of critically ill patients and induces significant antibiotic prescription pressure, accounting for half of all antibiotic use in the ICU. VAP significantly increases hospital length of stay and healthcare costs yet is also associated with long-term morbidity and mortality. The diagnosis of VAP continues to present challenges and pitfalls for the currently available clinical, radiological and microbiological diagnostic armamentarium. Biomarkers and artificial intelligence offer an innovative potential direction for ongoing future research. In this Review, we summarise the pathobiological heterogeneity and diagnostic challenges associated with VAP.

Incidence, etiology, and outcome of hospital-acquired pneumonia in patients with acute exacerbation of fibrotic idiopathic interstitial pneumonia

BACKGROUND

Acute exacerbations (AEs) of fibrotic idiopathic interstitial pneumonia (fIIP) that require hospitalization occur in some patients. During hospitalization, these patients can develop hospital-acquired pneumonia (HAP), a common hospital-acquired infection with a high mortality rate. However, the characteristics of HAP in AE-fIIP remain unknown. The purpose of this study was to determine the incidence, causative pathogens, and outcomes of HAP in patients with AE-fIIP.

METHODS

The medical records of consecutive patients who were hospitalized with AE-fIIP from January 2008 to December 2019 were analyzed for the incidence, causative pathogen, and survival of HAP. The records of patients with an obvious infection-triggered AE were excluded from analysis.

RESULTS

There were 128 patients with AE-fIIP (89 with idiopathic pulmonary fibrosis [IPF] and 39 with non-IPF fIIP) who were hospitalized a total of 155 times (111 with IPF and 44 with non-IPF fIIP). HAP occurred in 49 patients (40 with IPF and 9 with non-IPF fIIP). The incidence and the in-hospital mortality rates of HAP in patients with AE-fIIP were high, at 32.2% and 48.9%, respectively. Corynebacterium spp. was the most common causative pathogen, which was followed by human cytomegalovirus (HCMV).

CONCLUSIONS

The incidence and the in-hospital mortality rates of HAP in patients with AE-fIIP are high. To improve their survival, patients with fIIP who had AEs and HAP should receive prompt empirical treatment for possible infections with Corynebacterium spp. and testing for HCMV.

The impact of the COVID-19 pandemic on gram-negative bacteria susceptibility patterns in respiratory samples of intensive care units in the Brussels Capital Region, 2010-2021

BACKGROUND

The effect of the Coronavirus Disease 2019 (COVID-19) pandemic on gram-negative bacteria nonsusceptibility to antibiotics is unclear.

METHODS

Between January 1, 2010, and December 31, 2021, the respiratory samples of intensive care unit patients at 3 University Hospitals in Brussels were retrieved. Based on the nonsusceptibility to antimicrobial classes, drug-resistance patterns were defined as multi-drug-resistant, extensively drug-resistant, and pan-drug-resistant. The study time frame was divided into 6 periods of 2 years each, and the impact of the COVID-19 pandemic (last period: 2020-2021) was assessed.

RESULTS

During the current study, 10,577 samples were identified from 5,889 patients. While a significant augmentation of multi-drug-resistant isolates was noticed once comparing 2 prepandemic periods (2012-2013 and 2014-2015), all 3 patterns of nonsusceptibility significantly increased, comparing the years before and throughout the COVID-19 pandemic (2018-2019 and 2020-2021). Globally, the greatest increase in antimicrobial nonsusceptibility, comparing the last 2 periods, was reported for piperacillin-tazobactam (from 28% to 38%). Pseudomonas aeruginosa was the most isolated species, and the most involved in the appearance of resistance, with an augmentation of nonsusceptibility percentage to meropenem of 22% (from 25% to 47%), between the prepandemic and the pandemic periods.

CONCLUSIONS

The COVID-19 pandemic was associated with increasing trends of antimicrobial resistance in respiratory samples of patients admitted to the intensive care units in university hospitals with well-implemented antibiotic stewardship programs.

Surveillance of infections of surgical sites and lower respiratory tracts should be combined: experiences from the German surveillance module for operated patients (OP-KISS), 2018 to 2022

BackgroundSurveillance of lower respiratory tract infections (LRTI) of operated patients conventionally focuses on intubated patients in intensive care units (ICU). Post-operative immobilisation increases the risk of LRTI not associated with ventilators. Operated patients, however, have thus far not been a primary target for LRTI surveillance.AimWe aimed to describe the applied LRTI surveillance method in the German surveillance module for operated patients (OP-KISS) and to report data between 2018 and 2022.MethodsSurveillance of LRTI can be performed voluntarily in addition to surgical site infection (SSI) surveillance in OP-KISS. We calculated LRTI rates per 100 operations for all procedures combined, as well as for individual surgical groups and procedures. Additionally, a combined post-operative infection rate (SSI and LRTI) was calculated.ResultsSurveillance of LRTI was performed in 4% of all participating OP-KISS departments and for 2% (23,239 of 1,332,438) of all procedures in the OP-KISS database. The pooled LRTI rate was 0.9 per 100 operations, with marked differences between different types of surgery (3.6 for lobectomies, 0.1 for traumatology and orthopaedics). The share of LRTI among all post-operative infections was highly variable. For lobectomies, the LRTI rate was higher than the SSI rate (3.6 vs 1.5 per 100 operations).ConclusionSurveillance of post-operative LRTI is not yet widely adopted by German hospitals. Based on the data in this study, lobectomies represent a prime target for post-operative LRTI surveillance.

Genomic and metabolic versatility of Pseudomonas aeruginosa contributes to its inter-kingdom transmission and survival

Pseudomonas aeruginosa is one of the most versatile bacteria with renowned pathogenicity and extensive drug resistance. The diverse habitats of this bacterium include fresh, saline and drainage waters, soil, moist surfaces, taps, showerheads, pipelines, medical implants, nematodes, insects, plants, animals, birds and humans. The arsenal of virulence factors produced by P. aeruginosa includes pyocyanin, rhamnolipids, siderophores, lytic enzymes, toxins and polysaccharides. All these virulent elements coupled with intrinsic, adaptive and acquired antibiotic resistance facilitate persistent colonization and lethal infections in different hosts. To date, treating pulmonary diseases remains complicated due to the chronic secondary infections triggered by hospital-acquired P. aeruginosa. On the contrary, this bacterium can improve plant growth by suppressing phytopathogens and insects. Notably, P. aeruginosa is one of the very few bacteria capable of trans-kingdom transmission and infection. Transfer of P. aeruginosa strains from plant materials to hospital wards, animals to humans, and humans to their pets occurs relatively often. Recently, we have identified that plant-associated P. aeruginosa strains could be pathologically similar to clinical isolates. In this review, we have highlighted the genomic and metabolic factors that facilitate the dominance of P. aeruginosa across different biological kingdoms and the varying roles of this bacterium in plant and human health.

An assessment of burden of hospital-acquired pneumonia among abdominal surgical patients in tertiary university hospital in Serbia: A matched nested case-control study

Background

In the population of abdominal surgical patients hospital-acquired pneumonia (HAP) significantly increases morbidity and mortality.

Patients and methods

Through regular hospital surveillance of patients who received abdominal operations, we identified postoperative HAP from 2007 to 2019. In an initial nested case-control study, every surgical patient with HAP was compared with three control patients without HAP. Control patients were matched to the cases by age, gender, the American Society of Anesthesiologists score, and type of surgical operation. Also, the patients with HAP, who died were compared with those who survived.

Results

Multivariate logistic regression analysis (MLRA) revealed that other postoperative infections, length of intensive care unit stay, use of H2RA, use of PPI/ H2RA, multiple transfusion, and use of vancomycin in surgical prophylaxis were independent RFs for occurrence of HAP. Also, MLRA identified that age, lenght of hospital stay, use of mechanical ventilation and ceftriaxone in HAP therapy were indepedenttly associated with poor outcome of HAP. All Acinetobacter baumannii isolates were resistant to aminoglycoside antimicrobial agents and showed carbapenem resistance. The most frequently used antibiotics in patients with HAP and without HAP were vancomycin and metronidazole, respectively.

Conclusion

Our study provided an insight into the burden of HAP in abdominal surgical patients, and highlighted several priority areas and targets for quality improvement.

Contribution of IL-38 in Lung Immunity during Pseudomonas Aeruginosa-induced Pneumonia

OBJECTIVE

Interleukin-38 (IL-38), a new type of cytokine, is involved in processes such as tissue repair, inflammatory response, and immune response. However, its function in pneumonia caused by Pseudomonas aeruginosa (P. aeruginosa) is still unclear.

METHODS

In this study, we detected circulating IL-38 and cytokines such as IL-1β, IL-6, IL-17A, TNF-α, IL-8, and IL-10 in adults affected by early stage pneumonia caused by P. aeruginosa. Collected clinical data of these patients, such as the APACHE II score, levels of PCT, and oxygenation index when they entering the ICU. Using P. aeruginosa-induced pneumonia WT murine model to evaluate the effect of IL-38 on Treg differentiation, cell apoptosis, survival, tissue damage, inflammation, and bacterial removal.

RESULTS

In clinical research, although IL-38 is significantly increased during the early stages of clinical P. aeruginosa pneumonia, the concentration of IL-38 in the serum of patients who died with P. aeruginosa pneumonia was relatively lower than that of surviving patients. It reveals IL-38 may insufficiently secreted in patients who died with P. aeruginosa pneumonia. Besides, the serum IL-38 level of patients with P. aeruginosa pneumonia on the day of admission to the ICU showed significantly positive correlations with IL-10 and the PaO2/FiO2 ratio but negative correlations with IL-1β, IL-6, IL-8, IL-17, TNF-α, APACHE II score, and PCT In summary, IL-38 might be a molecule for adjuvant therapy in P. aeruginosa pneumonia. In experimental animal models, first recombinant IL-38 improved survival, whereas anti-IL-38 antibody reduced survival in the experimental pneumonia murine model. Secondly, IL-38 exposure reduced the inflammatory response, as suggested by the lung injury, and reduced cytokine levels (IL-1β, IL-6, IL- 17A, TNF-α, and IL-8, but not IL-10). It also increased bacterial clearance and reduced cell apoptosis in the lungs. Furthermore, IL-38 was shown to reduce TBK1 expression in vitro when naive CD4+ T lymphocytes were differentiated to Tregs and played a protective role in P. aeruginosa pneumonia.

CONCLUSIONS

To summarize, the above findings provide additional insights into the mechanism of IL-38 in the treatment of P. aeruginosa pneumonia.

Pretreatment with 6-Gingerol Ameliorates Sepsis-Induced Immune Dysfunction by Regulating the Cytokine Balance and Reducing Lymphocyte Apoptosis

Sepsis is characterized by an initial net hyperinflammatory response, followed by a period of immunosuppression, termed immunoparalysis. During this immunosuppressive phase, patients may have difficulty eradicating invading pathogens and are susceptible to life-threatening secondary hospital-acquired infections. Due to progress in antimicrobial treatment and supportive care, most patients survive early sepsis. Mortality is more frequently attributed to subsequent secondary nosocomial infections and multiorgan system failure. 6-Gingerol is the major pharmacologically active component of ginger. Although it is known to exhibit a variety of biological activities, including anti-inflammation and antioxidation, the role of 6-gingerol in sepsis-induced immune dysfunction remains elusive. Thus, we investigated whether 6-gingerol improves septic host response to infections during sepsis. 6-Gingerol-treated mice showed significantly lower mortality in polymicrobial sepsis induced by cecal ligation and puncture LPS via enhanced bacterial clearance in the peritoneum, blood, and organs (liver, spleen, and kidney) and inhibited the production of TNF-α and IL-6 in TLR2 and/or TLR4-stimulated macrophages. In addition, we demonstrated that survival improvement of secondary infection following septic insult was associated with an initial response of enhanced neutrophil numbers and function at the infection site, reduced apoptosis of immune cells, and a shift from a T helper cell type 2 (Th2) to a T helper cell type 1 (Th1) cytokine balance in the hypoinflammation phase. Our overall findings suggest that 6-gingerol potentially restores sepsis-induced immune dysfunction by shifting the balance of Th1/Th2 and by regulating apoptosis of immune cells.

Deep diagnostic agent forest (DDAF): A deep learning pathogen recognition system for pneumonia based on CT

BACKGROUND

Even though antibiotics agents are widely used, pneumonia is still one of the most common causes of death around the world. Some severe, fast-spreading pneumonia can even cause huge influence on global economy and life security. In order to give optimal medication regimens and prevent infectious pneumonia's spreading, recognition of pathogens is important.

METHOD

In this single-institution retrospective study, 2,353 patients with their CT volumes are included, each of whom was infected by one of 12 known kinds of pathogens. We propose Deep Diagnostic Agent Forest (DDAF) to recognize the pathogen of a patient based on ones' CT volume, which is a challenging multiclass classification problem, with large intraclass variations and small interclass variations and very imbalanced data.

RESULTS

The model achieves 0.899 ± 0.004 multi-way area under curves of receiver (AUC) for level-I pathogen recognition, which are five rough groups of pathogens, and 0.851 ± 0.003 AUC for level-II recognition, which are 12 fine-level pathogens. The model also outperforms the average result of seven human readers in level-I recognition and outperforms all readers in level-II recognition, who can only reach an average result of 7.71 ± 4.10% accuracy.

CONCLUSION

Deep learning model can help in recognition pathogens using CTs only, which might help accelerate the process of etiological diagnosis.

Lung-Targeting Lysostaphin Microspheres for Methicillin-Resistant Staphylococcus aureus Pneumonia Treatment and Prevention

Multifunctional antimicrobial strategies are urgently needed to treat methicillin-resistant Staphylococcus aureus (MRSA) caused pneumonia due to its increasing resistance, enhanced virulence, and high pathogenicity. Here, we report that lysostaphin, a bacteriolytic enzyme, encapsulated within poly(lactic-co-glycolic acid) microspheres (LyIR@MS) specially treats planktonic MRSA bacteria, mature biofilms, and related pneumonia. Optimized LyIR@MS with suitable diameters could deliver a sufficient amount of lysostaphin to the lung without a decrease in survival rate after intravenous injection. Furthermore, the degradable properties of the carrier make it safe for targeted release of lysostaphin to eliminate MRSA, repressing the expression of virulence genes and improving the sensitivity of biofilms to host neutrophils. In the MRSA pneumonia mouse model, treatment or prophylaxis with LyIR@MS significantly improved survival rate and relieved inflammatory injury without introducing adverse events. These findings suggest the clinical translational potential of LyIR@MS for the treatment of MRSA-infected lung diseases.

Evaluation of a Commercial Multiplexed Molecular Lower Respiratory Panel at a Tertiary Care Cancer Center

Diagnosis and management of bacterial pneumonia still relies on bacterial culture and antimicrobial susceptibility testing. The Unyvero Lower Respiratory Tract panel (LRT) is a multiplex molecular assay that provides results within approximately 4.5 hours. This study evaluated the analytical performance of the LRT on bronchoalveolar lavage (BAL) fluids and bronchial washings (BW) in a cancer patient population and retrospectively determined clinical impact on therapy. Sensitivity and specificity of LRT on BAL and BW compared with bacterial culture and susceptibilities were calculated. Chart reviews were performed to determine whether antibiotic management would have changed based on the LRT results. A total of 113 BAL and 123 BW respiratory samples from 191 patients were included. The overall sensitivity and specificity were 91.7% (95% CI, 77.5%-98.3%) and 92.0% (95% CI, 87.3%-95.4%), respectively. Staphylococcus aureus was the most common target detected (n = 21) with 89.5% (95% CI, 66.8%-98.7%) sensitivity and 98.2% (95% CI, 95.4%-99.5%) specificity. Based on availability of LRT results, 4.8% of patients could have been de-escalated faster. The LRT demonstrated an overall high accuracy for the detection of common bacteria associated with pneumonia. In this cancer inpatient cohort, treatment adjustment based on LRT results would have occurred in a small number of cases. Larger studies are necessary to understand the real-world impact within specific high-risk populations.

A multidisciplinary approach to complex oncological spine coverage in high-risk patients

OBJECTIVE

The consequences of failed spinal hardware secondary to wound complications can increase the burden on the patient while also significantly escalating the cost of care. The objective of this study was to demonstrate the effectiveness of a protocol-based multidisciplinary approach in optimizing wound outcome in complex oncological spine care patients.

METHODS

A retrospective consecutive case series was performed from 2015 to 2019 of all patients who underwent oncological spine surgery. A protocol was established to identify oncological patients at high risk for potential wound complications. Preoperative and postoperative treatment plans were developed by the multidisciplinary tumor board team members. Wound healing risk factors such as diabetes, obesity, prior spine surgery, pre- or postoperative chemotherapy or radiation exposure, perioperative steroid use, and poor nutritional status were recorded. Operative details, including the regions of spinal involvement, presence of instrumentation, and number of vertebral levels operated on, were reviewed. Primary outcomes were the length of hospitalization and major (requiring reoperation) and minor wound complications in the setting of the aforementioned identified risk factors.

RESULTS

A total of 102 oncological cases were recorded during the 5-year study period. Of these patients, 99 had local muscle flap reconstruction with layered closure over their surgical hardware. The prevalence of smoking, diabetes, and previous spine surgery for the cohort was 21.6%, 20.6%, and 27.5%, respectively. Radiation exposure was seen in 72.5% of patients (37.3% preoperative vs 48% postoperative exposure). Chemotherapy was given to 66.7% of the patients (49% preoperatively and 30.4% postoperatively). The rate of perioperative steroid exposure was 60.8%. Prealbumin and albumin levels were 15.00 ± 7.47 mg/dL and 3.23 ± 0.43 mg/dL, respectively. Overall, an albumin level of < 3.5 mg/dL and BMI < 18.5 were seen in 64.7% and 13.7% of the patients, respectively. The mean number of vertebral levels involved was 6.76 ± 2.37 levels. Instrumentation of 7 levels or more was seen in 52.9% of patients. The average spinal wound defect size was 22.06 ± 7.79 cm. The rate of minor wound complications, including superficial skin breakdown (epidermolysis) and nonoperative seromas, was 6.9%, whereas that for major complications requiring reoperation within 90 days of surgery was 2.9%.

CONCLUSIONS

A multidisciplinary team approach utilized in complex multilevel oncological spine reconstruction surgery optimizes surgical outcomes, reduces morbidities, and improves care and satisfaction in patients with known risk factors.

A National Comparison of Postoperative Outcomes in Completion Thyroidectomy and Total Thyroidectomy

OBJECTIVE

To characterize and assess the non-thyroid-specific postoperative complications of completion thyroidectomy as compared with total thyroidectomy.

STUDY DESIGN

Retrospective analysis: 2005 to 2017.

SETTING

National Surgical Quality Improvement Program database.

SUBJECTS AND METHODS

Patients aged >18 years receiving a completion or total thyroidectomy were eligible for inclusion. Patients not treated by otolaryngologists or general surgeons and with unknown demographic variables were excluded.

RESULTS

A total of 70,638 patients were analyzed, representing 64,763 total thyroidectomies and 5875 completion thyroidectomies. The 30-day mortality rate was 0.1% for both procedures (P > .05). Overall, 1.7% and 1.4% of patients undergoing total and completion thyroidectomies experienced at least 1 complication (P > .05), while 1.2% and 0.9% had a postoperative medical complication (P = .0186), respectively. On multivariable analysis, patients undergoing total thyroidectomies were significantly more likely to return to the operating room (odds ratio [OR], 1.36; 95% CI, 1.04-1.80; P = .027) and to be readmitted (OR, 1.45; 95% CI, 1.16-1.81; P = .001). Adjusted analysis also demonstrated that patients undergoing total thyroidectomies were more likely to be inpatients (OR, 1.17; 95% CI, 1.11-1.24; P < .001), be treated by nonotolaryngologists (OR, 1.36; 95% CI, 1.29-1.45; P < .001), and smoke (OR, 1.22; 95% CI, 1.13-1.33; P < .001).

CONCLUSION

National data suggest that total and completion thyroidectomies are relatively safe procedures but that completion thyroidectomies are associated with lower rates of postoperative complications. These findings may play a role in determining treatment plans for patients and optimizing risk reduction.

Prevalence, Determinants, and Prognostic Significance of Hospital Acquired Pneumonia in Patients with Acute Heart Failure

The prognostic impact of hospital-acquired pneumonia (HAP) in acute heart failure (AHF) patients have not been fully elucidated. We evaluated 776 consecutive hospitalized AHF patients. The primary in-hospital outcomes were all-cause death and worsening heart failure (WHF), while the outcome following discharge was all-cause death. The clinical diagnosis of HAP was based on clinical practice guidelines by the Infectious Diseases Society of America and the American Thoracic Society. Patients with HAP had a significantly higher incidence of in-hospital death (12% vs. 1%, p < 0.001), WHF during the hospitalization (28% vs. 7%, p < 0.001), and longer length of hospital stay (p = 0.003) than those without. Among patients who survived at discharge, during a median follow-up period of 741 (interquartile range 422–1000) days, the incidence of all-cause death was significantly higher in patients with HAP than in those without (p < 0.001). In the multivariable Cox regression, HAP development was independently associated with all-cause death after discharge (HR [hazard ratio] 1.86, 95%CI [confidence interval] 1.08–3.19). Furthermore, older age (OR [odds ratio] 1.04, 95%CI 1.01–1.08), male sex (OR 2.21, 95%CI 1.14–4.28), and higher serum white blood cell count (OR 1.18, 95%CI 1.09–1.29) and serum C-reactive protein (OR 1.08, 95%CI 1.01–1.06) were independently associated with HAP development. In hospitalized patients with AHF, HAP development was associated with worse clinical outcomes, suggesting the importance of prevention and early screening for HAP.

Non-ventilator health care-associated pneumonia (NV-HAP): NV-HAP Risk Factors

Several risk factors have a significant impact on the development of nonventilator health care-associated pneumonia (NV-HAP). This section discusses both the modifiable and nonmodifiable risk factors contributing to the incidence of NV-HAP. Lack of mobility, malnutrition, high blood glucose, inhibition of gastric acid and central nervous system depressants underscored in this section. Efforts to treat, modify, or alter these risk factors as opportunities to decrease the incidence of NV-HAP. In addition, we to address and assess nonmodifiable risk factors.

Perioperative Assessment of High-Risk Abdominal Surgery: A Case Study

Objectives • To outline the key components of a pre-operative cardiac risk assessment. • To review the major guidelines utilized to assess patients' surgical risks. • To discuss the perioperative management of surgical patients to prevent cardiac and pulmonary complications. • To review the utility of biomarkers in the pre- and post-operative period.

Mortality attributable to hospital acquired infections with multidrug-resistant bacteria in a large group of German hospitals

BACKGROUND

According to extrapolations, around 35,000 patients in Germany develop hospital acquired infections (HAI) with a multidrug-resistant organism (MDRO) every year, and about 1500 of them die. Previous estimations were based on laboratory data and prevalence studies. Aim of this study was to establish the incidences of hospital acquired MDRO infections and the resulting deaths by expert review.

METHODS

Data on patients suffering from a hospital acquired MDRO infection were collected from 32 hospitals from all care levels. Records of patients with MDRO infection who died in the year 2016 underwent an onsite review by two experts to determine the impact of the infection, if any, on the cause of death.

RESULTS

A total of 714,108 in-patients were treated in 32 hospitals participating in the study. Of these patients, 1136 suffered a hospital acquired MDRO infection (1.59 per 1000 patients). 215 patients with an MDRO infection died [0.301 per 1000, (95% CI 0,261-0,341)], but only in 78 cases this was estimated as the cause of death [0.109 per 1000 patients (95% CI 0.085-0.133)].

CONCLUSION

By putting the above rates in relation to the total number of in-patients in Germany, it can be rated that around 31,052 patients per year suffer a hospital acquired MDRO infection, and 2132 patients die from it. These results from our reviewer investigation confirm earlier extrapolations.

HIRA-TAN detects pathogens of pneumonia with a progressive course despite antibiotic treatment

BACKGROUND

Empiric antibiotics are administered for pneumonia when the causative pathogens are unidentified. Pathogen-directed therapy is impeded by negative culture results and/or culture time lag. This circumstance necessitates a salvage method for pathogen identification, especially when antibiotic therapy has failed. Here, we aimed to preliminarily investigate the HIRA-TAN method in pneumonia with a progressive course despite prior empiric antibiotic therapy.

METHODS

This prospective study was conducted for patients who were referred to Dr. Zainoel Abidin Hospital, Aceh, Indonesia, from December 2016 to January 2017, owing to pneumonia with a progressive course. Sputum or pleural effusion was subjected to culture and the HIRA-TAN assay. The HIRA-TAN identified the candidate causative pathogens based on the difference in the cycle threshold (Ct) between the targeted pathogen and the single-copy human gene.

RESULTS

Patients (n=27) were predominantly males (22 patients, 81.5%), with a median age of 62 years. All patients had comorbid disease and were classified as hospital-acquired pneumonia (25 patients, 92.6%) with multilobar infiltrates (22 patients, 81.5%). Bacterial culture identified causative pathogen(s) in some (14 patients, 51.8%), whereas the HIRA-TAN identified pathogen(s) in most (23 patients, 85.2%). The rapid pathogen identification by the HIRA-TAN will provide valuable information in guiding pathogen-directed therapy.

CONCLUSIONS

The result warrants a larger clinical trial to confirm the clinical efficacy of the HIRA-TAN in patients with progressive pneumonia despite previous antibiotic treatment.

The crowd-out effect of a mass casualty incident: Experience from a dust explosion with multiple burn injuries

A mass casualty incident (MCI) can have an enormous impact on an already crowded emergency department (ED), affecting the quality of health care provided to non-MCI ED patients. On June 26, 2015, a burn MCI (BMCI) occurred due to a cornstarch explosion at a party at a water park. The competing needs of the BMCI patients might have crowded out the needs of the non-BMCI patients. Although crowd-out effects have been previously documented in a variety of health care situations, they have not been extensively evaluated during MCIs. We aimed to determine whether the outcomes of the non-MCI patients were compromised during this incident.We conducted a retrospective observational study comparing several health care parameters and outcomes between non-BMCI patients and historical controls during the designated period using institutional electronic records and the National Health Insurance Research Database.On the night of the incident, 53 patients were sent to our ED; most of them arrived within 3 hours after the BMCI. There was a significant increase in the wait time for ICU beds among non-BMCI patients compared to the wait times during the corresponding week of the previous year (8.09 ± 4.21 hours vs 3.77 ± 2.15 hours, P = .008). At the hospital level, there was a significantly increased length of hospital stay (LOS) in the ICU after the MCI compared with the LOS in the ICU in the same week of the preceding year (median days: 15 vs 8, P ≤ .001). At the regional level, there were no significant differences between the 2 periods in the LOS in acute care, LOS in the ICU or mortality rates at the involved medical centers.Crowd-out effects from the MCI occurred in the ED and at the institutional level. Although there was an increased wait time for admission to the ICU and a longer LOS in the ICU, the LOS in acute care beds, treatment of time-sensitive diseases, and mortality rates were not compromised by the current MCI protocol at either the institutional or regional levels.

Incidence of Respiratory Complications Following Lumbar Spine Surgery

Background

The purpose of this study is to assess the incidence, risk factors for, and types of respiratory complications occurring in patients undergoing lumbar spine surgery.

Methods

Patients undergoing various lumbar spine surgeries from 2007 to 2014 were identified using the PearlDiver patient record database from the nationwide insurance provider Humana Inc. Patient records were analyzed using International Classification of Diseases, Ninth Revision codes and Current Procedural Terminology codes to determine the incidence of pneumonia, pleural effusion, pulmonary collapse, and acute respiratory failure for each procedure type. The incidence of these complications in patients with the risk factors diabetes mellitus, chronic obstructive pulmonary disease (COPD), and smoking was also examined.

Results

A total of 64,891 patients (33,280 females; 31,611 males) within the Humana database underwent various lumbar procedures from 2007 to 2014. The overall incidence of respiratory complications in patients undergoing lumbar procedures was 5.7% (n = 3694) within 1 month of having the procedure. Pulmonary collapse was the most common complication with an incidence of 4.3% (n = 2792), followed by pneumonia 1.98% (n = 1285), acute respiratory failure 1.97% (n = 1279), and pleural effusion 1.6% (n = 1048). For each respiratory complication studied, single level discectomy had the lowest complication rate and multilevel anterior lumbar interbody fusion had the highest complication rate. The incidence of each individual respiratory complication was higher in patients who had a history of smoking, COPD, or diabetes mellitus than it was in patients with none of these 3 risk factors (P < .01).

Conclusion

The results of this study show that patients who have a history of smoking, COPD, or diabetes mellitus are at a greater risk for respiratory complications following lumbar spine surgery. These findings are useful for patient selection, clinical decision-making, and preoperative counseling.

Characterization of Host Responses during Pseudomonas aeruginosa Acute Infection in the Lungs and Blood and after Treatment with the Synthetic Immunomodulatory Peptide IDR-1002

Pseudomonas aeruginosa is an opportunistic pathogen that causes nosocomial pneumonia and infects patients with cystic fibrosis. P. aeruginosa lung infections are difficult to treat due to bacterial resistance to antibiotics, and strains with multidrug resistance are becoming more prevalent.

Pseudomonas aeruginosa is an opportunistic pathogen that causes nosocomial pneumonia and infects patients with cystic fibrosis. P. aeruginosa lung infections are difficult to treat due to bacterial resistance to antibiotics, and strains with multidrug resistance are becoming more prevalent. Here, we examined the use of a small host defense peptide, innate defense regulator 1002 (IDR-1002), in an acute P. aeruginosa lung infection in vivo. IDR-1002 significantly reduced the bacterial burden in bronchoalveolar lavage fluid (BALF), as well as MCP-1 in BALF and serum, KC in serum, and interleukin 6 (IL-6) in BALF. Transcriptome sequencing (RNA-Seq) was conducted on lungs and whole blood, and the effects of P. aeruginosa, IDR-1002, and the combination of P. aeruginosa and IDR-1002 were evaluated. Differential gene expression analysis showed that P. aeruginosa increased multiple inflammatory and innate immune pathways, as well as affected hemostasis, matrix metalloproteinases, collagen biosynthesis, and various metabolism pathways in the lungs and/or blood. Infected mice treated with IDR-1002 had significant changes in gene expression compared to untreated infected mice, with fewer differentially expressed genes associated with the inflammatory and innate immune responses to microbial infection, and treatment also affected morphogenesis, certain metabolic pathways, and lymphocyte activation. Overall, these results showed that IDR-1002 was effective in treating P. aeruginosa acute lung infections and associated inflammation.

Susceptibility to ceftobiprole of respiratory-tract pathogens collected in the United Kingdom and Ireland during 2014-2015

Purpose

Lower respiratory tract infections (LRTIs) can cause significant morbidity and mortality and are becoming increasingly difficult to treat because of the growing prevalence of resistance to conventional antimicrobial agents. This study aimed to assess the current in vitro susceptibility of respiratory tract pathogens collected from the UK and Ireland to ceftobiprole, an advanced-generation cephalosporin, as compared with other antibiotics.

Methods

Pathogens isolated from patients with LRTIs were analyzed as part of the British Society for Antimicrobial Chemotherapy Antimicrobial Resistance Surveillance Programme during 2014–2015. Antibiotic susceptibility was evaluated using European Committee on Antimicrobial Susceptibility Testing breakpoints, including the ceftobiprole pharmacokinetic/pharmacodynamic non-species-specific breakpoint when species-specific breakpoints were not available.

Results

One thousand one hundred and sixty-eight isolates from community-onset LRTIs and 1,264 isolates from hospital-onset LRTIs were analyzed. The ceftobiprole susceptibility rate was 99.8% (428/429) for Streptococcus pneumoniae, 100% (502/502) for Haemophilus influenzae, and 99.6% (236/237) for Moraxella catarrhalis. All Staphylococcus aureus isolates, including methicillin-susceptible S. aureus (MSSA; N=181) and methicillin-resistant S. aureus (MRSA; N=35), were susceptible to ceftobiprole. Overall, ceftobiprole susceptibility was observed in 88.1% (215/244) of Escherichia coli isolates, 83.4% (156/187) of Klebsiella pneumoniae isolates and 86.7% (98/113) of Enterobacter spp. isolates.

Conclusion

Ceftobiprole had in vitro activity against all S. aureus (both MSSA and MRSA) isolates, and almost all S. pneumoniae isolates, as well as against Gram-negative bacteria associated with community-onset or hospital-onset LRTIs. Based on this analysis, ceftobiprole is a good treatment option when broad-spectrum antibiotic coverage is needed for LRTIs.

How do members of a fire and rescue service perceive expanding their roles to deliver more health care services?

Background

Increasingly, public sector workers are being required to expand their roles into public health. Fire and rescue services, as part of the Emergency Medical Response trial, are at the forefront of role expansion, with increasing capacity due to reducing numbers of fires in recent years. Firefighter roles, successfully implemented, include responding to cardiac arrests and conducting checks on health and wellbeing in people’s own homes. In this study, we explored fire service members’ perceptions about this role expansion, to increase understanding of how role expansion can be introduced and supported.

Methods

We interviewed 21 firefighters and team members about their perceptions of new roles. Interviews were conducted, transcribed and thematically analysed until reaching thematic saturation.

Results

Perspectives differed for responding to cardiac arrests and wellbeing checks. Cardiac arrests were seen as aligned with core roles and thus more acceptable. For both types of new role participants wanted more training and opportunities to provide feedback on implementation.

Conclusions

How team members viewed role expansion depended on new role alignment with core role, training and being able to give feedback to management to shape future services.

Complications after transcatheter aortic valve implantation using transfemoral and transapical approach in general anaesthesia

Background

Transcatheter aortic valve implantation (TAVI) is a minimally invasive procedure used to treat degenerative heart valve disease. The implantation requires a highly specific and interdisciplinary management approach. Currently, TAVI is performed with the patient under local or general anaesthesia.

Methods

This study was a retrospective analysis of all TAVI procedures performed at the University Hospital of Regensburg between January 2009 and July 2015. All pre-, intra and postoperative data focusing on perioperative complications were recorded.

Results

A total of 853 transfemoral- and transapical-TAVI patients were included in the study. All patients underwent general anaesthesia. The ASA classifications were primarily 3–4. The average logistic EuroScores for the transfemoral- and transapical-TAVI patients were 18 ± 12% and 21 ± 15% (p = 0.002), respectively. The anaesthesia coverage time was 170 ± 49 min., including 37 ± 12 minutes for anaesthetic management. Overall, 458 complications were recorded; with pneumonia, acute renal failure, indication for a permanent pacemaker and non-extubation in the operating theatre the most frequently recorded complications.

Conclusion

In the present study, we showed that our patients’ outcomes are comparable to those reported in the available literature. Compared to TF, TA patients show an overall worse physical condition as well as a higher perioperative morbidity and mortality. Consequently TA patients need additional care and should only be operated in appropriately experienced medical centres.

Umbrella Sampling and X-ray Crystallographic Analysis Unveil an Arg-Asp Gate Facilitating Inhibitor Binding Inside Phosphopantetheine Adenylyltransferase Allosteric Cleft

Phosphopantetheine adenylyltransferase (PPAT) is a rate-limiting enzyme essential for biosynthesis of coenzyme A (CoA), which in turn is responsible to regulate the secretion of exotoxins via type III secretion system in Pseudomonas aeruginosa, causing severe health concerns ranging from nosocomial infections to respiratory failure. Acetyl coenzyme A (AcCoA) is a newly reported inhibitor of PPAT, believed to regulate the cellular levels of CoA and thereby the pathogenesis. Very little is known so far regarding the mechanistic details of AcCoA binding inside PPAT-binding cleft. Herein, we have used extensive umbrella sampling simulations to decipher mechanistic insight into the inhibitor accommodation inside the binding cavity. We found that R90 and D94 residues act like a gate near the binding cavity to accommodate and stabilize the incoming ligand. Mutational models concerning these residues also show considerable difference in AcCoA-binding thermodynamics. To substantiate our findings, we have solved the first crystal structure of apo-PPAT from P. aeruginosa, which also found to agree with the simulation results. Collectively, these results describe the mechanistic details of accommodation of inhibitor molecule inside PPAT-binding cavity and also offer valuable insight into regulating cellular levels of CoA/AcCoA and thus controlling the pathogenicity.

Incidence and potential risk factors for hospital-acquired pneumonia in an emergency department of surgery

Objective

Hospital-acquired pneumonia (HAP) is associated with high mortality and is the second most common nosocomial infection. The aim of this study was to calculate the incidence and to identify potential risk factors for HAP in an emergency ward for surgical patients admitted because of acute abdomen or trauma.

Design

A structured review of medical records was conducted. Patients diagnosed with pneumonia >48 h after admittance, were compared with a randomly chosen age-matched reference group. Ten variables judged as potential risk factors for HAP were studied in 90 patients.

Setting

An emergency ward for surgical patients with acute abdomen or trauma at an Univerity hospital in Sweden.

Participants

A total of 90 patients with HAP and 120 age-matched controls were included.

Main Outcome Measures

Risk factors for HAP in patients at a surgical clinic.

Results

Of a total of 10 335 admitted patients, during 4.5 years the hospital stay was longer than 48 h in 4961 patients. Of these 90 (1.8%) fulfilled the strict criteria for HAP. Potential risk factors were suspected or verified aspiration (odds ratio (OR): 23.9) that was 2-fold higher than immobilization (OR: 11.2). Further, chronic pulmonary obstructive disease (COPD)/asthma, abdominal surgery and gastric retention/vomiting were risk factors for HAP.

Conclusion

Verified or suspected aspiration was the dominating risk factor for HAP but also immobilization was frequently associated with HAP. Various established preventive measures should be implemented in the nursing care to reduce the frequency of HAP.

Phenol-Soluble Modulin Peptides Contribute to Influenza A Virus-Associated Staphylococcus aureus Pneumonia

Influenza A virus (IAV) infection is often followed by secondary bacterial lung infection, which is a major reason for severe, often fatal pneumonia. Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) strains such as USA300 cause particularly severe and difficult-to-treat cases of IAV-associated pneumonia. CA-MRSA strains are known to produce extraordinarily large amounts of phenol-soluble modulin (PSM) peptides, which are important cytotoxins and proinflammatory molecules that contribute to several types of S. aureus infection. However, their potential role in pneumonia has remained elusive. We determined the impact of PSMs on human lung epithelial cells and found that PSMs are cytotoxic and induce the secretion of the proinflammatory cytokine interleukin-8 (IL-8) in these cells. Both effects were boosted by previous infection with the 2009 swine flu pandemic IAV H1N1 strain, suggesting that PSMs may contribute to lung inflammation and damage in IAV-associated S. aureus pneumonia. Notably, the PSM-producing USA300 strain caused a higher mortality rate than did an isogenic PSM-deficient mutant in a mouse IAV-S. aureus pneumonia coinfection model, indicating that PSMs are major virulence factors in IAV-associated S. aureus pneumonia and may represent important targets for future anti-infective therapies.

Epidemiology, microbiology and treatment implications in adult patients hospitalized with pneumonia in different regions of China: a retrospective study

Background

Data describing epidemiology, clinical outcomes and treatment patterns, of hospitalised patients with pneumonia in China are limited. We aimed to describe such information among adult pneumonia patients in southern and northern China.

Methods

We retrospectively reviewed electronic medical records of pneumonia patients aged ≥18 years, hospitalized between 2008 and 2013 at Guangdong Provincial Hospital of Chinese Medicine (n=3,636), southern China, and between 2010 and 2014 at Peking University People's Hospital, Beijing (n=1,689), northern China, in order to collect data on patient demographics, microbiology, clinical outcomes and treatment and resistance patterns.

Results

The mean (SD) age of patients was 60.0 (21.4) and 64.4 (18.4) years in Guangdong and Beijing, respectively. Mean length of hospital stay was 12.1 and 20.8 days, and overall mortality was 2.9% and 8.0%, respectively. Gram-negative bacilli were most frequently isolated, predominantly Acinetobacter baumannii, Klebsiella pneumoniae and Pseudomonas aeruginosa. Infection with these bacteria was associated with unfavourable clinical outcomes, and the antibiotic resistance among these bacteria increased between 2008-2010 and 2011-2013 in both regions of China. The treatment and choice of antibiotics slightly varied between the two regions based on the susceptible pathogens identified among their populations.

Conclusions

Of the pathogens identified, Staphylococcus aureus infection (particularly the methicillin-resistant S. aureus) was associated with poor clinical outcomes; however antibiotic resistance among S. aureus generally decreased during the study data collection periods. Also, disease severity was greater in Beijing as compared with Guangdong, and this may be associated with higher microbiological diagnosis rate and higher frequency of initial antibiotic modification among Beijing populations.

Particle engineering for intracellular delivery of vancomycin to methicillin-resistant Staphylococcus aureus (MRSA)-infected macrophages

Methicillin-resistant Staphylococcus aureus (MRSA) infection is a serious threat to the public health. MRSA is particularly difficult to treat when it invades host cells and survive inside the cells. Although vancomycin is active against MRSA, it does not effectively kill intracellular MRSA due to the molecular size and polarity that limit its cellular uptake. To overcome poor intracellular delivery of vancomycin, we developed a particle formulation (PpZEV) based on a blend of polymers with distinct functions: (i) poly(lactic-co-glycolic acid) (PLGA, P) serving as the main delivery platform, (ii) polyethylene glycol-PLGA conjugate (PEG-PLGA, p) to help maintain an appropriate level of polarity for timely release of vancomycin, (iii) Eudragit E100 (a copolymer based on dimethylaminoethyl methacrylate, butyl methacrylate and methyl methacrylate, E) to enhance vancomycin encapsulation, and (iv) a chitosan derivative called ZWC (Z) to trigger pH-sensitive drug release. PpZEV NPs were preferentially taken up by the macrophages due to its size (500-1000nm) and facilitated vancomycin delivery to the intracellular pathogens. Accordingly, PpZEV NPs showed better antimicrobial activity than free vancomycin against intracellular MRSA and other intracellular pathogens. When administered intravenously, PpZEV NPs rapidly accumulated in the liver and spleen, the target organs of intracellular infection. Therefore, PpZEV NPs is a promising carrier of vancomycin for the treatment of intracellular MRSA infection.

The respiratory threat posed by multidrug resistant Gram-negative bacteria

Respiratory infections are a major cause of global mortality and morbidity. In recent years, an increased incidence of multidrug-resistant (MDR) Gram-negative bacteria (GNB) has been described. Microorganisms such as Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae or Acinetobacter baumannii have been identified as causative pathogens of different respiratory tract infections. Several studies have detected MDR-GNB in patients with community-acquired and nosocomial pneumonia. Furthermore, MDR-GNB have also been isolated in patients with chronic obstructive pulmonary disease and bronchiectasis having acute or chronic bronchial infection. Prevalence varies depending on the geographical area but MDR-GNB has been reported in the Asia-Pacific region, Europe and the United States, reaching rates of 70% in hospital-acquired infection. The presence of MDR-GNB has been related to poor clinical outcomes, including increased mortality, although data regarding this relationship are limited. This is probably linked to inappropriate selection of empiric antibiotic treatment; this poses a threat of widespread resistance. GNB antibiotic resistance and the absence of new antibiotics are a major concern given limited treatment options; an aspect that deserves future research. We review current literature, highlight prevalence of MDR-GNB in different respiratory infections and explore their impact on clinical outcomes.

The Relationship of Paranasal Sinus Opacification to Hospital-Acquired Pneumonia in the Neurologic Intensive Care Unit Patient

BACKGROUND

The association between intensive care unit (ICU) sinusitis and the development of lower airway infections remains unclear. The objective of this study was to determine the correlation between the development of radiographic sinus opacification and pneumonia in the neurologic ICU setting.

METHODS

A retrospective review of head computed tomography or magnetic resonance imaging of 612 patients admitted to the neurocritical care unit at a tertiary care center from April 2013 through April 2014 was performed. Paranasal sinus opacification was measured using Lund-Mackay scores (LMS). A diagnosis of pneumonia was determined by the ICU team from radiographic, laboratory, and pulmonary data. Exclusion criteria included a history of endonasal surgery, sinonasal malignancy, facial fractures, ICU admission less than 3 days, or inadequate imaging.

RESULTS

Worsening sinus opacification occurred in 42.6% of patients and pneumonia in 18.5% of patients during ICU admission. Of the patients who developed pneumonia, 71.7% also developed worsening sinus opacification (P < .001). In 80.2% of cases, the sinus opacification developed prior to the diagnosis of pneumonia. The mean highest LMS for patients who developed pneumonia was 4.24 compared to 1.99 in patients who did not develop pneumonia (P < .001). Sinus air-fluid levels or complete sinus opacification occurred in a larger proportion of patients who developed pneumonia (46.9% vs 19.4%, P < .001). Mortality rates for patients with no pneumonia or sinusitis, pneumonia only, sinusitis only, and sinusitis with pneumonia were 7.6%, 15.6%, 18.3%, and 25.9%, respectively (P < .001).

CONCLUSIONS

This study finds a strong relationship between worsening sinus opacification in the neurologic ICU patient to the development of hospital-acquired pneumonia and increased mortality.

Incidence, Risk Factors, and Clinical Implications of Pneumonia Following Total Hip and Knee Arthroplasty

BACKGROUND

The purpose of this study is to determine the incidence, risk factors, and clinical implications of pneumonia following total joint arthroplasty (TJA).

METHODS

The American College of Surgeons National Surgical Quality Improvement Program was used to conduct a retrospective cohort study of patients undergoing TJA. Independent risk factors for the development of pneumonia within 30 days of TJA were identified using multivariate regression. Mortality and readmission rates were compared between patients who did and did not develop pneumonia. Multivariate regression was used to adjust for all demographic, comorbidity, and procedural characteristics.

RESULTS

In total, 171,200 patients met inclusion criteria, of whom 66,493 (38.8%) underwent THA and 104,707 (61.2%) underwent TKA. Of the 171,200 patients, 590 developed pneumonia, yielding a rate of 0.34% (95% confidence interval = 0.32%-0.37%). Independent risk factors for pneumonia were chronic obstructive pulmonary disease, diabetes mellitus, greater age (most notably ≥80 years), dyspnea on exertion, dependent functional status, lower body mass index, hypertension, current smoker status, and male sex. The subset of patients who developed pneumonia following discharge had a higher readmission rate (82.1% vs 3.4%, adjusted relative risk [RR] = 16.6, P < .001) and a higher mortality rate (3.7% vs 0.1%, adjusted RR = 19.4, P < .001). Among 124 total mortalities, 22 (17.7%) occurred in patients who had developed pneumonia.

CONCLUSION

Pneumonia is a serious complication following TJA that occurs in approximately 1 in 300 patients. Approximately 4 in 5 patients who develop pneumonia are subsequently readmitted, and approximately 1 in 25 die. Given the serious implications of this complication, evidence-based pneumonia prevention programs including oral hygiene with chlorhexidine, sitting upright for meals, elevation of the head of the bed to at least 30°, aggressive incentive spirometry, and early ambulation should be considered for patients at greatest risk.

Surgical Factors Associated with Prolonged Hospitalization after Reconstruction for Oncological Spine Surgery

Background:

Posterior trunk reconstruction is increasingly possible as a result of advances in spinal instrumentation, reconstructive approaches, and perioperative critical care. Extensive cases often require a muscle flap or complex closure to obliterate dead space. Postsurgical wound complications and subsequent reoperations can lead to neural injury, higher hospital costs, and longer hospitalizations. We aim to identify risk factors that are associated with increased length of stay (LOS) for patients receiving flaps to close a spinal defect.

Methods:

A single institution, retrospective cohort study was performed on all patients from 2002 to 2014 who received a muscle flap to close a spine defect. Medical and perioperative variables that were significantly associated with LOS (P < 0.05) in univariate analysis were included in a stepwise regression model.

Results:

A total of 288 cases were identified. Presence of instrumentation, preoperative chemotherapy, wound dehiscence, cerebrospinal fluid leak, partial/total flap loss, and medical morbidity occurrence were all independently associated with increased LOS in a combined multivariate model (P < 0.02 for each of the 6 variables). Importantly, Kaplan–Meier analysis demonstrated that postoperative wound dehiscence increased LOS by 12 days.

Conclusions:

Spinal tumor resections often create large cavitary defects that necessitate the use of muscle flaps for closure. Patients who have received adjuvant chemotherapy require instrumentation, or those who develop specific wound-related or medical complications are at increased risk for prolonged hospitalization after spinal reconstruction. Thus, implementing measures to mitigate the occurrence of these adverse events will reduce costs and decrease the length of hospitalization.

Pseudomonas aeruginosa infection liberates transmissible, cytotoxic prion amyloids

Patients who recover from pneumonia subsequently have elevated rates of death after hospital discharge as a result of secondary organ damage, the causes of which are unknown. We used the bacterium Pseudomonas aeruginosa, a common cause of hospital-acquired pneumonia, as a model for investigating this phenomenon. We show that infection of pulmonary endothelial cells by P. aeruginosa induces production and release of a cytotoxic amyloid molecule with prion characteristics, including resistance to various nucleases and proteases. This cytotoxin was self-propagating, was neutralized by anti-amyloid Abs, and induced death of endothelial cells and neurons. Moreover, the cytotoxin induced edema in isolated lungs. Endothelial cells and isolated lungs were protected from cytotoxin-induced death by stimulation of signal transduction pathways that are linked to prion protein. Analysis of bronchoalveolar lavage fluid collected from human patients with P. aeruginosa pneumonia demonstrated cytotoxic activity, and lavage fluid contained amyloid molecules, including oligomeric τ and Aβ. Demonstration of long-lived cytotoxic agents after Pseudomonas infection may establish a molecular link to the high rates of death as a result of end-organ damage in the months after recovery from pneumonia, and modulation of signal transduction pathways that have been linked to prion protein may provide a mechanism for intervention.-Balczon, R., Morrow, K. A., Zhou, C., Edmonds, B., Alexeyev, M., Pittet, J.-F., Wagener, B. M., Moser, S. A., Leavesley, S., Zha, X., Frank, D. W., Stevens, T. Pseudomonas aeruginosa infection liberates transmissible, cytotoxic prion amyloids.

Antimicrobial efficacy against Pseudomonas aeruginosa biofilm formation in a three-dimensional lung epithelial model and the influence of fetal bovine serum

In vitro models that mimic in vivo host-pathogen interactions are needed to evaluate candidate drugs that inhibit bacterial virulence traits. We established a new approach to study Pseudomonas aeruginosa biofilm susceptibility on biotic surfaces, using a three-dimensional (3-D) lung epithelial cell model. P. aeruginosa formed antibiotic resistant biofilms on 3-D cells without affecting cell viability. The biofilm-inhibitory activity of antibiotics and/or the anti-biofilm peptide DJK-5 were evaluated on 3-D cells compared to a plastic surface, in medium with and without fetal bovine serum (FBS). In both media, aminoglycosides were more efficacious in the 3-D cell model. In serum-free medium, most antibiotics (except polymyxins) showed enhanced efficacy when 3-D cells were present. In medium with FBS, colistin was less efficacious in the 3-D cell model. DJK-5 exerted potent inhibition of P. aeruginosa association with both substrates, only in serum-free medium. DJK-5 showed stronger inhibitory activity against P. aeruginosa associated with plastic compared to 3-D cells. The combined addition of tobramycin and DJK-5 exhibited more potent ability to inhibit P. aeruginosa association with both substrates. In conclusion, lung epithelial cells influence the efficacy of most antimicrobials against P. aeruginosa biofilm formation, which in turn depends on the presence or absence of FBS.

Bronchoalveolar lavage fluid cytokine bead array profile for prognostication of ventilated trauma patients

Aim of Study:

Ventilator-associated pneumonia (VAP) is a common cause of mortality in trauma patients admitted to Intensive Care Units. The outcome of such patients may be dependent on local host immune response, which may be best reflected in studies using bronchoalveolar lavage (BAL) fluid. The present study was conducted to ascertain the cytokine profile of BAL using the cytometric bead array (CBA) in a flow cytometer and to correlate the levels of Th-1/Th-2 cytokines in BAL with the clinical outcome of ventilated trauma patients.

Patients and Methods:

BAL was collected from the patients with suspected VAP. CBA was performed to assess the levels of interleukin-4 (IL-4), IL-6, IL-8, IL-1 β, interferon gamma (IFN-γ), and tumor necrosis factor-alpha in the BAL samples. After acquiring the BAL samples on the flow cytometer, the results were generated using FCAP Array™ software. The cytokine profile was correlated to clinical outcomes.

Results:

A total of forty patients were enrolled during the study period. Of these, 12 patients (30%) had confirmed VAP and 8 (20%) patients had a fatal outcome. The levels of IL-8 and IFN-γ correlated significantly with the development of VAP and elevated IL-6 in BAL was associated with a poor outcome.

Conclusion:

A proinflammatory response in the form of elevated IL-6 and IL-8 correlated poorly with the clinical outcome. Th-1 response was significantly reduced in patients with VAP. A proinflammatory response in the form of elevated IL-6 and IL-8 correlated poorly with the clinical outcome.

Risk factors for mortality in patients admitted to intensive care units with pneumonia

Background

Despite the high mortality in patients with pneumonia admitted to an ICU, data on risk factors for death remain limited.

Methods

In this secondary analysis of PROTECT (Prophylaxis for Thromboembolism in Critical Care Trial), we focused on the patients admitted to ICU with a primary diagnosis of pneumonia. The primary outcome for this study was 90-day hospital mortality and the secondary outcome was 90-day ICU mortality. Cox regression model was conducted to examine the relationship between baseline and time-dependent variables and hospital and ICU mortality.

Results

Six hundred sixty seven patients admitted with pneumonia (43.8 % females) were included in our analysis, with a mean age of 60.7 years and mean APACHE II score of 21.3. During follow-up, 111 patients (16.6 %) died in ICU and in total, 149 (22.3 %) died in hospital. Multivariable analysis demonstrated significant independent risk factors for hospital mortality including male sex (hazard ratio (HR) = 1.5, 95 % confidence interval (CI): 1.1 - 2.2, p-value = 0.021), higher APACHE II score (HR = 1.2, 95 % CI: 1.1 - 1.4, p-value < 0.001 for per-5 point increase), chronic heart failure (HR = 2.9, 95 % CI: 1.6 - 5.4, p-value = 0.001), and dialysis (time-dependent effect: HR = 2.7, 95 % CI: 1.3 - 5.7, p-value = 0.008). Higher APACHE II score (HR = 1.2, 95 % CI: 1.1 - 1.4, p-value = 0.002 for per-5 point increase) and chronic heart failure (HR = 2.6, 95 % CI: 1.3 – 5.0, p-value = 0.004) were significantly related to risk of death in the ICU.

Conclusion

In this study using data from a multicenter thromboprophylaxis trial, we found that male sex, higher APACHE II score on admission, chronic heart failure, and dialysis were independently associated with risk of hospital mortality in patients admitted to ICU with pneumonia. While high illness severity score, presence of a serious comorbidity (heart failure) and need for an advanced life support (dialysis) are not unexpected risk factors of mortality, male sex might necessitate further exploration. More studies are warranted to clarify the effect of these risk factors on survival in critically ill patients admitted to ICU with pneumonia.

Trial registration

ClinicalTrials.gov Identifier: NCT00182143.

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-016-0397-5) contains supplementary material, which is available to authorized users.

Incidence and Risk Factors for Pneumonia After Posterior Lumbar Fusion Procedures: An ACS-NSQIP Study

STUDY DESIGN

Retrospective study of data collected prospectively by the American College of Surgeons National Surgical Quality Improvement Program.

OBJECTIVE

To determine the incidence and risk factors for development of pneumonia after posterior lumbar fusion (PLF).

SUMMARY OF BACKGROUND DATA

Postoperative pneumonia has important clinical consequences for patients and the health care system. Few studies have examined pneumonia after spinal fusion procedures.

METHODS

Patients in the American College of Surgeons National Surgical Quality Improvement Program database who underwent PLF during 2005 to 2013 were included. The primary outcome was a diagnosis of pneumonia within the first 30 postoperative days. Independent risk factors for the development of postoperative pneumonia were identified using multivariate regression. Rates of sepsis and mortality were compared between patients who did and did not develop pneumonia using multivariate regression that adjusted for all demographic, comorbidity, and procedural characteristics.

RESULTS

A total of 12,428 patients undergoing PLF were identified. The incidence of pneumonia was 0.59%. Independent risk factors for the development of pneumonia were chronic obstructive pulmonary disease (relative risk [RR] = 2.7, P = 0.006), steroid use (RR = 2.6, P = 0.017), non-insulin-dependent diabetes mellitus (DM) (RR = 2.4, P = 0.003), insulin-dependent DM (RR = 2.9, P = 0.005), and greater number of operative levels (two level: RR = 1.7, P = 0.033; three level: RR = 2.7, P = 0.007). Patients who developed pneumonia had a higher rate of sepsis (15.1% vs. 0.8%, adjusted RR = 14.5, P < 0.001) and mortality (2.7% versus 0.1%, adjusted RR = 27.0, P < 0.001) than other patients. Of all sepsis cases and postoperative mortalities, 10.5% and 18.2% occurred in patients who had developed pneumonia, respectively.

CONCLUSION

Pneumonia occurs in approximately 1 in 200 patients after PLF. Pneumonia plays a significant role in the development of sepsis and mortality, with 10% of sepsis and 20% of mortality cases occurring in patients who had developed pneumonia. Patients with chronic obstructive pulmonary disease, steroid use, DM, and a greater number of operative levels are at greater risk. These patients should be counseled, monitored, and targeted with preventative interventions accordingly.

LEVEL OF EVIDENCE

3.

Clonality of Bacterial Pathogens Causing Hospital-Acquired Pneumonia

Hospital-acquired pneumonia (HAP) is one of the most serious complications in patients staying in intensive care units. This multicenter study of Czech patients with HAP aimed at assessing the clonality of bacterial pathogens causing the condition. Bacterial isolates were compared using pulsed-field gel electrophoresis. Included in this study were 330 patients hospitalized between May 1, 2013 and December 31, 2014 at departments of anesthesiology and intensive care medicine of four big hospitals in the Czech Republic. A total of 531 bacterial isolates were obtained, of which 267 were classified as etiological agents causing HAP. Similarity or identity was assessed in 231 bacterial isolates most frequently obtained from HAP patients. Over the study period, no significant clonal spread was noted. Most isolates were unique strains, and the included HAP cases may therefore be characterized as mostly endogenous. Yet there were differences in species and potential identical isolates between the participating centers. In three hospitals, Gram-negative bacteria (Enterobacteriaceae and Pseudomonas aeruginosa) prevailed as etiological agents, and Staphylococcus aureus was most prevalent in the fourth center.

Spacer-free BODIPY fluorogens in antimicrobial peptides for direct imaging of fungal infection in human tissue

Fluorescent antimicrobial peptides are promising structures for in situ, real-time imaging of fungal infection. Here we report a fluorogenic probe to image Aspergillus fumigatus directly in human pulmonary tissue. We have developed a fluorogenic Trp-BODIPY amino acid with a spacer-free C-C linkage between Trp and a BODIPY fluorogen, which shows remarkable fluorescence enhancement in hydrophobic microenvironments. The incorporation of our fluorogenic amino acid in short antimicrobial peptides does not impair their selectivity for fungal cells, and enables rapid and direct fungal imaging without any washing steps. We have optimized the stability of our probes in human samples to perform multi-photon imaging of A. fumigatus in ex vivo human tissue. The incorporation of our unique BODIPY fluorogen in biologically relevant peptides will accelerate the development of novel imaging probes with high sensitivity and specificity.

Incidence and risk factors for pneumonia following anterior cervical decompression and fusion procedures: an ACS-NSQIP study

BACKGROUND CONTEXT

Postoperative pneumonia has important clinical consequences for both patients and the health-care system. Few studies have examined pneumonia following anterior cervical decompression and fusion (ACDF) procedures.

PURPOSE

This study aimed to determine the incidence and risk factors for development of pneumonia following ACDF procedures.

STUDY DESIGN/SETTING

A retrospective cohort study of data collected prospectively by the American College of Surgeons National Surgical Quality Improvement Program was carried out.

PATIENT SAMPLE

This study comprised 11,353 patients undergoing ACDF procedures during 2011-2013.

OUTCOME MEASURES

The primary outcome was diagnosis of pneumonia in the first 30 postoperative days.

METHODS

Independent risk factors for the development of pneumonia were identified using multivariate regression. Readmission rates were compared between patients who did and did not develop pneumonia using multivariate regression that adjusted for all demographic, comorbidity, and procedural characteristics.

RESULTS

The incidence of pneumonia was 0.45% (95% confidence interval=0.33%-0.57%). In the multivariate analysis, independent risk factors for the development of pneumonia were greater age (p<.001), dependent functional status (relative risk [RR]=5.3, p<.001), chronic obstructive pulmonary disease (RR=4.4, p<.001), and greater operative duration (p=.020). Patients who developed pneumonia following discharge had a higher readmission rate than other patients (72.7% vs. 2.4%, adjusted RR=24.5, p<.001). In total, 10.2% of all readmissions were caused by pneumonia.

CONCLUSIONS

Pneumonia occurs in approximately 1 in 200 patients following ACDF procedures. Patients who are older, are functionally dependent, or have chronic obstructive pulmonary disease are at greater risk. These patients should be counseled, monitored, and targeted with preventative interventions accordingly. Greater operative duration is also an independent risk factor. Approximately three in four patients who develop pneumonia following hospitalization for ACDF procedures are readmitted. This elevated readmission rate has implications for bundled payments and hospital performance reports.

Non-Intensive Care Unit Acquired Pneumonia: A New Clinical Entity?

Hospital-acquired pneumonia (HAP) is a frequent cause of nosocomial infections, responsible for great morbidity and mortality worldwide. The majority of studies on HAP have been conducted in patients hospitalized in the intensive care unit (ICU), as mechanical ventilation represents a major risk factor for nosocomial pneumonia and specifically for ventilator-associated pneumonia. However, epidemiological data seem to be different between patients acquiring HAP in the ICU vs. general wards, suggesting the importance of identifying non ICU-acquired pneumonia (NIAP) as a clinical distinct entity in terms of both etiology and management. Early detection of NIAP, along with an individualized management, is needed to reduce antibiotic use and side effects, bacterial resistance and mortality. The present article reviews the pathophysiology, diagnosis, treatment and prevention of NIAP.

Current and Future Considerations for the Treatment of Hospital-Acquired Pneumonia

Hospital-acquired pneumonia (HAP) and health-care-associated pneumonia (HCAP) are leading causes of death, morbidity, and resource utilization in hospitalized patients, and are associated with a broad range of Gram-positive and Gram-negative pathogens. Here, we discuss the different definitions of HAP and HCAP, review current guidelines regarding the treatment of these conditions, highlight the shortcomings of current therapeutic options, and discuss new antibiotic treatments. To optimize therapeutic outcomes in patients with HAP/HCAP, initial antimicrobial treatment must be appropriate and should be given as soon as possible; inappropriate or delayed therapy greatly increases morbidity and mortality. Selection of the most appropriate antimicrobial agent depends on the causative pathogen(s); initial broad-spectrum therapy is commonly recommended and should cover all pathogens that may be present. Treatment selection should also take into consideration the following factors: knowledge of underlying local risk factors for antimicrobial resistance, disease staging, and risk factors related to specific pathogens such as Pseudomonas aeruginosa, Acinetobacter spp., and methicillin-resistant Staphylococcus aureus (MRSA). Guidelines consistently emphasize the importance of treating HAP and HCAP with early and appropriate broad-spectrum antibiotics, and recent developments in this field have resulted in the availability of several additional treatment options. Telavancin shows potent activity against Gram-positive bacteria including MRSA and can be administered once daily; it was approved in the USA and European Union for the treatment of HAP after demonstrating non-inferiority to vancomycin. Ceftobiprole medocaril exhibits rapid antimicrobial activity against a broad range of both Gram-positive and Gram-negative pathogens, including MRSA. It was approved for the treatment of HAP (excluding ventilator-associated pneumonia) and community-acquired pneumonia in Europe in 2013. These new treatments may offer effective alternative therapeutic options for the management of HAP.

FUNDING

Basilea Pharmaceutica Ltd., Basel, Switzerland.

Matrix metalloproteinases in pneumonia

Pneumonia is a worldwide infectious disease that is associated with significant morbidity and mortality and is the most common fatal infection acquired in hospitals. Despite advances in preventive strategies, such as antibiotic therapies and intensive care, the mortality rate still requires substantial improvement. Matrix metalloproteinases (MMPs) are a large family of zinc-dependent endopeptidases, which are known as the major enzymes responsible for the proteolytic degradation of proteinaceous components of the extracellular matrix (ECM). Although the main function of MMPs is the removal of the ECM during tissue resorption and progression of various diseases, MMPs also interact with multiple cytokines, participating in the pathology of infection and inflammation. This review presents a schematic overview of the different MMPs expressed in pneumonia. MMPs are key factors in the pathogenesis of various types of pneumonia, such as community-acquired pneumonia, hospital-acquired pneumonia, and ventilator-associated pneumonia. Here, we review the pathological roles of various MMPs in pneumonia.

In the absence of effector proteins, the Pseudomonas aeruginosa type three secretion system needle tip complex contributes to lung injury and systemic inflammatory responses

Herein we describe a pathogenic role for the Pseudomonas aeruginosa type three secretion system (T3SS) needle tip complex protein, PcrV, in causing lung endothelial injury. We first established a model in which P. aeruginosa wild type strain PA103 caused pneumonia-induced sepsis and distal organ dysfunction. Interestingly, a PA103 derivative strain lacking its two known secreted effectors, ExoU and ExoT [denoted PA103 (ΔU/ΔT)], also caused sepsis and modest distal organ injury whereas an isogenic PA103 strain lacking the T3SS needle tip complex assembly protein [denoted PA103 (ΔPcrV)] did not. PA103 (ΔU/ΔT) infection caused neutrophil influx into the lung parenchyma, lung endothelial injury, and distal organ injury (reminiscent of sepsis). In contrast, PA103 (ΔPcrV) infection caused nominal neutrophil infiltration and lung endothelial injury, but no distal organ injury. We further examined pathogenic mechanisms of the T3SS needle tip complex using cultured rat pulmonary microvascular endothelial cells (PMVECs) and revealed a two-phase, temporal nature of infection. At 5-hours post-inoculation (early phase infection), PA103 (ΔU/ΔT) elicited PMVEC barrier disruption via perturbation of the actin cytoskeleton and did so in a cell death-independent manner. Conversely, PA103 (ΔPcrV) infection did not elicit early phase PMVEC barrier disruption. At 24-hours post-inoculation (late phase infection), PA103 (ΔU/ΔT) induced PMVEC damage and death that displayed an apoptotic component. Although PA103 (ΔPcrV) infection induced late phase PMVEC damage and death, it did so to an attenuated extent. The PA103 (ΔU/ΔT) and PA103 (ΔPcrV) mutants grew at similar rates and were able to adhere equally to PMVECs post-inoculation indicating that the observed differences in damage and barrier disruption are likely attributable to T3SS needle tip complex-mediated pathogenic differences post host cell attachment. Together, these infection data suggest that the T3SS needle tip complex and/or another undefined secreted effector(s) are important determinants of P. aeruginosa pneumonia-induced lung endothelial barrier disruption.

Impact of chronic liver disease in intensive care unit acquired pneumonia: a prospective study

PURPOSE

To assess the impact of chronic liver disease (CLD) on ICU-acquired pneumonia.

METHODS

This was a prospective, observational study of the characteristics, microbiology, and outcomes of 343 consecutive patients with ICU-acquired pneumonia clustered according to the presence of CLD.

RESULTS

Sixty-seven (20%) patients had CLD (67% had liver cirrhosis, LC), MELD score 26 ± 9, 20% Child-Pugh class C). They presented higher severity scores than patients without CLD both on admission to the ICU (APACHE II, LC 19 ± 6 vs. other CLD 18 ± 6 vs. no CLD 16 ± 6; p < 0.001; SOFA, 10 ± 3 vs. 8 ± 4 vs. 7 ± 3; p < 0.001) and at onset of pneumonia (APACHE II, 19 ± 6 vs. 17 ± 6 vs. 16 ± 5; p = 0.001; SOFA, 11 ± 4 vs. 9 ± 4 vs. 7 ± 3; p < 0.001). Levels of CRP were lower in patients with LC than in the other two groups (day 1, 6.5 [2.5-11.5] vs. 13 [6-23] vs. 15.5 [8-24], p < 0.001, day 3, 6 [3-12] vs. 16 [9-21] vs. 11 [5-20], p = 0.001); all the other biomarkers were higher in LC and other CLD patients. LC patients had higher 28- and 90-day mortality (63 vs. 28%, p < 0.001; 72 vs. 38%, p < 0.001, respectively) than non-CLD patients. Presence of LC was independently associated with decreased 28- and 90-day survival (95% confidence interval [CI], 1.982-17.250; p = 0.001; 95% confidence interval [CI], 2.915-20.699, p = 0.001, respectively).

CONCLUSIONS

In critically ill patients with ICU-acquired pneumonia, CLD is associated with a more severe clinical presentation and poor clinical outcomes. Moreover, LC is independently associated with 28- and 90-day mortality. The results of this study are important for future trials focused on mortality.

Acinetobacter baumannii nosocomial pneumonia: is the outcome more favorable in non-ventilated than ventilated patients?

Background

Acinetobacter baumannii hospital-acquired pneumonia (HAP) is associated with a high mortality worldwide. Non-ventilated patients with HAP (NVHAP) caused by nosocomial pathogens are reported to have a more favorable outcome than those with ventilator-associated pneumonia (VAP). The current study was designed to determine whether bacteremic patients with A. baumannii NVHAP also have a lower mortality than those receiving assisted ventilation.

Methods

This retrospective 10-year study was conducted at a 2900-bed teaching hospital located in Northern Taiwan. The population consisted of 144 patients with A. baumannii bacteremia and HAP. Of these 96 had VAP and 48 had NVHAP. Charts were reviewed for demographic characteristics, comorbidities, clinical manifestations, antimicrobial susceptibility, and 14-day mortality. Clonal relationships were determined by molecular typing.

Results

There were no significant differences between the two groups in comorbidities (Charlson scores). Patients with NVHAP were more likely to have developed bacteremia earlier, outside the ICU and undergone fewer invasive procedures. They had significantly lower APACHE II scores, fewer bilateral pneumonias and lower rates of antimicrobial resistance. No specific clones were identified in either group. The unadjusted (crude) 14-day mortality rates were not significantly different between the groups (NVHAP 43.8% vs. VAP 31.3%, p = 0.196). The adjusted 14-day mortality risk was significantly lower in ventilator-assisted patients (odds ratio = 0.201; 95% confidence interval = 0.075-0.538; p = 0.001).

Conclusions

Patients with bacteremic NVHAP and VAP caused by A. baumannii had similar crude mortality rates, but on logistic regression analysis those receiving ventilator assistance had a significantly lower mortality. This may have been due to better airway protection, more intensive monitoring with earlier diagnosis and treatment in patients with VAP, greater innate susceptibility to infection in those with NVHAP and differences in the virulence of A. baumannii.