Seventy-eight (24%) episodes of nosocomial pneumonia (NP) were detected in 322 consecutive mechanically ventilated patients admitted to a 1,000-bed teaching hospital from April 1987 through May 1988 to assess the incidence, risk, and prognosis factors of NP acquired during mechanical ventilation (MV). The risk and prognosis factors for developing NP during MV were studied using both univariate and multivariate statistical techniques. Multivariate analysis selected the following variables significantly associated with a higher risk for developing ventilator-associated pneumonia: more than one intubation during MV (p = 0.000012), a prior episode of aspiration of gastric content (p = 0.00018), a MV period longer than 3 days (p = 0.015), the presence of chronic obstructive pulmonary disease (COPD) (p = 0.048), and the use of positive end-expiratory pressure (PEEP) during MV (p = 0.092). The presence of an ultimately or rapidly fatal underlying disease (p = 0.0018), worsening of acute respiratory failure caused by pneumonia (p = 0.0096), the presence of septic shock (p = 0.016), an inappropriate antibiotic treatment (p = 0.02), and the type of intensive care unit (ICU) hospitalization (noncardiac surgery and nonsurgical ICU compared with post-cardiac surgery ICU) (p = 0.08) were those factors selected by a stepwise logistic regression analysis as independently worsening the prognosis. The overall fatality rate was 23% (73 of 322). The mortality of patients with NP was higher (33%; 26 of 78; p less than 0.01) when compared with fatality rates of patients without NP (19%; 47 of 244).(ABSTRACT TRUNCATED AT 250 WORDS)

Over a period of 4 consecutive yr, 92 nonimmunosuppressed patients (21 women and 71 men aged 53 +/- 16 yr, means = SD) with critical acute respiratory failure (PaO2/FiO2, 209 +/- 9 mm Hg) caused by severe community-acquired pneumonia were admitted to the respiratory intensive care unit (RICU) of a general hospital. The most frequent underlying clinical condition was chronic obstructive pulmonary disease (44 patients, 48%). A total of 56 patients (61%) required mechanical ventilation for a mean period of 10.7 +/- 12.5 days, 29 of them (52%) needing PEEP (9.9 +/- 3.8 cm H2O). A group of 23 (25%) patients had criteria of adult respiratory distress syndrome (ARDS). A causal microorganism was identified in 48 patients (52%), the two most frequent etiologies being Streptococcus pneumoniae (14, 15%) and Legionella pneumophila (13, 14%). Pseudomonas aeruginosa (5, 5%) was always associated with bronchiectasis. Mortality due to severe community-acquired pneumonia was 22% (20 patients). According to univariate analysis, mortality was associated with anticipated death within 4 to 5 yr, inadequate antibiotic treatment before RICU admission, mechanical ventilation requirements, use of PEEP, FIO2 greater than 0.6, coexistence of ARDS, radiographic spread of the pneumonia during RICU admission, septic shock, bacteremia, and P. aeruginosa as the cause of the pneumonia. Further, recursive partitioning analysis selected two factors significantly related to the prognosis: the radiographic spread of the pneumonia during RICU admission and the presence of septic shock.(ABSTRACT TRUNCATED AT 250 WORDS)

Background Chronic obstructive pulmonary disease (COPD) is increasingly considered a heterogeneous condition. It was hypothesised that COPD, as currently defined, includes different clinically relevant subtypes. Methods To identify and validate COPD subtypes, 342 subjects hospitalised for the first time because of a COPD exacerbation were recruited. Three months after discharge, when clinically stable, symptoms and quality of life, lung function, exercise capacity, nutritional status, biomarkers of systemic and bronchial inflammation, sputum microbiology, CT of the thorax and echocardiography were assessed. COPD groups were identified by partitioning cluster analysis and validated prospectively against cause-specific hospitalisations and all-cause mortality during a 4 year follow-up. Results Three COPD groups were identified: group 1 (n¼126, 67 years) was characterised by severe airflow limitation (postbronchodilator forced expiratory volume in 1 s (FEV 1 ) 38% predicted) and worse performance in most of the respiratory domains of the disease; group 2 (n¼125, 69 years) showed milder airflow limitation (FEV 1

Mechanisms of worsening gas exchange during acute exacerbations of chronic obstructive pulmonary disease. J. A. Barberà, J. Roca, A. Ferrer, M.A. Félez, O. Díaz, N. Roger, R. Rodriguez-Roisin. ERS Journals Ltd 1997. ABSTRACT: This study was undertaken to investigate the mechanisms that determine abnormal gas exchange during acute exacerbations of chronic obstructive pulmonary disease (COPD). Thirteen COPD patients, hospitalized because of an exacerbation, were studied after admission and 38±10 (±SD) days after discharge, once they were clinically stable. Measurements included forced spirometry, arterial blood gas values, minute ventilation (V ' 'E), cardiac output (Q ' '), oxygen consumption (V ' 'O 2 ), and ventilation/perfusion (V ' 'A/Q ' ') relationships, assessed by the inert gas technique.Exacerbations were characterized by very severe airflow obstruction (forced expiratory volume in one second (FEV1) We conclude that worsening of gas exchange during exacerbations of chronic obstructive pulmonary disease is primarily produced by increased ventilation/perfusion inequality, and that this effect is amplified by the decrease of mixed venous oxygen tension that results from greater oxygen consumption, presumably because of increased work of the respiratory muscles. Eur Respir J 1997; 10: 1285-1291 Episodes of acute exacerbation are one of the most common complications in the evolution of chronic obstructive pulmonary disease (COPD). Irrespective of the precipitating factor, these episodes are characterized by worsening of pulmonary gas exchange that results in severe hypoxaemia with or without hypercapnia [1]. Abnormal gas exchange is thought to have a multifactorial origin [2], although some evidence suggests greater ventilation/perfusion (V'A/Q') inequality as the major determinant of respiratory failure [3,4]. However, little information exists concerning the characteristics of the V 'A/Q ' distributions and their interrelations with the conditions under which the lung operates, namely the extrapulmonary factors (i.e. ventilation, cardiac output, oxygen uptake) that also influence the arterial blood gas values. This lack of information is due essentially to the difficulty of assessing and quantifying the degree of V'A/Q' mismatch. In this regard, the use of the multiple inert gas elimination technique has been a major advance in interpreting gas exchange abnormalities, as it allows quantitation of V'A/Q' distributions and characterization of the different factors that produce hypoxaemia [5]. Identification and interpretation of the pathophysiological determinants of abnormal gas exchange during exacerbations of COPD should help to optimize the management of such episodes [6,7].Accordingly, the present study was undertaken to investigate the contribution of the different mechanisms that determine abnormal gas exchange during acute exacerbations of COPD by using the inert gas elimination technique, and to examine how the factors contributing to abnormal gas exchange vary during recovery.

The present study aims to describe the pattern of physical activity and the frequency, duration and intensity of physical activity bouts in patients with chronic obstructive pulmonary disease (COPD), to assess how these patterns differ according to COPD severity, and to explore whether these patients meet the general guidelines for physical activity for older adults.177 patients (94% male, mean¡SD age 71¡8 years and forced expiratory volume in 1 s 52¡16% predicted) wore the SenseWear Pro 2 Armband accelerometer for eight consecutive days. Physical activity bouts were defined as periods of o10 min above 1.5 metabolic equivalent tasks and classified according to their median intensity.Patients engaged in activity a median of 153 min?day -1 and 57% of that time was spent in bouts. Median frequencies of bouts per day were four and three for all and moderate-to-vigorous intensities, respectively. With increasing COPD severity, time in physical activity, proportion of time in bouts and frequency of bouts decreased. 61% of patients fulfilled the recommended physical activity guidelines.In conclusion, COPD patients of all spirometric severity stages engage in physical activity bouts of moderate-to-vigorous intensities. Patients with severe and very severe COPD perform their daily activities in fewer and shorter bouts than those in mild and moderate stages. @ERSpublications Patients with severe COPD perform their daily activities in fewer, shorter bouts than those in mild and moderate stages http://ow.ly/nug7k