Ventilator-associated pneumonia: a review

Pain management during a bromelain-based selective enzymatic debridement in paediatric and adult burn patients

BACKGROUND

Pain associated with surgical or enzymatic burn wound debridement prevents many burn centres from working outside an operating theatre, creating a burden. Alternatives for general anaesthesia to manage pain in burn patients treated with enzymatic debridements, such as regional anaesthesia, have not been studied in detail. This study explores the different possibilities for pain management during a bedside NexoBrid™ procedure.

MATERIAL AND METHODS

We performed a single-centre retrospective study that included 82 paediatric, adolescent, and adult patients with deep dermal and full-thickness burns treated bedside with NexoBrid™ under regional or general anaesthesia. Outcome measures were pain during the NexoBrid™ procedure, the safety of the anaesthesia and the NexoBrid™ procedure, logistics of the bedside NexoBrid™ procedure, and time to wound closure.

RESULTS

Forty-three patients in the adult group (43/67, 64%) only presented with burn wounds on one upper or the one or two lower extremities. In 29 of them (29/43, 67%), a NexoBrid™ procedure was performed under regional anaesthesia, which resulted in low pain levels without any adverse events. All seven patients in the paediatric group, where only one upper or one or two lower limbs were involved (7/15, 47%), underwent a NexoBrid™ procedure performed under regional anaesthesia where no adverse events were reported. In these children, the use of regional anaesthesia was associated with a significant decrease in time to wound closure (average treatment effect on the treated = -22.5 days, p = 0.021).

CONCLUSION

This study highlights that regional anaesthesia administered at the bedside should be the method of choice for pain management during NexoBrid™ procedures because often, it can be adequately and safely performed in all age groups. This approach will reduce the burden on operating theatres. A flow chart has been developed to guide pain management during a NexoBrid™ procedure.

Clinical Microbiology in the Intensive Care Unit: Time for Intensivists to Rejuvenate this Lost Art

We live in an era of evolving microbial infections and equally evolving drug resistance among microorganisms. In any healthcare facility, intensivists play the most pivotal role with critically ill patients under their direct care. Majority of the critically ill patients already harbor a microorganism at admission or acquire one in the form of healthcare-associated infections during their course of intensive care unit stay. It is therefore rather imperative for intensivists to possess sound knowledge in clinical microbiology. On a negative note, most clinicians have very meager and remote knowledge acquired during their undergraduate years. This knowledge is rather theoretical than applied and wanes over the years becoming nonbeneficial in intensive patient care. We, therefore, intend to explore important concepts in applied microbiology and infection control that intensivists should know and implement in their clinical practice on a day-to-day basis.

How to cite this article: Princess I, Vadala R. Clinical Microbiology in the Intensive Care Unit: Time for Intensivists to Rejuvenate this Lost Art. Indian J Crit Care Med 2021;25(5):566–574.

Multi-criteria risk evaluation model for developing ventilator-associated pneumonia

Ventilator-associated pneumonia is a hospital-acquired infection of the lungs occurring in mechanically ventilated patients. An active risk management approach can prevent the occurrence of the disease and promote positive organizational changes, subsequently decreasing mortality and hospitalization costs. Using scientific and clinical practice knowledge, a risk evaluation model was developed to identify patients more at risk of developing the disease. For this purpose, a Decision Expert qualitative multi-criteria decision method was used, in which alternatives are evaluated according to predetermined hierarchically arranged criteria. Characteristics of each evaluated alternative are described by the members of an interdisciplinary expert team and are represented by the values of the basic criteria. Values of hierarchically higher aggregated criteria are computed in an upwards fashion according to utility functions, which are defined as simple logical rules. This method is integrated into a software solution, DEXi. The approach is applicable to vastly diverse decision problems and has been successfully used before for health-related decision support. The designed model was tested using actual clinical data. Evaluations of alternatives that most distinctly demonstrated the functionality of the evaluation model were selected and are presented in the results. The evaluation model is intended to assist a holistic evaluation of the risk of developing ventilator-associated pneumonia, by considering patient-related risk factors and the use of preventive measures. The model incorporates nursing-specific data that have hitherto been poorly utilized in preventing ventilator-associated pneumonia and promotes the active engagement of nurses in confronting this interdisciplinary healthcare problem, which has gained more prominence with the onset of COVID-19 disease.

A mobile terminal application program was used for endotracheal tube cuff pressure measurement

We studied the application of a mobile terminal application program in endotracheal tube (ETT) cuff pressure measurement to improve the implementation rate of scientific ETT cuff pressure measurement and to ensure that the pressure falls within the recommended range. A pre-post controlled study lasting for 18 months was undertaken in a 40-bed general intensive care unit (GICU). This included a 6-month baseline period (baseline group) and a 6-month intervention period (intervention group). The mobile terminal application program was applied to monitor the cuff pressure of endotracheal intubation as an intervention measure during the intervention period. ETT pressure was the main outcome measure, while gender, age, causes for ICU admission, sedation score, duration of prior intubation, size of ETT, and number of VAP patients were secondary outcomes. ETT cuff pressure was monitored 742 times in both the baseline group and the intervention group. A total of 56.9% of the cuff pressure measurements in the baseline group were within the recommended range, while 78.4% of measurements in the intervention group were within the recommended range, reflecting a statistically significant difference (P < 0.05). The application of the mobile terminal application program used for ETT cuff pressure measurement could improve the percentage of ETT cuff pressure measurements falling within the recommended range.

Achromobacter spp. healthcare associated infections in the French West Indies: a longitudinal study from 2006 to 2016

Background

Bacteria of the Achromobacter genus, more particularly xylosoxidans species, are responsible for various healthcare associated infections (HAI) which are increasingly described since the last decade. Cystic fibrosis (CF) patients are considered as potential reservoirs in hospitals. We performed a retrospective study to estimate the frequencies of Achromobacter spp. HAI among patients from French West Indies, to determine characteristics of infected patients and establish a possible link between CF and infections.

Methods

All adults with at least one Achromobacter spp. positive sample and infection criteria in accordance with European official definitions of HAI, hospitalized in University Hospital of Martinique from 2006 to 2016 for more than 48 h, were included. Patient clinical features, immune status and underlying diseases were obtained from medical files. A list of CF patients was given by clinicians.

Antibiotic-susceptibility profiles of the strains were determined using an automated method.

Results

Mean incidence density was 0.038/1000 days of hospitalization. Achromobacter spp. HAI evolved as an endemic situation with a low but pretty much stable incidence rate over the 11-year observation period. An epidemic peak was noticed in 2013. Among the 66 included patients, 56.1% were immunocompetent and no one had CF. Pneumonia and bacteraemia were the two main HAI. Among the 79 isolated strains, 92.4% were resistant to at least 1 major antibiotic and 16.4% met the definition of multidrug-resistant bacteria.

Conclusions

This microorganism, little known in our country because of the scarcity of CF patients, represents a threat for both immunosuppressed and immunocompetent patients and a therapeutic challenge because of its high resistance.

Chest physiotherapy for the prevention of ventilator-associated pneumonia: A meta-analysis

BACKGROUND

Ventilator-associated pneumonia (VAP) remains a frequent and severe complication in mechanically ventilated patients. We undertook a meta-analysis to evaluate the efficacy of chest physiotherapy (CPT) for the prevention of VAP.

METHODS

A systematic literature search of PubMed and Embase databases were searched up until November 25, 2018 for published studies of mechanically ventilated patients comparing CPT with controls and reporting on the occurrence of VAP. Two authors independently selected studies and abstracted data on study quality and outcomes. We pooled data using random-effects models.

RESULTS

A total of 6 randomized (n = 704) controlled trials were identified. CPT did not significantly reduce the incidence of VAP (risk ratio = 1.02; 95% confidence interval, 0.82-1.26; P = .87), but reduced hospital mortality (risk ratio = 0.68; 95% confidence interval, 0.48-0.95; P = .02). No significant differences were observed regarding intensive care unit mortality, length of intensive care unit stay, and duration of mechanical ventilation.

CONCLUSIONS

CPT may not significantly reduce the incidence of VAP and alter other important clinical outcomes in adult patients receiving mechanical ventilation. However, the results should be interpreted cautiously owing to the heterogeneity and the limited trials. Further large-scale, well-designed randomized controlled trials are needed.

High seroprevalence of anti-Helicobacter pylori antibodies in patients with ventilator-associated pneumonia

Background:

The pathogenesis of ventilator-associated pneumonia (VAP) is not clearly known. Recently, the role of gastric bacterial colonization has been proposed. The role of gastric colonization with Helicobacter pylori in pathogenesis of VAP was determined by comparing the prevalence of H. pylori in patients with VAP and control participants.

Materials and Methods:

One hundred and eighteen mechanically ventilated patients were divided into two groups; 59 participants with VAP and 59 without VAP. Serologic tests for H. pylori were registered.

Results:

Mean age in seropositive patients was significantly higher. About 71.2% in VAP group and 61.01% in controls were IgG seropositive (P = 0.24). IgM seropositivity was 23.73% versus 8.47% in VAPs and controls, respectively (P = 0.024). By increasing the time of intubation, more patients became seropositive for IgM (Pearson's correlation coefficient = 0.4, P = 0.002).

Conclusion:

IgM seropositivity and serum levels were significantly higher in VAP patients. Furthermore, by increasing the duration of intubation, serum levels for IgM increased significantly.

Pre-intensive care unit intubation and subsequent delayed intensive care unit admission is independently associated with increased occurrence of ventilator-associated pneumonia

INTRODUCTION

Critically ill intubated patients are at risk for ventilator-associated pneumonia. However, intubation may not occur in intensive care unit (ICU) and subsequent ICU admission may be delayed.

OBJECTIVES

To evaluate whether intubation >24 h prior ICU admission and delay in ICU admission is associated with ventilator-associated pneumonia (VAP) in non-trauma critically ill patients.

MATERIALS AND METHODS

Prospective observational study conducted in a medical-surgical ICU of a tertiary hospital. Consecutive patients with >48 h of invasive mechanical ventilation and >72 h hospitalization, were recruited in the study. Pre-ICU intubation and delay in ICU admission, demographical, clinical, microbiological data and ICU interventions were assessed as risk factors for VAP and ICU mortality.

RESULTS

100 patients were included in the study. Pre-ICU intubation and delayed (>24 h) ICU admission (PDA patients) (P = 0.014, OR = 3.294, confidence interval 1.268-8.557) and SOFA score on ICU admission (P = 0.045, OR = 1.154, confidence interval 1.003-1.328) were independent risk factors for VAP in ICU care setting. Yet, PDA patients, presented significantly increased incidence of VAP due to MDR bacteria, mainly from Acinetobacter baumannii. Acinetobacter baumannii infection was the only independent risk factor for ICU mortality (P = 0.049, OR = 3.253, confidence interval 1.006-10.521). SOFA score on ICU admission, presented a fair prognostic accuracy of overall ICU mortality (SOFA ≥ 8.5, AUC = 0.850, P < 0.001).

CONCLUSIONS

Pre-ICU intubation and delayed ICU admission was independent risk factor for VAP Acinetobacter baumannii infection and a high SOFA score on ICU admission were predictors of increased ICU mortality.

The barriers to the prevention of ventilator-associated pneumonia from the perspective of critical care nurses: A qualitative descriptive study

AIMS AND OBJECTIVES

The aim of this study was to explore the perspectives of Iranian critical care nurses on the barriers to ventilator-associated pneumonia prevention in intensive care units.

BACKGROUND

Most patients hospitalized in intensive care units need mechanical ventilation. One of the most prevalent and serious complications of mechanical ventilation is ventilator-associated pneumonia. There are different barriers to the prevention of this kind of pneumonia.

DESIGN

Qualitative descriptive design was used.

METHODS

In this qualitative study, 23 critical care nurses were recruited via purposive sampling. Semi-structured interviews were done for data collection. The interviews were recorded digitally, transcribed word by word, and analyzed using the inductive content analysis approach.

RESULTS

The barriers to the prevention of ventilator-associated pneumonia fell into three main categories, namely nurses' limited professional competence, unfavorable environmental conditions, and passive human resource management. The 10 subcategories of these main categories were unfavorable professional attitude, limited professional knowledge, low job motivation, limited professional accountability, non-standard physical structure, inadequate or inappropriate equipment, heavy workload, staff shortage, inadequate staff training, and ineffective supervision.

CONCLUSION

The barriers to the prevention of ventilator-associated pneumonia in intensive care units are very diverse and complex and include a wide range of interrelated personal, environmental, and organizational barriers.

RELEVANCE TO CLINICAL PRACTICE

This study created a better understanding of the barriers to ventilator-associated pneumonia prevention. Moreover, highlighted the importance of sufficient resources, adequate staffing level, and contextually-appropriate evidence-based guidelines for effective ventilator-associated pneumonia prevention.

Respiratory mechanics, ventilator-associated pneumonia and outcomes in intensive care unit

AIM

To evaluate the predictive capability of respiratory mechanics for the development of ventilator-associated pneumonia (VAP) and mortality in the intensive care unit (ICU) of a hospital in southern Brazil.

METHODS

A cohort study was conducted between, involving a sample of 120 individuals. Static measurements of compliance and resistance of the respiratory system in pressure-controlled ventilation (PCV) and volume-controlled ventilation (VCV) modes in the 1^st and 5^th days of hospitalization were performed to monitor respiratory mechanics. The severity of the patients’ illness was quantified by the Acute Physiology and Chronic Health Evaluation II (APACHE II). The diagnosis of VAP was made based on clinical, radiological and laboratory parameters.

RESULTS

The significant associations found for the development of VAP were APACHE II scores above the average (P = 0.016), duration of MV (P = 0.001) and ICU length of stay above the average (P = 0.003), male gender (P = 0.004), and worsening of respiratory resistance in PCV mode (P = 0.010). Age above the average (P < 0.001), low level of oxygenation on day 1 (P = 0.003) and day 5 (P = 0.004) and low lung compliance during VCV on day 1 (P = 0.032) were associated with death as the outcome.

CONCLUSION

The worsening of airway resistance in PCV mode indicated the possibility of early diagnosis of VAP. Low lung compliance during VCV and low oxygenation index were death-related prognostic indicators.

Antimicrobials for the treatment of drug-resistant Acinetobacter baumannii pneumonia in critically ill patients: a systemic review and Bayesian network meta-analysis

BACKGROUND

An optimal therapy for the treatment of pneumonia caused by drug-resistant Acinetobacter baumannii remains unclear. This study aims to compare various antimicrobial strategies and to determine the most effective therapy for pneumonia using a network meta-analysis.

METHODS

Systematic search and quality assessment were performed to select eligible studies reporting one of the following outcomes: all-cause mortality, clinical cure, and microbiological eradication. The primary outcome was all-cause mortality. A network meta-analysis was conducted with a Bayesian approach. Antimicrobial treatments were ranked based on surface under the cumulative ranking curve (SUCRA) value along with estimated median outcome rate and corresponding 95% credible intervals (CrIs). Two treatments were considered significantly different if a posterior probability of superiority (P) was greater than 97.5%.

RESULTS

Twenty-three studies evaluating 15 antimicrobial treatments were included. Intravenous colistin monotherapy (IV COL) was selected as a common comparator, serving as a bridge for developing the network. Five treatments ranked higher than IV COL (SUCRA, 57.1%; median all-cause mortality 0.45, 95% CrI 0.41-0.48) for reducing all-cause mortality: sulbactam monotherapy (SUL, 100.0%; 0.18, 0.04-0.42), high-dose SUL (HD SUL, 85.7%; 0.31, 0.07-0.71), fosfomycin plus IV COL (FOS + IV COL, 78.6%; 0.34, 0.19-0.54), inhaled COL plus IV COL (IH COL + IV COL, 71.4%; 0.39, 0.32-0.46), and high-dose tigecycline (HD TIG, 71.4%; 0.39, 0.16-0.67). Those five treatments also ranked higher than IV COL (SUCRA, 45.5%) for improving clinical cure (72.7%, 72.7%, 63.6%, 81.8%, and 90.9%, respectively). Among the five treatments, SUL (P = 98.1%) and IH COL + IV COL (P = 99.9%) were significantly superior to IV COL for patient survival and clinical cure, respectively. In terms of microbiological eradication, FOS + IV COL (P = 99.8%) and SUL (P = 98.9%) were significantly superior to IV COL.

CONCLUSIONS

This Bayesian network meta-analysis demonstrated the comparative effectiveness of fifteen antimicrobial treatments for drug-resistant A. baumannii pneumonia in critically ill patients. For survival benefit, SUL appears to be the best treatment followed by HD SUL, FOS + IV COL, IH COL + IV COL, HD TIG, and IV COL therapy, in numerical order.

Molecular analysis of endotracheal tube biofilms and tracheal aspirates in the pediatric intensive care unit

BACKGROUND

Ventilator-associated pneumonia (VAP) is a known complication of mechanically ventilated children in the pediatric intensive care unit (PICU). Endotracheal tube (ETT) biofilms are often implicated in the development of VAP by providing a conduit for pathogens to the lower respiratory tract.

METHODS

A prospective cohort study from April 2010-March 2011 of children 4 weeks to 18 years of age ventilated for greater than 72 hours to determine the microbiota of ETT biofilms and tracheal aspirates.

RESULTS

Thirty-three patients were included with a mean age of 6.1 years (SD ± 5.1 years) and average length of intubation of 8.8 days (SD ± 5.0 days). Bacterial communities from tracheal aspirates and the proximal and distal ends of ETTs were determined using 16S rRNA gene libraries. Statistical analysis utilized two-part statistics and the Wilcoxon signed rank sum test for comparison of bacterial communities. Sequencing revealed a predominance of oropharyngeal microbiota including Prevotella and Streptococcus spp. Pathogenic bacterial genera including Staphylococcus, Burkholderia, Moraxella, and Haemophilus were also represented. Bacterial load was greatest at the proximal aspect of the ETT. Duration of intubation did not significantly impact bacterial load. Morisita Horn analysis across sites showed similar communities in 24/33 (72%) of patients.

CONCLUSIONS

ETT biofilms and tracheal aspirates of intubated patients in the PICU primarily consisted of oropharyngeal microbiota, but had a significant representation of potentially pathogenic genera. While the majority of patients had similar microbiota when comparing their ETT biofilms and tracheal aspirates, a subset of patients showed a divergence between communities that requires further investigation.

Hospital-acquired lower respiratory tract infections among high risk hospitalized patients in a tertiary care teaching hospital in China: An economic burden analysis

BACKGROUND

Data on the economic burden of hospital-acquired lower respiratory tract infection (LRTI) among high risk hospitalized patients are lacking in China. This study aims to fill this knowledge gap.

METHODS

We used a prospective matched cohort design, comparing patients with LRTIs and 1:1 matched patients without LRTIs. Study period was from January 2013 to December 2015 analyzing inpatients from high risk wards - intensive care unit (ICU), dialysis, hematology, etc. - in a tertiary hospital. Hospital information system and hospital infection surveillance system were applied to extract necessary information. The primary outcome was incidence of hospital-acquired LRTIs, and the secondary was economic burden outcomes, including incremental medical costs and prolonged length of stay (LOS). Wilcoxon's signed rank test was used to explore the differences in the economic burden.

RESULTS

Among 5990 hospital visitors over the period of time, 895 (14.94%) had hospital-acquired LRTIs. We analyzed 340 patients with LRTIs and 340 respective controls without infections. The median hospital costs for patients with ICU-acquired LRTIs were significantly higher than those without LRTIs in other wards ($12,301.17 vs. $4674.64, P<0.01). The average attributable cost per patient was $2853.93 ($6916.48 vs. $4062.55, P<0.01). Patients from hematology department had the longest LOS, at 15days (25days vs. 10 days, P<0.01). An LRTI led to an attributable increase in LOS by 8days on average (P<0.01). Western medicine, treatment and laboratory test were the dominant contributors to the growth in overall medical costs in hospital-acquired LRTIs.

CONCLUSIONS

Hospital-acquired LRTI imposed considerable economic burden on patients hospitalized in high risk wards in China. This study provides the first data for economic evaluation of LRTI, highlighting the urgent need to establish targeted preventive strategies to minimize the occurrence of this complication to reduce economic burden.

Management of mechanical ventilation in patients with hospital-acquired pneumonia: A retrospective, observational study

BACKGROUND

Hospital-acquired pneumonia (HAP) in intensive care patients is a frequent reason for mechanical ventilation (MV). The management of MV and ventilator weaning vary, depending on the type of lung inflammation. This retrospective, observational study screened the data from all patients admitted to the intensive care unit (ICU) of the Department of Anaesthesiology and Intensive Care Medicine, Faculty of Medicine and Dentistry, Palacky University Olomouc between 2011 and 2016. The aims were to determine the parameters of pressure-controlled ventilation, the frequencies of tracheostomy, bronchoscopy, reconnection to MV, the length of ICU and hospital stay and the mortality in subgroups with early-/late-onset HAP compared to a subgroup with community-acquired pneumonia (CAP) and patients with MV without pneumonia. The primary outcome of this study was MV length.

RESULTS

Over the study period, a total of 2672 patients were hospitalised. Excluded were 137 organ donors, 66 patient without MV and 20 patients placed on volume-controlled ventilation. The cohort comprised 2.447 patients requiring MV. A total of 1.927 patients (78.7%) were indicated for MV without signs of pneumonia. CAP was diagnosed in 131 patients (5.4%). The criteria for HAP were met by 389 patients (16.0%). Early-onset and late-onset HAP was diagnosed in 63 (2.6%) and 326 (13.3%) patients, respectively. In the subgroups without pneumonia, with CAP, early- and late-onset HAP, the median MV times were 3, 6, 6 and 12 days, respectively, and the median peak inspiratory pressure (Pinsp) of MV was 20, 25, 25 and 27 cm H₂O, respectively. The median positive end-expiratory pressure (PEEP) was 5, 8, 8 and 11 cm H₂O, respectively. The median inspired oxygen concentrations (FiO₂) were 0.45, 0.7, 0.7 and 0.8, respectively. The median length of hospital stays was 8, 15, 15 and 17 days. The mortality rates were 11.4%, 3.8%, 9.5% and 31.3%, respectively.

CONCLUSIONS

During MV, the late-onset HAP subgroup was shown to have the highest Pinsp, PEEP and FiO₂, the longest MV time, ICU and hospital stay, the highest frequency of tracheostomy, reconnection to MV, pulmonary hygiene bronchoscopy and the highest mortality compared to the early-onset HAP and CAP subgroups. The lowest values were found in the mechanically ventilated patients without pneumonia. The differences were due to the severity of lung damage that is graduated from CAP over early-onset HAP after late-onset HAP.

The function of probiotics on the treatment of ventilator-associated pneumonia (VAP): facts and gaps

Probiotics have been used for centuries in making fermented dairy products. The health benefits related to probiotics consumption are well recognized and they are generally regarded as safe (GRAS). Their therapeutic effects are due to the production of a variety of antimicrobial compounds, such as short-chain fatty acids, organic acids (such as lactic, acetic, formic, propionic and butyric acids), ethanol, hydrogen peroxide and bacteriocins. Ventilator-associated pneumonia (VAP) is a nosocomial infection associated with high mortality in intensive care units. VAP can result from endotracheal intubation and mechanical ventilation. These interventions increase the risk of infection as patients lose the natural barrier between the oropharynx and the trachea, which in turn facilitates the entry of pathogens through the aspiration of oropharyngeal secretions containing bacteria into the lung. In order to prevent this, probiotics have been used extensively against VAP. This review is an update containing information extracted from recent studies on the use of probiotics to treat VAP. In addition, probiotic safety, the therapeutic properties of probiotics, the probiotic strains used and the action of the probiotics mechanism are reviewed. Furthermore, the therapeutic effects of probiotic treatment procedures for VAP are compared to those of antibiotics. Finally, the influences of bacteriocin on the growth of human pathogens, and the side-effects and limitations of using probiotics for the treatment of VAP are addressed.

Surveillance of preventive measures for ventilator associated pneumonia (VAP) and its rate in Makkah Region hospitals, Saudi Arabia

BACKGROUND/AIM

The present study aimed to assess the VAP rate and to identify VAP prevention activities in public sector hospitals situated in the Makkah Region, Saudi Arabia (SA).

MATERIALS AND METHODS

In this cross-sectional study, the VAP data from 13 public sector hospitals were collected from January to December 2013 and analyzed using SPSS 16.

RESULTS

The overall VAP rate in Makkah Region hospitals was 6.89 cases per 1000 ventilator-days. There was a significant difference in VAP rate among the hospitals of the Makkah Region (P < 0.001). There was no significant difference in the VAP rate among hospitals, which were using only one, two, or all three VAP preventive approaches (P = 0.26) accredited by the Joint Commission International (JCI) and Central Board for Accreditation of Health Care Institution (CBAHI) (P = 0.12), and using the form in intensive care units (ICUs) (P = 0.85). There was a significant difference in the VAP rate among hospitals having different bed capacities (P < 0.001), data regularly collected (P = 0.03), and had a team to supervise the VAP project (P = 0.04).

CONCLUSION

The VAP rate in Makkah Region hospitals is 6.89 cases per 1000 ventilator-days.

Injury Region and Risk of Hospital-Acquired Pneumonia Among Pediatric Trauma Patients

OBJECTIVE

To describe the relationship between injury region and risk of hospital-acquired pneumonia (HAP) in pediatric trauma patients.

METHODS

Analyses included patients <19 years of age from the National Trauma Data Bank, during 2009-2011. Multivariable logistic regression was used to examine the association between injury region and odds of developing HAP stratified by age group.

RESULTS

A total of 71 377 patients were eligible for analysis, and 1818 patients developed pneumonia. In adjusted regression models both younger (11-15 years) and older (16-18 years) adolescents with multisite injuries including the head and neck had higher odds of developing HAP compared with adolescents with isolated head and neck injuries (odds ratio [OR] = 2.04, 95% confidence interval [CI] 1.34-3.10; OR = 1.47, 95% CI 1.14-1.89, respectively), and younger adolescents with multisite injuries not involving the head and neck also had higher odds of developing HAP (OR = 1.97, 95% CI 1.08-3.60). We found no significant association between injury region and risk of HAP in children <11 years of age. Younger and older adolescents with firearm (OR = 1.85, 95% CI 1.00-3.42; OR = 1.39, 95% CI 1.02-1.88, respectively) or pulmonary (OR = 3.78, 95% CI 1.26-11.3; OR = 2.56, 95% CI 1.01-6.51, respectively) injuries had higher odds of developing HAP compared with those with motor vehicle collision injuries.

CONCLUSIONS

Adolescent trauma patients with multisite injuries including the head and neck have a higher risk of developing HAP compared with those with isolated head and neck injuries. We identified several risk factors that can be used to inform future research focused on identifying subgroups at high risk for the development of HAP.

Cuff pressure monitoring by manual palpation in intubated patients: How accurate is it? A manikin simulation study

BACKGROUND

Endotracheal intubation (ETI) for mechanical ventilation has a central role in the Intensive Care Unit (ICU). ETI is one of the main risk factors for the development of ventilator-associated pneumonia (VAP) as its presence reduces the natural defences of the upper airway and allows the micro-suction of secretions in the airways. In order to minimise such complications, it is fundamental to maintain a suitable pressure inside the tube cuff.

AIM AND SCOPE

The main objective of the present study is to evaluate the effectiveness and reliability of palpation method, performed with the operators fingers, for detecting the tube cuff pressure.

RESULTS

The study was performed using a manikin to test the pressure of the ETT cuff, on a sample constituted by nurses employed in three Italian ICU from two different Umbrian hospitals. From a total of 68 participants, detection by palpation method revealed to be not correct in 68% of cases; in particular, only 10% of respondents can correctly detect a pressure in the recommended range (20-30cmH₂O) using palpation. Moreover it was possible to highlight that the participation in emergency courses has a positive effect on the correct measurement of cuff pressure using the palpation method (V=0.501).

CONCLUSIONS

The study, in agreement with the literature, confirms the thesis that the palpation method is inadequate to determine an estimate of the pressure existing inside the cuff.

Effects of hydrogen peroxide mouthwash on preventing ventilator-associated pneumonia in patients admitted to the intensive care unit

AIMS

The aim of the study was to determine the effect of hydrogen peroxide (HP) mouthwash on the incidence of ventilator associated pneumonia (VAP) in patients admitted to the intensive care unit (ICU).

METHODS

This was a randomized clinical trial conducted on 68 patients. The intervention group used 3% HP as mouthwash and the control group used mouthwashes with 0.9% normal saline (NS) twice a day. Data were collected using a questionnaire and the Modified Clinical Pulmonary Infection Score (MCPIS). MCPIS includes five items, body temperature: white blood cell count, pulmonary secretions, the ratio of pressure of arterial oxygen (PaO2) to fraction of inspired oxygen (FiO2), and the chest X-ray. Each of these items scored 0-2. Scores ≥6 were considered as VAP signs. The SPSS-20 software was employed to analyze the data.

RESULTS

In total, 14.7% patients of the HP group and 38.2% patients of the NS group contracted VAP. The risk of VAP in the NS group was 2.60 times greater than that in the HP group (RR=2.60, 95% CI: 1.04-6.49, p=0.0279). The mean±SD MCPIS was calculated as 3.91±1.35 in the HP group and 4.65±1.55 in the NS group, a difference statistically significant (p=0.042). There were no significant differences in the risk factors for VAP between the two groups.

CONCLUSION

HP mouthwash was found more effective than NS in reducing VAP. HP mouthwash can therefore be used in routine nursing care for reducing VAP.

Ventilator-associated pneumonia: the influence of bacterial resistance, prescription errors, and de-escalation of antimicrobial therapy on mortality rates

Ventilator-associated pneumonia is the most prevalent nosocomial infection in intensive care units and is associated with high mortality rates (14–70%).

Aim

This study evaluated factors influencing mortality of patients with Ventilator-associated pneumonia (VAP), including bacterial resistance, prescription errors, and de-escalation of antibiotic therapy.

Methods

This retrospective study included 120 cases of Ventilator-associated pneumonia admitted to the adult adult intensive care unit of the Federal University of Uberlândia. The chi-square test was used to compare qualitative variables. Student's t-test was used for quantitative variables and multiple logistic regression analysis to identify independent predictors of mortality.

Findings

De-escalation of antibiotic therapy and resistant bacteria did not influence mortality. Mortality was 4 times and 3 times higher, respectively, in patients who received an inappropriate antibiotic loading dose and in patients whose antibiotic dose was not adjusted for renal function. Multiple logistic regression analysis revealed the incorrect adjustment for renal function was the only independent factor associated with increased mortality.

Conclusion

Prescription errors influenced mortality of patients with Ventilator-associated pneumonia, underscoring the challenge of proper Ventilator-associated pneumonia treatment, which requires continuous reevaluation to ensure that clinical response to therapy meets expectations.

Antibiotic Utilization Patterns in Patients with Ventilator-Associated Pneumonia: A Canadian Context

This retrospective cohort study describes the patterns of antibiotic use for the treatment of ventilator-associated pneumonia (VAP) in the Calgary Zone of Alberta Health Services. Timing, appropriateness, and duration of antibiotics were evaluated in two hundred consecutive cases of VAP derived from 4 adult intensive care units (ICU). Antibiotic therapy was initiated in less than 24 hours from VAP diagnosis in 83% of cases. Although most patients (89%) received empiric therapy that demonstrated in vitro sensitivity to the identified pathogens, only 24% of cases were congruent with the 2008 Association of Medical Microbiology and Infectious Disease (AMMI) guidelines. Both ICU (p = 0.001) and hospital (p = 0.015) mortality were significantly lower and there was a trend for shorter ICU length of stay (p = 0.051) in patients who received appropriate versus inappropriate initial antibiotics. There were no outcome differences related to compliance with AMMI guidelines. This exploratory study provides insight into the use of antimicrobials for the treatment of VAP in a large Canadian health region. The discordance between the assessments of appropriateness of empiric therapy based on recovered pathogens versus AMMI guidelines is notable, emphasizing the importance of using as much as possible local microbiologic and antimicrobial resistance data.

Clonality of Bacterial Pathogens Causing Hospital-Acquired Pneumonia

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

Epidemiology of hospital-acquired pneumonia: Results of a Central European multicenter, prospective, observational study compared with data from the European region

BACKGROUND

Hospital-acquired pneumonia (HAP) is associated with high mortality. In Central Europe, there is a dearth of information on the prevalence and treatment of HAP. This project was aimed at collecting multicenter epidemiological data on patients with HAP in the Czech Republic and comparing them with supraregional data.

METHODS

This prospective, multicenter, observational study processed data from a database supported by a Czech Ministry of Health grant project. Included were all consecutive patients aged 18 and over who were admitted to participating intensive care units (ICUs) between 1 May 2013 and 31 December 2014 and met the inclusion criterion of having HAP. The primary endpoint was to analyze the relationships between 30-day mortality (during the stay in or after discharge from ICUs) and the microbiological etiological agent and adequacy of initial empirical antibiotic therapy in HAP patients.

RESULTS

The group dataset contained data on 330 enrolled patients. The final validated dataset involved 214 patients, 168 males (78.5%) and 46 females (21.5%), from whom 278 valid lower airway samples were obtained. The mean patient age was 59.9 years. The mean APACHE II score at admission was 21. Community-acquired pneumonia was identified in 13 patients and HAP in 201 patients, of whom 26 (12.1%) had early-onset and 175 (81.8%) had late-onset HAP. Twenty-two bacterial species were identified as etiologic agents but only six of them exceeded a frequency of detection of 5% (Klebsiella pneumoniae 20.4%, Pseudomonas aeruginosa 20.0%, Escherichia coli 10.8%, Enterobacter spp. 8.1%, Staphylococcus aureus 6.2% and Burkholderia cepacia complex 5.8%). Patients infected with Staphylococcus aureus had significantly higher rates of early-onset HAP than those with other etiologic agents. The overall 30-day mortality rate for HAP was 29.9%, with 19.2% mortality for early-onset HAP and 31.4% mortality for late-onset HAP. Patients with late-onset HAP receiving adequate initial empirical antibiotic therapy had statistically significantly lower 30-day mortality than those receiving inadequate initial antibiotic therapy (23.8% vs 42.9%). Patients with ventilator-associated pneumonia (VAP) had significantly higher mortality than those who developed HAP with no association with mechanical ventilation (34.6% vs 12.7%). Patients having VAP treated with adequate initial antibiotic therapy had lower 30-day mortality than those receiving inadequate therapy (27.2% vs 44.8%).

CONCLUSIONS

The present study was the first to collect multicenter data on the epidemiology of HAP in the Central European Region, with respect to the incidence of etiologic agents causing HAP. It was concerned with relationships between 30-day patient mortality and the type of HAP, etiologic agent and adequacy of initial empirical antibiotic therapy.

Effect of using Richmond Agitation Sedation Scale on duration of mechanical ventilation, type and dosage of sedation on hospitalized patients in intensive care units

Background:

Mechanical ventilation is one of the supporting treatments that are used for different reasons. To reduce patients’ inconvenience caused due to using tracheal tube and ventilator, sedation is routinely used. Using scales for the sedation, for example, Richmond Agitation Sedation Scale (RASS), may reduce dose of sedation and length of mechanical ventilation.

Materials and Methods:

This study is a randomized clinical trial on 64 patients selected from three intensive care units (ICUs) in Isfahan, Iran. Through random allocation, 32 patients were assigned to each of the study and control groups. In the control group, patients’ level of consciousness and the amount of drug consumption in every shift, based on physician order, were recorded. In the study group, RASS score was recorded every hour and sedation was administered based on that. The purpose of the study was to investigate of application of RASS for drug consumption until weaning of the patient from the ventilator. Independent t-test with significance level of 0.05 was used.

Results:

Results showed no significant difference in the mean consumption of midazolam and morphine after intervention, but there was a significant difference in fentanyl (P = 0.03) consumption (379 μg in the control group vs 75 μg in the study group) between groups after the intervention. The mean duration of being connected to the ventilator was significantly less in the study group (P = 0.03).

Conclusions:

Application of RASS by nurses leads to a decrease in sedation consumption, connection to ventilator, and length of stay in the hospital.

Elevated Plasma Matrix Metalloproteinase-9 and Its Correlations with Severity of Disease in Patients with Ventilator-Associated Pneumonia

Ventilator-associated pneumonia (VAP) increases patient mortality and medical expenditure, and a real-time and reliable method for the rapid diagnosis of VAP may help reduce fatal complications. Matrix metalloproteinases-9 (MMP-9) is considered significant in the pathogenesis of lung inflammation and infection. Therefore, we examined its relationship with the clinical course of VAP. This retrospective observational study recruited 30 healthy volunteers, 12 patients who used mechanical ventilation without the development of VAP (hereafter, patients without VAP), and 30 patients with a clinical diagnosis of VAP (hereafter, patients with VAP). The activity and level of plasma MMP-9 were determined through a gelatin zymography assay and ELISA. Our results report that both plasma MMP-9 activity and concentration were significantly elevated in the acute stage of patients with VAP when compared with control group and patients without VAP (p < 0.001). Subsequently, the plasma MMP-9 of patients with VAP decreased significantly after antibiotic treatment. Furthermore, plasma MMP-9 concentration was positively correlated with the clinical pulmonary infection score (r = 0.409, p = 0.007), WBCs (r = 0.620, p < 0.001), and neutrophils counts (r = 0.335, p = 0.035). In addition, plasma MMP-9 is an excellent tool for recognizing VAP when the cutoff level is set to 92.62 ng/mL (AUC = 0.863, 95% CI = 0.761 to 0.932). In conclusions, we concluded that MMP-9 levels play a role in the development of VAP and might have the potential to be applied in the development of VAP therapies.

Incidence of ventilator-associated pneumonia in Australasian intensive care units: use of a consensus-developed clinical surveillance checklist in a multisite prospective audit

OBJECTIVES

With disagreements on diagnostic criteria for ventilator-associated pneumonia (VAP) hampering efforts to monitor incidence and implement preventative strategies, the study objectives were to develop a checklist for clinical surveillance of VAP, and conduct an audit in Australian/New Zealand intensive care units (ICUs) using the checklist.

SETTING

Online survey software was used for checklist development. The prospective audit using the checklist was conducted in 10 ICUs in Australia and New Zealand.

PARTICIPANTS

Checklist development was conducted with members of a bi-national professional society for critical care physicians using a modified Delphi technique and survey. A 30-day audit of adult patients mechanically ventilated for >72 h.

PRIMARY AND SECONDARY OUTCOME MEASURES

Presence of items on the screening checklist; physician diagnosis of VAP, clinical characteristics, investigations, treatments and patient outcome.

RESULTS

A VAP checklist was developed with five items: decreasing gas exchange, sputum changes, chest X-ray infiltrates, inflammatory response, microbial growth. Of the 169 participants, 17% (n=29) demonstrated characteristics of VAP using the checklist. A similar proportion had an independent physician diagnosis (n=30), but in a different patient subset (only 17% of cases were identified by both methods). The VAP rate per 1000 mechanical ventilator days for the checklist and clinician diagnosis was 25.9 and 26.7, respectively. The item 'inflammatory response' was most associated with the first episode of physician-diagnosed VAP.

CONCLUSIONS

VAP rates using the checklist and physician diagnosis were similar to ranges reported internationally and in Australia. Of note, different patients were identified with VAP by the checklist and physicians. While the checklist items may assist in identifying patients at risk of developing VAP, and demonstrates synergy with the recently developed Centers for Disease Control (CDC) guidelines, decision-making processes by physicians when diagnosing VAP requires further exploration.

Effectiveness of the endotracheal tube cuff on the trachea: physical and mechanical aspects

Introduction

The inflation pressure of the endotracheal tube cuff can cause ischemia of the tracheal mucosa at high pressures; thus, it can cause important tracheal morbidity and tracheal microaspiration of the oropharyngeal secretion, or it can even cause pneumonia associated with mechanical ventilation if the pressure of the cuff is insufficient.

Objective

In order to investigate the effectiveness of the RUSCH® 7.5 mm endotracheal tube cuff, this study was designed to investigate the physical and mechanical aspects of the cuff in contact with the trachea.

Methods

For this end, we developed an in vitro experimental model to assess the flow of dye (methylene blue) by the inflated cuff on the wall of the artificial material. We also designed an in vivo study with 12 Large White pigs under endotracheal intubation. We instilled the same dye in the oral cavity of the animals, and we analyzed the presence or not of leakage in the trachea after the region of the cuff after their deaths (animal sacrifice). All cuffs were inflated at the pressure of 30 cmH₂O.

Results

We observed the passage of fluids through the cuff in all in vitro and in vivo experimental models.

Conclusion

We conclude that, as well as several other cuff models in the literature, the RUSCH® 7.5 mm tube cuffs are also not able to completely seal the trachea and thus prevent aspiration of oropharyngeal secretions. Other prevention measures should be taken.

Improving patient safety by optimizing the use of nursing human resources

Background

Recent ecological studies have suggested that inadequate nurse staffing may contribute to the incidence of adverse events in acute care hospitals. However, longitudinal studies are needed to further examine these associations and to identify the staffing patterns that are of greatest risk. The aims of this study are to determine if (a) nurse staffing levels are associated with an increased risk of adverse events, (b) the risk of adverse events in relationship to nurse staffing levels is modified by the complexity of patient requirements, and (c) optimal nurse staffing levels can be established.

Methods/design

A dynamic cohort of all adult medical, surgical, and intensive care unit patients admitted between 2010 and 2015 to a Canadian academic health center will be followed during the inpatient and 7-day post-discharge period to assess the occurrence and frequency of adverse events in relationship to antecedent nurse staffing levels. Four potentially preventable adverse events will be measured: (a) hospital-acquired pneumonia, (b) ventilator-associated pneumonia, (c) venous thromboembolism, and (d) in-hospital fall. These events were selected for their high incidence, morbidity and mortality rates, and because they are hypothesized to be related to nurse staffing levels. Adverse events will be ascertained from electronic health record data using validated automated detection algorithms. Patient exposure to nurse staffing will be measured on every shift of the hospitalization using electronic payroll records. To examine the association between nurse staffing levels and the risk of adverse events, four Cox proportional hazards regression models will be used (one for each adverse event), while adjusting for patient characteristics and risk factors of adverse event occurrence. To determine if the association between nurse staffing levels and the occurrence of adverse events is modified by the complexity of patient requirements, interaction terms will be included in the regression models, and their significance assessed. To assess for the presence of optimal nurse staffing levels, flexible nonlinear spline functions will be fitted.

Discussion

This study will likely generate evidence-based information that will assist managers in making the most effective use of scarce nursing resources and in identifying staffing patterns that minimize the risk of adverse events.

Electronic supplementary material

The online version of this article (doi:10.1186/s13012-015-0278-1) contains supplementary material, which is available to authorized users.

[Collection of tracheal aspirate: safety and microbiological concordance between two techniques]

OBJECTIVE

To evaluate the safety of the performance of the traditional and protected collection techniques of tracheal aspirate and to identify qualitative and quantitative agreement of the results of microbiological cultures between the techniques.

METHOD

Clinical, prospective, comparative, single-blind research. The sample was composed of 54 patients of >18 years of age, undergoing invasive mechanical ventilation for a period of ≥ 48 hours and with suspected Ventilator Associated Pneumonia. The two techniques were implemented in the same patient, one immediately after the other, with an order of random execution, according to randomization by specialized software.

RESULTS

No significant events occurred oxygen desaturation, hemodynamic instability or tracheobronchial hemorrhage (p<0.05) and, although there were differences in some strains, there was qualitative and quantitative agreement between the techniques (p<0.001).

CONCLUSION

Utilization of the protected technique provided no advantage over the traditional and execution of both techniques was safe for the patient.

Accuracy of using automated methods for detecting adverse events from electronic health record data: a research protocol

Background

Adverse events are associated with significant morbidity, mortality and cost in hospitalized patients. Measuring adverse events is necessary for quality improvement, but current detection methods are inaccurate, untimely and expensive. The advent of electronic health records and the development of automated methods for encoding and classifying electronic narrative data, such as natural language processing, offer an opportunity to identify potentially better methods. The objective of this study is to determine the accuracy of using automated methods for detecting three highly prevalent adverse events: a) hospital-acquired pneumonia, b) catheter-associated bloodstream infections, and c) in-hospital falls.

Methods/design

This validation study will be conducted at two large Canadian academic health centres: the McGill University Health Centre (MUHC) and The Ottawa Hospital (TOH). The study population consists of all medical, surgical and intensive care unit patients admitted to these centres between 2008 and 2014. An automated detection algorithm will be developed and validated for each of the three adverse events using electronic data extracted from multiple clinical databases. A random sample of MUHC patients will be used to develop the automated detection algorithms (cohort 1, development set). The accuracy of these algorithms will be assessed using chart review as the reference standard. Then, receiver operating characteristic curves will be used to identify optimal cut points for each of the data sources. Multivariate logistic regression and the areas under curve (AUC) will be used to identify the optimal combination of data sources that maximize the accuracy of adverse event detection. The most accurate algorithms will then be validated on a second random sample of MUHC patients (cohort 1, validation set), and accuracy will be measured using chart review as the reference standard. The most accurate algorithms validated at the MUHC will then be applied to TOH data (cohort 2), and their accuracy will be assessed using a reference standard assessment of the medical chart.

Discussion

There is a need for more accurate, timely and efficient measures of adverse events in acute care hospitals. This is a critical requirement for evaluating the effectiveness of preventive interventions and for tracking progress in patient safety through time.

Microbial composition and antibiotic resistance of biofilms recovered from endotracheal tubes of mechanically ventilated patients

In critically ill patients, breathing is impaired and mechanical ventilation, using an endotracheal tube (ET) connected to a ventilator, is necessary. Although mechanical ventilation is a life-saving procedure, it is not without risk. Because of several reasons, a biofilm often forms at the distal end of the ET and this biofilm is a persistent source of bacteria which can infect the lungs, causing ventilator-associated pneumonia (VAP). There is a link between the microbial flora of ET biofilms and the microorganisms involved in the onset of VAP. Culture dependent and independent techniques were already used to identify the microbial flora of ET biofilms and also, the antibiotic resistance of microorganisms obtained from ET biofilms was determined. The ESKAPE pathogens play a dominant role in the onset of VAP and these organisms were frequently identified in ET biofilms. Also, antibiotic resistant microorganisms were frequently present in ET biofilms. Members of the normal oral flora were also identified in ET biofilms but it is thought that these organisms initiate ET biofilm formation and are not directly involved in the development of VAP.

Gastropulmonary Route of Infection and the Prevalence of Microaspiration in the Elderly Patients with Ventilator-Associated Pneumonia Verified by Molecular Microbiology-GM-PFGE

Gastropulmonary route of infection was considered to be an important mechanism of ventilator-associated pneumonia (VAP). However there is little evidence to support this assumption. Moreover, the prevalence of microaspiration in elderly ventilated patients was not well understood. To confirm gastropulmonary infection route and investigate the prevalence of microaspiration in elderly ventilated patients using genome macrorestriction-pulsed field gel electrophoresis (GM-PFGE). Patients over 60 years old, expected to receive mechanical ventilation longer than 48 h, were prospectively enrolled from October 2009 to January 2012. Clinical data were collected and recorded until they died, developed pneumonia, or were extubated. Samples from gastric fluid, subglottic secretion and lower respiratory tract (LRT) were collected during the follow-up for microbiological examination. To evaluate the homogeneity, GM-PFGE was performed on strains responsible for VAP that had the same biochemical phenotype as those isolated from gastric juice and subglottic secretions sequentially. Among 44 VAP patients, 76 strains were isolated from LRT and considered responsible for VAP. Twenty-two isolates had the same biochemical phenotype with the corresponding gastric isolates. The homology was further confirmed using GM-PFGE in 12 episodes of VAP. Nearly 30% of VAPs were caused by microaspiration based on the analysis of bacterial phenotype or GM-PFGE. In addition, 58.3% patients with gastric colonization developed VAP, especially late-onset VAP (LOP). Gastropulmonary infection route exists in VAP especially LOP in elderly ventilated patients. It is one of the important mechanisms in the development of VAP.

Prior oropharyngeal colonization and ventilator-associated pneumonia

This study evaluated the relationship between previous colonization of the oropharynx and development of ventilator-associated pneumonia through the classification of genomic fingerprint pattern by pulsed-field gel electrophoresis of both oxacillin-resistant and oxacillin-susceptible Staphylococcus aureus isolates obtained from hospitalized patients in an intensive care unit.

Emergence of carbapenem-resistant Acinetobacter baumannii as the major cause of ventilator-associated pneumonia in intensive care unit patients at an infectious disease hospital in southern Vietnam

Ventilator-associated pneumonia (VAP) is a serious healthcare-associated infection that affects up to 30 % of intubated and mechanically ventilated patients in intensive care units (ICUs) worldwide. The bacterial aetiology and corresponding antimicrobial susceptibility of VAP is highly variable, and can differ between countries, national provinces and even between different wards in the same hospital. We aimed to understand and document changes in the causative agents of VAP and their antimicrobial susceptibility profiles retrospectively over an 11 year period in a major infectious disease hospital in southern Vietnam. Our analysis outlined a significant shift from Pseudomonas aeruginosa to Acinetobacter spp. as the most prevalent bacteria isolated from quantitative tracheal aspirates in patients with VAP in this setting. Antimicrobial resistance was common across all bacterial species and we found a marked proportional annual increase in carbapenem-resistant Acinetobacter spp. over a 3 year period from 2008 (annual trend; odds ratio 1.656, P = 0.010). We further investigated the possible emergence of a carbapenem-resistant Acinetobacter baumannii clone by multiple-locus variable number tandem repeat analysis, finding a blaOXA-23-positive strain that was associated with an upsurge in the isolation of this pathogen. We additionally identified a single blaNDM-1-positive A. baumannii isolate. This work highlights the emergence of a carbapenem-resistant clone of A. baumannii and a worrying trend of antimicrobial resistance in the ICU of the Hospital for Tropical Diseases in Ho Chi Minh City, Vietnam.

Identification of microorganisms based on headspace analysis of volatile organic compounds by gas chromatography-mass spectrometry

The identification of specific volatile organic compounds (VOCs) produced by microorganisms may assist in developing a fast and accurate methodology for the determination of pulmonary bacterial infections in exhaled air. As a first step, pulmonary bacteria were cultured and their headspace analyzed for the total amount of excreted VOCs to select those compounds which are exclusively associated with specific microorganisms. Development of a rapid, noninvasive methodology for identification of bacterial species may improve diagnostics and antibiotic therapy, ultimately leading to controlling the antibiotic resistance problem. Two hundred bacterial headspace samples from four different microorganisms (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Klebsiella pneumoniae) were analyzed by gas chromatography-mass spectrometry to detect a wide array of VOCs. Statistical analysis of these volatiles enabled the characterization of specific VOC profiles indicative for each microorganism. Differences in VOC abundance between the bacterial types were determined using ANalysis of VAriance-principal component analysis (ANOVA-PCA). These differences were visualized with PCA. Cross validation was applied to validate the results. We identified a large number of different compounds in the various headspaces, thus demonstrating a highly significant difference in VOC occurrence of bacterial cultures compared to the medium and between the cultures themselves. Additionally, a separation between a methicillin-resistant and a methicillin-sensitive isolate of S. aureus could be made due to significant differences between compounds. ANOVA-PCA analysis showed that 25 VOCs were differently profiled across the various microorganisms, whereas a PCA score plot enabled the visualization of these clear differences between the bacterial types. We demonstrated that identification of the studied microorganisms, including an antibiotic susceptible and resistant S. aureus substrain, is possible based on a selected number of compounds measured in the headspace of these cultures. These in vitro results may translate into a breath analysis approach that has the potential to be used as a diagnostic tool in medical microbiology.

Risk factors for ventilator-associated pneumonia in the neonatal intensive care unit: a meta-analysis of observational studies

Ventilator-associated pneumonia (VAP) is a common and serious problem among mechanically ventilated patients in intensive care units (ICU), especially for the newborn. However, limited literatures have been reviewed to synthesize the finding of previous papers to investigate the risk factors for VAP although it has been a serious complication of mechanical ventilation (MV) with a high morbidity and mortality in the newborn. We performed this meta-analysis to extend previous knowledge for developing VAP prevention strategies by identifying the potential risk factors related to VAP in the neonatal intensive care unit (NICU). The relevant literatures published up to July 2013 were searched in the databases of PubMed, Cochrane Central Register of Controlled Trials, Embase, and Web of Science. Three reviewers screened those literatures and extracted data according to the inclusion and exclusion criteria independently. A total of eight studies including 370 cases and 1,071 controls were identified. Ten risk factors were found to be related to neonatal VAP which were listed as follows in order by odds ratios (ORs): length of stay in NICU (OR 23.45), reintubation (OR 9.18), enteral feeding (OR 5.59), mechanical ventilation (OR 4.04), transfusion (OR 3.32), low birth weight (OR 3.16), premature infants (OR 2.66), parenteral nutrition (OR 2.30), bronchopulmonary dysplasia (OR 2.21), and tracheal intubation (OR 1.12).

CONCLUSION

We identified ten variables as independent risk factors for the development of VAP: length of stay in NICU, reintubation, enteral feeding, mechanical ventilation, transfusion, low birth weight, premature infants, parenteral nutrition, bronchopulmonary dysplasia, and tracheal intubation. Due to several limitations in the present study, further large and well-designed studies are needed to confirm the conclusion.

Prevention of ventilator-associated pneumonia

Invasive mechanical ventilation (IMV) represents a risk factor for the development of ventilator-associated pneumonia (VAP), which develops at least 48h after admission in patients ventilated through tracheostomy or endotracheal intubation. VAP is the most frequent intensive-care-unit (ICU)-acquired infection among patients receiving IMV. It contributes to an increase in hospital mortality, duration of MV and ICU and length of hospital stay. Therefore, it worsens the condition of the critical patient and increases the total cost of hospitalization. The introduction of preventive measures has become imperative, to ensure control and to reduce the incidence of VAP. Preventive measures focus on modifiable risk factors, mediated by non-pharmacological and pharmacological evidence based strategies recommended by guidelines. These measures are intended to reduce the risk associated with endotracheal intubation and to prevent microaspiration of pathogens to the lower airways.

Diabetes and hemoglobin a1c as risk factors for nosocomial infections in critically ill patients

Objective. To evaluate whether diabetes mellitus (DM) and hemoglobin A1c (HbA1c) are risk factors for ventilator-associated pneumonia (VAP) and bloodstream infections (BSI) in critically ill patients. Methods. Prospective observational study; patients were recruited from the intensive care unit (ICU) of a general district hospital between 2010 and 2012.

INCLUSION CRITERIA

ICU hospitalization >72 hours and mechanical ventilation >48 hours. HbA1c was calculated for all participants. DM, HbA1c, and other clinical and laboratory parameters were assessed as risk factors for VAP or BSI in ICU. Results. The overall ICU incidence of VAP and BSI was 26% and 30%, respectively. Enteral feeding OR (95%CI) 6.20 (1.91-20.17; P = 0.002) and blood transfusion 3.33 (1.23-9.02; P = 0.018) were independent risk factors for VAP. BSI in ICU (P = 0.044) and ICU mortality (P = 0.038) were significantly increased in diabetics. Independent risk factors for BSI in ICU included BSI on admission 2.45 (1.14-5.29; P = 0.022) and stroke on admission2.77 (1.12-6.88; P = 0.029). Sepsis 3.34 (1.47-7.58; P = 0.004) and parenteral feeding 6.29 (1.59-24.83; P = 0.009) were independently associated with ICU mortality. HbA1c ≥ 8.1% presented a significant diagnostic performance in diagnosing repeated BSI in ICU. Conclusion. DM and HbA1c were not associated with increased VAP or BSI frequency. HbA1c was associated with repeated BSI episodes in the ICU.

Predicting the need for urgent intubation in a surgical/trauma intensive care unit

BACKGROUND

Analysis and modeling of data monitoring vital signs and waveforms in patients in a surgical/trauma intensive care unit (STICU) may allow for early identification and treatment of patients with evolving respiratory failure.

METHODS

Between February 2011 and March 2012, data of vital signs and waveforms for STICU patients were collected. Every-15-minute calculations (n = 172,326) of means and standard deviations of heart rate (HR), respiratory rate (RR), pulse-oxygen saturation (SpO2), cross-correlation coefficients, and cross-sample entropy for HR-RR, RR-SpO2, and HR-SpO2, and cardiorespiratory coupling were calculated. Urgent intubations were recorded. Univariate analyses were performed for the periods <24 and ≥24 hours before intubation. Multivariate predictive models for the risk of unplanned intubation were developed and validated internally by subsequent sample and bootstrapping techniques.

RESULTS

Fifty unplanned intubations (41 patients) were identified from 798 STICU patients. The optimal multivariate predictive model (HR, RR, and SpO2 means, and RR-SpO2 correlation coefficient) had a receiving operating characteristic (ROC) area of 0.770 (95% confidence interval [CI], 0.712-0.841). For this model, relative risks of intubation in the next 24 hours for the lowest and highest quintiles were 0.20 and 2.95, respectively (15-fold increase, baseline risk 1.46%). Adding age and days since previous extubation to this model increased ROC area to 0.865 (95 % CI, 0.821-0.910).

CONCLUSION

Among STICU patients, a multivariate model predicted increases in risk of intubation in the following 24 hours based on vital sign data available currently on bedside monitors. Further refinement could allow for earlier detection of respiratory decompensation and intervention to decrease preventable morbidity and mortality in surgical/trauma patients.

Management and prevention of ventilator-associated pneumonia caused by multidrug-resistant pathogens

Ventilator-associated pneumonia (VAP) due to multidrug-resistant (MDR) pathogens is a leading healthcare-associated infection in mechanically ventilated patients. The incidence of VAP due to MDR pathogens has increased significantly in the last decade. Risk factors for VAP due to MDR organisms include advanced age, immunosuppression, broad-spectrum antibiotic exposure, increased severity of illness, previous hospitalization or residence in a chronic care facility and prolonged duration of invasive mechanical ventilation. Methicillin-resistant Staphylococcus aureus and several different species of Gram-negative bacteria can cause MDR VAP. Especially difficult Gram-negative bacteria include Pseudomonas aeruginosa, Acinetobacter baumannii, carbapenemase-producing Enterobacteraciae and extended-spectrum β-lactamase producing bacteria. Proper management includes selecting appropriate antibiotics, optimizing dosing and using timely de-escalation based on antiimicrobial sensitivity data. Evidence-based strategies to prevent VAP that incorporate multidisciplinary staff education and collaboration are essential to reduce the burden of this disease and associated healthcare costs.

The effects of the semirecumbent position on hemodynamic status in patients on invasive mechanical ventilation: prospective randomized multivariable analysis

INTRODUCTION

Adopting the 45° semirecumbent position in mechanically ventilated critically ill patients is recommended, as it has been shown to reduce the incidence of ventilator-associated pneumonia. Although the benefits to the respiratory system are clear, it is not known whether elevating the head of the bed results in hemodynamic instability. We examined the effect of head of bed elevation (HBE) on hemodynamic status and investigated the factors that influence mean arterial pressure (MAP) and central venous oxygen saturation (ScvO2) when patients were positioned at 0°, 30°, and 45°.

METHODS

Two hundred hemodynamically stable adults on invasive mechanical ventilation admitted to a multidisciplinary surgical intensive care unit were recruited. Patients' characteristics included catecholamine and sedative doses, the original angle of head of bed elevation (HBE), the level of positive end expiratory pressure (PEEP), duration and mode of mechanical ventilation. A sequence of HBE positions (0°, 30°, and 45°) was adopted in random order, and MAP and ScvO2 were measured at each position. Patients acted as their own controls. The influence of degree of HBE and of the covariables on MAP and ScvO2 was analyzed by using liner mixed models. Additionally, uni- and multivariable logistic regression models were used to indentify risk factors for hypotension during HBE, defined as MAP <65 mmHg.

RESULTS

Changing HBE from supine to 45° caused significant reductions in MAP (from 83.8 mmHg to 71.1 mmHg, P < 0.001) and ScvO2 (76.1% to 74.3%, P < 0.001). Multivariable modeling revealed that mode and duration of mechanical ventilation, the norepinephrine dose, and HBE had statistically significant influences. Pressure-controlled ventilation was the most influential risk factor for hypotension when HBE was 45° (odds ratio (OR) 2.33, 95% confidence interval (CI), 1.23 to 4.76, P = 0.017).

CONCLUSIONS

HBE to the 45° position is associated with significant decreases in MAP and ScvO2 in mechanically ventilated patients. Pressure-controlled ventilation, higher simplified acute physiology (SAPS II) score, sedation, high catecholamine, and PEEP requirements were identified as independent risk factors for hypotension after backrest elevation. Patients at risk may need positioning at 20° to 30° to overcome the negative effects of HBE, especially in the early phase of intensive care unit admission.

Attributable costs of ventilator-associated lower respiratory tract infection (LRTI) acquired on intensive care units: a retrospectively matched cohort study

Background

Lower respiratory tract infections (LRTI) are the most common hospital-acquired infections on ICUs. They have not only an impact on each patient’s individual health but also result in a considerable financial burden for the healthcare system. Our aim was to determine the costs and the length of stay of patients with ICU-acquired LRTI.

Methods

We used a retrospectively matched cohort design, comparing patients with ICU-acquired LRTI and ICU patients without LRTI. LRTI was diagnosed using the definitions of the Centers for Disease Control and Prevention (CDC). Study period was from January to December 2010 analyzing patients from 10 different ICUs (medical, surgical, interdisciplinary). The device utilization ratio was defined as number of ventilator days divided by number of patient days and the device-associated LRTI rate was defined as number of ventilator associated LRTI divided by number of ventilator days. Patients were matched by age, sex, and prospectively obtained Simplified Acute Physiology Score II (SAPS II). The length of ICU stay of control patients needed to be at least as long as that of LRTI-patients before onset of LRTI. We used the Wilcoxon signed-rank test for continuous variables and the McNemar’s test for categorical variables.

Results

The analyzed ICUs had 40,772 patient days in the study period with a median ventilation utilization ratio of 56 (IQR 42–65). The median device-associated LRTI rate was 3.35 (IQR 0.96-5.36) per 1,000 ventilation days. We analyzed 49 patients with ICU-acquired LRTI and 49 respective controls without LRTI. The median hospital costs for LRTI patients were significantly higher than for patients without LRTI (45,041 € vs. 26,467 €; p < .001). The attributable costs per LRTI patient were 17,015 € (p < .001). Patients with ICU acquired LRTI stayed longer in the hospital than patients without (36 days vs. 24 days; p = 0.011). An LRTI lead to an attributable increase in length of stay by 9 days (p = 0.011).

Conclusions

ICU-acquired LRTI is associated with increased hospital costs and prolonged hospital stay. Hospital management should therefore implement control measurements to keep the incidence of ICU-acquired LRTI as low as possible.