Can Neutrophils Prevent Nosocomial Pneumonia after Serious Injury?

Nosocomial pneumonia is a leading cause of critical illness and mortality among seriously injured trauma patients. However, the link between injury and the development of nosocomial pneumonia is still not well recognized. Our work strongly suggests that mitochondrial damage-associated molecular patterns (mtDAMPs), especially mitochondrial formyl peptides (mtFPs) released by tissue injury, play a significant role in developing nosocomial pneumonia after a serious injury. Polymorphonuclear leukocytes (neutrophils, PMN) migrate toward the injury site by detecting mtFPs through formyl peptide receptor 1 (FPR1) to fight/contain bacterial infection and clean up debris. Activation of FPR1 by mtFPs enables PMN to reach the injury site; however, at the same time it leads to homo- and heterologous desensitization/internalization of chemokine receptors. Thus, PMN are not responsive to secondary infections, including those from bacteria-infected lungs. This may enable a progression of bacterial growth in the lungs and nosocomial pneumonia. We propose that the intratracheal application of exogenously isolated PMN may prevent pneumonia coupled with a serious injury.

Deep immune profiling of whole blood to identify early immune signatures that correlate to patient outcome after major trauma.

BACKGROUND: Major injury results in an early cascade of immunologic responses that increase susceptibility to infection and multiorgan dysfunction. Detailed immune profiling by mass cytometry has the potential to identify immune signatures that correspond to patient outcomes. Our objective was to determine the prognostic value of immune signatures early after major trauma injury. METHODS: Trauma patients (n = 17) were prospectively enrolled between September 2018 and December 2019. Serial whole blood samples were obtained from trauma patients (mean Injury Severity Score, 26.2; standard error of the mean, 3.7) at Days 1 and 3 after injury, and from age- and sex-matched uninjured controls using a standardized protocol for fixation, storage, and labeling. Computational analyses including K-nearest neighbor automated clustering of immune cells and Spearman's correlation analysis were used to identify correlations between cell populations, clinical measures, and patient outcomes. RESULTS: Analysis revealed nine immune cell clusters that correlated with one or more clinical outcomes. On Days 1 and 3 postinjury, the abundance of immature neutrophil and classical monocytes exhibited a strong positive correlation with increased intensive care unit and hospital length of stay. Conversely, the abundance of CD4 T-cell subsets, namely Th17 cells, is associated with improved patient outcomes including decreased ventilator days (r = -0.76), hospital-acquired pneumonia (r = -0.69), and acute kidney injury (r = -0.73). CONCLUSION: Here, we provide a comprehensive multitime point immunophenotyping analysis of whole blood from patients soon after traumatic injury to determine immune correlates of adverse outcomes. Our findings indicate that alterations in myeloid-origin cell types may contribute to immune dysfunction after injury. Conversely, the presence of effector T cell populations corresponds with decreased hospital length of stay and organ dysfunction. Overall, these data identify novel immune signatures following traumatic injury that support the view that monitoring of immune (sub)-populations may provide clinical decision-making support for at-risk patients early in their hospital course. LEVEL OF EVIDENCE: Prognostic/Epidemiologic, Level IV.

Postoperative Physical Therapy to Prevent Hospital-acquired Pneumonia in Patients Over 80 Years Undergoing Hip Fracture Surgery-A Quasi-experimental Study.

BACKGROUND: Hip fracture requiring surgical fixation is a common condition with high mortality and morbidity in the geriatric population. The patients are usually frail, and vulnerable to postoperative complications and delayed recovery. Few studies have investigated physical therapy methods to prevent hospital-acquired pneumonia (HAP) after hip fracture surgery. OBJECTIVE: To explore whether an intensified physical therapy regimen can prevent HAP and reduce hospital length of stay in patients aged 80 and older, following hip fracture surgery. PATIENTS AND METHODS: The inclusion criterion was patients aged 80 or older who had undergone hip fracture surgery at Örebro University Hospital, Sweden during eight months in 2015-2016 (the "physical therapy group") (n=69). The study has a quasi-experimental design with a historical control group (n=64) who had received routine physical therapy treatment. The physical therapy group received intensified postoperative physical therapy treatment, which included daily supervised early mobilization and coached deep breathing exercises with positive expiratory pressure (PEP). The patients were instructed to take deep breaths, and then exhale through the PEP-valve in three sessions of 10 deep breaths, at least four times daily. Early mobilization to a sitting position and walking was advised as soon as possible after surgery. RESULTS: There was a significantly lower incidence of HAP in the physical therapy group; 2/69 (3%, 95%CI: 1- 10) compared to the historical control group 13/64 (20%, 95%CI: 12-32%) (p=0.002). Patients in the physical therapy group had a significantly shorter length of stay than the control group (10.6±4 vs 13.4±9 days, p=0.022). CONCLUSION: Intensified physical therapy treatment after hip fracture surgery may be of benefit to reduce the incidence of HAP in patients over 80 years; however, the results need to be confirmed in randomized controlled trials.

Pneumonia prevention effects of perioperative oral management in approximately 25,000 patients following cancer surgery.

AIM: We conducted a multicenter study to explore the risk factors of developing pneumonia and the effectiveness of perioperative oral management (POM) for the prevention of pneumonia in postsurgical patients. METHODS AND RESULTS: A survey covering eight regional hospitals was conducted over 4 years, from April 2010 to March 2014. Using the Diagnosis Procedure Combination database, a target group of 25,554 patients with cancer who underwent surgery was selected and assessed from a population of 346,563 patients without pneumonia on admission (sample population). The study compared the incidence of pneumonia and attempted to identify the significant predictive factors for its occurrence in these patients using multiple logistic regression analysis. Comparative assessment for the occurrence of pneumonia before and after POM implementation showed a significant incidence decrease after POM introduction in the target group, with no such change observed in the sample population. Multiple logistic regression analysis showed that the odds ratio for pneumonia occurrence after POM introduction was 0.44, indicating a reduced risk of pneumonia. CONCLUSION: POM in cancer patients was indeed effective in reducing the incidence of pneumonia in hospitals and thereby helped in preventing pneumonia during hospitalization.

[Nosocomial pneumonia]. / Nosokomiale Pneumonien.

Nosocomial pneumonia is one of the leading entities of nosocomial infections in Germany and worldwide with invasive ventilation being one of the major risk factors. However nosocomial pneumonia without ventilator support is an underappreciated complication as demonstrated by prevalence studies of the European Centre for Disease Control in 2011 and 2016. Major general risk factors include old age, multi-morbidity, preexisting pulmonary disease, immunosuppression and abdominal or thoracic surgery. Evidence based prevention measures for ventilated patients include hand hygiene, aseptic handling techniques of the ventilator circuit, subglottic suctioning for patients intubated more than 72 hours, cuff pressure control, mouth and dental care, daily spontaneous breathing trials, use of sedation protocols and head of bed 30-45 degrees. For non-ventilated patients early mobilization and/or frequent position changes, correct use of feeding tubes and mouth care are key components. In preoperative patients training of a simple breathing exercise combined with mnemonic aids for its use in the postoperative period has been proven to be helpful.

Development and validation of a semi-automated surveillance system-lowering the fruit for non-ventilator-associated hospital-acquired pneumonia (nvHAP) prevention.

OBJECTIVES: Conducting manual surveillance of non-ventilator-associated hospital-acquired pneumonia (nvHAP) using ECDC (European Centre for Disease Prevention and Control) surveillance criteria is very resource intensive. We developed and validated a semi-automated surveillance system for nvHAP, and describe nvHAP incidence and aetiology at our hospital. METHODS: We applied an automated classification algorithm mirroring ECDC definition criteria to distinguish patients 'not at risk' from patients 'at risk' for suffering from nvHAP. 'At risk'-patients were manually screened for nvHAP. For validation, we applied the reference standard of full manual evaluation to three validation samples comprising 2091 patients. RESULTS: Among the 39 519 University Hospital Zurich inpatient discharges in 2017, the algorithm identified 2454 'at-risk' patients, reducing the number of medical records to be manually screened by 93.8%. From this subset, nvHAP was identified in 251 patients (0.64%, 95%CI: 0.57-0.73). Sensitivity, negative predictive value, and accuracy of semi-automated surveillance versus full manual surveillance were lowest in the validation sample consisting of patients with HAP according to the International Classification of Diseases (ICD-10) discharge diagnostic codes, with 97.5% (CI: 93.7-99.3%), 99.2% (CI: 97.9-99.8%), and 99.4% (CI: 98.4-99.8%), respectively. The overall incidence rate of nvHAP was 0.83/1000 patient days (95%CI: 0.73-0.94), with highest rates in haematology/oncology, cardiac and thoracic surgery, and internal medicine including subspecialties. CONCLUSIONS: The semi-automated surveillance demonstrated a very high sensitivity, negative predictive value, and accuracy. This approach significantly reduces manual surveillance workload, thus making continuous nvHAP surveillance feasible as a pivotal element for successful prevention efforts.

Sustaining Quality Improvement: Long-Term Reduction of Nonventilator Hospital-Acquired Pneumonia.

BACKGROUND: Hospital-acquired pneumonia is now the number one hospital-acquired infection. Hospitals have addressed ventilator-associated pneumonia; however, patients not on a ventilator acquire more pneumonia with significant associated mortality rates. LOCAL PROBLEM: In our hospital, non-ventilator-associated pneumonia was occurring on all types of units. METHODS: The Influencer Model was used to reduce nonventilator hospital-acquired pneumonia rates. Statistical process control R and X-bar-charts were monitored monthly. INTERVENTIONS: After a gap analysis, an interdisciplinary team implemented enhanced oral care before surgery and on the units, changed tube management, and monitored stress ulcer medication. RESULTS: We achieved a statistically significantly reduction (P = .01) in pneumonia rates that have been sustained over 4 years. CONCLUSIONS: Sustaining change requires (a) a continued team-based, collaborative approach, (b) ongoing stakeholder and executive leadership engagement, (c) monitoring that easy-to-use protocols and required equipment remain in place, and (d) embedded analytics to monitor results over a prolonged period.