Cholinergic hyperresponsiveness of peripheral lung parenchyma in chronic obstructive pulmonary disease.

BACKGROUND: Up to 60% of chronic obstructive pulmonary disease (COPD) patients can present airway hyperresponsiveness. However, it is not known whether the peripheral lung tissue also shows an exaggerated response to agonists in COPD. OBJECTIVES: To investigate the in vitro mechanical behavior and the structural and inflammatory changes of peripheral lung tissue in COPD patients and compare to nonsmoking controls. METHODS: We measured resistance and elastance at baseline and after acetylcholine (ACh) challenge of lung strips obtained from 10 COPD patients and 10 control subjects. We also assessed the alveolar tissue density of neutrophils, eosinophils, macrophages, mast cells and CD8+ and CD4+ cells, as well as the content of α-smooth muscle actin-positive cells and elastic and collagen fibers. We further investigated whether changes in in vitro parenchymal mechanics correlated to structural and inflammatory parameters and to in vivo pulmonary function. RESULTS: Values of resistance after ACh treatment and the percent increase in tissue resistance (%R) were higher in the COPD group (p ≤ 0.03). There was a higher density of macrophages and CD8+ cells (p < 0.05) and a lower elastic content (p = 0.003) in the COPD group. We observed a positive correlation between %R and eosinophil and CD8+ cell density (r = 0.608, p = 0.002, and r = 0.581, p = 0.001, respectively) and a negative correlation between %R and the ratio of forced expiratory volume in 1 s to forced vital capacity (r = -0.451, p < 0.05). CONCLUSIONS: The cholinergic responsiveness of parenchymal lung strips is increased in COPD patients and seems to be related to alveolar tissue eosinophilic and CD8 lymphocytic inflammation and to the degree of airway obstruction on the pulmonary function test.

Respiratory support withdrawal in intensive care units: families, physicians and nurses views on two hypothetical clinical scenarios.

INTRODUCTION: Evidence suggests that dying patients' physical and emotional suffering is inadequately treated in intensive care units. Although there are recommendations regarding decisions to forgo life-sustaining therapy, deciding on withdrawal of life support is difficult, and it is also difficult to decide who should participate in this decision. METHODS: We distributed a self-administered questionnaire in 13 adult intensive care units (ICUs) assessing the attitudes of physicians and nurses regarding end-of-life decisions. Family members from a medical-surgical ICU in a tertiary cancer hospital were also invited to participate. Questions were related to two hypothetical clinical scenarios, one with a competent patient and the other with an incompetent patient, asking whether the ventilator treatment should be withdrawn and about who should make this decision. RESULTS: Physicians (155) and nurses (204) of 12 ICUs agreed to take part in this study, along with 300 family members. The vast majority of families (78.6%), physicians (74.8%) and nurses (75%) want to discuss end-of-life decisions with competent patients. Most of the physicians and nurses desire family involvement in end-of-life decisions. Physicians are more likely to propose withdrawal of the ventilator with competent patients than with incompetent patients (74.8% × 60.7%, P = 0.028). When the patient was incompetent, physicians (34.8%) were significantly less prone than nurses (23.0%) and families (14.7%) to propose decisions regarding withdrawal of the ventilator support (P < 0.001). CONCLUSIONS: Physicians, nurses and families recommended limiting life-support therapy with terminally ill patients and favored family participation. In decisions concerning an incompetent patient, physicians were more likely to maintain the therapy.

Heparin Therapy Improving Hypoxia in COVID-19 Patients - A Case Series.

INTRODUCTION: Elevated D-dimer is a predictor of severity and mortality in COVID-19 patients, and heparin use during in-hospital stay has been associated with decreased mortality. COVID-19 patient autopsies have revealed thrombi in the microvasculature, suggesting that hypercoagulability is a prominent feature of organ failure in these patients. Interestingly, in COVID-19, pulmonary compliance is preserved despite severe hypoxemia corroborating the hypothesis that perfusion mismatch may play a significant role in the development of respiratory failure. METHODS: We describe a series of 27 consecutive COVID-19 patients admitted to Sirio-Libanes Hospital in São Paulo-Brazil and treated with heparin in therapeutic doses tailored to clinical severity. RESULTS: PaO2/FiO2 ratio increased significantly over the 72 h following the start of anticoagulation, from 254(±90) to 325(±80), p = 0.013, and 92% of the patients were discharged home within a median time of 11 days. There were no bleeding complications or fatal events. DISCUSSION: Even though this uncontrolled case series does not offer absolute proof that micro thrombosis in the pulmonary circulation is the underlying mechanism of respiratory failure in COVID-19, patient's positive response to heparinization contributes to the understanding of the pathophysiological mechanism of the disease and provides valuable information for the treatment of these patients while we await the results of further prospective controlled studies.

Saline instillation before tracheal suctioning decreases the incidence of ventilator-associated pneumonia.

OBJECTIVES: To compare the incidence of ventilator-associated pneumonia (VAP) with or without isotonic saline instillation before tracheal suctioning. As a secondary objective, we compared the incidence of endotracheal tube occlusion and atelectasis. DESIGN: Randomized clinical trial. SETTING AND PATIENTS: The study was conducted in a medical surgical intensive care unit of an oncologic hospital. We selected consecutive patients needing mechanical ventilation for >72 hrs. Patients were allocated into two groups: a saline group that received instillation of 8 mL of saline before tracheal suctioning and a control group which did not. VAP was diagnosed based on clinical suspicion and confirmed by bronchoalveolar lavage quantitative culture. The incidence of atelectasis on daily chest radiography and endotracheal tube occlusions were recorded. The sample size was calculated to a power of 80% and a type I error probability of 5%. MEASUREMENTS AND MAIN RESULTS: One hundred thirty patients were assigned to the saline group and 132 to the control group. The baseline demographic variables were similar between groups. The rate of clinically suspected VAP was similar in both groups. The incidence of microbiological proven VAP was significantly lower in the saline group (23.5% x 10.8%; p = 0.008) (incidence density/1.000 days of ventilation 21.22 x 9.62; p < 0.01). Using the Kaplan-Meier curve analysis, the proportion of patients remaining without VAP was higher in the saline group (p = 0.02, log-rank test). The relative risk reduction of VAP in the saline instillation group was 54% (95% confidence interval, 18%-74%) and the number needed to treat was eight (95% confidence interval, 5-27). The incidence of atelectases and endotracheal tube occlusion were similar between groups. CONCLUSIONS: Instillation of isotonic saline before tracheal suctioning decreases the incidence of microbiological proven VAP.

Noninvasive ventilation in immunocompromised pediatric patients: eight years of experience in a pediatric oncology intensive care unit.

OBJECTIVE: The experience of noninvasive positive pressure ventilation (NPPV) in the pediatric setting is limited. The aim of the present study is to retrospectively evaluate the effectiveness of NPPV in pediatric immunocompromised patient admitted in our PICU (Pediatric Intensive Care Unit) for acute respiratory failure. DESIGN/SETTING: Retrospective cohort study of children admitted to the PICU of Hospital do Cancer between June 1997 and May 2005 requiring ventilatory support. RESULTS: A total of 239 admissions were included. The first mechanical ventilation (MV) technique used was NPPV in 120 (50.2%) patients [noninvasive ventilation (NIV) group] and conventional MV in 119 (49.8%) [invasive ventilation (IV) group]; 25.8% of the patients from the NIV group subsequently required intubation. Patients in the IV group were more likely to be in a severe clinical status. Characteristics associated with severe clinical status were median value for therapeutic intervention scoring system score (37.5 points IV vs. 29 points NIV, P<0.0001), presence of >2 organs failure (63.6% IV vs. 36.4% NIV, P<0.0001), cardiac failure (62.5% IV vs. 37.5% NIV, P<0.0001), and septic shock (63.9% IV vs. 36.1% NIV, P<0.0001). Documented severe pulmonary disease was significantly higher (67.6%) in IV group, P=0.02. Baseline values of arterial pCO2, hypoxemia, arterial pH, and respiratory rate did not differ between the groups. Multivariate analysis showed that independent predictive factors for intubation were solid tumors (P=0.012), cardiovascular dysfunction (P<0.0001), and therapeutic intervention scoring system score >or=40 points (P=0.018). CONCLUSIONS: Our results encourage the use of NPPV as a first-line treatment in children with malignancies who develops acute respiratory failure, except in those with severe hemodynamic status.

Trend of maximal inspiratory pressure in mechanically ventilated patients: predictors.

INTRODUCTION: It is known that mechanical ventilation and many of its features may affect the evolution of inspiratory muscle strength during ventilation. However, this evolution has not been described, nor have its predictors been studied. In addition, a probable parallel between inspiratory and limb muscle strength evolution has not been investigated. OBJECTIVE: To describe the variation over time of maximal inspiratory pressure during mechanical ventilation and its predictors. We also studied the possible relationship between the evolution of maximal inspiratory pressure and limb muscle strength. METHODS: A prospective observational study was performed in consecutive patients submitted to mechanical ventilation for > 72 hours. The maximal inspiratory pressure trend was evaluated by the linear regression of the daily maximal inspiratory pressure and a logistic regression analysis was used to look for independent maximal inspiratory pressure trend predictors. Limb muscle strength was evaluated using the Medical Research Council score. RESULTS: One hundred and sixteen patients were studied, forty-four of whom (37.9%) presented a decrease in maximal inspiratory pressure over time. The members of the group in which maximal inspiratory pressure decreased underwent deeper sedation, spent less time in pressure support ventilation and were extubated less frequently. The only independent predictor of the maximal inspiratory pressure trend was the level of sedation (OR=1.55, 95% CI 1.003 - 2.408; p = 0.049). There was no relationship between the maximal inspiratory pressure trend and limb muscle strength. CONCLUSIONS: Around forty percent of the mechanically ventilated patients had a decreased maximal inspiratory pressure during mechanical ventilation, which was independently associated with deeper levels of sedation. There was no relationship between the evolution of maximal inspiratory pressure and the muscular strength of the limb.

Effects of overinflation on procollagen type III expression in experimental acute lung injury.

INTRODUCTION: In acute lung injury (ALI), elevation of procollagen type III (PC III) occurs early and has an adverse impact on outcome. We examined whether different high-inflation strategies of mechanical ventilation (MV) in oleic acid (OA) ALI alter regional expression of PC III. METHODS: We designed an experimental, randomized, and controlled protocol in which rats were allocated to two control groups (no injury, recruited [alveolar recruitment maneuver after tracheotomy without MV; n = 4 rats] and control [n = 5 rats]) or four injured groups (one exposed to OA only [n = 10 rats] and three OA-injured and ventilated). The three OA-injured groups were ventilated for 1 hour according to the following strategies: LVHP-S (low volume-high positive end-expiratory pressure [PEEP], supine; n = 10 rats, tidal volume [VT] = 8 ml/kg, PEEP = 12 cm H2O), HVLP-S (high volume-low PEEP, supine; n = 10 rats, VT = 20 ml/kg, PEEP = 5 cm H2O), and HVLP-P (high volume-low PEEP, prone; n = 10 rats). Northern blot analysis for PC III and interleukin-1-beta (IL-1beta) and polymorphonuclear infiltration index (PMI) counting were performed in nondependent and dependent regions. Regional differences between groups were assessed by two-way analysis of variance after logarithmic transformation and post hoc tests. RESULTS: A significant interaction for group and region effects was observed for PC III (p = 0.012) with higher expression in the nondependent region for HVLP-S and LVHP-S, intermediate for OA and HVLP-P, and lower for control (group effect, p < 0.00001, partial eta2 = 0.767; region effect, p = 0.0007, partial eta2 = 0.091). We found high expression of IL-1beta (group effect, p < 0.00001, partial eta2 = 0.944) in the OA, HVLP-S, and HVLP-P groups without regional differences (p = 0.16). PMI behaved similarly (group effect, p < 0.00001, partial eta2 = 0.832). CONCLUSION: PC III expression is higher in nondependent regions and in ventilatory strategies that caused overdistension. This response was partially attenuated by prone positioning.

Measuring satisfaction in family members of critically ill cancer patients in Brazil.

OBJECTIVE: To assess the determinants for satisfaction of cancer patients' family members with the intensive care unit. DESIGN: Prospective cohort study. SETTING: A 13-bed intensive care unit in a tertiary cancer centre. PATIENTS AND PARTICIPANTS: 164 families of consecutive patients with a length of stay greater than 48 h. INTERVENTION: None. MEASUREMENT: A modified version of the Critical Care Family Needs Inventory was applied and compared with the families' perception of prognosis, previous information given to them, and patients' severity of disease (SAPS). RESULTS: The median score of the questionnaire was 11 (2-14), and the cut-off for satisfaction was established at 9 (1st quartile). SAPS >41 was associated with lower satisfaction [(p<0.05, chi-square, OR 2.49 (CI 1.1-5.4)]. When those interviewed surmised a prognosis different from the final outcome [p<0.05, chi-square, OR 2.70 (1.2-6.0)], a significant association with dissatisfaction was found. CONCLUSION: More discussion about prognosis may improve the level of satisfaction of cancer patients' family members with the intensive care unit.

Metastatic breast cancer: do current treatments improve quality of life? A prospective study.

CONTEXT AND OBJECTIVE: In metastatic breast cancer cases, the currently available therapeutic approaches provide minimal improvement in survival. As such, quality of life (QOL) becomes one of the main objectives of treatment. It is not known whether current treatments derived from trials improve QOL. The aim was to evaluate changes in QOL among metastatic breast cancer patients receiving treatment derived from trials. DESIGN AND SETTING: Prospective observational QOL survey in a tertiary cancer center. METHODS: To evaluate the influence of current treatments on patients' QOL, the Medical Outcomes Study Short Form-36 (SF-36) and the Beck Depression Inventory (BDI) were applied on three occasions: before starting treatment and at the 6th and 12th weeks, to consecutive metastatic breast cancer patients over a one-year period. RESULTS: We found an improvement in QOL in the sample evaluated (n = 40), expressed by changes in the overall SF-36 score (p = 0.002) and the BDI (p = 0.004). Taken individually, the SF-36 components Pain, Social Functioning and Mental Health also improved significantly. Patients with worse initial performance status and secondary symptoms displayed greater improvement than those with better initial performance status and asymptomatic disease (p < 0.001). Patients who received more than one type of therapy showed larger gains than those given only one type (p = 0.038). CONCLUSIONS: In our environment, current metastatic breast cancer treatments can improve QOL, especially among symptomatic patients and those with low performance status.

[Primary mediastinal germ cell tumors]. / Tumores de células germinativas primários do mediastino.

Primary mediastinal germ cell tumors account for approximately 10% to 20% of all neoplasms of the mediastinum. It is generally accepted that they represent the malignant transformation of germinal elements without a gonadal focus. These tumors can be classified as teratomas, seminomas, nonseminomatous (yolk sac tumor, embryonal carcinoma, choriocarcinoma) and combined germ-cell tumors without teratomatous components. This review purposes to discuss the different primary mediastinal germ-cell tumors, their clinical presentation and options for treatment.

Soft-tissue sarcomas of the chest wall: prognostic factors.

OBJECTIVE: To evaluate factors that are predictive of outcome for patients with chest wall soft-tissue sarcomas. PATIENTS AND METHODS: A retrospective review of 55 surgically treated patients, from March 1964 to October 1996. RESULTS: The median age of the patients was 47.5 years (age range, 15 to 76.3 years), and 56.4% were men. The most common presenting symptom was chest wall mass in 29 patients (52.7%). The median symptom duration was 12 months. Tumor size ranged from 1 to 26 cm (median size, 9.7 cm). The most common histologic type of tumor was fibrosarcoma (52.7%). Twenty-three sarcomas (41.8%) were high-grade, and 32 sarcomas (52.8%) were low-grade. Of the 55 patients, 27 (49.1%) had previously been treated elsewhere (surgical resection, 23 patients; radiation therapy and surgery, 3 patients; chemoradiation therapy, 1 patient). Previously treated patients presented either with residual disease (10 cases) or recurrence of disease (17 cases). All 55 patients underwent surgical resection, 15 patients (27.3%) were treated by neoadjuvant chemoradiation therapy, and 2 patients were treated by adjuvant radiotherapy. Wide surgical resection was performed in 45 patients (81.8%), and marginal resection was performed in 10 patients (18.2%). The median follow-up time was 51.9 months. Local recurrence of disease developed in 6 patients, and metastases developed in 10 patients. The overall survival rates at 5 and 10 years were 87.3% and 79.3%, respectively. Tumor size < 5 cm and low histologic grade were determinants of better survival at univariate analyses. Multivariate analyses disclosed only histologic grade as an independent predictor for the risk of death. Disease-free survival rates at 5 and 10 years were 75.3% and 64.2%, respectively. Tumor size < 5 cm, performance of wide surgical resection, and low histologic grade were determinants of a better disease-free survival rate. Independent prognostic factors for disease-free survival were histologic grade and type of surgical resection. CONCLUSION: The clinical behavior of chest wall soft-tissue sarcomas is similar to that of extremity sarcomas. Thoracic wall soft-tissue sarcomas are best controlled by wide surgical resection.

Functional analysis of cells obtained from bronchoalveolar lavage fluid (BALF) of lung cancer patients.

BALF from tumor segments provides access to immune system cells in contact with lung tumors. We analyzed BALF cells as to their production of H2O2 and NO, comparing tumor-affected to non-affected lung segments. Twelve patients were studied (4 NSCLC, 3 SCC, 5 Adenocarcinoma). The cell numbers recovered from BALF varied, and, in adenocarcinoma patients, smaller numbers were recovered from tumor-affected segments. H2O2 production (up to 6.3 nmoles/2x10(5)cells) was obtained in 7/12 patients and, in these, it was more frequent in non-affected segments (7/7) than in affected segments (2/7). After culture, NO production was observed in three patients (6 to 314 microM) that also produced H2O2. These functional characteristics of cells in contact with neoplasia may have a role in determining the fate of the interactions between the immune system and lung cancer.

Pulmonary capillary pressure in pulmonary hypertension.

INTRODUCTION: Pulmonary capillary pressure (PCP), together with the time constants of the various vascular compartments, define the dynamics of the pulmonary vascular system. Our objective in the present study was to estimate PCPs and time constants of the vascular system in patients with idiopathic pulmonary arterial hypertension (IPAH), and compare them with these measures in patients with acute respiratory distress syndrome (ARDS). METHODS: We conducted the study in two groups of patients with pulmonary hypertension: 12 patients with IPAH and 11 with ARDS. Four methods were used to estimate the PCP based on monoexponential and biexponential fitting of pulmonary artery pressure decay curves. RESULTS: PCPs in the IPAH group were considerably greater than those in the ARDS group. The PCPs measured using the four methods also differed significantly, suggesting that each method measures the pressure at a different site in the pulmonary circulation. The time constant for the slow component of the biexponential fit in the IPAH group was significantly longer than that in the ARDS group. CONCLUSION: The PCP in IPAH patients is greater than normal but methodological limitations related to the occlusion technique may limit interpretation of these data in isolation. Different disease processes may result in different times for arterial emptying, with resulting implications for the methods available for estimating PCP.

The level of nicotine dependence is an independent risk factor for cancer: a case control study.

BACKGROUND: Less than 20% of lifetime smokers will ever develop cancer. Smoking habits characteristics, particularly the level of nicotine dependence level, were not fully evaluated as a marker of risk. METHODS: Case-control study of voluntary patients prospectively enrolled in a smoking cessation program in a cancer hospital. For each cancer case, patients of the same age and sex were selected. The Beck Depression Inventory, an instrument for the diagnosis of depressive mood and clinical depression, and the Fagerström Test Questionnaire, a questionnaire that has a good correlation with nicotine levels, used to determine the degree of dependence on nicotine, were applied. Age on admission to the study, sex, and number of pack-years were also evaluated. RESULTS: From May 1999 to May 2002, 56 cancer patients (case) and 85 matching controls (control) were identified in the population studied. There was no difference regarding pack-years. Fagerström Test Questionnaire was significantly higher in patients with cancer (7.5+/-1.9) compared to controls (6.3+/-2.0). We found a Fagerström Test Questionnaire>7 in 73.2% of the cancer cases versus 43.5% of the controls (p=0.001). The proportion of depressed patients was higher in the cancer group (37.5% x 17.6%). Logistic regression adjusted for age and tobacco consumption disclosed that Fagerström Test Questionnaire score>7 has an odds ratio for cancer of 3.45 (95% CI 1.52-7.83, p=0.003). CONCLUSION: Fagerström Test Questionnaire higher than 7 was identified as a risk factor for cancer in smokers with similar tobacco consumption.

Inspiratory muscle training is ineffective in mechanically ventilated critically ill patients.

PURPOSE: Invasive mechanical ventilation is associated with complications, and its abbreviation is desirable. The imbalance between increased workload, decreased inspiratory muscle strength and endurance is an important determinant of ventilator dependence. Low endurance may be present due to respiratory muscle atrophy, critical illness, or steroid use. Specific inspiratory muscle training may increase or preserve endurance. The objective of the study was to test the hypothesis that inspiratory muscle training from the beginning of mechanical ventilation would abbreviate the weaning duration and decrease reintubation rate. As a secondary objective, we described the evolution of inspiratory muscle strength with and without inspiratory muscle training. METHODS: Prospective, randomized clinical trial in an adult clinical-surgical intensive care unit. Twelve patients trained the inspiratory muscles twice a day, and 13 patients did not (control). Training was performed adjusting the sensitivity of the ventilator based on the maximal inspiratory pressure. Patients underwent daily surveillance of the maximal inspiratory pressure. RESULTS: The weaning duration (31 +/- 22 hr, control and 23 +/- 11 hr, training group; P = .24) and reintubation rate (5 control and 3 training group; P = .39) were not statistically different. The maximal inspiratory pressure of the control group showed a trend toward a modest increase. In contrast, the training group showed a small decrease (P = .34). CONCLUSIONS: In acute critically ill patients, inspiratory muscle training from the beginning of mechanical ventilation neither abbreviated the weaning duration, nor decreased the reintubation rate. Inspiratory muscle strength tended to stay constant, along the mechanical ventilation, with or without this specific inspiratory muscle training.

Low tidal volume ventilation induces proinflammatory and profibrogenic response in lungs of rats.

OBJECTIVE: We examined whether mechanical ventilation with low tidal volume induces polymorphonuclear infiltration and proinflammatory and profibrogenic responses in rat lungs compared dependent and nondependent lung region to expression of interleukin-1beta (IL-1beta) and alpha-1 procollagen III (PC III) mRNA. DESIGN: An experimental, randomized and controlled protocol with previously normal rats. INTERVENTIONS: Three groups of ten animals were studied. Two groups were ventilated (FIO2=0.3) in supine position for 1 h without positive end expiratory pressure, one group with a low tidal volume (6 ml/kg), and the other with a high tidal volume (24 ml/kg). In the third group animals were kept in spontaneous ventilation for 1 h. MEASUREMENTS AND RESULTS: After ventilation the right lung was used to quantify polymorphonuclear infiltration. The left lung was divided into dependent and nondependent regions, and expression of IL-1beta and PC III mRNA was quantified by northern blot analysis. The group ventilated with low tidal volume had greater polymorphonuclear infiltration IL-1beta and PC III mRNA expression than the nonventilated group. Similar results were observed with high tidal volumes. There was no difference between low and high tidal volume ventilation. Expression levels of IL-1beta and PC III mRNA were higher in the nondependent region of ventilated groups and equal in the nonventilated group. CONCLUSIONS: Even a low tidal volume mode of mechanical ventilation induces proinflammatory and profibrogenic response, with a nondependent predominance for IL-1beta and PC III mRNA expression in supine, ventilated, previously normal rats.

When to remove a chest tube? A randomized study with subsequent prospective consecutive validation.

BACKGROUND: Operative procedures on the pleural space are usually managed by chest tube drainage. Timing for removing the tube is empirically established, with wide variation among surgeons. Our objective was to evaluate the effectiveness and safety of establishing a volume of 200 mL/d of uninfected drainage as a threshold for removal of chest tube, as compared with more frequently used volumes of 100 and 150 mL/d. STUDY DESIGN: A prospective randomized study was performed in a single institution. Patients (n = 139) submitting to pleural drainage after surgical procedures were randomized to one of three groups, defined by the planned timing of chest tube removal (depending on the threshold volume per day of pleural fluid drained): G-100 (< or = 100 mL/d, n = 44); G-150 (< or =150 mL/d, n = 58); and G-200 (< or = 200 mL/d, n = 37). Subsequently, another 91 consecutive patients had chest tubes removed when drainage was less than 200 mL/d (G-val, prospective validation group). All patients had similar discharge and 60-day followup. Drainage time, hospital stay, and reaccumulation rate were registered. RESULTS: Drainage time (median days: 3.5 for G-100, 3 for G-150, 3 for G-200, 3 for G-val) and hospital stay (median days: 4 for G-100, 3 for G-150, 3 for G-200, 3 for G-val) were not statistically different among groups. Radiologic reaccumulation rates were 9.1% for G-100, 13.1% for G-150, 5.4% for G-200, and 10.9% for G-val, and the thoracenteses rates were 2.3%, 0.8%, 2.7%, and 3.3%, respectively, with no major differences among groups (G-100 versus G-150 versus G-200; G-200 versus G-val). CONCLUSIONS: Increasing the threshold of daily drainage to 200 mL before removing the chest tube did not markedly affect drainage, hospitalization time, or overall costs, nor did it increase the likelihood of major pleural fluid reaccumulation. This volume (200 mL/d) could be recommended for chest tube withdrawal decision for uninfected pleural fluid with no evidence of air leaks.

What increases type III procollagen mRNA levels in lung tissue: stress induced by changes in force or amplitude?

We hypothesized that stress determined by force could induce higher type III procollagen (PCIII) mRNA expression than the stress determined by amplitude. To that end, rat lung tissue strips were oscillated for 1h under different amplitudes [1, 5 and 10% of resting length (L(B)), at 0.5 x 10(-2) N] and forces (0.25 x 10(-2), 0.5 x 10(-2) and 10(-2)N, at 5% L(B)). Resistance (R), elastance (E) and hysteresivity (eta) were analysed during sinusoidal oscillations at 1Hz. After 1h of oscillation, PCIII mRNA expression was determined by Northern-blot and semiquantitative RT-PCR. Control value of PCIII mRNA was obtained from unstressed strips. E and R increased with augmenting force and decreased with increasing amplitude, while eta remained unaltered. PCIII mRNA expression increased significantly after 1h of oscillation at 10(-2)N and 5% L(B) and remained unchanged for 6h. In conclusion, the stress induced by force but not by amplitude led to the increment in PCIII mRNA expression.

Centrilobular fibrosis: a novel histological pattern of idiopathic interstitial pneumonia.

The classification of idiopathic interstitial pneumonias (IIP) is still under debate. In this context, we observed in some of our patients with a clinical and radiological diagnosis of IIP a different histological picture with an aggressive centrilobular scarring centered in the bronchiolar epithelia, but involving the surrounding parenchyma, which underwent extensive remodeling. We hypothesized that this pattern is a form of IIP that could be separated out histologically from the previously described patterns, in particular from usual interstitial pneumonia (UIP) and non-specific interstitial pneumonia (NSIP). Forty-nine patients with clinical and radiological diagnosis of IIP and open-lung biopsies were retrospectively selected from 1982 to 1998. The biopsies were reviewed according to the following criteria: derangement of lobular architecture, temporal homogeneity and subpleural or bronchocentric distribution of the lesions, fibroblast foci, bronchial epithelium necrosis and regeneration, exposure of the basal membrane, squamous metaplasia, basophilic intraluminal contents, and foreign bodies within the remodeling airspaces. Three groups were found: UIP (24 patients), NSIP (13), and a third that we named centrilobular fibrosis (CLF) (12). All histological parameters were significantly different among the three groups (p < 0.001). CLF is a specific, homogeneous, and recognizable histological pattern of IIP, and can be isolated from UIP and NSIP.