Chronic obstructive pulmonary disease and the risk for ventilator-associated pneumonia:

Predictive value of fluid balance before extubation on its outcome in mechanically ventilated adults in the intensive care unit

BACKGROUND

Although there are many reasons for extubation failure, maintaining negative or lower positive fluid balances 24 hours before extubation may be a key measure for successful extubation.

AIM

To assess the predictive value of fluid balance before extubation and its outcome in mechanically ventilated cases in the intensive care unit (ICU).

STUDY DESIGN

This retrospective cohort study involved collecting clinical data from patients undergoing mechanical ventilation in Lanzhou general adult ICU from January 2022 to December 2022. Based on extubation outcomes, the patients were divided into a successful extubation group and a failed extubation group. Their fluid balance levels 24 h before extubation were compared with analyse the predictive value of fluid balance on extubation outcomes in patients undergoing mechanical ventilation.

RESULTS

In this study, clinical data from 545 patients admitted to a general adult ICU were collected. According to the inclusion and exclusion criteria, 265 (48.6%) patients were included, of which 197 (74.3%) were successfully extubated; extubation was unsuccessful in 68 (25.7%) patients. The total intake and fluid balance levels in patients in the failed extubation group 24 h before extubation were significantly higher than those in the successful extubation group, with a median of 2679.00 (2410.44-3193.50) mL versus 2435.40 (1805.04-2957.00) mL, 831.50 (26.25-1407.94) mL versus 346.00 (-163.00-941.50) mL. Receiver operating characteristic (ROC) curve analysis showed that the optimal cut-off value for predicting extubation outcomes was 497.5 mL (sensitivity 64.7%, specificity 59.4%) for fluid balance 24 h before extubation. The area under the ROC curve was 0.627 (95% confidence interval [CI] 0.547-0.707). Based on the logistic regression model, cumulative fluid balance >497.5 mL 24 h before extubation could predict its outcomes in mechanically ventilated patients in the ICU (OR = 5.591, 95% CI [2.402-13.015], p < .05).

CONCLUSIONS

The fluid balance level 24 h before extubation was correlated with the outcome of extubation in mechanically ventilated patients in the ICU. The risk of extubation failure was higher when the fluid balance level was >497.5 mL.

RELEVANCE TO CLINICAL PRACTICE

Tracheal intubation is a crucial life support technique for many critically ill patients, and determining the appropriate time for extubation remains a challenge for clinicians. Although there are many reasons for extubation failure, acute pulmonary oedema caused by continuous positive fluid balance and volume overload is one of the main reasons for extubation failure. Therefore, it is very important to study the relationship between fluid balance and extubation outcome to improve the prognosis of patients with invasive mechanical ventilation in ICU.

The Association between Non-Invasive Ventilation and the Rate of Ventilator-Associated Pneumonia

Ventilator-associated pneumonia (VAP) has significant effects on patient outcomes, including prolonging the duration of both mechanical ventilation and stay in the intensive care unit (ICU). The aim of this study was to assess the association between non-invasive ventilation/oxygenation (NIVO) prior to intubation and the rate of subsequent VAP. This was a multicenter retrospective cohort study of adult patients who were admitted to the medical ICU from three tertiary care academic centers in three distinct regions. NIVO was defined as continuous positive airway pressure (CPAP), bilevel positive airway pressure (BiPAP), or high-flow nasal cannula (HFNC) for any duration during the hospitalization prior to intubation. The primary outcome variable was VAP association with NIVO. A total of 17,302 patients were included. VAP developed in 2.6% of the patients (444/17,302), 2.3% (285/12,518) of patients among those who did not have NIVO, 1.6% (30/1879) of patients who had CPAP, 2.5% (17/690) of patients who had HFNC, 8.1% (16/197) of patients who had BiPAP, and 4.8% (96/2018) of patients who had a combination of NIVO types. Compared to those who did not have NIVO, VAP was more likely to develop among those who had BiPAP (adj OR 3.11, 95% CI 1.80-5.37, p < 0.001) or a combination of NIVO types (adj OR 1.91, 95% CI 1.49-2.44, p < 0.001) after adjusting for patient demographics and comorbidities. The use of BiPAP or a combination of NIVO types significantly increases the odds of developing VAP once receiving IMV.

A risk nomogram for predicting prolonged intensive care unit stays in patients with chronic obstructive pulmonary disease

Background

Providing intensive care is increasingly expensive, and the aim of this study was to construct a risk column line graph (nomograms)for prolonged length of stay (LOS) in the intensive care unit (ICU) for patients with chronic obstructive pulmonary disease (COPD).

Methods

This study included 4,940 patients, and the data set was randomly divided into training (n = 3,458) and validation (n = 1,482) sets at a 7:3 ratio. First, least absolute shrinkage and selection operator (LASSO) regression analysis was used to optimize variable selection by running a tenfold k-cyclic coordinate descent. Second, a prediction model was constructed using multifactorial logistic regression analysis. Third, the model was validated using receiver operating characteristic (ROC) curves, Hosmer-Lemeshow tests, calibration plots, and decision-curve analysis (DCA), and was further internally validated.

Results

This study selected 11 predictors: sepsis, renal replacement therapy, cerebrovascular disease, respiratory failure, ventilator associated pneumonia, norepinephrine, bronchodilators, invasive mechanical ventilation, electrolytes disorders, Glasgow Coma Scale score and body temperature. The models constructed using these 11 predictors indicated good predictive power, with the areas under the ROC curves being 0.826 (95%CI, 0.809-0.842) and 0.827 (95%CI, 0.802-0.853) in the training and validation sets, respectively. The Hosmer-Lemeshow test indicated a strong agreement between the predicted and observed probabilities in the training (χ² = 8.21, p = 0.413) and validation (χ² = 0.64, p = 0.999) sets. In addition, decision-curve analysis suggested that the model had good clinical validity.

Conclusion

This study has constructed and validated original and dynamic nomograms for prolonged ICU stay in patients with COPD using 11 easily collected parameters. These nomograms can provide useful guidance to medical and nursing practitioners in ICUs and help reduce the disease and economic burdens on patients.

The Fungal and Bacterial Interface in the Respiratory Mycobiome with a Focus on Aspergillus spp

The heterogeneity of the lung microbiome and its alteration are prevalently seen among chronic lung diseases patients. However, studies to date have primarily focused on the bacterial microbiome in the lung rather than fungal composition, which might play an essential role in the mechanisms of several chronic lung diseases. It is now well established that Aspergillus spp. colonies may induce various unfavorable inflammatory responses. Furthermore, bacterial microbiomes such as Pseudomonas aeruginosa provide several mechanisms that inhibit or stimulate Aspergillus spp. life cycles. In this review, we highlighted fungal and bacterial microbiome interactions in the respiratory tract, with a focus on Aspergillus spp.

Construction and Validation of a Predictive Model for the Risk of Ventilator-Associated Pneumonia in Elderly ICU Patients

Background

Ventilator-associated pneumonia (VAP) is among the most important hospital-acquired infections in an intensive-care unit setting. However, clinical practice lacks effective theoretical tools for preventing VAP in the elderly.

Aim

To describe the independent factors associated with VAP in elderly intensive-care unit (ICU) patients on mechanical ventilation (MV) and to construct a risk prediction model.

Methods

A total of 1851 elderly patients with MV in ICUs from January 2015 to September 2019 were selected from 12 tertiary hospitals. Study subjects were divided into a model group (n = 1219) and a validation group (n = 632). Two groups of patients were divided into a VAP group and a non-VAP group and compared. Univariate and logistic regression analyses were used to explore influencing factors for VAP in elderly ICU patients with MV, establish a risk prediction model, and draw a nomogram. We used the area under the receiver operating characteristic curve (AUROC) and the Hosmer-Lemeshow goodness-of-fit test to evaluate the predictive effect of the model. Findings regarding the length of ICU stay, surgery, C-reactive protein (CRP), and the number of reintubations were independent risk factors for VAP in elderly ICU patients with MV. Predictive-model verification results showed that the area under the curve (AUC) of VAP risk after MV in the modeling and verification groups was 0.859 and 0.813 (P < 0.001), respectively, while P values for the Hosmer-Lemeshow test in these two groups were 0.365 and 0.485, respectively.

Conclusion

The model could effectively predict the occurrence of VAP in elderly patients with MV in ICUs. This study is a retrospective study, so it has not been registered as a clinical study.

Probiotic Supplementation Prevents the Development of Ventilator-Associated Pneumonia for Mechanically Ventilated ICU Patients: A Systematic Review and Network Meta-analysis of Randomized Controlled Trials

Background

Ventilator-associated pneumonia (VAP) is one of the common critical complications of nosocomial infection (NI) in invasive mechanically ventilated intensive care unit (ICU) patients. The efficacy of total parenteral nutrition (TPN), enteral nutrition and/or adjuvant peripheral parenteral nutrition (EPN) supplemented with or without probiotic, prebiotic, and synbiotic therapies in preventing VAP among these patients has been questioned. We aimed to systematically and comprehensively summarize all available studies to generate the best evidence of VAP prevention for invasive mechanically ventilated ICU patients.

Methods

Randomized controlled trials (RCTs) for the administration of TPN, EPN, probiotics-supplemented EPN, prebiotics-supplemented EPN, and synbiotics-supplemented EPN for VAP prevention in invasive mechanically ventilated ICU patients were systematically retrieved from four electronic databases. The incidence of VAP was the primary outcome and was determined by the random-effects model of a Bayesian framework. The secondary outcomes were NI, ICU and hospital mortality, ICU and hospital length of stay, and mechanical ventilation duration. The registration number of Prospero is CRD42020195773.

Results

A total of 8339 patients from 31 RCTs were finally included in network meta-analysis. The primary outcome showed that probiotic-supplemented EPN had a higher correlation with the alleviation of VAP than EPN in critically invasive mechanically ventilated patients (odds ratio [OR] 0.75; 95% credible intervals [CrI] 0.58–0.95). Subgroup analyses showed that probiotic-supplemented EPN prevented VAP in trauma patients (OR 0.30; 95% CrI 0.13–0.83), mixed probiotic strain therapy was more effective in preventing VAP than EPN therapy (OR 0.55; 95% CrI 0.31–0.97), and low-dose probiotic therapy (less than 10¹⁰ CFU per day) was more associated with lowered incidence of VAP than EPN therapy (OR 0.16; 95% CrI 0.04–0.64). Secondary outcomes indicated that synbiotic-supplemented EPN therapy was more significantly related to decreased incidence of NI than EPN therapy (OR 0.34; 95% CrI 0.11–0.85). Prebiotic-supplemented EPN administration was the most effective in preventing diarrhea (OR 0.05; 95% CrI 0.00–0.71).

Conclusion

Probiotic supplementation shows promise in reducing the incidence of VAP in critically invasive mechanically ventilated patients. Currently, low quality of evidence reduces strong clinical recommendations. Further high-quality RCTs are needed to conclusively prove these findings.

Systamatic Review Registration

[https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020195773], identifier [CRD42020195773].

Ventilator-associated pneumonia in patients on prolonged mechanical ventilation: description, risk factors for mortality, and performance of the SOFA score

Objective:

Ventilator-associated pneumonia (VAP) is a serious complication of mechanical ventilation (MV). However, data on VAP in patients on prolonged MV (PMV) are scarce. We aimed to describe the characteristics of VAP patients on PMV and to identify factors associated with mortality.

Methods:

This was a retrospective cohort study including VAP patients on PMV. We recorded baseline characteristics, as well as 30-day and 90-day mortality rates. Variables associated with mortality were determined by Kaplan-Meier survival analysis and Cox regression model.

Results:

We identified 80 episodes of VAP in 62 subjects on PMV. The medians for age, Charlson Comorbidity Index, SOFA score, and days on MV were, respectively, 69.5 years, 5, 4, and 56 days. Episodes of VAP occurred between days 21 and 50 of MV in 28 patients (45.2%) and, by day 90 of MV, in 48 patients (77.4%). The 30-day and 90-day mortality rates were 30.0% and 63.7%, respectively. There were associations of 30-day mortality with the SOFA score (hazard ratio [HR] = 1.30; 95% CI: 1.12-1.52; p < 0.001) and use of vasoactive agents (HR = 4.0; 95% CI: 1.2-12.9; p = 0.02), whereas 90-day mortality was associated with age (HR = 1.03; 95% CI: 1.00-1.05; p = 0.003), SOFA score (HR = 1.20; 95% CI: 1.07-1.34; p = 0.001), use of vasoactive agents (HR = 4.07; 95% CI: 1.93-8.55; p < 0.001), and COPD (HR = 3.35; 95% CI: 1.71-6.60; p < 0.001).

Conclusions:

Mortality rates in VAP patients on PMV are considerably high. The onset of VAP can occur various days after MV initiation. The SOFA score is useful for predicting fatal outcomes. The factors associated with mortality could help guide therapeutic decisions and determine prognosis.

Gender differences in incidence and in-hospital outcomes of community-acquired, ventilator-associated and nonventilator hospital-acquired pneumonia in Spain

AIMS

We aim to compare the incidence and in-hospital outcomes of community-acquired pneumonia (CAP), ventilator-associated pneumonia (VAP) and nonventilator hospital-acquired pneumonia (NV-HAP) according to gender.

METHODS

This was a retrospective observational epidemiological study using the Spanish National Hospital Discharge Database for the years 2016 and 2017.

RESULTS

Of 277 785 hospital admissions, CAP was identified in 257 455 (41.04% females), VAP was identified in 3261 (30.42% females) and NV-HAP was identified in 17 069 (36.58% females). The incidence of all types of pneumonia was higher amongst males (CAP: incidence rate ratio [IRR] 1.05, 95% CI 1.03-1.06; VAP: IRR 1.36, 95% CI 1.26-1.46; and NV-HAP: IRR 1.16, 95% CI 1.14-1.18). The crude in-hospital mortality (IHM) rate for CAP was 11.44% in females and 11.80% in males (P = .005); for VAP IHM, the rate was approximately 35% in patients of both genders and for NV-HAP IHM, the rate was 23.97% for females and 26.40% for males (P < .001). After multivariable adjustment, in patients of both genders, older age and comorbidities were factors associated with IHM in the three types of pneumonia analysed. Female gender was a risk factor for IHM after VAP (OR 1.24; 95% CI 1.06-1.44), and no gender differences were found for CAP or NV-HAP.

CONCLUSIONS

Our findings show a difference between females and males, with females presenting a lower incidence of all types of pneumonia. However, female gender was a risk factor for IHM after VAP.

Is COPD associated with increased risk for microaspiration in intubated critically ill patients?

Background

Although COPD patients are at higher risk for aspiration when breathing spontaneously, no information is available on the risk for microaspiration in invasively ventilated COPD patients. The aim of our study was to determine the relationship between COPD and abundant microaspiration in intubated critically ill patients.

Methods

This was a retrospective analysis of prospectively collected data, provided by 3 randomized controlled trials on microaspiration in critically ill patients receiving invasive mechanical ventilation for more than 48 h. Abundant microaspiration was defined as the presence of pepsin and or alpha-amylase at significant levels in tracheal aspirates. In all study patients, pepsin and alpha-amylase were quantitatively measured in all tracheal aspirates collected during a 48-h period. COPD was defined using spirometry criteria.

Results

Among the 515 included patients, 70 (14%) had proven COPD. Pepsin and alpha-amylase were quantitatively measured in 3873 and 3764 tracheal aspirates, respectively. No significant difference was found in abundant microaspiration rate between COPD and non-COPD patients (62 of 70 patients (89%) vs 366 of 445 (82%) patients, p = 0.25). Similarly, no significant difference was found in abundant microaspiration of gastric contents (53% vs 45%, p = 0.28), oropharyngeal secretions (71% vs 71%, p = 0.99), or VAP (19% vs 22%, p = 0.65) rates between the two groups. No significant difference was found between COPD and non-COPD patients in duration of mechanical ventilation, ICU length of stay, or ICU mortality.

Conclusions

Our results suggest that COPD is not associated with increased risk for abundant microaspiration in intubated critically ill patients.

Hospital admissions for community-acquired, ventilator-associated and nonventilator hospital-acquired pneumonia in COPD patients in Spain (2016-2017)

BACKGROUND

To examine the incidence, characteristics and outcomes of community-acquired pneumonia (CAP), ventilator-associated pneumonia (VAP) and nonventilator hospital-acquired pneumonia (NV-HAP) in patients with or without COPD; compare in-hospital outcomes; and identify factors associated with in-hospital mortality (IHM) for pneumonia.

METHODS

We carried out a retrospective observational study using the hospital discharge records from 2016-17 of the Spanish National Health System. Propensity score matching was used for data analysis.

RESULTS

We found 245,905 patients (≥40 years) with pneumonia; we identified CAP in 228,139 patients (19.85% with COPD), VAP in 2,771 patients (8.55% with COPD) and NV-HAP in 14,995 patients (14.17% with COPD). The incidence for the three types of pneumonia was higher in COPD patients (CAP: incidence rate ratio (IRR) 2.23, 95% CI 2.21-2.26; VAP: IRR 1.25, 95% CI 1.08-1.42; and NV-HAP: IRR 1.55, 95% CI 1.48-1.63). The IHM for CAP was 10.35% in COPD patients and 12.91% in the controls (p<0.001). In patients with VAP and NV-HAP, IHM was not significantly different between those with and without COPD (43.88% vs. 41.77%;p=0.643 and 29.21% vs. 30.57%;p=0.331, respectively). Factors associated with IHM for all types of pneumonia analyzed in COPD patients were older age and receiving dialysis.

CONCLUSIONS

The incidence of hospitalizations for all types of pneumonia was significantly higher in COPD patients than in the non-COPD population. In contrast, IHM was significantly lower among COPD patients with CAP than among matched non-COPD patients. Higher mortality rates in COPD patients with any pneumonia type were associated with increasing age and receiving dialysis.

Ventilator-associated pneumonia in adults: a narrative review

Ventilator-associated pneumonia (VAP) is one of the most frequent ICU-acquired infections. Reported incidences vary widely from 5 to 40% depending on the setting and diagnostic criteria. VAP is associated with prolonged duration of mechanical ventilation and ICU stay. The estimated attributable mortality of VAP is around 10%, with higher mortality rates in surgical ICU patients and in patients with mid-range severity scores at admission. Microbiological confirmation of infection is strongly encouraged. Which sampling method to use is still a matter of controversy. Emerging microbiological tools will likely modify our routine approach to diagnosing and treating VAP in the next future. Prevention of VAP is based on minimizing the exposure to mechanical ventilation and encouraging early liberation. Bundles that combine multiple prevention strategies may improve outcomes, but large randomized trials are needed to confirm this. Treatment should be limited to 7 days in the vast majority of the cases. Patients should be reassessed daily to confirm ongoing suspicion of disease, antibiotics should be narrowed as soon as antibiotic susceptibility results are available, and clinicians should consider stopping antibiotics if cultures are negative.

Impact of Chronic Obstructive Pulmonary Disease on Incidence, Microbiology and Outcome of Ventilator-Associated Lower Respiratory Tract Infections

Objectives: To determine the impact of chronic obstructive pulmonary disease (COPD) on incidence, microbiology, and outcomes of ventilator-associated lower respiratory tract infections (VA-LRTI). Methods: Planned ancillary analysis of TAVeM study, including 2960 consecutive adult patients who received invasive mechanical ventilation (MV) > 48 h. COPD patients (n = 494) were compared to non-COPD patients (n = 2466). The diagnosis of ventilator-associated tracheobronchitis (VAT) and ventilator-associated pneumonia (VAP) was based on clinical, radiological and quantitative microbiological criteria. Results: No significant difference was found in VAP (12% versus 13%, p = 0.931), or VAT incidence (13% versus 10%, p = 0.093) between COPD and non-COPD patients. Among patients with VA-LRTI, Escherichia coli and Stenotrophomonas maltophilia were significantly more frequent in COPD patients as compared with non-COPD patients. However, COPD had no significant impact on multidrug-resistant bacteria incidence. Appropriate antibiotic treatment was not significantly associated with progression from VAT to VAP among COPD patients who developed VAT, unlike non-COPD patients. Among COPD patients, patients who developed VAT or VAP had significantly longer MV duration (17 days (9–30) or 15 (8–27) versus 7 (4–12), p < 0.001) and intensive care unit (ICU) length of stay (24 (17–39) or 21 (14–40) versus 12 (8–19), p < 0.001) than patients without VA-LRTI. ICU mortality was also higher in COPD patients who developed VAP (44%), but not VAT(38%), as compared to no VA-LRTI (26%, p = 0.006). These worse outcomes associated with VA-LRTI were similar among non-COPD patients. Conclusions: COPD had no significant impact on incidence or outcomes of patients who developed VAP or VAT.

Using flexible methods to determine risk factors for ventilator-associated pneumonia in the Netherlands

Seven hospitals participated in the Dutch national surveillance for ventilator-associated pneumonia (VAP) and its risk factors. We analysed time-independent and time-dependent risk factors for VAP using the standard Cox regression and the flexible Weighted Cumulative Effects method (WCE) that evaluates both current and past exposures. The prospective surveillance of intensive care patients aged ≥16 years and ventilated ≥48 hours resulted in the inclusion of 940 primary ventilation periods, comprising 7872 ventilation days. The average VAP incidence density was 10.3/1000 ventilation days. Independent risk factors were age (16–40 years at increased risk: HR 2.42 95% confidence interval 1.07–5.50), COPD (HR 0.19 [0.04–0.78]), current sedation score (higher scores at increased risk), current selective oropharyngeal decontamination (HR 0.19 [0.04–0.91]), jet nebulizer (WCE, decreased risk), intravenous antibiotics for selective decontamination of the digestive tract (ivSDD, WCE, decreased risk), and intravenous antibiotics not for SDD (WCE, decreased risk). The protective effect of ivSDD was afforded for 24 days with a delay of 3 days. For some time-dependent variables, the WCE model was preferable over standard Cox proportional hazard regression. The WCE method can furthermore increase insight into the active time frame and possible delay herein of a time-dependent risk factor.

Airway Devices in Ventilator-Associated Pneumonia Pathogenesis and Prevention

Airway devices play a major role in the pathogenesis of microaspiration of contaminated oropharyngeal and gastric secretions, tracheobronchial colonization, and ventilator-associated pneumonia (VAP) occurrence. Subglottic secretion drainage is an effective measure for VAP prevention, and no routine change of ventilator circuit. Continuous control of cuff pressure, silver-coated tracheal tubes, low-volume low-pressure tracheal tubes, and the mucus shaver are promising devices that should be further evaluated by large randomized controlled trials. Polyurethane-cuffed, conical-shaped cuff, and closed tracheal suctioning system are not effective and should not be used for VAP prevention.

Case-control study investigating parameters affecting ventilator-associated events in mechanically ventilated patients

We analyzed a set of clinical parameters using Cox proportional hazard regressions to yield significant factors associated with the development of ventilator-associated events. In our study, intubation site, certain comorbidities, morphine, prednisone, and nutrition emerged as factors. Additionally, we presented potential mechanisms that require further research to validate.

Microbial infection pattern, pathogenic features and resistance mechanism of carbapenem-resistant Gram negative bacilli during long-term hospitalization

BACKGROUND

Carbapenem-resistant Gram-negative bacilli (GNB) have become an important cause of nosocomial infections of hospitalized patients.

METHODS

To investigate the microbial infection patterns and molecular epidemiology characteristics of the carbapenem-resistant GNB isolates from a long-term hospitalized patient, antimicrobial susceptibility testing, phenotypic screening test for carbapenemase production, PCR screening and DNA sequencing of carbapenemase genes, repetitive extragenic palindromic sequence-based PCR (REP-PCR), multilocus sequencing typing (MLST) and genetic environment analysis were performed.

RESULTS

Twelve strains with carbapenemase genes were detected from 63 carbapenem-resistant isolates, including two bla_IMP-25-carrying Pseudomonas aeruginosa, one bla_NDM-1-carrying Citrobacter freundii, three bla_NDM-1-carrying Klebsiella pneumoniae and six bla_KPC-2-carrying K. pneumoniae. Only the bla_NDM-1 genes were successfully transferred from three K. pneumoniae strains to Escherichia coli C600 by conjugation. Genetic environment of bla_IMP-25, bla_NDM-1 and bla_KPC-2 genes in our study were consistent with previous reports. Molecular typing of K. pneumoniae performed by MLST revealed that most of the isolates belonged to ST11. bla_NDM-1-carrying K. pneumoniae sequencing type 1416 was first reported in our study.

CONCLUSIONS

Carbapenem-resistant GNB are common pathogens during long-term hospitalization, and ST11 bla_KPC-2-carrying K. pneumoniae is the dominant bacterium in our study. Colonization and horizontal transmission of resistance by plasmids of carbapenem-resistant GNB have increased the risks of persistent infection and mortality of long-term hospitalized patients.

Risk factors for nosocomial infection among hospitalised severe influenza A(H1N1)pdm09 patients

BACKGROUND AND OBJECTIVE

Nosocomial infections following influenza are important causes of death, requiring early implementation of preventive measures, but predictors for nosocomial infection in the early stage remained undetermined. We aimed to determine risk factors that can help clinicians identify patients with high risk of nosocomial infection following influenza on admission.

METHOD

Using a database prospectively collected through a Chinese national network for hospitalised severe influenza A(H1N1)pdm09 patients, we compared the characteristics on admission between patients with and without nosocomial infection.

RESULT

A total of 2146 patients were enrolled in the final analysis with a median age of 36.0 years, male patients comprising 50.2% of the sample and 232 (10.8%) patients complicated with nosocomial infection. Acinetobacter baumannii, Pseudomonas aeruginosa, Stenotrophomonas maltophilia and Staphylococcus aureus were the leading pathogens, and invasive fungal infection was found in 30 cases (12.9%). The in-hospital mortality was much higher in patients with nosocomial infection than those without (45.7% vs 11.8%, P < 0.001). Need for mechanical ventilation (OR: 3.336; 95% CI 2.362-4.712), sepsis (OR: 2.125; 95% CI 1.236-3.651), ICU admission on first day (OR: 2.074; 95% CI 1.425-3.019), lymphocytopenia (OR: 1.906; 95% CI 1.361-2.671), age > 65 years (OR: 1.83; 95% CI 1.04-3.21) and anaemia (OR: 1.39; 95% CI 1.39-2.79) were independently associated with nosocomial infection.

CONCLUSION

Need for mechanical ventilation, sepsis, ICU admission on first day, lymphocytopenia, older age and anaemia were independent risk factors that can help clinicians identify severe influenza A(H1N1)pdm09 patients at high risk of nosocomial infection.

Retrospective cohort evaluation on risk of pneumonia in patients with pulmonary tuberculosis

Pulmonary tuberculosis (PTb) and pneumonia are diseases that may exist concomitantly. Population study investigating the subsequent pneumonia development in PTb patients is limited. This study compares the risk of pneumonia between cohorts with and without PTb.We used the claims data of the Taiwan National Health Insurance to identify a cohort with PTb (N = 3417) newly diagnosed in 2000-2006 without pneumonia history, and a randomly selected comparison cohort (N = 6834) free of PTb and pneumonia, frequency matched by propensity score. Incidence rates and hazard ratios of pneumonia were calculated by sex, age, and comorbidity starting in the 7th month after the cohorts being established until the end of 2011.We found the incidence of pneumonia to be 1.9-fold higher in the PTb cohort than in the PTb free cohort (51.6 vs 27.0 per 1000 person-years). The PTb cohort had a Cox method estimated adjusted hazard ratio of 2.14 (95% confidence interval = 1.96-2.32). We also found that the risk was greater for men than for women, but lower for young adults aged 20-39 years. Comorbidity interacted with PTb by aggravating the pneumonia risk, particularly for those with asthma. For PTb patients comorbid with asthma, the pneumonia incidence was 2.5-fold higher than for PTb patients free of comorbidities (75.9 vs 29.3 per 1000 person-years).Our results display that PTb patients have an elevated risk of developing pneumonia. Adequate follow-up should be provided to the PTb patients, especially those with comorbidity.

Prone positioning improves oxygenation in spontaneously breathing nonintubated patients with hypoxemic acute respiratory failure: A retrospective study

PURPOSE

Prone positioning (PP) improves oxygenation and outcome of patients with acute respiratory distress syndrome undergoing invasive ventilation. We evaluated feasibility and efficacy of PP in awake, non-intubated, spontaneously breathing patients with hypoxemic acute respiratory failure (ARF).

MATERIAL AND METHODS

We retrospectively studied non-intubated subjects with hypoxemic ARF treated with PP from January 2009 to December 2014. Data were extracted from medical records. Arterial blood gas analyses, respiratory rate, and hemodynamics were retrieved 1 to 2 hours before pronation (step PRE), during PP (step PRONE), and 6 to 8 hours after resupination (step POST).

RESULTS

Fifteen non-intubated ARF patients underwent 43 PP procedures. Nine subjects were immunocompromised. Twelve subjects were discharged from hospital, while 3 died. Only 2 maneuvers were interrupted, owing to patient intolerance. No complications were documented. PP did not alter respiratory rate or hemodynamics. In the subset of procedures during which the same positive end expiratory pressure and Fio2 were utilized throughout the pronation cycle (n=18), PP improved oxygenation (Pao2/Fio2 124±50 mmHg, 187±72 mmHg, and 140±61 mmHg, during PRE, PRONE, and POST steps, respectively, P<.001), while pH and Paco2 were unchanged.

CONCLUSIONS

PP was feasible and improved oxygenation in non-intubated, spontaneously breathing patients with ARF.

Antifungal therapy in patients with pulmonary Candida spp. colonization may have no beneficial effects

Background

In critically ill patients, Candida spp. can often be identified in pulmonary samples. The impact of prompt antifungal therapy in these patients is unknown.

Methods

In this retrospective study, 500 adult patients with pulmonary Candida spp. colonization admitted to the intensive care unit (ICU) between 2010 and 2012 were included. The patients were analyzed according to whether or not they received antifungal therapy, which was administered at the discretion of the attending physician. Logistic regression analysis was performed to investigate the impact of antifungal therapy on hospital mortality and new onset of ventilator-associated pneumonia. In a stepwise backward elimination, the impact of age, cancer as an underlying disease, Simplified Acute Physiology Score (SAPS) II, and Sequential Organ Failure Assessment (SOFA) score were considered.

Results

After excluding 178 patients with multifocal Candida spp., isolated pulmonary Candida spp. colonization was found in 322 patients (cohort 1). Pre-existing pneumonia was found in 147/322 patients. Out of the remaining 175 patients (cohort 2), 44 patients received any antifungal therapy, and 131 were defined as the control group. Patients who received antifungal therapy had higher hospital mortality (50 vs. 30 %, p = 0.02) and pneumonia rates (47.7 vs. 16.8 %; p < 0.001) than those who did not. In Cox regression analysis, antifungal therapy was not independently associated with favorable outcome (mortality: odds ratio 0.854 (95 % CI 0.467–1.561); new pneumonia: 1.048 (0.536–2.046)), but SAPS II and SOFA score were significantly (p < 0.05) independent covariates for worse outcome.

Conclusions

In critically ill patients with pulmonary Candida spp. colonization, antifungal therapy may not have an impact on the incidence of new pneumonia or in-hospital mortality after adjustment for confounders.

Electronic supplementary material

The online version of this article (doi:10.1186/s40560-015-0097-0) contains supplementary material, which is available to authorized users.

The potential impact of the pulmonary microbiome on immunopathogenesis of Aspergillus-related lung disease

Aspergillosis is an infection or allergic response caused by fungi of the genus Aspergillus. The most common forms of aspergillosis are allergic bronchopulmonary aspergillosis, chronic pulmonary aspergillosis, and invasive pulmonary aspergillosis. Aspergillus also plays an important role in fungal sensitized asthma. Humans inhale Aspergillus spores every day and when the host is immunocompromised, Aspergillus spp. may cause severe pulmonary disease. There is increasing evidence that the microbiome plays a significant role in immune regulation, chronic inflammatory diseases, metabolism, and other physiological processes, including recovery from the effects of antibiotic treatment. Bacterial microbiome mediated resistance mechanisms probably play a major role in limiting fungal colonization of the lungs, and may therefore prevent humans from contracting Aspergillus-related diseases. In this perspective, we review this emerging area of research and discuss the role of the microbiome in aspergillosis, role of Aspergillus in the microbiome, and the influence of the microbiome on anti-Aspergillus host defense and its role in preventing aspergillosis.