Ventilator-Associated Pneumonia: When to hold the breath?

Trends in Molecular Diagnosis of Nosocomial Pneumonia Classic PCR vs. Point-of-Care PCR: A Narrative Review

Nosocomial pneumonia is one of the most frequent hospital-acquired infections. One of the types of nosocomial pneumonia is ventilator-associated pneumonia, which occurs in endotracheally intubated patients in intensive care units (ICU). Ventilator-associated pneumonia may be caused by multidrug-resistant pathogens, which increase the risk of complications due to the difficulty in treating them. Pneumonia is a respiratory disease that requires targeted antimicrobial treatment initiated as early as possible to have a good outcome. For the therapy to be as specific and started sooner, diagnostic methods have evolved rapidly, becoming quicker and simpler to perform. Polymerase chain reaction (PCR) is a rapid diagnostic technique with numerous advantages compared to classic plate culture-based techniques. Researchers continue to improve diagnostic methods; thus, the newest types of PCR can be performed at the bedside, in the ICU, so-called point of care testing-PCR (POC-PCR). The purpose of this review is to highlight the benefits and drawbacks of PCR-based techniques in managing nosocomial pneumonia.

Promoting subglottic secretion drainage: a quality improvement project in a UK critical care unit

The aim of the study was to promote the practice of subglottic secretion drainage (SSD) in a UK critical care unit. SSD is a technique employed to reduce microaspiration of oropharyngeal secretions in patients with cuffed endotracheal airways. Aspiration of oropharyngeal secretions is the accepted cause of the majority of ventilator-associated pneumonia (VAP), a complication of invasive ventilation with high associated mortality. The plan–do–study–act methodology was employed. The local critical care patient database was searched for patients requiring mechanical ventilation via a tracheostomy tube with subglottic port in the 3 months prior to intervention. Patient records were interrogated for evidence of the practice of SSD. The intervention involved the introduction of a tracheostomy care bundle to be prescribed on insertion of a tracheostomy on the critical care unit, in combination with departmental teaching. The bundle included prompts for nursing staff to practise regular SSD and to complete a tracheostomy care plan at the end of shift. A total of 24 patients were included. A review of practice was conducted every 3 months for 1 year. This showed an improvement in documented evidence of SSD from 0% of days at baseline to 85.7% of days at 1 year. Implementation of a tracheostomy order set prescribing regular SSD resulted in an improvement in the practice of SSD in patients ventilated via tracheostomy. This has implications for patient outcomes and healthcare costs, given that SSD has been shown to reduce incidence of VAP.

Emergency nurses' knowledge about ventilator-associated pneumonia

INTRODUCTION

Given the increasing number of patients requiring mechanical ventilation in emergency departments in recent years, prevention of ventilator-associated pneumonia is very important. Nurses play a significant role in prevention of ventilator-associated pneumonia. This study aimed to determine the emergency nurses knowledge about prevention of ventilator-associated pneumonia.

METHODS

The present descriptive study was conducted in Iran, from July to October 2018. All the nurses with at least a bachelor degree, who are working in two emergency departments of two teaching hospitals, were asked to participate in this study. The "knowledge about ventilator-associated pneumonia" questionnaire consisting of 9 items was used to assess the knowledge of nurses. The results were analyzed using SPSS-16.

RESULTS

In total, 53 nurses participated in this study. The mean score of correct answers of nurses to these 9 items was 4.4 ± 1.6. Nurses give the most correct answer to the item about patient's position on the bed so as to reduce the risk of pneumonia with a correct answer of 72.9%. The least correct answer was also given to the item about how humidifier was changed with a correct answer of 1.9%. None of the nurses participating in the study were able to answer all the items correctly. The mean score of knowledge of nurses who had participated in workshops about taking care of patients on mechanical ventilation was significantly higher than those who had not participated in such workshops (4.8 vs. 3.8) (p = 0.045). The mean score of knowledge in nurses who were familiar with the international guidelines for ventilator-associated pneumonia prevention was significantly higher than those who were not familiar with such guidelines (5.1 vs. 4.1) (p = 0.045).

CONCLUSION

Emergency nurses participated in this study had inadequate knowledge about the prevention of ventilator-associated pneumonia. Nurse's knowledge affected by participation in related workshop and familiarity with ventilator-associated pneumonia guidelines. Considering the importance of this issue, it is necessary to improve the knowledge of the emergency nurses in this matter by holding training courses.

Is intra-abdominal hypertension a risk factor for ventilator-associated pneumonia?

In the last years, there has been a significant amount of research about the impact of intra-abdominal hypertension (IAH) on the outcomes of critical care patients. IAH is increasingly recognized as potential complication in intensive care unit (ICU) patients. IAH affects all body systems, most notably the cardiac, respiratory, renal, and neurologic systems. IAH affects blood flow to various organs and plays a significant role in the prognosis of the patients. Recognition of IAH, its risk factors and clinical signs can reduce the morbidity and mortality associated. Moreover, knowledge of the pathophysiology may help rationalize the therapeutic approach. On the other hand, ICU patients present frequently ventilator- associated respiratory infections. Ventilator-associated pneumonia (VAP) is the most common healthcare-associated infection (HAI) in adult critical care units. It is associated with increased ICU stay, patient ventilator days and mortality. This paper reviews the relationship between IAH and VAP. Despite animal experimentation and physiological studies on humans, in favor of the impact of IAH to VAP, there is no definitive clinical data that IAH is associated with VAP. Microaspirations form the gastrointestinal track is a pathophysiological mechanism for VAP. This review provides data suggesting that under IAH conditions bacterial translocation might be an additional responsible mechanism for VAP in those patients that merits further investigation in the future.

Th17 cells are associated with protection from ventilator associated pneumonia

BACKGROUND

CD4+ T-helper 17 (Th17) cells and Interleukin (IL)-17A play an important role in clearing pathogens in mouse models of pneumonia. We hypothesized that numbers of Th17 cells and levels of IL-17A are associated with risk for nosocomial pneumonia in humans.

METHODS

We collected bronchoalveolar lavage (BAL) fluid from mechanically ventilated (n = 25) patients undergoing quantitative bacterial culture to evaluate for ventilator associated pneumonia (VAP). We identified Th17 cells by positive selection of CD4+ cells, stimulation with ionomycin and PMA, then staining for CD4, CD45, CCR6, IL-17A, and IFN-γ followed by flow cytometric analysis (n = 21). We measured inflammatory cytokine levels, including IL-17A, in BAL fluid by immunoassay.

RESULTS

VAP was detected in 13 of the 25 subjects. We identified a decreased percentage of IL-17A producing Th17 cells in BAL fluid from patients with VAP compared to those without (p = 0.02). However, we found no significant difference in levels of IL-17A in patients with VAP compared to those without (p = 0.07). Interestingly, IL-17A levels did not correlate with Th17 cell numbers. IL-17A levels did show strong positive correlations with alveolar neutrophil numbers and total protein levels.

CONCLUSIONS

Th17 cells are found at lower percentages in BAL fluid from mechanically ventilated patients with VAP and IL-17A levels correlated with Th17 cell percentages in non-VAP subjects, but not those with VAP. These findings suggest that Th17 cells may be protective against development of nosocomial pneumonia in patients receiving mechanical ventilation and that alveolar IL-17A in VAP may be derived from sources other than alveolar Th17 cells.

Is survival improved by the use of NIV and PEG in amyotrophic lateral sclerosis (ALS)? A post-mortem study of 80 ALS patients

Background

Non-invasive ventilation (NIV) and percutaneous gastrostomy (PEG) are guideline-recommended interventions for symptom management in amyotrophic lateral sclerosis (ALS). Their effect on survival is controversial and the impact on causes of death is unknown.

Objective

To investigate the effect of NIV and PEG on survival and causes of death in ALS patients.

Methods

Eighty deceased ALS patients underwent a complete post mortem analysis for causes of death between 2003 and 2015. Forty-two of these patients consented for genetic testing. Effects of NIV and PEG on survival and causes of death were analyzed in a multivariable Cox proportional hazard regression.

Results

Six patients, who requested assisted suicide causing drug-induced hypoxia, were excluded from final analysis. Respiratory failure was the main cause of death in 72 out of 74 patients. Fifteen out of 74 died of aspiration pneumonia 23/74 of bronchopneumonia and 8/74 of a combination of aspiration pneumonia and bronchopneumonia. Twenty died of hypoxia without concomitant infection, and six patients had pulmonary embolism alone or in combination with pneumonia. NIV (p = 0.01) and PEG (p<0.01) had a significant impact on survival. In patients using NIV bronchopneumonia was significantly more frequent (p <0.04) compared to non-NIV patients. This effect was even more pronounced in limb onset patients (p<0.002). Patients with C9orf72 hexanucleotide repeat expansions showed faster disease progression and shorter survival (p = 0.01).

Conclusion

The use of NIV and PEG prolongs survival in ALS. This study supports current AAN and EFNS guidelines which recommend NIV and PEG as a treatment option in ALS. The risk of bronchopneumonia as cause of death may be increased by NIV.

Diagnostic Efficacy of Serum Amyloid A Protein and Soluble Intercellular Adhesion Molecule 1 in Pediatric Ventilator-Associated Pneumonia

Objectives:

Study of inflammatory biomarkers which may aid in early detection of ventilator-associated pneumonia (VAP) in children and predicting their outcome.

Patients:

Thirty-five children, aged 2 months to 13 years, needed mechanical ventilation (MV) for more than 48 hours due to causes other than pneumonia.

Methods:

Measurement of serum amyloid A (SAA) protein, soluble intercellular adhesion molecule 1 (sICAM-1), and C-reactive protein (CRP), modified clinical pulmonary infection score (CPIS) and performing culture of endotracheal aspirate at the start and on the third day of MV.

Results:

Ventilator-associated pneumonia was diagnosed by CPIS in 6 (17.1%) of 35 patients. On the third day of MV, there was a significant increase in serum mean levels of SAA, sICAM-1, and CRP in comparison to the start of MV ( P = .005, .004, and .01, respectively). Three (50%) of 6 patients with VAP died, while 4 (14.28%) of 28 patients without VAP died. The sensitivity of serum SAA, sICAM-1, and CPIS were 100% for predicting VAP, while specificity was highest for CPIS (96.55%) followed by SAA (93.1%). Combination of CPIS and SAA increased the specificity to 100%. For predicting nonsurvival, serum SAA and sICAM-1 had a sensitivity of 100% and a specificity of 92.86% and 89.29%, respectively.

Conclusion:

Serum amyloid A and sICAM-1 may be considered as reliable markers for detection of VAP. Combination of serum SAA with CPIS increased the specificity to 100%. Measurement of SAA in patients with VAP also had a good predictive value for nonsurvival in such patients.

Shock Management for Cardio-surgical Intensive Care Unit Patient: The Silver Days

Shock in cardio-surgical intensive care unit (ICU) patients requires prompt identification of the underlying condition and timely therapeutic interventions. Management during the first 6 hours, also referred to as "the golden hours", is of paramount importance to reverse the shock state and improve the patient's outcome. The authors have previously described a state-of-the-art diagnostic work-up and discussed how to optimise preload, vascular tone, contractility, heart rate and oxygen delivery during this phase. Ideally, shock can be reversed during this initial period. However, some patients might have developed multiple organ dysfunction, which persists beyond the first 6 hours despite the early haemodynamic treatment goals having been accomplished. This period, also referred to as "the silver days", is the focus of this review. The authors discuss how to reduce vasopressor load and how to minimise adrenergic stress by using alternative inotropes, extracorporeal life-support and short acting beta-blockers. The review incorporates data on fluid weaning, safe ventilation, daily interruption of sedation, delirium management and early rehabilitation. It includes practical recommendations in areas where the evidence is scarce or controversial. Although the focus is on cardio-surgery ICU patients, most of the considerations apply to critical ill patients in general.

Ventilator-associated pneumonia

BACKGROUND

Ventilator-associated pneumonia (VAP) is a type of nosocomial pneumonia that occurs in patients who receive mechanical ventilation (MV). According to the International Nosocomial Infection Control Consortium (INICC), the overall rate of VAP is 13.6 per 1,000 ventilator days. The incidence varies according to the patient group and hospital setting. The incidence of VAP ranges from 13-51 per 1,000 ventilation days. Early diagnosis of VAP with appropriate antibiotic therapy can reduce the emergence of resistant organisms.

METHOD

The aim of this review was to provide an overview of the incidence, risk factors, aetiology, pathogenesis, treatment, and prevention of VAP. A literature search for VAP was done through the PUBMED/MEDLINE database. This review outlines VAP's risk factors, diagnostic methods, associated organisms, and treatment modalities.

CONCLUSION

VAP is a common nosocomial infection associated with ventilated patients. The mortality associated with VAP is high. The organisms associated with VAP and their resistance pattern varies depending on the patient group and hospital setting. The diagnostic methods available for VAP are not universal; however, a proper infection control policy with appropriate antibiotic usage can reduce the mortality rate among ventilated patients.

Risk factors for mortality in patients with septic acute kidney injury in intensive care units in Beijing, China: a multicenter prospective observational study

Objective. To discover risk factors for mortality of patients with septic AKI in ICU via a multicenter study. Background. Septic AKI is a serious threat to patients in ICU, but there are a few clinical studies focusing on this. Methods. This was a prospective, observational, and multicenter study conducted in 30 ICUs of 28 major hospitals in Beijing. 3,107 patients were admitted consecutively, among which 361 patients were with septic AKI. Patient clinical data were recorded daily for 10 days after admission. Kidney Disease: Improving Global Outcomes (KDIGO) criteria were used to define and stage AKI. Of the involved patients, 201 survived and 160 died. Results. The rate of septic AKI was 11.6%. Twenty-one risk factors were found, and six independent risk factors were identified: age, APACHE II score, duration of mechanical ventilation, duration of MAP <65 mmHg, time until RRT started, and progressive KIDGO stage. Admission KDIGO stages were not associated with mortality, while worst KDIGO stages were. Only progressive KIDGO stage was an independent risk factor. Conclusions. Six independent risk factors for mortality for septic AKI were identified. Progressive KIDGO stage is better than admission or the worst KIDGO for prediction of mortality. This trial is registered with ChiCTR-ONC-11001875.