Diagnosis Of Pneumonia In Patients Research Articles

The study on the predictive accuracy of artificial intelligence (AI) Lunit INSIGHT CXR Version 3.0 for pneumonia diagnosis in COVID-19 patients

Background: Millions of people in Thailand have been infected and died from the infection of the COVID-19. As a result, the country’s public health system is greatly affected due to the limitation of the number of physicians. Artificial intelligence (AI) is, therefore, used to reduce the working load of physicians in the diagnosis of COVID-19 patients. Objective: To study on the predictive accuracy of AI Lunit INSIGHT CXR Version 3.0 for pneumonia diagnosis in COVID-19 patients. Materials and Methods: This study was a retrospective study. The data was collected from 256 confirmed cases of COVID-19 infection admitted as new patients in the Nimibutr Pre-Admission Centre of the Institute of Neurology, the Ministry of Public Health. They were randomly selected from the database. Seven radiologists and Lunit INSIGHT CXR Version 3.0 software interpret the CXR film to diagnose pneumonia in COVID-19 patients from chest radiographs (CXR). Results: The research results of the diagnosis of pneumonia in patients infected with COVID-19 between from radiologists and using AI Lunit INSIGHT CXR Version 3.0 software revealed 97.87% (95%CI 88.71-99.95%) of sensitivity, 99.04% (95%CI 96.59-99.88%) of specificity, accuracy = 98.83%, positive predictive value (PPV) = 95.83%, and negative predictive value (NPV) = 99.52%, positive likelihood ratio (+LR) = 102.28, negative likelihood ratio (-LR) = 0.02. Conclusion: The artificial intelligence software Lunit INSIGHT CXR Version 3.0 can be used to interpret the diagnosis of pneumonia in patients infected with COVID-19 in order to reduce radiologists’ workloads during the COVID pandemic when medical staff were limited.

2420. Analysis of Diagnostic Criteria for ECMO-Associated Pneumonia

Abstract Background Ventilator-associated pneumonia (VAP) is a well-established cause of morbidity and mortality in critically ill patients, but diagnostic criteria exclude patients on extracorporeal membrane oxygenation (ECMO). Despite this, VAP has been used to approximate pneumonia in patients on ECMO for study purposes (Figure 1). An adequate definition to recognize and prevent nosocomial pneumonia in this population is needed. Our institution began looking at a set of diagnostic criteria for EAP (ECMO-Associated Pneumonia, Figure 2). We performed a retrospective analysis to test the validity of VAP and our new EAP definition as diagnostic criteria for pneumonia in ECMO patients.Figure 1.Criteria for Probable VAP. Simplified from NHSN criteria. VAC=ventilator-associated condition. iVAC=infection-related ventilator-associated condition. VAP=ventilator-associated pneumonia.Figure 2.Proposed diagnostic criteria for ECMO-associated pneumonia (EAP) Methods Our center maintains a database of clinical parameters for patients on ECMO, which includes outcomes of interest verified in real time. Patient charts coded as having an outcome of pneumonia from 2018 to 2021 were pulled and independently adjudicated to determine if they met our inclusion criteria (Figure 3). 20 patients were identified as having at least one event. We observed their stay on ECMO up to 30 days. We calculated the established VAP criteria (Figure 1) and our proposed EAP criteria (Figure 2) daily. Dates of clinical pneumonia were time of positive culture and subsequent 5 days.Figure 3.Selection process for study population. BAL=bronchoalveolar lavage Results 85% of patients were on VV ECMO and 50% patients with SARS-CoV-2 (Table 1). In 20 patients with clinically diagnosed, culture confirmed pneumonia, only 1% of patients met criteria for Probable VAP (sensitivity 4%, Table 2). Probable EAP Definition 2 was the most sensitive model for predicting clinical pneumonia (sensitivity 91.1%), followed distantly by the Confirmed EAP model (sensitivity 19.6%). The EAP model had a stronger relationship with clinical pneumonia than the VAP model as demonstrated by the ROC curves (Figure 4). Individual components (flow, sweep, FiO2, PEEP) could not predict onset of clinical pneumonia within 48 to 72 hours.Table 1.Characteristics of study population Table 2. Percentage of days with pneumonia as identified by each set of diagnostic criteria, with sensitivity calculated. Figure 4 ROC curves for comparison. Probable EAP Definition 2 had the highest sensitivity for diagnosing EAP. Conclusion Our study reiterates that VAP criteria should not be used to approximate diagnosis of pneumonia in patients on ECMO. As oxygenation and sepsis triggers adjustment of flow and sweep we found this in combination with infectious parameters, and BAL culture that was more sensitive in predicting clinical pneumonia. These measures require validation in a larger cohort. Disclosures James Kirklin, MD, Data Center for STS Intemacs/Pedimacs Registries: Director, partial salary support|Kirklin Solutions, Inc.: Ownership Interest

THE FEATURES OF THE RADIOLOGICAL IMAGE OF COMMUNITY-ACQUIRED PNEUMONIA AT INTERSTITIAL LUNG DISEASES

Community-acquired pneumonia (CAP) in patients with interstitial lung diseases is a terrible complication and has an atypical course. Diagnosis of CAP is difficult, since the clinical symptoms of inflammation are similar to those of ILD. The results of radiation studies are not pathognomonic, they are not always correctly interpreted, which leads to errors in diagnosis, delay in the examination and treatment of the patient.Aims: to evaluate the possibilities of CT in the detection and differential diagnosis of pneumonia in patients with ILD.Material and methods. The results of a complex clinical and radiological studies of 336 patients with IZL, 48 patients showed infiltrative changes in the lungs that were not characteristic of the main process.Results. Nonspecific inflammatory changes in the lung tissue were manifested by the following CT symptoms: alveolar type with local infiltration of the lung tissue corresponding to the segmental structure of the lungs (segment, lobe), the appearance of peribronchial alveolar type lung tissue that is not characteristic of radiation semiotics of the underlying disease.Conclusions: рerforming CT and VRKT reveals the appearance of infiltrative and focal changes that are atypical for IL, characteristic of specific and non-specific inflammatory processes, which affects the treatment tactics of patients.

2008. Effective and Early Diagnosis of Pneumonia in Patients With Acute Leukemia in a Comprehensive Cancer Center: How Can We Improve the Microbiological Diagnosis?

BackgroundPneumonia is one of the main causes of morbi-mortality in acute leukemia (AL) patients. The positive yield of microbiology diagnosis is still significantly low. The aim of the study was to evaluate the possible impact of use of diagnostic methods (within first 48 hours of diagnosis) in AL patients with pneumonia during chemotherapy.MethodsRetrospective study (January 2017–December 2017) at MD Anderson Cancer Center. The medical records of adult patients with AML, MDS, or ALL who developed CT-confirmed pneumonia after induction or second-line chemotherapy were reviewed, including demographic, clinical, microbiology data, and outcomes.ResultsDuring 2017, 174 patients with AL developed pneumonia confirmed by CT chest. Fifty (29%) of them during induction/second-line chemotherapy: 42 (84%) AML, five (10%) MDS, and three (6%) ALL. Thirty-one (62%) showed consolidation in CT, 14 (28%) nodules, and five (10%) both findings. Mean age was 65 (SD: 11.5, range: 24–87) years with 46% males. Thirty-three (66%) patients had neutropenia (ANC<500) at the time of pneumonia. ID was consulted in 38 (76%) and pulmonary in 37 (74%) patients. Bronchoscopy/BAL (bronch) was performed in only 24 (48%) patients, still with the highest diagnostic yield (13/24, 54%) compared with other diagnostic methods (sputum and blood cultures; and galactomannan, β-glucan, and cryptococcal antigen in serum). Twelve of 24 (50%) patients had an early bronch (within 48 hours), with higher identification of bacteria (3/12, 25%), fungi (2/12, 16.7%), and virus (3/12, 25%) compared with those 12 performed later. A trend of more viral infection (6/12, 50%), including CMV, was found in late-performed bronch (>48 hours after diagnosis). The patients with early bronch were sicker, with higher rate of ICU admission (42% vs. 0% in late group) and in-hospital mortality (25% vs. 8% in late group). However, those patients who underwent bronch later had a higher rate of 30-day re-admission (33% vs. 22% in early group).ConclusionBronchoscopy/BAL was the best diagnostic test in patients with AL and CT-confirmed pneumonia, even though it was only performed in 48% of patients. Early bronchoscopy (first 48 hs) has better diagnostic yield than late bronchoscopy (>48 hs), directing the antimicrobial therapy on these patients (based on the identification of bacteria, fungus or viruses), and decreasing the 30-day re-admission rate. Disclosures J. Adachi, Merck: Grant Investigator, Research grant.

Diagnostic and Prognostic Utility of Procalcitonin in Patients Presenting to the Emergency Department with Dyspnea

BackgroundAmong patients in the emergency department, dyspnea is a common complaint and can pose a diagnostic challenge. Biomarkers are used increasingly to improve diagnostic accuracy and aid with prognostication in dyspneic patients. The purpose of this study was to examine the clinical utility of serum procalcitonin (PCT) for the diagnosis of pneumonia in patients presenting to the emergency department with dyspnea. A secondary objective was to evaluate the prognostic value of PCT for death to 1 year. MethodsThis study pooled the patient populations of 2 prospective cohorts that previously enrolled patients presenting to 2 urban emergency departments with dyspnea. A total of 453 patients had serum samples available for biomarker analysis. Clinician certainty for the diagnosis of acutely decompensated heart failure was reviewed. Discrimination, calibration, and net reclassification improvement for the diagnosis of pneumonia as well as fatal outcomes were considered. The main outcome was accuracy of PCT for diagnostic categorization of pneumonia. The prognostic value of PCT for survival to 1 year was a secondary outcome. ResultsPneumonia alone was diagnosed in 30 patients (6.6%), heart failure without pneumonia in 212 patients (47%), and both diagnoses in 30 patients (6.6%). Procalcitonin concentrations were higher in subjects with pneumonia (0.38 vs 0.06 ng/mL; P < .001). Area under the receiver operating characteristic curve for the diagnosis of pneumonia based on PCT was 0.84 (95% confidence interval [CI], 0.77-0.91; P < .001). Across all levels of clinician-based estimates of heart failure, PCT was sensitive and specific; notably, in patients judged with diagnostic uncertainty (n = 70), a PCT value of 0.10 ng/mL had the optimal balance of sensitivity and specificity (80% and 77%, respectively) for pneumonia. Adding PCT results to variables predictive of pneumonia resulted in a net reclassification improvement of 0.54 (95% CI, 0.24-0.83; P < .001) for both up- and down-reclassifying events. In adjusted analyses, elevated PCT was a predictor of 1-year mortality (hazard ratio 1.8; 95% CI, 1.4-2.3; P < .001) and was additive when elevated in conjunction with natriuretic peptides for this application. ConclusionIn emergency department patients with acute dyspnea, PCT is an accurate diagnostic marker for pneumonia and adds independent prognostic information for 1-year mortality.

Hospital-acquired pneumonia in patients undergoing coronary artery bypass graft; comparison of the center for disease control clinical criteria with physicians' judgment.

Background:Following coronary artery bypass graft (CABG), patients are at high risk (3.2%-8.3%) for developing hospital-acquired pneumonia (HAP) with mortality rate of 24% to 50%. Some of routine features in patients undergoing CABG are similar to clinical criteria of Center of Disease Control (CDC) for diagnosis of pneumonia. This may lead to over-diagnosis of pneumonia in these patients.Objectives:This study aimed to assess the frequency of CDC criteria for diagnosis of pneumonia in patients undergoing CABG.Patients and Methods:This study was performed on CABG candidates admitted to post cardiac surgery Intensive Care Unit (ICU) in a six-month period. Patient’s records, Chest-X-Ray, and Laboratory tests were assessed for PNU1-CDC criteria for HAP diagnosis. At the same time, a physician who was unaware of the study protocol assessed the clinical diagnosis. Then the results were compared with CDC criteria-based diagnosis.Results:Of total 300 patients, 9 (3%) met CDC criteria for diagnosis of pneumonia while none of the cases were diagnosed as HAP according to the physicians’ clinical diagnosis. All nine patients were discharged with proper general condition and no need of antibiotic therapy. This study showed that loss of consciousness, tachypnea, dyspnea, PaO2 < 60 mm Hg, PaO2/FiO2 < 240, and local infiltration in 24 hours of operation were misleading features of CDC criteria, which were not considered in physicians’ clinical judgment to establish the diagnosis.Conclusions:Our findings suggest that in Post-CABG patients, physicians could judge the occurrence of HAP more accurately in comparison to making the diagnosis based on CDC criteria alone. Expert physician may intentionally do not take some of these criteria into account according the patients’ course of disease. Therefore, it is suggested that the value of these criteria in special group of patients like those undergoing CABG should be re-evaluated.

Postliver Transplantation Pulmonary Complications

We appreciate your thoughtful response to our recent manuscript on pulmonary complications after elective liver transplantation (1). We would like to begin with a few general comments and then address your specific queries individually. The diagnosis of pneumonia is challenging for physicians who care for critically ill patients. In the setting of liver transplantation with immunocompromised patients, underestimating the probability of pneumonia can lead to increased mortality. For us, these patients should be treated aggressively to diminish the morbidity and mortality associated with these complications. Conversely, overestimated probability of pneumonia can lead to inappropriate antibiotic use with emergence of multiresistant organisms in patients with many hospitalizations. Consistent with previous studies in critical care and, in particular, the study recently published by Weiss et al. (2), in the liver transplantation context, we choose a combined criteria, widely accepted (3), to retain the diagnosis of pneumonia in patients admitted in the intensive care unit after liver transplantation. In practice, in patients with several criteria of pneumonia and a microorganism identified, the diagnosis of pneumonia has been retained (n=39). In the situation where no microorganism has been isolated (because the samples were not feasible because of the severity of patients or because the results were negative), the calculation of the modified clinical pulmonary infection score allowed a positive confirmation of the diagnosis of pneumonia (n=16). In this subgroup of our cohort, the modified clinical pulmonary infection score value is 7 (5–9). Among the 55 episodes of pneumonia, the rate of ventilator-associated pneumonia was 49% (27/55). In our cohort, no patient was still on antibiotics prophylaxis (piperacillin for the first 48 hr) when the diagnosis of pneumonia was retained. However, in three patients, where a diagnosis of late pulmonary infection (>6 days) was made, the patients were already on antibiotics. In these three cases, a new microorganism (Pseudomonas) had been isolated resistant to the previous antibiotic treatment. Although there is a lack of information in the data provided by Hong et al. (4) (only 7 patients with infectious complications after liver transplantation in their article), it may be interesting to know whether there is a correlation between the infection, the acute cellular rejection, and the immunosuppressive regimen. The aim of our study was to identify risk factors for pulmonary complications among preoperative and intraoperative variables. We did not seek to find the associated factors of pneumonia. However, in our cohort, we have diagnosed 27 patients with a history of acute cellular rejection (confirmed by a liver histology with the Banff internationally accepted criteria [5]). No significant difference has been found between patients who developed pneumonia and those who did not (4 [8.5%] in patients with pneumonia and 23 [13.9%] in patients without pneumonia, P=0.45). The same reasoning can be held for patients with renal dysfunction, and no association between dialysis and pneumonia has been observed. We thank the readers for their comment about the age of recipients: an error has crept into the text. Indeed, patients who developed pneumonia were older in the univariate analysis (P=0.036). In the logistic regression analysis, the age was not an independent risk factor of pneumonia. For the study, we did not modify the practice in the preoperative management of ascites and pleural effusions, including the period before performing the pulmonary function tests. Our results require us to question the preoperative management of patients awaiting transplantation (for example, with a systematic preoperative pleural evacuation). Finally, we agree with the readers that the pleural effusion is present from the immediate postoperative period. We choose to quantify the postoperative pleural effusion on the seventh day by a computed tomographic scan to homogenize the measures. In practice, we evaluate the pleural effusion by bedside chest x-ray and ultrasound 7 days before, and when the pleural effusion is abundant or associated with respiratory failure, a percutaneous pleural drainage is performed. In our experience, most patients have, after liver transplantation, an early effusion that resolves within weeks. Thank you again for your interest in our study. Eric Levesque 1 Didier Samuel1,2,3 1Assistance Publique des Hôpitaux de Paris Hôpitaux Paul Brousse Centre Hépato-Biliaire Villejuif, France 2 Université Paris-Sud Unité mixte de recherche UMR-S785 Villejuif, France 3 Inserm, Unité 785, Villejuif, France

Computer-aided diagnosis of pneumonia in patients with chronic obstructive pulmonary disease

Early diagnosis of pneumonia and discrimination between this disease and chronic obstructive pulmonary disease (COPD) exacerbations in patients with COPD are crucial for optimal clinical management and treatment. To examine the use of computerized analysis of respiratory sounds, a hybrid system based on principal component analysis (PCA) and probabilistic neural networks (PNNs), to aid the detection of coexisting pneumonia in patients with COPD. A convenience sample of 58 patients with COPD (25 patients hospitalized for community-acquired pneumonia and 33 owing to acute exacerbation of COPD) was studied. Auscultations were performed by the patients themselves on their suprasternal notch. Short-time Fourier transform analysis was used to extract features from the recorded respiratory sounds, PCA was selected for dimensionality reduction and a PNN was trained as classifier. 10-Fold cross-validation and receiver operating characteristic curve analysis were used to estimate the system performance. Based on the cross-validation results, a sensitivity and a specificity of 72% and 81.8%, respectively, were achieved in validation data. The operating point was selected to maximize the specificity and sensitivity pair in the training set. The results strongly suggest that electronic self-auscultation at a single location (suprasternal notch) can support diagnosis of pneumonia in patients with COPD. A simple, cost-effective method has been proposed to aid decision-making in areas with no radiological facilities available and in resource-constrained settings, and could have a great diagnostic impact on telemedicine applications.

Use of procalcitonin for the diagnosis of pneumonia in patients presenting with a chief complaint of dyspnoea: results from the BACH (Biomarkers in Acute Heart Failure) trial

AimsBiomarkers have proven their ability in the evaluation of cardiopulmonary diseases. We investigated the utility of concentrations of the biomarker procalcitonin (PCT) alone and with clinical variables for the diagnosis of pneumonia in patients presenting to emergency departments (EDs) with a chief complaint of shortness of breath.Methods and resultsThe BACH trial was a prospective, international, study of 1641 patients presenting to EDs with dyspnoea. Blood samples were analysed for PCT and other biomarkers. Relevant clinical data were also captured. Patient outcomes were assessed at 90 days. The diagnosis of pneumonia was made using strictly validated guidelines. A model using PCT was more accurate [area under the curve (AUC) 72.3%] than any other individual clinical variable for the diagnosis of pneumonia in all patients, in those with obstructive lung disease, and in those with acute heart failure (AHF). Combining physician estimates of the probability of pneumonia with PCT values increased the accuracy to >86% for the diagnosis of pneumonia in all patients. Patients with a diagnosis of AHF and an elevated PCT concentration (>0.21 ng/mL) had a worse outcome if not treated with antibiotics (P = 0.046), while patients with low PCT values (<0.05 ng/mL) had a better outcome if they did not receive antibiotic therapy (P = 0.049).ConclusionProcalcitonin may aid in the diagnosis of pneumonia, particularly in cases with high diagnostic uncertainty. Importantly, PCT may aid in the decision to administer antibiotic therapy to patients presenting with AHF in which clinical uncertainty exists regarding a superimposed bacterial infection.Trial registration: NCT00537628

Use of procalcitonin for the diagnosis of pneumonia in patients presenting with a chief complaint of dyspnoea: Results from the BACH (Biomarkers in Acute Heart Failure) trial

A.M., research support from Roche, Biosite, and Bayer; consultant for Biosite. S.-X.N., consultant for ThermoFisher Scientific. C.M., research grants from The Swiss National Science Foundation, the Swiss Heart Foundation, the Novartis Foundation, the Krokus Foundation, Abbott, Biosite, BRAHMS, Roche, and the University of Basel. R.M.N., research support from BRAHMS. W.F.P., Scientific Advisory Board of Abbott, Beckman-Coulter, Biosite, Inverness, Ortho Clinical Diagnostics, and Response Biomedical; research grants from Abbott, Biosite, and Inverness. M.R., Scientific Advisory Board of Inverness Medical; travel support, honoraria, and research grants from Roche Diagnostics and Inverness Medical (Biosite). G.S.F., research support from Biosite, BRAHMS, and Roche. S.D.S., consultant for Biosite. L.L.N., research support from BRAHMS, Inverness, and Medical Innovations. L.B.D., research grant from Roche. O.H., employee of BRAHMS GmbH. A.B. and N.G.M., former employees of BRAHMS GmbH. S.D.A., research support from BRAHMS; honoraria from Abbott and Biosite; consultant for BRAHMS.

Application of procalcitonin to the diagnosis of pneumonia in patients after kidney transplantation

Objective To evaluate the practical value of procaleitonin(PCT)in diagnosis of pneumonia in patients after kidney transplantation.Method A total of 102 patients with pneumonia after kidney transplantation were reviewed.According to the diagnostic criteria of pathogens of pneumonia,32 patients were enrolled in bacterial group and 70 patients in non-bacterial group.The data of the PCT level and the C-reactive protein (CRP) level of the two groups were determined and compared with each other.Results There was significant difference in PCT level between bacterial pneumonia patients after kidney transplantation and non-bacterial pneumonia patients group (P 0.05).The changes of PCT level and the CRP level in 32 patients with bacterial pneumonia after kidney transplantation were not significant (P>0.05),and they were not associated with each other.Conclusions Monitoring the PCT level in patients with bacterial pneumonia after kidney transplantation would have an obviously clinical significance in diagnostic value. Key words: Procalcitonin; Kidney transplantation; Bacterial pneumonia; C-reactive protein

The feasibility and safety of fiberoptic bronchoscopy during noninvasive ventilation in patients with established acute lung injury: another small brick in the wall

In hypoxemic patients needing fiberoptic bronchoscopy (FOB), noninvasive ventilation (NIV) has been used to prevent gas-exchange deterioration associated with FOB and to compensate for the increase in work of breathing occurring during FOB, thus avoiding endotracheal intubation and its related complications. The application of NIV to allow FOB has been found of particular interest in the diagnosis of pneumonia in patients spontaneously breathing and in those who started NIV to assist FOB. There is less information for patients who were already receiving NIV for acute respiratory failure and who were scheduled to undergo FOB. In the previous issue of Critical Care, the study by Baumann and colleagues adds new information to this specific issue, addressing the feasibility and safety of FOB during NIV in patients with established hypoxemic respiratory failure.

Time trends in primary-care morbidity, hospitalization and mortality due to pneumonia

Most studies reporting pneumonia morbidity are restricted to hospitalized patients, although only a minority of pneumonia patients are admitted to hospital. To get a better understanding of the burden of disease in the general population, we conducted a population-based retrospective study to examine trends in pneumonia incidence in general practice, hospitalization, and mortality due to pneumonia in The Netherlands between 1997 and 2007. Between 2001/2002 and 2006/2007 there was an adjusted yearly increase of 12% in the clinical diagnosis of pneumonia in patients consulting general practitioners. Hospitalizations increased 5% per year between 1999/2000 and 2006/2007, while mortality annually decreased by 2% between 1997/1998 and 2006/2007. Our study suggests that the morbidity of pneumonia in the Dutch population increased considerably over this period, especially in primary-care settings, and that focusing only on hospitalization might underestimate the increasing public health burden of pneumonia.

Procalcitonina y proteína C reactiva en el diagnóstico de neumonías bacterianas en pacientes de urgencias

The diagnosis of pneumonia requires a chest X-ray, however to determine the aetiological agent a microbiological study is required, which slows down the definitive results. Acute phase proteins such as C-reactive protein (CRP) and Procalcitonin (PCT) are elevated in these pathological processes and would help the diagnosis. The aim of this study was to compare the usefulness of CRP and PCT in the diagnosis of pneumonia in patients admitted to the Emergency unit. The study was carried out in 40 patients. Serum samples were obtained for measuring CRP and PCT, as well as sputum and blood samples for culture. A chest X-ray was obtained on all patients to classify them in 2 groups, one with proven pneumonia and another without pneumonia. Once all data was collected, the prognostic value of PCT and CRP was evaluated by taking the chest X-ray as a diagnostic reference. The results showed that PCT had a lower sensitivity than CRP, but had a higher specificity. On the other hand, PCT values above 2 ng/ml correlated with most of the bacterial culture isolations, therefore if we take the microbiology as a reference, PCT sensitivity increases markedly. In conclusion, increased levels of PCT are possibly suggestive of bacterial aetiology, and may help the physician to choose an appropriate treatment.

Plasticity of the Systemic Inflammatory Response to Acute Infection during Critical Illness: Development of the Riboleukogram

BackgroundDiagnosis of acute infection in the critically ill remains a challenge. We hypothesized that circulating leukocyte transcriptional profiles can be used to monitor the host response to and recovery from infection complicating critical illness.Methodology/Principal FindingsA translational research approach was employed. Fifteen mice underwent intratracheal injections of live P. aeruginosa, P. aeruginosa endotoxin, live S. pneumoniae, or normal saline. At 24 hours after injury, GeneChip microarray analysis of circulating buffy coat RNA identified 219 genes that distinguished between the pulmonary insults and differences in 7-day mortality. Similarly, buffy coat microarray expression profiles were generated from 27 mechanically ventilated patients every two days for up to three weeks. Significant heterogeneity of VAP microarray profiles was observed secondary to patient ethnicity, age, and gender, yet 85 genes were identified with consistent changes in abundance during the seven days bracketing the diagnosis of VAP. Principal components analysis of these 85 genes appeared to differentiate between the responses of subjects who did versus those who did not develop VAP, as defined by a general trajectory (riboleukogram) for the onset and resolution of VAP. As patients recovered from critical illness complicated by acute infection, the riboleukograms converged, consistent with an immune attractor.Conclusions/SignificanceHere we present the culmination of a mouse pneumonia study, demonstrating for the first time that disease trajectories derived from microarray expression profiles can be used to quantitatively track the clinical course of acute disease and identify a state of immune recovery. These data suggest that the onset of an infection-specific transcriptional program may precede the clinical diagnosis of pneumonia in patients. Moreover, riboleukograms may help explain variance in the host response due to differences in ethnic background, gender, and pathogen. Prospective clinical trials are indicated to validate our results and test the clinical utility of riboleukograms.

Comparative study of etiological diagnosis of nosocomial pneumonia

Nosocomial pneumonia is a common complication in patients on mechanical ventilation and results in significant mortality. Diagnosis of pneumonia in patients who are intubated and under mechanical ventilation is difficult, even with the aid of clinical, laboratory, and endoscopic tests. The objective of this study was to compare three methods of tracheal sputum collection in patients with a clinical and radiological diagnosis of pneumonia. Twenty-two patients with a clinical diagnosis of liver disease were enrolled, 18 years of age or older, 13 males and nine females, who had been mechanically ventilated over an intubation period of 5.86 +/- 4.62 days. These patients were being treated in intensive care unit (ICU) of the Liver Transplant department. Secretion collection was carried out according to a protocol with three distinct methods: endotracheal aspiration with a closed aspiration system, Bal cath and bronchoalveolar lavage. Of the 22 patients analyzed, 21 (95.4%) showed one or more infectious agent when the closed aspiration system was used. With the Bal cathâ collection, 19 patients (86.3%) had one or more infectious agents; in the collection by bronchoalveolar lavage, 10 patients (45.4%) presented one or more infectious agent. According to the laboratory analysis, 14 different microorganisms were isolated, the most frequent of which were Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae. We concluded that aspiration with the closed system produced the most effective results in comparison with those of bronchoalveolar lavage and the Bal cathâ, and may be an acceptable method for diagnosing hospital-acquired pneumonia when no fiberoptic technique is available.

Ventilator-Associated Pneumonia: The Role of Bronchoscopy

The diagnosis of pneumonia in patients on mechanical ventilation is often based on nonspecific signs, including pulmonary infiltrates, fever, and

The Role of Bronchoalveolar Lavage in the Microbiological Diagnosis of Pneumonia in Patients with Haematological Malignancies

In the aetiological diagnosis of pulmonary infections in patients affected by haematological malignancies we evaluated the utility of bronchoalveolar lavage (BAL). One hundred and twenty-seven BAL were performed in 119 patients. In our series, we identified the agent of pneumonia in 53.5% of episodes with the best results in aspergillosis, very common in these patients. The previous empirical anti-infective treatment was modified in 14 episodes (11%). The procedure was generally well tolerated and only one patient bled. We maintain that BAL is a useful diagnostic tool for detecting the agents of pulmonary infections in patients with haematological malignancies, especially when the routine microbiological procedures fail, and it also represents a good alternative to more invasive procedures.

Pneumonia and ARDS in patients receiving mechanical ventilation: diagnostic accuracy of chest radiography.

This study was done to evaluate the diagnostic accuracy of bedside chest radiography for pneumonia, adult respiratory distress syndrome (ARDS), or both in patients receiving mechanical ventilation. The series consisted of 40 patients; diagnostic accuracy was defined as the area under the receiver operating characteristic curve. Overall diagnostic accuracy for ARDS was 0.84. Overall diagnostic accuracy for pneumonia was 0.52. Review of previous radiographs and knowledge of clinical data did not enhance diagnostic accuracy for ARDS or pneumonia. Diagnostic accuracy for pneumonia was minimally reduced when ARDS was present. There was an increase in false-negative results because the diffuse areas of increased opacity in ARDS obscured the radiographic features of pneumonia. The authors conclude that chest radiography is of limited value for the diagnosis of pneumonia in patients receiving mechanical ventilation. The high false-negative and false-positive ratings for pneumonia resulted in a low diagnostic accuracy. The high diagnostic accuracy for ARDS was primarily due to the well-defined radiographic appearance of ARDS and few false-positive ratings.

Bronchoalveolar lavage in the diagnosis of pneumocystis carinii pneumonia in patients with hematologic malignancies

Bronchoalveolar lavage in the diagnosis of pneumocystis carinii pneumonia in patients with hematologic malignancies