Nosocomial respiratory tract infections in multiple trauma patients. Influence of level of consciousness with implications for therapy

Clinical, Microbiological and Treatment Characteristics of Severe Postoperative Respiratory Infections: An Observational Cohort Study

Respiratory infections are frequent and life-threatening complications of surgery. This study aimed to evaluate the clinical, microbiological and treatment characteristics of severe postoperative pneumonia (POP) and tracheobronchitis (POT) in a large series of patients. This single-center, prospective observational cohort study included patients with POP or POT requiring intensive care unit admission in the past 10 years. We recorded demographic, clinical, microbiological and therapeutic data. A total of 207 patients were included, and 152 (73%) were men. The mean (SD) age was 70 (13) years and the mean (SD) ARISCAT score was 46 (19). Ventilator-associated pneumonia was reported in 21 patients (10%), hospital-acquired pneumonia was reported in 132 (64%) and tracheobronchitis was reported in 54 (26%). The mean (SD) number of days from surgery to POP/POT diagnosis was 6 (4). The mean (SD) SOFA score was 5 (3). Respiratory microbiological sampling was performed in 201 patients (97%). A total of 177 organisms were cultured in 130 (63%) patients, with a high proportion of Gram-negative and multi-drug resistant (MDR) bacteria (20%). The most common empirical antibiotic therapy was a triple-drug regimen covering MDR Gram-negative bacteria and MRSA. In conclusion, surgical patients are a high-risk population with a high proportion of early onset severe POP/POT and nosocomial bacteria isolation.

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.

Performance of the Cepheid Methicillin-Resistant Staphylococcus aureus/S. aureus Skin and Soft Tissue Infection PCR Assay on Respiratory Samples from Mechanically Ventilated Patients for S. aureus Screening during the Phase 2 Double-Blind SAATELLITE Study

We investigated the performance of the Xpert methicillin-resistant Staphylococcus aureus (MRSA)/S. aureus skin and soft tissue (SSTI) quantitative PCR (qPCR) assay in SAATELLITE, a multicenter, double-blind, phase 2 study of suvratoxumab, a monoclonal antibody (MAb) targeting S. aureus alpha-toxin, for reducing the incidence of S. aureus pneumonia. The assay was used to detect methicillin-susceptible S. aureus (MSSA) and MRSA in lower respiratory tract (LRT) samples from mechanically ventilated patients. LRT culture results were compared with S. aureus protein A (spa) gene cycle threshold (C_T) values. Receiver operating characteristic (ROC) and Youden index were used to determine the C_T cutoff for best separation of culture-S. aureus-negative and S. aureus-positive patients. Of 720 screened subjects, 299 (41.5%) were S. aureus positive by qPCR, of whom 209 had culture data: 162 (77.5%) were S. aureus positive and 47 (22.5%) were S. aureus negative. Culture results were negatively affected by antibiotic use and cross-laboratory variability. An inverse linear correlation was observed between C_T values and quantitative S. aureus culture results. A spa C_T value of 29 (≈2 × 10³ CFU/mL) served as the best cutoff for separation between culture-negative and culture-positive samples. The associated area under the ROC curve was 83.8% (95% confidence interval [CI], 78 to 90%). Suvratoxumab provided greater reduction in S. aureus pneumonia or death than placebo in subjects with low S. aureus load (C_T ≥ 29; relative risk reduction [RRR], 50.0%; 90% CI, 2.7 to 74.4%) versus the total study population (RRR, 25.2%; 90% CI, -4.3 to 46.4%). The qPCR assay was easy to perform, sensitive, and standardized and provided better sensitivity than conventional culture for S. aureus detection. Quantitative PCR C_T output correlated with suvratoxumab efficacy in reducing S. aureus pneumonia incidence or death in S. aureus-colonized, mechanically ventilated patients.

Sepsis in Traumatic Brain Injury: Epidemiology and Outcomes

BACKGROUND

Traumatic brain injury (TBI) is a leading cause of death and disability. Risk factors for in-hospital mortality include older age, co-morbidity, and TBI severity. Few studies have investigated the role of sepsis in individuals with TBI.

METHODS

We studied adult patients with TBI admitted to intensive care over a 5-year period. Patient characteristics were identified by linking clinical and administrative databases. Charts of individuals with TBI and sepsis were manually reviewed. Predictors of ICU and hospital mortality were identified using logistic regression modeling.

RESULTS

Four hundred eighty-six individuals with TBI were admitted to intensive care. Sixteen (3.3%) developed sepsis. Pneumonia was the most common source (94%). Staphylococcus aureus was the most common pathogen (75%). ICU lengths of stay (LOS) (12.2 days [interquartile range (IQR) 4.4-23.5] versus 3.7 days [IQR 1.7-8.2]; p < 0.001) and hospital LOS (28.0 days [IQR 11.8-41.4] versus 15.3 days [IQR 5.0-30.9]; p = 0.017) were longer in patients with TBI and sepsis. Sepsis was not associated with ICU (adjusted odds ratio [aOR] 0.51; 95%CI 0.12-2.27; p = 0.38) or hospital (aOR 0.78; 95% CI 0.21-2.96; p = 0.78) mortality, though age (aOR 1.02; 95% CI 1.00-1.04; p = 0.014 for hospital mortality), severe TBI (aOR 3.71; 95% CI 1.52-9.08; p = 0.004 for ICU mortality and 4.10; 95% CI 1.95-8.65; p < 0.001 for hospital mortality), and APACHE II score (aOR 1.19; 95% CI 1.11-1.28; p < 0.001 for ICU mortality and 1.22; 95% CI 1.14-1.31; p < 0.001 for hospital mortality) were.

CONCLUSION

Sepsis in patients with TBI was not associated with mortality; however, sepsis was associated with increased health care utilization (ICU and hospital LOS).

Nosocomial Infections in Patients with Traumatic Brain Injury: A Hospital-Based Study from North India

Background Traumatic brain injury (TBI) is a major global health concern, it being a leading cause of morbidity and mortality in young adults. Infections acquired in the hospital setting are one of many risk factors that are associated with higher mortality in this population. Despite significant impact on the overall outcome, infections in TBI patients are largely understudied and underreported. The purpose of this study was to study the profile of infectious complications in patients with TBI and impact of these infections on the hospital outcome of these patients.

Materials and Methods The medical records of all the patients with a diagnosis of TBI admitted in our hospital from January 2017 to January 2020 were reviewed. They were screened for presence of any predefined infection acquired at any time during their hospital stay. Data regarding demographics, focus of infection, results of various cultures, and hospital outcome was recorded.

Results A total of 60 patients with TBI who had developed nosocomial infections were included in this observational study. Patients were mostly young, with a mean age of 36.6 years. Majority (66.6%) of patients who developed infectious complications had Glasgow coma scale (GCS) score of less than 10. Respiratory tract and urinary tract were the most common sites of infections in these patients. Burkholderia cepecia and Acinetobacter baumannii were the two most common isolated organisms. All-cause mortality in this population was 23.3%.

Conclusions Most TBI patients are young, in their productive period of lives, and do not have major comorbidities. Invariably, they have low GCS scores and encounter a breach of their surface immunity due to catheters, procedures, and intubation. Such patients make an extremely significant impact on hospital resources as well as poor economic outcomes.

Ventilator-Associated Tracheobronchitis: To Treat or Not to Treat?

Ventilator-associated tracheobronchitis (VAT) is an infection commonly affecting mechanically ventilated intubated patients. Several studies suggest that VAT is associated with increased duration of mechanical ventilation (MV) and length of intensive care unit (ICU) stay, and a presumptive increase in healthcare costs. Uncertainties remain, however, regarding the cost/benefit balance of VAT treatment. The aim of this narrative review is to discuss the two fundamental and inter-related dilemmas regarding VAT, i.e., (i) how to diagnose VAT? and (ii) should we treat VAT? If yes, should we treat all cases or only selected ones? How should we treat in terms of antibiotic choice, route, treatment duration?

Incidence of post-traumatic pneumonia in poly-traumatized patients: identifying the role of traumatic brain injury and chest trauma

Purpose

Traumatic brain injury (TBI) and chest trauma are common injuries in severely injured patients. Both entities are well known to be associated with severe post-traumatic complications, including pneumonia, a common complication with a significant impact on the further clinical course. However, the relevance of TBI, chest trauma and particularly their combination as risk factors for the development of pneumonia and its impact on outcomes are not fully elucidated.

Methods

A retrospective analysis of poly-traumatized patients treated between 2010 and 2015 at a level I trauma centre was performed. Inclusion criteria were: Injury Severity Score ≥ 16 and age ≥ 18 years. TBI and chest trauma were classified according to the Abbreviated Injury Scale. Complications (i.e. acute respiratory distress syndrome (ARDS), multi-organ dysfunction syndrome (MODS) and pneumonia) were documented by a review of the medical records. The primary outcome parameter was in-hospital mortality.

Results

Over the clinical course, 19.9% of all patients developed pneumonia, and in-hospital mortality was 25.3%. Pneumonia (OR 5.142, p = 0.001) represented the strongest independent predictor of in-hospital mortality, followed by the combination of chest injury and TBI (OR 3.784, p = 0.008) and TBI (OR 3.028, p = 0.010). Chest injury alone, the combination of chest injury and TBI, and duration of ventilation were independent predictors of pneumonia [resp. OR 4.711 (p = 0.004), OR 4.193 (p = 0.004), OR 1.002 (p < 0.001)].

Conclusions

Chest trauma alone and especially its combination with TBI represent high-risk injury patterns for the development of pneumonia, which forms the strongest predictor of mortality in poly-traumatized patients.

World-Wide Variation in Incidence of Staphylococcus aureus Associated Ventilator-Associated Pneumonia: A Meta-Regression

Staphylococcus aureus (S. aureus) is a common Ventilator-Associated Pneumonia (VAP) isolate. The objective here is to define the extent and possible reasons for geographic variation in the incidences of S. aureus-associated VAP, MRSA-VAP and overall VAP. A meta-regression model of S. aureus-associated VAP incidence per 1000 Mechanical Ventilation Days (MVD) was undertaken using random effects methods among publications obtained from a search of the English language literature. This model incorporated group level factors such as admission to a trauma ICU, year of publication and use of bronchoscopic sampling towards VAP diagnosis. The search identified 133 publications from seven worldwide regions published over three decades. The summary S. aureus-associated VAP incidence was 4.5 (3.9–5.3) per 1000 MVD. The highest S. aureus-associated VAP incidence is amongst reports from the Mediterranean (mean; 95% confidence interval; 6.1; 4.1–8.5) versus that from Asian ICUs (2.1; 1.5–3.0). The incidence of S. aureus-associated VAP varies by up to three-fold (for the lowest versus highest incidence) among seven geographic regions worldwide, whereas the incidence of VAP varies by less than two-fold. Admission to a trauma unit is the most important group level correlate for S. aureus-associated VAP.

Inapparent Outbreaks of Ventilator-Associated Pneumonia An Ecologic Analysis of Prevention and Cohort Studies

Objective:

To compare ventilator-associated pneumonia (VAP) rates and patterns of isolates across studies of antibiotic and non-antibiotic methods for preventing VAP.

Design:

With the use of 42 cohort study groups as the reference standard, the prevalence of VAP was modeled in two linear regressions: one with the control groups and the other with the intervention groups of 96 VAP prevention studies. The proportion of patients admitted with trauma and the VAP diagnostic criteria were used as ecologic correlates. Also, the patterns of pathogenic isolates were available for 117 groups.

Results:

In the first regression model, the VAP rates for the control groups of antibiotic-based prevention studies were at least 18 (CI95, 12 to 24) per 100 patients higher than those in the cohort study groups (P< .001). By contrast, comparisons of cohort study groups with all other control and intervention groups in the first and second regression models yielded differences that were less than 6 per 100 and not significant (P> .05). For control groups with VAP rates greater than 35%, the patterns of VAP isolates, such as the proportion ofStaphylococcus aureus,more closely resembled those in the corresponding intervention groups than in the cohort groups.

Conclusions:

The rates of VAP in the control groups of the antibiotic prevention studies were significantly higher than expected and the patterns of pathogenic isolates were unusual. These observations suggest that inapparent outbreaks of VAP occurred in these studies. The possibility remains that antibiotic-based VAP prevention presents a major cross-infection hazard.

Impact of selective digestive decontamination on respiratory tract Candida among patients with suspected ventilator-associated pneumonia. A meta-analysis

The purpose here is to establish the incidence of respiratory tract colonization with Candida (RT Candida) among ICU patients receiving mechanical ventilation within studies in the literature. Also of interest is its relationship with candidemia and the relative importance of topical antibiotic (TA) use as within studies of selective digestive decontamination (SDD) versus other candidate risk factors towards it. The incidence of RT Candida was extracted from component (control and intervention) groups decanted from studies of various TA and non-TA ICU infection prevention methods with summary estimates derived using random effects. A benchmark RT Candida incidence to provide overarching calibration was derived using (observational) groups from studies without any prevention method under study. A multi-level regression model of group level data was undertaken using generalized estimating equation (GEE) methods. RT Candida data were sourced from 113 studies. The benchmark RT Candida incidence is 1.3; 0.9-1.8 % (mean and 95 % confidence intervals). Membership of a concurrent control group of a study of SDD (p = 0.02), the group-wide presence of candidemia risk factors (p < 0.001), and proportion of trauma admissions (p = 0.004), but neither the year of study publication, nor membership of any other component group, nor the mode of respiratory sampling are predictive of the RT Candida incidence. RT Candida and candidemia incidences are correlated. RT Candida incidence can serve as a basis for benchmarking. Several relationships have been identified. The increased incidence among concurrent control groups of SDD studies cannot be appreciated in any single study examined in isolation.

Does low-dose hydrocortisone therapy prevent ventilator-associated pneumonia in trauma patients?

The incidence of ventilator-associated pneumonia (VAP) is particularly high in trauma patients. Immediate acute inflammation response is one of the hallmarks of multiple trauma. This phenomenon is associated with an immunosuppression state and may increase the risk of VAP. In our study, we aimed to evaluate whether low-dose steroids prevent VAP onset in multiple trauma patients. All adult patients admitted in our intensive care unit (ICU) for multiple trauma with predicted duration of mechanical ventilation over 48 hours were included. We compared 2 different periods: a retrospective cohort of patients who did not receive low-dose steroids for VAP prevention and a prospective cohort of patients who received hydrocortisone with a dose of 100 mg/8 hours for a scheduled period of 7 days. We included 175 patients: 92 in the steroids (-) group and 83 in the steroids (+) group. The incidence of VAP was not different between the 2 studied groups (29.3% and 26.5%; P = 0.676). When predictive factors of VAP onset were studied in multivariate analysis, steroids had no preventive effect on VAP [OR = 1.6; 95% confidence interval, 0.73-3.6; P = 0.234]. We did not find any difference between the 2 groups, neither in terms of ICU length of stay (respectively, 11 ± 9.7 days vs. 12.3 ± 10.7 days; P = 0.372) nor in terms of ICU mortality (29.3% vs 24.1%; P = 0.434).

Does selective digestive decontamination prevent ventilator-associated pneumonia in trauma patients?

The incidence of ventilator-associated pneumonia (VAP) is particularly high in patients with trauma. The efficacy and safety of selective digestive decontamination (SDD) was not studied extensively. We aimed in our randomized double-blind, placebo-controlled study to evaluate whether SDD prevents VAP onset in multiple trauma patients. All adult patients admitted in our intensive care unit for multiple trauma with a predicted duration of mechanical ventilation (MV) over 48 hours were included. We included 44 patients who were divided into 4 groups: group A receiving subglottic and gastric treatment suspension (polymyxin E 100 mg, vancomycin 1 g, and amphotericin B 500 mg), group B receiving placebo, group C receiving subglottic placebo and gastric treatment suspension, and group D receiving subglottic treatment suspension and gastric placebo. The suspension was given 4 times a day during 7 consecutive days. To this topical treatment, we associated an intravenous administration of cefotaxime (1 g 3 times a day during 4 consecutive days). The incidence of VAP in the 4 groups was, respectively, 45.5%, 46.2%, 22.2%, and 27.3% (P=0.236). In multivariate analysis, none of the 3 tested regimens was identified as a protective factor against VAP. However, prolonged duration of MV was the only independent factor predicting VAP onset (odds ratio=1.1; 95% confidence interval [1.1-1.4]; P=0.049).

Prognostic value of serum procalcitonin and C-reactive protein levels in critically ill patients who developed ventilator-associated pneumonia

INTRODUCTION:

Ventilator-associated pneumonia (VAP) is an important cause of mortality and morbidity in critically ill patients. We sought to determine the prognostic value of procalcitonin (PCT) and C-reactive protein (CRP) kinetics in critically ill patients who developed VAP.

METHODS:

Patients who were admitted to the intensive care unit (ICU) and developed VAP were eligible. Patients were followed for 28 days after the pneumonia diagnosis and blood samples for PCT and CRP were collected on the day of the pneumonia diagnosis (D0), and days 3 (D3) and 7 (D7) after the diagnosis. Patients were grouped as survivors and non-survivors, and the mean PCT and CRP values and their kinetics were assessed.

RESULTS:

In total, 45 patients were enrolled. Of them, 22 (48.8%) died before day 28 after the pneumonia diagnosis. There was no significant difference between the survivor and non-survivor groups in terms of PCT on the day of pneumonia diagnosis or CRP levels at any point. However, the PCT levels days 3 and 7 were significantly higher in the non-survivor group than the survivor group. Whereas PCT levels decreased significantly from D0 to D7 in the survivor group, CRP did not. A PCT level above 1 ng/mL on day 3 was the strongest predictor of mortality, with an odds ratio of 22.6.

CONCLUSION:

Serum PCT was found to be a superior prognostic marker compared to CRP in terms of predicting mortality in critically ill patients who developed VAP. The PCT level on D3 was the strongest predictor of mortality in VAP.

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.

Aerosolized antibiotics in the intensive care unit

This review summarizes recent clinical data examining the use of aerosolized antimicrobial therapy for the treatment of respiratory tract infections in mechanically ventilated patients in the intensive care unit. Aerosolized antibiotics provide high concentrations of drug in the lung without the systemic toxicity associated with the intravenous antibiotics. First introduced in the 1960s as a treatment of tracheobronchitis and bronchopneumonia caused by Pseudomonas aeruginosa, now, more than 40 years later, there is a resurgence of interest in using this mode of delivery as a primary therapy for ventilator-associated tracheobronchitis and an adjunctive therapy for ventilator-associated pneumonia.

Ventilator-associated tracheitis in children: does antibiotic duration matter?

BACKGROUND

The optimal duration of antibiotic therapy for ventilator-associated tracheitis (VAT) has not been defined, which may result in unnecessarily prolonged courses of antibiotics. The primary objective of this study was to determine whether prolonged-course (≥7 days in duration) therapy for VAT was more protective against progression to hospital-acquired pneumonia (HAP) or ventilator-associated pneumonia (VAP), compared with short-course antibiotics (<7 days in duration). The secondary objective was to determine whether prolonged-course therapy was more likely to result in the acquisition of multidrug-resistant organisms (MDROs) compared with short-course therapy.

METHODS

We conducted a retrospective cohort study of children ≤18 years of age hospitalized in the intensive care unit and intubated for ≥48 h from January 2007 through December 2009 who received antibiotic therapy for VAT.

RESULTS

Of the 1616 patients intubated for at least 48 h, 150 received antibiotics for clinician-suspected VAT, although only 118 of these patients met VAT criteria. Prolonged-course antibiotics were not protective against subsequent development of HAP or VAP (hazard ratio [HR], 1.08; 95% confidence interval [CI], 0.40-2.91). Factors associated with subsequent MDRO colonization or infection included prolonged-course antibiotic therapy (HR, 5.15; 95% CI, 1.54-7.19), receipt of combination antibiotic therapy (HR, 3.24; 95% CI, 1.54-6.82), and days of hospital exposure prior to completing antibiotic therapy (HR, 1.08; 95% CI, 1.04-1.12).

CONCLUSIONS

A prolonged course of antibiotics for VAT does not appear to protect against progression to HAP or VAP compared with short-course therapy. Furthermore, prolonged antibiotic courses were associated with a significantly increased risk of subsequent MDRO acquisition.

Paradoxical ventilator associated pneumonia incidences among selective digestive decontamination studies versus other studies of mechanically ventilated patients: benchmarking the evidence base

Introduction

Selective digestive decontamination (SDD) appears to have a more compelling evidence base than non-antimicrobial methods for the prevention of ventilator associated pneumonia (VAP). However, the striking variability in ventilator associated pneumonia-incidence proportion (VAP-IP) among the SDD studies remains unexplained and a postulated contextual effect remains untested for.

Methods

Nine reviews were used to source 45 observational (benchmark) groups and 137 component (control and intervention) groups of studies of SDD and studies of three non-antimicrobial methods of VAP prevention. The logit VAP-IP data were summarized by meta-analysis using random effects methods and the associated heterogeneity (tau²) was measured. As group level predictors of logit VAP-IP, the mode of VAP diagnosis, proportion of trauma admissions, the proportion receiving prolonged ventilation and the intervention method under study were examined in meta-regression models containing the benchmark groups together with either the control (models 1 to 3) or intervention (models 4 to 6) groups of the prevention studies.

Results

The VAP-IP benchmark derived here is 22.1% (95% confidence interval; 95% CI; 19.2 to 25.5; tau² 0.34) whereas the mean VAP-IP of control groups from studies of SDD and of non-antimicrobial methods, is 35.7 (29.7 to 41.8; tau² 0.63) versus 20.4 (17.2 to 24.0; tau² 0.41), respectively (P < 0.001). The disparity between the benchmark groups and the control groups of the SDD studies, which was most apparent for the highest quality studies, could not be explained in the meta-regression models after adjusting for various group level factors. The mean VAP-IP (95% CI) of intervention groups is 16.0 (12.6 to 20.3; tau² 0.59) and 17.1 (14.2 to 20.3; tau² 0.35) for SDD studies versus studies of non-antimicrobial methods, respectively.

Conclusions

The VAP-IP among the intervention groups within the SDD evidence base is less variable and more similar to the benchmark than among the control groups. These paradoxical observations cannot readily be explained. The interpretation of the SDD evidence base cannot proceed without further consideration of this contextual effect.

Retrospective analysis of the risk factors and pathogens associated with early-onset ventilator-associated pneumonia in surgical-ICU head-trauma patients

BACKGROUND

Early-onset ventilator associated pneumonia (EOVAP) are frequent in head-trauma patients, but specific risk factors are poorly studied in this population.

METHODS

We conducted a retrospective cohort study in a surgical intensive care unit. Consecutive severe head-trauma patients admitted from January 2000 to December 2002 were studied. Microorganisms, and risks factors for EOVAP were analyzed.

RESULTS

During the 3-year period, 161 patients were studied; 21.1% of them developed an EOVAP. On univariate analysis 6 variables were associated with EOVAP: early enteral feeding, barbiturate use, immunosuppression, mean Simplified Acute Physiology Score 2, acute respiratory distress syndrome, and initial neurosurgery procedures. On multivariate analysis, enteral feeding >2000 Kcal before day 5 [odds ratio (OR): 0.33, 95% confidence interval (CI): 0.21-0.85] and initial neurosurgical procedure (OR: 0.36, 95% CI: 0.15-0.89) remained protective factors for EOVAP, whereas immunosuppression (OR: 7.15, 95% CI: 1.66-30.73) and barbiturate use (OR: 2.68, 95% CI: 1.06-6.80) remained risk factors for EOVAP. EOVAP was also significantly associated with a longer duration of mechanical ventilation (14.0 vs. 11.0 d, P=0.024), and a longer sedation duration (8.3 vs. 5.8 d P=0.005). Methicillin-susceptible Staphylococcus aureus was the most common pathogen involved in EOVAP (46%).

CONCLUSIONS

We demonstrate for the first time that early enteral feeding is a protective factor for EOVAP, and this result could have clinical implications for the prevention of EOVAP after traumatic brain injury. This study also confirms that barbiturate use is an important risk factor of EOVAP whereas Methicillin-susceptible S. aureus was found to be the main pathogen involved in EOVAP.

Frequency and predictors of ventilator-associated pneumonia recurrence: a meta-analysis

Large clinical series focusing on the risk factors associated with recurrence after the onset of an initial episode of ventilator-associated pneumonia (VAP) produced inconsistent results. A meta-analysis would be helpful to shed light on the issue. Our objective was to estimate the frequency of VAP recurrence and to identify risk factors associated with it. PubMed, Scopus, Current Contents, and references of retrieved articles were searched without language restrictions. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by using both the Mantel-Haenszel fixed-effect and the DerSimonian-Laird random effects models. The overall frequency of VAP recurrence in 969 patients of the seven eligible reports was 26.8%. Among the 20 evaluated risk factors, only acute lung injury/acute respiratory distress syndrome (OR, 1.76; 95% CI, 1.12-2.75) and shock (OR, 1.55; 95% CI, 1.01-2.41) at the day of diagnosis of the first VAP episode were found to be associated with VAP recurrence. There was also evidence, albeit inconsistent, that severity of illness at intensive care unit admission was associated with VAP recurrence. Recurrence involves almost one in four cases of VAP and is associated with acute lung injury/acute respiratory distress syndrome and shock, but not with first-episode causative pathogens. Recognition of these predictors may permit the timely implementation of measures to prevent recurrence of VAP.

Ventilator-associated tracheobronchitis: the impact of targeted antibiotic therapy on patient outcomes

Nosocomial lower respiratory tract infections are a common cause of morbidity and mortality in ICU patients receiving mechanical ventilation. Many studies have investigated the management and prevention of ventilator-associated pneumonia (VAP), but few have focused on the role of ventilator-associated tracheobronchitis (VAT). The pathogenesis of lower respiratory tract infections often begins with tracheal colonization that may progress to VAT, and in selected patients to VAP. Since there is no well-established definition of VAT, discrimination between VAT and VAP can be challenging. VAT is a localized disease with clinical signs (fever, leukocytosis, and purulent sputum), microbiologic information (Gram stain with bacteria and leukocytes, with either a positive semiquantitative or a quantitative sputum culture), and the absence of a new infiltrate on chest radiograph. Monitoring endotracheal aspirates has been used to identify and quantify pathogens colonizing the lower airway, to diagnose VAT or VAP, and to initiate early, targeted antibiotic therapy. Recent data suggest that VAT appears to be an important risk factor for VAP and that targeted antibiotic therapy for VAT may be a new paradigm for VAP prevention and better patient outcomes.

Management of ventilator-associated pneumonia in a multidisciplinary intensive care unit: does trauma make a difference?

OBJECTIVE

Antibiotic exposure and timing of pneumonia onset influence ventilator-associated pneumonia (VAP) isolates. The first goal of this investigation was to evaluate whether trauma also influences prevalence of microorganisms.

DESIGN

A retrospective, single-center, observational cohort study.

SETTING

Multidisciplinary teaching ICU.

PATIENTS

Adult patients requiring mechanical ventilation identified as having VAP.

INTERVENTIONS

Retrospective evaluation of a prospective manual database.

MEASUREMENTS AND MAIN RESULTS

VAP isolates in a multidisciplinary ICU documented by quantitative respiratory cultures and recorded in a 42-month database were compared, based on the presence or absence of trauma. Causative microorganisms were classified in four groups, based on mechanical ventilation duration (> 5 days), and previous antibiotic exposure. One hundred eighty-three patients developed 196 episodes of VAP (98 trauma). Methicillin-sensitive Staphylococcus aureus (MSSA) was more frequent (34.5% vs. 11.5%, p < 0.01) in trauma, whereas methicillin-resistant Staphylococcus aureus (MRSA) was more frequent (2% vs. 11.5%, p < 0.01) in non-trauma. No significant differences were found between trauma and non-trauma patients regarding prevalence of other microorganisms. In trauma patients, MSSA episodes were equally distributed between early- and late-onset VAP (51% vs. 49%), but no MRSA episode occurred in the early-onset group.

CONCLUSIONS

Trauma influences the microbiology of pneumonia and it should be considered in the initial antibiotic regimen choice. Our data demonstrate that patients with trauma had a higher prevalence of MSSA, but the overall prevalence was sufficiently high to warrant S. aureus coverage for both groups. On the other hand, since no MRSA was isolated during the first 10 days of mechanical ventilation on trauma patients, MRSA coverage in these patients becomes necessary only 10 days after admission.

Aerosolized ceftazidime prophylaxis against ventilator-associated pneumonia in high-risk trauma patients: results of a double-blind randomized study

BACKGROUND

Ventilator-associated pneumonia (VAP) is a frequent complication during recovery of severely traumatized patients. The primary objective of this study was to determine if prophylactic administration of aerosolized ceftazidime reduced the incidence of VAP in high-risk injured patients without altering the incidence of other infectious complications.

PATIENTS AND METHODS

This was a single-institution double-blind, randomized trial that compared a seven-day course of aerosolized ceftazidime with placebo. Intubated high-risk patients admitted to the trauma intensive care unit at a large regional trauma center between February 2003 and September 2005 were eligible for enrollment. The main outcome evaluated was the incidence of VAP at two weeks and 30 days. The incidences of multi-drug-resistant infections and other infectious complications were secondary outcomes.

RESULTS

A total of 105 patients were randomized, resulting in 52 patients in the placebo arm and 53 patients in the ceftazidime arm. There was no statistical difference between the groups with regard to demographic data, injury severity, calculated risk of VAP, or the number of doses received. In the intention-to-treat analysis, the incidence of VAP at two weeks was 24/52 (46%) in the placebo group and 21/53 (40%) in the ceftazidime group. The number of patients with VAP at 30 days was 26/52 (50%) in the placebo group and 26/53 (49%) in the ceftazidime group. There was no statistical difference in the development of multi-drug-resistant VAP or other infectious complications in the two groups.

CONCLUSION

The use of aerosolized ceftazidime did not reduce the rate of VAP in high-risk patients admitted after traumatic injury, but neither did it increase the incidence of other infectious complications. Routine use of prophylactic aerosolized ceftazidime to prevent VAP in trauma patients cannot be recommended.

Gram-positive cocci infections in intensive care: guide to antibacterial selection

The incidence of multiresistance in Gram-positive cocci causing infections in critically ill patients admitted to the intensive care unit (ICU) has increased notably in recent years. Thus, therapeutic proposals have been modified according to the emergence of multiresistant cocci and adapted to epidemiological markers of individual infectious processes, geographical variations of these markers, the availability of new antibacterials, and advances in the knowledge of pharmacokinetic and pharmacodynamic aspects of their use. The current management of critically ill patients should consider new therapeutic approaches, such as the "de-escalating strategy", which includes the administration of empirical antibacterials active against multiresistant pathogens followed by directed treatment based on unequivocal data from antibacterial-susceptibility testing. Optimisation of antibacterial treatment should be viewed in the context of the need to determine plasma drug concentrations, pharmacoeconomic considerations and control of drug-related adverse events. Therapeutic proposals should be developed within the framework of the antibacterial policy of each hospital. The present review is focused on the description of the therapeutic strategies for the main infectious processes caused by Gram-positive cocci in severely ill patients admitted to the ICU according to a review of the pertinent literature and the clinical experience of the authors.

Impact of ventilator-associated pneumonia in patients with severe head injury

BACKGROUND

The impact of ventilator-associated pneumonia (VAP) on outcome seems to vary depending on the critically ill patients we analyze. Our objective, therefore, has been to evaluate the influence of VAP on the mortality and morbidity in patients with severe head injury (Glasgow Coma Scale score </= 8).

METHODS

A prospective, matched, case-control study was conducted in our intensive care unit (ICU) for a 3-year period (1998-2000). Seventy-two patients with severe head injury (HI) who developed VAP were matched with 72 patients with severe HI without VAP. The matching criteria were as follows: age (+/- 5 years); category of HI based on computed tomographic scanning; Acute Physiology and Chronic Health Evaluation II (+/- 4 points) score; Injury Severity Score (+/- 4 points); and duration of mechanical ventilation. VAP was diagnosed on the basis of quantitative microbiologic criteria.

RESULTS

Mortality did not differ significantly between cases and matched control subjects (15 [20.8%] vs. 11 [15.3%], p = 0.54). However, patients with VAP had a significantly longer duration of mechanical ventilation (median, 14 vs. 10 days; p = 0.015) and ICU stay (median, 21 vs. 15.5 days; p = 0.008). The occurrence of multiple organ failure was also significantly more frequent among the case group (33.3% vs. 12.5%, p = 0.004) during the overall ICU stay.

CONCLUSION

VAP does not seem to be associated with a significantly increased risk of death in patients with severe HI, but it may be associated with greater morbidity during the ICU stay.

[Management of ventilator acquired pneumonia]

Ventilator-associated pneumonia occurs in the evolution of 8 to 70% of patients in the Intensive Care Unit. It is the main site of nosocomial infection for mechanically ventilated patients. Nosocomial pneumonia represents an important cause of morbidity and mortality, despite progresses in antibiotic prescription, use of intensive care and prevention. This review is based on the ATS guidelines, and reviews epidemiology, diagnosis and treatment of ventilator-acquired pneumonia, in non-immunocompromised adults.

Effect of oropharyngeal decontamination by povidone-iodine on ventilator-associated pneumonia in patients with head trauma*

OBJECTIVE

To evaluate the effect of a regular oropharyngeal application of povidone-iodine on the prevalence of ventilator-associated pneumonia in patients with severe head trauma.

DESIGN

Prospective randomized study.

SETTING

A surgical intensive care unit of a university hospital.

INTERVENTIONS

Patients with severe head trauma (Glasgow Coma Score of < or =8) expected to need ventilation for > or =2 days were prospectively randomized into three groups: those receiving nasopharynx and oropharynx rinsing with 20 mL of a 10% povidone-iodine aqueous solution, reconstituted in a 60-mL solution with sterile water (povidone-iodine group); those receiving nasopharynx and oropharynx rinsing with 60 mL of saline solution (saline group); or those undergoing a standard regimen without any instillation but with aspiration of oropharyngeal secretions (control group).

MEASUREMENTS AND MAIN RESULTS

The prevalence of ventilator-associated pneumonia was compared among the three groups. A total of 98 patients were analyzed (povidone-iodine group, n = 36; saline group, n = 31; and control group, n = 31). A total of 28 cases of ventilator-associated pneumonia were diagnosed. There was a significant decrease in the rate of ventilator-associated pneumonia in the povidone-iodine group when compared with the saline and control groups (3 of 36 patients [8%] vs. 12 of 31 patients [39%] and 13 of 31 patients [42%], respectively; p = .003 and .001, respectively). The length of stay and mortality in the surgical intensive care unit were not statistically different between the three groups.

CONCLUSIONS

The regular administration of povidone-iodine may be an effective strategy for decreasing the prevalence of ventilator-associated pneumonia in patients with severe head trauma.

New antibiotics for the treatment of severe staphylococcal infection in the critically ill patient

PURPOSE OF REVIEW

Infection by Staphylococcus aureus in critically ill patients is usually associated with antimicrobial resistance and high mortality. A more effective antibiotic treatment is needed to replace older drugs that have limited efficacy. Novel substances active on methicillin-resistant Staphylococcus aureus, which are already available on the market or are still in development, are discussed in this review, with emphasis on nosocomial infections.

RECENT FINDINGS

A number of new antibiotics are on the market (linezolid, quinupristin-dalfopristin, daptomycin) and there is good evidence regarding their efficacy, especially in methicillin-resistant Staphylococcus aureus infections. Linezolid is, to date, the best alternative in treating nosocomial pneumonia by methicillin-resistant Staphylococcus aureus. It is cost-effective; resistance levels are still very low but there are some concerns regarding its adverse events. Quinupristin-dalfopristin shows good activity in vitro but its efficacy in patients with pneumonia by methicillin-resistant Staphylococcus aureus is modest. Daptomycin is not recommended for pulmonary infections because of its reduced penetration in the lung tissue. Under current phase III trials in patients with nosocomial infections are tigecycline, ceftobiprole, and three new glycopeptides, all with particular activity against methicillin-resistant Staphylococcus aureus.

SUMMARY

For the moment, there are limited and rather expensive therapeutic options for the infections by Staphylococcus aureus in the critically ill. No dramatic superiority of the new drugs in comparison to the standard therapies was observed in most of the clinical trials. Better results on the efficacy of the drugs under investigation are expected.

Surveillance of nosocomial infections in a neurologic intensive care unit

OBJECTIVE

To assess data on the epidemiology of nosocomial infection (NI) among neurologic intensive care patients.

DESIGN

Prospective periodic surveillance study.

SETTING

An 8-bed neurologic intensive care unit (ICU).

PATIENTS

All those admitted for more than 24 hours during five 3-month periods between January 1999 and March 2003.

METHODS

Standardized surveillance within the German infection surveillance system.

RESULTS

Three hundred thirty-eight patients with a total of 2,867 patient-days and a mean length of stay of 8.5 days were enrolled during the 15-month study period. A total of 71 NIs were identified among 52 patients. Urinary tract infections (UTIs) were the most frequent NI (36.6%), followed by pneumonia (29.6%) and bloodstream infections (BSIs) (15.5%). The overall incidence and incidence density of NIs were 21.0 per 100 patients and 24.8 per 1,000 patient-days, respectively. Incidence densities were 9.8 UTIs per 1,000 urinary catheter-days (CI95, 6.4-14.4), 5.6 BSIs per 1,000 central venous catheter-days (CI9s, 2.8-10.0), and 12.8 cases of pneumonia per 1,000 ventilation-days (Cl95, 8.0-19.7). Device-associated UTI and pneumonia rates were in the upper range of national and international reference data for medical ICUs, despite the intensive infection control and prevention program in operation in the hospital.

CONCLUSION

Neurologic intensive care patients have relatively high rates of device-associated nosocomial pneumonia and UTI. For a valid comparison of surveillance data and implementation of targeted prevention strategies, we would strongly recommend provision of national benchmarks for the neurologic ICU setting.

Intrahospital transport of critically ill ventilated patients: A risk factor for ventilator-associated pneumonia—A matched cohort study*

OBJECTIVE

To evaluate the impact of intrahospital transport of critically ill ventilated patients on the acquisition of ventilator-associated pneumonia.

DESIGN

An exposed/unexposed matched cohort study.

SETTING

An 18-bed adult medical-surgical intensive care unit in a 1,100-bed regional and teaching hospital in France.

PATIENTS

From January 1, 2001, to December 31, 2002, 118 of 228 ventilated patients transported out of the intensive care unit (exposed patients) were matched with 118 unexposed patients selected among 295 ventilated patients who did not undergo intrahospital transport.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The matching process was conducted according to six criteria: duration of mechanical ventilation, duration of antibiotherapy, indication for ventilatory support, age, probability of death, and surgical procedures or not during intensive care unit stay. The rates of ventilator-associated pneumonia (as defined by usual clinical and biological criteria plus positive culture of bronchoscopy directed catheter) acquisition between exposed and unexposed patients were compared by univariate analysis and then by multivariate analysis (conditional logistic regression and Cox's proportional-hazards model) to account for potential confounding factors. The ventilator-associated pneumonia rate was 26% in exposed patients compared with 10% in the matched unexposed patients. Using conditional logistic regression, two factors were independently associated with ventilator-associated pneumonia: intrahospital transport (odds ratio, 3.1; 95% confidence interval, 1.4-6.7) and the need for reintubation. Using Cox's model, three independent risk factors were identified: the need for reintubation, enteral nutrition, and intrahospital transport (odds ratio, 2.9; 95% confidence interval, 1.4-5.7). The intensive care unit mortality rate was similar (p > .1) in exposed (35%) and unexposed patients (26%).

CONCLUSIONS

Intrahospital transport appears to be a significant risk factor for ventilator-associated pneumonia. However, the respective roles of intrahospital transport and of the cause that leads clinicians to transport patients (mainly for radiographic examinations) are difficult to dissociate even after multiple statistical adjustments. When intrahospital transport is needed, very cautious measures must be taken before and during intrahospital transport to prevent ventilator-associated pneumonia. In addition, in the few days after intrahospital transport, intensive search for ventilator-associated pneumonia is justified.

Effect of ventilator-associated tracheobronchitis on outcome in patients without chronic respiratory failure: a case-control study

Introduction

Our objective was to determine the effect of ventilator-associated tracheobronchitis (VAT) on outcome in patients without chronic respiratory failure.

Methods

This was a retrospective observational matched study, conducted in a 30-bed intensive care unit (ICU). All immunocompetent, nontrauma, ventilated patients without chronic respiratory failure admitted over a 6.5-year period were included. Data were collected prospectively. Patients with nosocomial pneumonia, either before or after VAT, were excluded. Only first episodes of VAT occurring more than 48 hours after initiation of mechanical ventilation were studied. Six criteria were used to match cases with controls, including duration of mechanical ventilation before VAT. Cases were compared with controls using McNemar's test and Wilcoxon signed-rank test for qualitative and quantitative variables, respectively. Variables associated with a duration of mechanical ventilation longer than median were identified using univariate and multivariate analyses.

Results

Using the six criteria, it was possible to match 55 (87%) of the VAT patients (cases) with non-VAT patients (controls). Pseudomonas aeruginosa was the most frequently isolated bacteria (34%). Although mortality rates were similar between cases and controls (29% versus 36%; P = 0.29), the median duration of mechanical ventilation (17 days [range 3–95 days] versus 8 [3–61 days]; P < 0.001) and ICU stay (24 days [range 5–95 days] versus 12 [4–74] days; P < 0.001) were longer in cases than in controls. Renal failure (odds ratio [OR] = 4.9, 95% confidence interval [CI] = 1.6–14.6; P = 0.004), tracheostomy (OR = 4, 95% CI = 1.1–14.5; P = 0.032), and VAT (OR = 3.5, 95% CI = 1.5–8.3; P = 0.004) were independently associated with duration of mechanical ventilation longer than median.

Conclusion

VAT is associated with longer durations of mechanical ventilation and ICU stay in patients not suffering from chronic respiratory failure.

Etiology of Ventilator-Associated Pneumonia

This review focuses on the top ten causes of ventilator-associated pneumonia (VAP), updating an earlier study. These pathogens have specific risk factors, different patterns of clinical resolution, and a wide range of attributable mortality. The discussion herein analyzes these aspects, placing particular emphasis on risk factors, attributable mortality, resistance, and the implications for management.

Prevention and Treatment of Aspiration Pneumonia in Intensive Care Units

Aspiration is a leading cause of nosocomial infection in the intensive care unit. Techniques to avoid or reduce aspiration are important in preventing pneumonia and pneumonitis. The most important preventive measures include the semi-recumbent position, the surveillance of enteral feeding, the use of promotility agents, and avoiding excessive sedation. The analysis of the pathogens involved in these syndromes usually shows a minor role for the anerobes. With regard to treatment, aspiration pneumonitis does not require any antimicrobials; on the contrary, aspiration pneumonia has to be treated. Empiric antimicrobials treatment should be started on clinical suspicion. The choice of the drug has to be guided by local pathogen epidemiology and clinical features; in fact, community type pneumonia requires a first-line antimicrobial such as amoxicillin/clavulanic acid. On the contrary, a nosocomial type of infection needs to be treated as a ventilator-associated pneumonia in agreement with published guidelines. Nevertheless, quantitative culture should be obtained in order to de-escalate antimicrobials. In conclusion, aspiration pneumonia is a frequently encountered disease that can be prevented by relatively simple measures.

Risk factors for late-onset ventilator-associated pneumonia in trauma patients receiving selective digestive decontamination

OBJECTIVE

To determine the independent risk factors for late-onset ventilator-associated pneumonia (VAP) in trauma patients receiving selective digestive decontamination (SDD).

DESIGN

A 4-year, prospective cohort study of trauma patients meeting the following criteria: injury severity score >15, and duration of mechanical ventilation >5 days. Predictors of late-onset VAP occurrence were assessed by logistic regression analysis.

POPULATION

All patients received SDD consisting of polymixin E, gentamicin, and amphotericin B applied in nostrils, mouth, and gut with a 3-day course of parenteral cefazolin. VAP was suspected on clinical and radiological signs, and confirmed by the presence of at least one microorganism at a concentration of at least 10(4) CFU/ml on the broncho-alveolar lavage.

MEASUREMENT

Independent risk factors for late-onset VAP.

RESULTS

A late-onset VAP was diagnosed in 90 (56%) out of 159 patients. Predicting factors for late-onset VAP were: use of non-depolarizing muscle relaxant agents for intubation [3.4 (CI 1.08-10.73)], duration of intubation [1.06 (CI 1.01-1.17)], length of intensive care unit (ICU) stay [1.05 (CI 1.02-1.09)], and prior tracheal colonization [1.03 (CI 1.02-1.21)]. Exposure to prior antimicrobial treatment, except SDD, conferred protection [0.3 (0.12-0.74)].

CONCLUSION

This study confirms the role of duration of intubation, length of ICU stay, and prior tracheal colonization in the development of late-onset VAP. The results also highlight the importance of the initial management on the development of late-onset VAP. The type of neuromuscular blocking agents to intubate trauma patients should be evaluated in future studies.

Weaning of the neurologically impaired patient

Many studies have been published on weaning patients from mechanical ventilation, but few have addressed the unique needs of patients with neurologic impairment. Typically, neuroscience patients remain intubated because of concerns over airway protection or neuromuscular weakness. This article discusses special weaning considerations for this patient population. Neurologic-specific weaning trends from a comprehensive ventilator weaning program are also presented.

Incidence, risk factors and mortality of nosocomial pneumonia in intensive care units: a prospective study

To determine the frequency, risk factors and mortality of nosocomial pneumonia a prospective study was conducted in the intensive care units. In the study period, 2402 patients were included. The nosocomial pneumonia was defined according to the Centers for Disease Control Criteria. Overall, 163 (6.8%) of the patients developed nosocomial pneumonia and 75.5% (n = 123) of all patients with nosocomial pneumonia were ventilator-associated pneumonia. 163 patients who were admitted to the intensive care unit during the same period but had no bacteriologic or histologic evidence of pneumonia were used as a control group. The APACHE II score, coma, hypoalbuminemia, mechanical ventilation, tracheotomy, presence of nasogastric tube were found as independent risk factors. Crude and attributable mortality were 65% and 52.6%, respectively. The mortality rate was five times greater in the cases (OR: 5.2; CI 95%: 3.2–8.3). The mean length of stay in the intensive care unit and hospital in the cases were longer than controls (p < 0.0001). Patients requiring mechanical ventilation have a high frequency of nosocomial pneumonia.

Nosocomial lung infections in adult intensive care units

Nosocomial respiratory tract infections are the leading type of nosocomial infections. Despite the development of new antibiotic therapies, they are associated with an increased morbidity and mortality. Patients with comorbidities are especially predisposed to acquire these infections, as are patients exposed to respiratory therapy. Aspiration of colonized secretions from the oropharynx is the main mechanism of infection development. Barrier techniques to reduce aspiration and antimicrobial agents to alter bacterial flora are important in preventing pneumonia episodes. The initial institution of an adequate antibiotic regimen is a determinant of outcome. Nosocomial pneumonias are often difficult to treat due to antibiotic-resistant bacteria. Antibiotic policies are crucial in avoiding a progression in antibiotic resistance.