Positive Tracheal Aspirate Research Articles

Ventilator-associated pneumonia risk factors in patients with severe COVID-19 in southern Brazil: A retrospective observational study

BackgoundDuring the SARS-CoV-2 pandemic, a significant number of critical patients required ventilatory assistance in health institutions. In this context, Ventilator-Associated Pneumonia (VAP) was the most prevalent nosocomial infection among critically ill patients. We aimed to analyze the occurrence of VAP in critically ill patients with SARS-CoV-2 and the risk factors associated with the outcome. MethodThis is a multicenter, retrospective cohort study which included patients ≥18 years old, diagnosed with COVID-19, admitted to intensive care units (ICU) and who received invasive mechanical ventilation (MV) for >2 consecutive days. The associations between the variables were initially tested, and those that showed potential associations (p<0.05) were included in the multivariate logistic regression model. ResultsOne third of patients had an episode of VAP, with an incidence density of 34.97 cases per 1000 MV days. In addition, 42.37% (50) of the microorganisms causing VAP were multidrug-resistant, predominantly gram-negative bacteria (61.32%). More than 50% of participants developed healthcare-associated infections and 243 (73.64%) died. The factors associated with greater chances of VAP were: prone position (OR= 3.77), BMI 25-29.9 kg/m2 (OR= 4.76), pressure injury (OR= 4.41), length of stay in the ICU (OR= 1.06), positive tracheal aspirate before VAP (OR= 5.41) and dyspnea (OR= 3.80). ConclusionsPatients with COVID-19 are at high risk of VAP, which leads to an increased risk of death (OR = 2.18). Multiple factors increase the chances of VAP in this population, namely: work overload in health institutions, prone position, prolonged ICU time, infusion of multiple drugs, invasive devices, and in particular, immobility in bed.

The Effect of Body Temperature Changes on the Course of Treatment in Patients With Pneumonia and Sepsis: Results of an Observational Study.

Traditionally, patients who are critically ill with infection and fever have been treated with antipyretics or even physically cooled. Presumed benefits of the reduction of body temperature are mostly based on decreased metabolic demands. However, it has been shown that decreasing body temperature in patients who are critically ill is not associated with improvement in treatment outcomes. Additionally, there is some data to support the use of temperature modulation (therapeutic hyperthermia) as an adjuvant treatment strategy in patients with infection. This study aims to determine the effect of body temperature on the course of intensive care unit (ICU) treatment of patients who are mechanically ventilated with pneumonia, sepsis, and positive tracheal aspirates on admission. We performed a single-center retrospective study. Core body temperature was measured in all patients. We analyzed associations between average temperatures in the first 48 hours after admission to ICU and ICU treatment parameters. Additionally, patients were divided into three groups: patients with negative tracheal aspirates 1 week after ICU admission (P-N group), patients with a different pathogen in tracheal aspirates 1 week after ICU admission (P-HAP group), and patients with a persisting pathogen in tracheal aspirates 1 week after ICU admission (P-P group). Differences in body temperature and interventions aimed at temperature modulation were determined. We observed a significantly higher average temperature in the first 48 hours after admission to ICU in patients who survived to hospital discharge compared to nonsurvivors (mean 37.2 °C, SD 1 °C vs mean 36.9 °C, SD 1.6 °C; P=.04). We observed no associations between average temperatures in the first 48 hours after ICU admission and days of mechanical ventilation in the first 7 days of treatment (ρ=-0.090; P=.30), the average maximum daily requirement for noradrenaline in the first 7 days of treatment (ρ=-0.029; P=.80), average maximum FiO2 in the first 7 days of ICU treatment (ρ=0.040; P=.70), and requirement for renal replacement therapy in the first 7 days of ICU treatment (mean 37.3 °C, SD 1.4 °C vs mean 37.0 °C, SD 1.3 °C; P=.23). In an additional analysis, we observed a significantly greater use of paracetamol in the P-N group (mean 1.0, SD 1.1 g vs mean 0.4, SD 0.7 g vs mean 0.4, SD 0.8 g; P=.009), a trend toward greater use of active cooling in the first 24 hours after ICU admission in the P-N group (n=11, 44% vs n=14, 33.3% vs n=16, 32%; P=.57), and no other significant differences in parameters of ICU treatment between patient groups. We observed better survival in patients who developed higher body temperatures in the first 48 hours after admission to the ICU; however, we observed no changes in other treatment parameters. Similarly, we observed greater use of paracetamol in patients with negative tracheal aspirates 1 week after ICU admission. Our results support the strategy of temperature tolerance in patients who are intubated with pneumonia and sepsis.

The effect of prolonged intubation on ventilator associated pneumonia: endotracheal tube cuff is really steril or not?

Aims: Endotracheal tube (ETT) design, size, cuff material, cuff pressure, and intubation duration are critical in preventing nosocomial pneumonia. We aimed to evaluate the possible infection focus potential of ETT cuff and pilot balloon, particularly in prolonged intubated patients. Methods: A total number of 66 patients who underwent orotracheal intubation and received conventional mechanical ventilation more than 48 hours in the intensive care unit (ICU), were included in this prospective cohort study. Results:The mean duration of intubation was 10.36±4.82 days. Bacteriologically confirmed positive tracheal aspirate culture was 18.2% (n=12). The most frequent positive culture was detected inside of ETT lumen with a percentage of 83.3% (n=55) and followed by cuff (27.3%, n=18), pilot balloon (13.6%, n=9), respectively. It was documented that rates of lung infections were significantly increased after 14 days (p = 0.017) and rates of cuff positive cultures were significantly increased after 10 and 14 days of incubation (p= 0.001, p=0.004). The same type of bacteriological strains was identified from both pilot balloon (n=9) and ETT cuff (n=9), simultaneously. In the remaining 9-cuff positive patients pilot balloons were sterile and ETT lumens were positive culture with the same strains as identified from the cuff. There was a statistically significant positive correlation between the intubation duration and the number of infected ETT parts (p&lt;0.001). Conclusion: ETT cuff was demonstrated to be a potential infection focus in the present study. In addition, it was observed that ETT cuff colonization increased in proportion to the intubation duration. We suggest changing ETT at appropriate time intervals in order to reduce ventilator-associated pneumonia in intubated patients.

Diagnosis of Bacterial Tracheostomy-Associated Respiratory Tract Infections in Pediatric Patients.

To identify demographic and clinical characteristics of children with fever and/or respiratory illness associated with a diagnosis of bacterial tracheostomy-associated respiratory tract infections (bTARTI). Secondary objectives included comparison of diagnostic testing, length of stay (LOS), and readmission rates between children diagnosed with bTARTI and others. We performed a retrospective chart review of encounters over 1 year for fever and/or respiratory illness at a single academic children's hospital for children with tracheostomy dependence. Patient characteristics, features of presenting illness, and laboratory and imaging results were collected. Generalized linear mixed models were employed to study associations between patient characteristics, diagnosis of bTARTI, and impact on LOS or readmission rates. Among 145 children with tracheostomies identified, 79 children contributed 208 encounters. bTARTI was diagnosed in 66 (31.7%) encounters. Significant associations with bTARTI diagnosis included chest radiograph consistent with bacterial pneumonia (odds ratio [OR], 1.77; 95% confidence interval [CI], 1.50-2.08), positive tracheal aspirate culture (OR, 1.3; 95% CI, 1.05-1.61), higher white blood cell count (16.4 vs 13.1 × 103/µ; P = .03), change in oxygen requirement (OR, 1.14; 95% CI, 1.00-1.31), telephone encounter (OR, 1.41; 95% CI, 1.09-1.81), and living at home with family (OR, 1.42; 95% CI, 1.06-1.92). LOS for admitted patients with bTARTI was 2.19 times longer (CI, 1.23-3.88). In our single-center study, we identified several clinical and nonclinical factors associated with a diagnosis of bTARTI. Despite widespread use, few laboratory tests were predictive of a diagnosis of bTARTI. There is need for standardization in diagnosis.

Indications for and Utility of Tracheal Aspirate Cultures for the Diagnosis of VAI

Background: Tracheal aspirate bacterial cultures are routinely collected in mechanically ventilated children for the evaluation of ventilator-associated infections (VAIs). However, frequent bacterial colonization of endotracheal and tracheostomy tubes contribute to the marginal performance characteristics of the test for diagnosing VAI. Published literature characterizing drivers of culture collection and the predictive value of positive cultures are limited. Methods: This single-center, retrospective cohort study included children admitted to the pediatric intensive care unit who were receiving mechanical ventilation for at least 48 hours and had 1 or more semiquantitative tracheal aspirate cultures collected between September 1, 2019, and August 31, 2020. Indications for culture collection were determined through medical record review and included fever, hypothermia, tracheal secretion changes, radiographic pneumonia, increased oxygen requirement, and/or increased positive end-expiratory pressure (PEEP). A positive culture was defined as moderate or heavy growth of a noncommensal bacterial organism. A purulent Gram stain was defined as detection of moderate or many white blood cells. Diagnosis of VAI was based on treating-clinician documentation and was ascertained through medical record review. Logistic regression accounting for clustering by patient was performed to estimate the association between indications for culture collection and (1) culture positivity, (2) purulent Gram stain, and (3) diagnosis of VAI. Results: In total, 625 tracheal aspirate cultures were performed in 261 unique patients. Common indications for culture collection included isolated fever or hypothermia (n = 124, 20%), fever with an increase in oxygen requirement or PEEP (n = 71, 11%), isolated increase in oxygen requirement or PEEP (n = 67, 11%), or isolated secretion change (n = 54, 9%) (Figure 1). Overall, 230 cultures (37%) were positive and 218 (35%) Gram stains were purulent. There were no associations between culture indications and a positive culture. Presence of isolated fever was negatively associated with a purulent Gram stain (odds ratio [OR], 0.49; 95% CI, 0.30–0.81; P = .005); otherwise, there were no associations between indication and purulent Gram stain. Finally, in a multivariable model, odds of VAI diagnosis increased with both the number of indications for culture collection and purulent Gram stain, but not with positive culture (Figure 2). Conclusions: Number and type of clinical signs were not associated with tracheal aspirate culture positivity or purulence on Gram stain, but they were associated with a clinical diagnosis of VAI. These findings suggest that positive tracheal aspirate cultures may not aid clinicians in the diagnosis of VAI, and they highlight the opportunity for improved diagnostic stewardship.Funding: NoDisclosures: None

Tocilizumab in Critically Ill COVID-19 Patients: An Observational Study

Tocilizumab is one of the IL-6 antagonists hypothesized to decrease the inflammatory response in the cytokine storm, postulated to be one of the mechanisms behind development of ARDS in COVID-19 patients. The objective of our study was to determine the response of tocilizumab in patients suffering from SARS-CoV-2 by analyzing the clinical parameters and inflammatory markers. A single-arm observational study was conducted from March 15, 2020, to March 15, 2021. The clinical outcomes in terms of mortality, weaning from mechanical ventilator, improvement in laboratory parameters including inflammatory cytokines and length of hospital stay were documented. Reduction in values of inflammatory markers and patients discharged home in stable condition was defined as improvement after tocilizumab administration. A total of 514 patients received tocilizumab. Critically sick patients 333 (64.8%) constituted he majority of study population. 363 (70.6%) patients were discharged home. Overall mean length of stay was found to be 11.50 ± 8.4 days. There was significant difference in length of stay of patients who required invasive mechanical ventilation as compared to those who were kept only on supplemental oxygen ( p <0.05) . Patients who were discharged showed significant improvement in all inflammatory markers and neutrophil to lymphocyte ratio as compared to those who expired ( p <0.05). 21 (4.1%) patients had a positive blood culture while 57 (11.1%) had a positive tracheal aspirate. In conclusion, tocilizumab is a reasonable therapeutic option for worsening COVID-19 pneumonia by decreasing the need for mechanical ventilation. However, its use is associated with significant adverse events including secondary bacterial and fungal infections.

Lack of utility of tracheal aspirates in the management of suspected pneumonia in intubated neonates.

To evaluate the utility of tracheal aspirates in suspected pneumonia in intubated neonates and to measure the burden of antibiotic use associated with a positive tracheal aspirate culture. Retrospective cohort study between January 2016 and December 2017. A level IV neonatal intensive care unit (NICU). Intubated patients with a tracheal aspirate culture. Data on temporally associated clinical measures of illness, laboratory and radiographic testing, and clinical demographic information were analyzed. Positive tracheal aspirate cultures were associated with lower birth weight and a normal immature to total neutrophil ratio (I/T ratio). Positive tracheal aspirates were not significantly associated with clinical, laboratory, or radiographic markers used in clinical practice to screen for infection. Despite the lack of positive clinical associations, a positive tracheal aspirate culture was associated with increased risk of prolonged antibiotic exposure. These findings suggest that positive tracheal aspirates do not always represent clinical infection and may result in unnecessary antibiotic exposure.

Decision-Making Around Positive Tracheal Aspirate Cultures: The Role of Neutrophil Semiquantification in Antibiotic Prescribing

Ventilator-associated infections are a major contributor to antibiotic use in the PICU. Quantitative or semiquantitative assessment of neutrophils (microscopic purulence) is routinely reported in positive cultures from tracheal aspirates. The role of microscopic purulence in guiding antibiotic therapy or its association with symptoms of ventilator-associated infections is less described in children. We examine microscopic purulence as an independent predictor of antibiotic use for positive tracheal aspirate cultures in the PICU. Retrospective cohort study. Tertiary care pediatric hospital. Children admitted to the PICU, neuro-PICU, or cardiac PICU with a positive tracheal aspirate culture from January 1, 2016, to December 31, 2016. None. Positive tracheal aspirate cultures were reviewed. The outcome variable was antibiotic treatment that targeted the positive tracheal aspirate culture. The predictor variable was microscopic purulence, defined as moderate or many neutrophils on Gram stain report. Competing predictors included demographics, comorbidities, vital signs changes, respiratory support, and laboratory values. Of 361 positive cultures in the cohort, 81 (22%) were treated with antibiotics. Positive cultures with microscopic purulence were targeted for therapy more frequently (30% vs 11%). Microscopic purulence was the strongest predictor for antibiotic therapy (odds ratio, 3.3; 95% CI, 1.6-6.8) compared with fever (odds ratio, 2.0; 95% CI, 1.0-4.1) or increased respiratory support (odds ratio, 2.3; 95% CI, 1.2-4.3). There was no significant variation in symptomatology between microscopic purulence reported as moderate or many versus other (e.g., fever -24% vs 22%, increased respiratory support -36% vs 28%). Microscopic purulence was less prevalent with longer ventilator durations at the time of sampling. Microscopic purulence was an independent predictor of antibiotic therapy for positive tracheal aspirate cultures in our PICUs. However, microscopic purulence was not associated with clinical symptomatology.

A multicenter, randomized, double-blind study of ulimorelin and metoclopramide in the treatment of critically ill patients with enteral feeding intolerance: PROMOTE trial.

Enteral feeding intolerance (EFI) is a frequent problem in the intensive care unit (ICU), but current prokinetic agents have uncertain efficacy and safety profiles. The current study compared the efficacy and safety of ulimorelin, a ghrelin agonist, with metoclopramide in the treatment of EFI. One hundred twenty ICU patients were randomized 1:1 to ulimorelin or metoclopramide for 5days. EFI was diagnosed by a gastric residual volume (GRV) ≥ 500ml. A volume-based feeding protocol was employed, and enteral formulas were standardized. The primary end point was the percentage daily protein prescription (%DPP) received by patients over 5days of treatment. Secondary end points included feeding success, defined as 80% DPP; gastric emptying, assessed by paracetamol absorption; incidences of recurrent intolerance (GRV ≥ 500ml); vomiting or regurgitation; aspiration, defined by positive tracheal aspirates for pepsin; and pulmonary infection. One hundred twenty patients were randomized and received the study drug (ulimorelin 62, metoclopramide 58). Mean APACHE II and SOFA scores were 21.6 and 8.6, and 63.3% of patients had medical reasons for ICU admission. Ulimorelin and metoclopramide resulted in comparable %DPPs over 5days of treatment (median [Q1, Q3]: 82.9% [38.4%, 100.2%] and 82.3% [65.6%, 100.2%], respectively, p = 0.49). Five-day rates of feeding success were 67.7% and 70.6% when terminations unrelated to feeding were excluded, and there were no differences in any secondary outcomes or adverse events between the two groups. Both prokinetic agents achieved similar rates of feeding success, and no safety differences between the two treatment groups were observed.

Silver-Coated Endotracheal Tubes Cleaned With a Mechanism for Secretion Removal.

Biofilm on the surface of endotracheal tubes (ETTs) is associated with ventilator-associated pneumonia. The use of silver-coated ETTs has been suggested to reduce the occurrence of ventilator-associated pneumonia by preventing biofilm formation. However, mucus accumulation can reduce the antibacterial activity of silver-coated ETTs by isolating bacterial colonies from the silver surface. We hypothesized that, in mechanically ventilated subjects, periodic removal of secretions through the use of a cleaning device would enhance the antimicrobial properties of silver-coated ETTs and thus reduce bacterial colonization. Subjects were randomized to either standard suctioning (blind tracheal suctioning, control group) or blind tracheal suctioning plus cleaning maneuver every 8 h (treatment group). Tracheal aspirates were collected immediately before extubation for microbiological culture. After extubation, ETTs were collected for both cultural and non-cultural microbiological analysis and biofilm isolation. 39 subjects expected to be ventilated for > 48 h were enrolled; 36 ETTs (18 control, 18 treatment) and 29 tracheal samples (15 control, 14 treatment) were collected. Among the ETTs positive for bacterial colonization (15 vs 9, P = .18), cleaning maneuvers did not reduce microbial load, shown as the decimal logarithm of colony-forming units (CFU) per mL (1.6 ± 1.2 vs 0.9 ± 1.2 logCFU/mL, P = .15). There was a trend toward decreased biofilm deposition (439.5 ± 29.0 vs 288.9 ± 157.7 mg, P = .09) in the treated ETTs. No significant differences were observed in the number of positive tracheal aspirates (13 vs 10, P = .39) or in the microbial load (4.8 ± 4.0 vs 4.2 ± 3.8 logCFU/mL, P = .70) of tracheal secretions. Finally, no differences in the microbial load of Gram-positive organisms, Gram-negative organisms, or yeasts were found between the ETTs and tracheal aspirates of the 2 groups. In 39 critically-ill subjects intubated with silver-coated ETTs, periodic cleaning maneuvers did not decrease bacterial colonization of the ETTs and did not lower respiratory tract colonization compared to the standard suctioning. (Clinicaltrials.gov registration NCT02120001.).

Incidence of Ventilator-associated pneumonia in the critical care unit at Kenyatta National Hospital, a public tertiary care hospital

Background: Ventilator-associated pneumonia (VAP), a severe type of hospitalacquired pneumonia develops 48-72 hours after initiation of mechanical ventilation. Objectives: This study aimed to determine incidence of VAP using the Clinical Pulmonary Infection Score (CPIS) which combines clinical, radiographic, physiologic and microbiological data into a numerical result, ranging from 0 to 12, and to identify risk factors associated with its development. A secondary objective was to assess the diagnostic utility of a positive culture of pathogenic bacteria on tracheal aspirate in predicting a positive culture on a mini-Broncho Alveolar Lavage (Mini-BAL). Design: A hospital-based, prospective cross-sectional study carried between 01st January 2015 to 31st March 2015. Setting: Kenyatta National Hospital, a tertiary care hospitalSubjects: Ninety-two subjects who met the inclusion criteria were included. Results: Of the 92 patients studied, 50 had a CPIS of ≥6, an incidence of 54.4% (C.I. 44.0-64.7%). Factors that appeared to show an association with VAP included documented aspiration (OR 2.0), a high nurse to patient ratio (OR 4.0), postsurgical patients (OR 2.5) and those who were nasally intubated (OR 4.0) and those with oral candidiasis (OR 3.5). Of the 50 patients that showed a CPIS of ≥6, 46 (92%) patients had a positive culture on tracheal aspirate and 31 (62%) patients demonstrated a positive mini-BAL culture. The sensitivity and specificity of a positive tracheal aspirate in predicting a positive min-BAL culture were 100% (C.I 88.7-100.0%) and 21.1% (C.I 6.2-45.6%) respectively. Negative predictive value of 100.0% (C.I 40.2-100.0%) and a positive predictive value of 67.4% (C.I 52.0-80.5%). Conclusion: Our study, the first documented in East Africa, found a high incidence of VAP. Further studies are needed to compare the diagnostic utility of various invasive and non-invasive tests for diagnosis of VAP.

Epidemiology of bacteriological analyses in adult patients supported by veinoarterial extracorporeal membrane oxygenation

Nosocomial infections (NIs) occurrence during veno-arterial extracorporeal membrane oxygenation (VA-ECMO) support and their complications appear to contribute to the high mortality rates (40–60%) of these patients. The most common ones are ventilator-associated pneumonia and bloodstream infections (BSI). In clinical practice, detection of NIs is difficult due to confounding factors caused by the device. The objectives of our study were to analyze BSI and positive tracheal aspirate (TA) culture incidences, distribution of microorganisms and risk factors in adult undergoing veinoarterial ECMO (VA-ECMO). We prospectively and consecutively included all adult patients who underwent VA-ECMO between May 2014 and March 2016 in our intensive care unit. Anamnestic data, blood culture and TA culture were analyzed. Primary endpoint was the occurrence of a BSI or a positive TA culture more than 24 hours after ECMO initiation and within 48 hours after ECMO discontinuation. Among the 56 patients who underwent ECMO support for more than 48 hours, the BSI prevalence was 27.4 cases per 1000 ECMO days and microorganisms associated were most frequently gram-negative bacilli. As for positive TA cultures, microorganisms associated were oropharyngeal germs and gram-negative bacilli. Two risk factors were associated with nosocomial bacteria occurrence in TA cultures: prior antibiotics and duration of mechanical ventilation more than 5 days. We demonstrated a link between “positive TA culture” and “positive blood culture” and we showed a protective effect of using an antibioprophylaxis on “positive TA culture” and “global positive cultures” development ( Table 1 ). Use of an antibioprophylaxis at ECMO implantation is associated with a decrease of global positive cultures development.

Middle East respiratory syndrome coronavirus on inanimate surfaces: A risk for health care transmission

The Middle East Respiratory syndrome coronavirus (MERS-CoV) has been responsible for multiple health care–associated outbreaks. We investigated whether high-touch surfaces in 3 rooms of laboratory-confirmed MERS-CoV patients were contaminated with MERS-CoV RNA. We found 2 out of 51 surfaces were contaminated with MERS-CoV viral genetic material. Hence, environmental contamination may be a potential source of health care transmission and outbreaks. Meticulous environmental cleaning may be important in preventing transmission within the health care setting.

The Association between Positive Tracheal Aspirate Cultures and Adverse Pulmonary Outcomes in Preterm Infants with Severe Bronchopulmonary Dysplasia.

Objective Bacterial colonization of the airway may contribute to the development of bronchopulmonary dysplasia. Whether airway colonization increases risk for later adverse respiratory outcomes is less clear. We described tracheal aspirate culture results obtained from preterm infants receiving mechanical ventilation at 36 weeks postmenstrual age (PMA) and evaluated the association between bacteria type and the risk for prolonged supplemental oxygen use. Study Design We conducted a retrospective, single-center cohort study comparing infants (1) with and without a tracheal aspirate culture that grew a Gram-negative rod (GNR) and (2) with and without a culture that grew a Gram-positive cocci (GPC). Results Among 121 infants, 65 (53.7%) and 51 (42.2%) had a tracheal aspirate culture that grew a potentially pathogenic GNR and GPC prior to 36 weeks PMA, respectively. GNR were associated with increased risk for death or use of supplemental oxygen at discharge (adjusted odds ratio [aOR], 6.2; 95% confidence interval [CI], 1.8-21.1), and use of supplemental oxygen at discharge among survivors (aOR, 5.5; 95% CI, 1.6-19.0). GPC did not affect the risk for any study outcomes. Conclusion GNR but not GPC in the airways of preterm infants receiving mechanical ventilation at 36 weeks PMA is associated with increased risk for prolonged supplemental oxygen use.

Diagnosis of Ventilator-Associated Pneumonia: A Pilot, Exploratory Analysis of a New Score Based on Procalcitonin and Chest Echography

BACKGROUND:To facilitate the clinical diagnosis of ventilator-associated pneumonia (VAP) in the ICU, the Clinical Pulmonary Infection Score (CPIS) has been proposed but has shown a low diagnostic performance in subsequent studies. We propose a new score based on procalcitonin level and chest echography with the aim of improving VAP diagnosis: the Chest Echography and Procalcitonin Pulmonary Infection Score (CEPPIS).METHODS:This retrospective pilot study recruited patients admitted to the Intensive Care Unit of the Emergency Department, Careggi University Hospital (Florence, Italy), from January 2009 to December 2011. Patients were retrospectively divided into a microbiologically confirmed VAP group or a control group based on diagnosis of VAP and positive tracheal aspirate culture.RESULTS:A total of 221 patients were included, with 113 in the microbiologically confirmed VAP group and 108 in the control group. A CEPPIS > 5 retrospectively fixed was significantly better in predicting VAP (OR, 23.78; sensitivity, 80.5%; specificity, 85.2%) than a CPIS > 6 (OR, 3.309; sensitivity, 39.8%; specificity, 83.3%). The receiver operating characteristic area under the curve analysis also showed a significantly higher diagnostic value for CEPPIS > 5 than CPIS > 6 (0.829 vs 0.616, respectively;P< .0001).CONCLUSIONS:In this pilot, exploratory analysis, CEPPIS is effective in predicting VAP. Prospective validation is needed to confirm the potential value of this score to facilitate VAP diagnosis.

The Lack of Specificity of Tracheal Aspirates in the Diagnosis of Pulmonary Infection in Intubated Children

Ventilator-associated pneumonia is the first or second most commonly diagnosed nosocomial infection in the PICU. Centers for Disease Control diagnostic criteria include clinical signs or symptoms in conjunction with a "positive" tracheal aspirate, defined as more than 10 colony-forming units/mL of bacteria on quantitative culture and/or more than 25 polymorphonuclear neutrophils per low-power field on Gram stain. We hypothesized that tracheal aspirate cultures and Gram stains would not correlate with clinical signs and symptoms and would therefore not distinguish between colonization and infection. Prospective observational study. PICU in an academic tertiary care center. Children intubated more than 48 hours. Sequential tracheal aspirate quantitative cultures and Gram stains in conjunction with daily collection of concordant clinical signs and symptoms. Time since intubation correlated strongly (p < 0.001) with the proportion of positive (> 10 colony-forming units/mL) tracheal aspirate quantitative cultures, but Centers for Disease Control-defined clinical signs or symptoms of ventilator-associated pneumonia, either singly or in combination, did not. Use of in-line suction catheters versus new, sterile catheters to obtain tracheal aspirates was associated with significantly greater proportion of positive tracheal aspirate bacterial cultures (p < 0.001). Most subjects had more than 25 polymorphonuclear neutrophils per low-power field on Gram stain; polymorphonuclear neutrophils on Gram stain correlated with positive bacterial culture (p = 0.04). Seventy-seven percent of the bacterial isolates detected in positive quantitative cultures were "pathogens." Antibiotic use at the time tracheal aspirates were obtained was associated with a lower frequency of positive quantitative cultures only with antibiotic regimens that included cefepime. Positive bacterial cultures of tracheal aspirates increase rapidly after intubation and usually include bacteria considered to be pathogens. Tracheal aspirate cultures and Gram stains do not appear to distinguish between infection and colonization. Antibiotic regimens that include cefepime decrease the frequency of positive cultures, but the significance of this is unclear.

Accuracy of Alpha Amylase in Diagnosing Microaspiration in Intubated Critically-Ill Patients

ObjectivesAmylase concentration in respiratory secretions was reported to be a potentially useful marker for aspiration and pneumonia. The aim of this study was to determine accuracy of α-amylase in diagnosing microaspiration in critically ill patients.MethodsRetrospective analysis of prospectively collected data collected in a medical ICU. All patients requiring mechanical ventilation for at least 48 h, and included in a previous randomized controlled trial were eligible for this study, provided that at least one tracheal aspirate was available for α-amylase measurement. As part of the initial trial, pepsin was quantitatively measured in all tracheal aspirates during a 48-h period. All tracheal aspirates were frozen, allowing subsequent measurement of α-amylase for the purpose of the current study. Microaspiration was defined as the presence of at least one positive tracheal aspirate for pepsin (>200 ng.mL−1). Abundant microaspiration was defined as the presence of pepsin at significant level in >74% of tracheal aspirates.ResultsAmylase was measured in 1055 tracheal aspirates, collected from 109 patients. Using mean α-amylase level per patient, accuracy of α-amylase in diagnosing microaspiration was moderate (area under the receiver operator curve 0.72±0.05 [95%CI 0.61–0.83], for an α-amylase value of 1685 UI.L−1). However, when α-amylase levels, coming from all samples, were taken into account, area under the receiver operator curve was 0.56±0.05 [0.53–0.60]. Mean α-amylase level, and percentage of tracheal aspirates positive for α-amylase were significantly higher in patients with microaspiration, and in patients with abundant microaspiration compared with those with no microaspiration; and similar in patients with microaspiration compared with those with abundant microaspiration. α-amylase and pepsin were significantly correlated (r2 = 0.305, p = 0.001).ConclusionAccuracy of mean α-amylase in diagnosing microaspiration is moderate. Further, when all α-amylase levels were taken into account, α-amylase was inaccurate in diagnosing microaspiration, compared with pepsin.

Impact of appropriate antimicrobial treatment on transition from ventilator-associated tracheobronchitis to ventilator-associated pneumonia.

IntroductionTwo small randomized controlled trials have suggested beneficial effects of antibiotic treatment in patients with ventilator-associated tracheobronchitis (VAT). The primary aim of this study is to determine the impact of appropriate antibiotic treatment on transition from VAT to ventilator-associated pneumonia (VAP) in critically ill patients. The secondary objective was to determine the incidence of VAP in patients with VAT.MethodsThis was a prospective observational multicenter study. All patients with a first episode of VAT were eligible. Patients with tracheostomy at intensive care unit (ICU) admission, and those with VAP prior to VAT were excluded. VAT was defined using all the following criteria: fever > 38°C with no other cause, purulent tracheal secretions, positive tracheal aspirate (≥105 cfu/mL), and absence of new infiltrate on chest X ray. Only VAP episodes diagnosed during the 96 h following VAT, and caused by the same bacteria, were taken into account. Antibiotic treatment was at the discretion of attending physicians. Risk factors for transition from VAT to VAP were determined using univariate and multivariate analysis. All variables from univariate analysis with P values <0.1 were incorporated in the multivariate logistic regression analysis.ResultsOne thousand seven hundred and ten patients were screened for this study. Eighty-six, and 123 patients were excluded for tracheostomy at ICU admission, and VAP prior to VAT; respectively. One hundred and twenty two (7.1%) patients were included. 17 (13.9%) patients developed a subsequent VAP. The most common microorganisms in VAT patients were Pseudomonas aeruginosa (30%), Staphylococcus aureus (18%), and Acinetobacter baumannii (10%). Seventy-four (60%) patients received antimicrobial treatment, including 58 (47.5%) patients who received appropriate antimicrobial treatment. Appropriate antibiotic treatment was the only factor independently associated with reduced risk for transition from VAT to VAP (OR [95% CI] 0.12[0.02-0.59], P = 0.009). The number of patients with VAT needed to treat to prevent one episode of VAP, or one episode of VAP related to P. aeruginosa was 5, and 34; respectively.ConclusionsAppropriate antibiotic treatment is independently associated with reduced risk for transition from VAT to VAP.

Ventilator-associated tracheobronchitis: where are we now?

Histological studies revealed a continuum between these two infections. Several definitions are available for VAT. However, all of these definitions have some limitations. The most accepted and frequently used definition include the following criteria: fever >38o C with no other cause, purulent tracheal secretions, positive tracheal aspirate (≥10

Exploring the Use of Mothers' Own Milk as Oral Care for Mechanically Ventilated Very Low-Birth-Weight Preterm Infants

The purpose of this study was to explore the use of mothers' own milk (colostrums, transitional milk, and mature milk) as oral care in the ventilator-associated pneumonia (VAP)-prevention bundle of mechanically ventilated preterm infants weighing 1500 g or less. Mechanically ventilated preterm infants weighing 1500 g or less admitted to a regional level III NICU in the Gulf South between January 1, 2006, and December 31, 2009. Retrospective descriptive. Oral care with mothers' own milk was implemented as part of the VAP-prevention bundle in the neonatal intensive care unit in the fourth quarter of 2007. Using retrospective deidentified data retrieved from the electronic medical record, the primary and secondary outcome variables were collected among eligible infants (≤1500 g) admitted January 1, 2006, to December 31, 2007 (before implementation) and January 1, 2008, to December 31, 2009 (after implementation). Sample characteristics, including infant gestational age, birth weight, and gender, as well as maternal age, type of delivery, and incidence of maternal chorioamnionitis, were also collected. Data analysis included frequencies and distributions to summarize sample characteristics and variables of interest. Appropriate tests for differences were conducted on outcome variables between the before and after groups of the human milk oral care intervention. The feasibility outcome variable included nursing compliance with the oral care procedure. The safety outcome variable included record of any adverse events associated with the oral care procedure. The efficacy health outcomes included the rate of positive tracheal aspirates, positive blood cultures, the number of ventilator days, and length of stay. Infant age (26.1-26.6 weeks) and weight (840-863 g) were similar in the before (n = 70) and after (n = 68) sample subjects. There were no statistically significant differences in ventilator days, χ² (46, n = 115) = 46.22, P = .46, and length of stay, χ (75, n = 115) = 78.78, P = .36, between groups. Although the rate of positive tracheal aspirates and positive blood cultures reduced after implementation of oral care with mothers' own milk, these differences were not statistically significant (U(47) = 250, z = -7.1, P = .48; U(47) = 217.5, z = -1.44, P = .15). There were no statistically significant differences in the rates of positive tracheal aspirates and blood cultures after implementation of oral care with mothers' own milk. The findings of this study suggest that using mothers' own milk as part of the VAP-prevention bundle is a feasible and safe practice; however, further research is needed to determine the immunological benefits of this practice.