Objective: Failure of noninvasive ventilation (NIV) has been associated with short-term adverse effects related to the use of masks. The aim of this study was to compare the incidence, type and intensity of adverse effects, as well as the comfort, of total face masks (TFMs), facial masks (FMs) and nasal masks (NMs) during NIV. Methods: This was a randomized crossover trial involving 24 healthy volunteers submitted to six sessions of NIV in bilevel positive airway pressure mode using the TFM, FM and NM masks at low and moderate-to-high pressure levels. A written questionnaire was applied in order to evaluate eleven specific adverse effects related to the use of the masks. Comfort was assessed using a visual analog scale. The CO2 exhaled into the ventilator circuit was measured between the mask and the exhalation port. Results: The performance of the TFM was similar to that of the NM and FM in terms of comfort scores. Higher pressure levels reduced comfort and increased adverse effects, regardless of the mask type. When the TFM was used, there were fewer air leaks and less pain at the nose bridge, although there was greater oronasal dryness and claustrophobia. Air leaks were most pronounced when the FM was used. The partial pressure of exhaled CO2 entering the ventilator circuit was zero for the TFM. Conclusions: The short-term adverse effects caused by NIV interfaces are related to mask type and pressure settings. The TFM is a reliable alternative to the NM and FM. Rebreathing of CO2 from the circuit is less likely to occur when a TFM is used.

Keywords: Intermittent positive-pressure ventilation; Masks/adverse effects; Respiratory insufficiency;Equipment failure analysis.

Objective: To analyze bronchoalveolar lavage (BAL) specimens of burn victims who inhaled smoke, in order to identify alterations associated with mortality or survival. Methods: Eighteen victims of facial burns were submitted to BAL up to 24 h after the event. We investigated cell and protein content, including TNF-α, HLA-DR, CD14, CD68 and iNOS. Results: Of the 18 patients submitted to bronchoscopy, 8 (44.4%) died during the follow-up period. The mean age of patients who died was significantly higher (44.7 vs. 31.5 years). On average, the patients who died had burns covering 60.1% of the total body surface area, compared with 26.1% in the survivors (p < 0.0001). Of the 18 patients submitted to bronchoscopy, 11 (61.1%) showed endoscopic signs of smoke inhalation injury, and 4 (36.4%) of those 11 died. Of the 7 patients with no signs of smoke inhalation injury, 4 (57.1%) died. The mean number of ciliated epithelial cells in the BAL fluid was significantly higher in the patients who died than in the survivors (6.6% vs. 1.4%; p = 0.03). There were no significant differences between the groups in terms of any of the other parameters evaluated. Conclusions: The total body surface area burned was a predictive factor for mortality. Increased numbers of ciliated epithelial cells in the BAL fluid, denoting bronchial epithelial desquamation, were associated with higher mortality in patients with facial burns.

Keywords: Burns; Smoke inhalation injury; Bronchoalveolar lavage; Epithelial cells; Macrophages;Tumor necrosis factor-alpha.

Objective: To determine whether serum total IgE levels and total eosinophil counts have any relationship with the response to routine pharmacological treatment in patients with acute asthma. Methods: A cross-sectional study involving 162 patients with acute asthma. Serum total IgE levels, peripheral blood cell counts and eosinophil counts were determined. The treatment was adjusted for each patient according to the severity of asthma. Spirometry was performed at baseline and two weeks after the treatment. The patients were divided into two groups: high IgE (≥100 IU/mL) and low IgE (<100 IU/mL). We compared the two groups in terms of the relationships between baseline values and final values (percentage change) for the following parameters: FEV1, FVC, FEF25-75%, peripheral white blood cell counts and eosinophil counts. Results: There were no significant differences between the groups regarding the percentage changes of the studied parameters. Nor were there significant differences between the groups regarding FEV1, FVC, and FEF25-75% (% of the predicted values) at baseline. Conclusions: On the basis of these findings, we conclude that serum total IgE levels, peripheral white blood cell counts and eosinophil counts cannot predict the response to the pharmacological treatment of patients with acute asthma.

Keywords: Asthma/drug therapy; Eosinophils; Immunoglobulin E

Objective: Primary benign tumors of the trachea and main bronchi are uncommon. Interventional bronchoscopy allows the diagnosis and the treatment of some of these lesions. Methods: We reviewed four cases endoscopically treated at our institution. Results: Two patients had hamartoma, and two patients had endobronchial lipoma. In all of the cases, the interventional technique for the resection was the use of a polypectomy snare and electrocautery. The only complication reported was one episode of bronchospasm. Conclusions: Minimally invasive bronchoscopic resection is a safe, effective method for treating selected benign tumors of the main airway and has a low complication rate.

Keywords: Bronchoscopy; Bronchial neoplasms; Hamartoma; Lipoma.

In 1993 the first Brazilian cluster of Hantavirus Cardiopulmonary Syndrome (HCPS) was described in Juquitiba, SP. Since then, there have been descriptions of new cases specially on the southeast and south states of Brazil. Only in 2002 there were observed the first three cases of HCPS in our city: São Carlos. One of our patients was successfully supported with CPAP through facial mask. This is the first severe case of acute respiratory failure induced by Hantavirus that was successfully managed with this kind of respiratory strategy.

Keywords: Noninvasive Ventilation, CPAP, Hantavirus Pulmonary and Cardiovascular Syndrome, Acute Hipoxemic Respiratory Failure.

Objective: To study the effects of an oronasal interface (OI) for noninvasive ventilation, using a three-dimensional (3D) computational model with the ability to simulate and evaluate the main pressure zones (PZs) of the OI on the human face. Methods: We used a 3D digital model of the human face, based on a pre-established geometric model. The model simulated soft tissues, skull, and nasal cartilage. The geometric model was obtained by 3D laser scanning and post-processed for use in the model created, with the objective of separating the cushion from the frame. A computer simulation was performed to determine the pressure required in order to create the facial PZs. We obtained descriptive graphical images of the PZs and their intensity. Results: For the graphical analyses of each face-OI model pair and their respective evaluations, we ran 21 simulations. The computer model identified several high-impact PZs in the nasal bridge and paranasal regions. The variation in soft tissue depth had a direct impact on the amount of pressure applied (438-724 cmH2O). Conclusions: The computer simulation results indicate that, in patients submitted to noninvasive ventilation with an OI, the probability of skin lesion is higher in the nasal bridge and paranasal regions. This methodology could increase the applicability of biomechanical research on noninvasive ventilation interfaces, providing the information needed in order to choose the interface that best minimizes the risk of skin lesion.

Keywords: Noninvasive ventilation; Computer simulation; Respiration, artificial.

Objective: To compare the incidence and intensity of acute adverse effects and the variation in the temperature of facial skin by thermography after the use of noninvasive ventilation (NIV). Methods: We included 20 healthy volunteers receiving NIV via oronasal mask for 1 h. The volunteers were randomly divided into two groups according to the ventilatory mode: bilevel positive airway pressure (BiPAP) or continuous positive airway pressure (CPAP). Facial thermography was performed in order to determine the temperature of the face where it was in contact with the mask and of the nasal dorsum at various time points. After removal of the mask, the volunteers completed a questionnaire about adverse effects of NIV. Results: The incidence and intensity of acute adverse effects were higher in the individuals receiving BiPAP than in those receiving CPAP (16.1% vs. 5.6%). Thermographic analysis showed a significant cooling of the facial skin in the two regions of interest immediately after removal of the mask. The more intense acute adverse effects occurred predominantly among the participants in whom the decrease in the mean temperature of the nasal dorsum was lower (14.4% vs. 7.2%). The thermographic visual analysis of the zones of cooling and heating on the face identified areas of hypoperfusion or reactive hyperemia. Conclusions: The use of BiPAP mode was associated with a higher incidence and intensity of NIV-related acute adverse effects. There was an association between acute adverse effects and less cooling of the nasal dorsum immediately after removal of the mask. Cutaneous thermography can be an additional tool to detect adverse effects that the use of NIV has on facial skin.

Keywords: Masks; Noninvasive ventilation; Thermography.

Objective: Discomfort and noncompliance with noninvasive ventilation (NIV) interfaces are obstacles to NIV success. Total face masks (TFMs) are considered to be a very comfortable NIV interface. However, due to their large internal volume and consequent increased CO2 rebreathing, their orifices allow proximal leaks to enhance CO2 elimination. The ventilators used in the ICU might not adequately compensate for such leakage. In this study, we attempted to determine whether ICU ventilators in NIV mode are suitable for use with a leaky TFM. Methods: This was a bench study carried out in a university research laboratory. Eight ICU ventilators equipped with NIV mode and one NIV ventilator were connected to a TFM with major leaks. All were tested at two positive end-expiratory pressure (PEEP) levels and three pressure support levels. The variables analyzed were ventilation trigger, cycling off, total leak, and pressurization. Results: Of the eight ICU ventilators tested, four did not work (autotriggering or inappropriate turning off due to misdetection of disconnection); three worked with some problems (low PEEP or high cycling delay); and one worked properly. Conclusions: The majority of the ICU ventilators tested were not suitable for NIV with a leaky TFM.

Keywords: Ventilators, mechanical; Positive-pressure Respiration; Noninvasive ventilation; Equipment safety; Equipment failure; Masks.

Objective: To propose a new classification criterion for the differentiation between pleural exudates and transudates-quantifying total proteins in pleural fluid (TP-PF) and lactate dehydrogenase in pleural fluid (LDH-PF) exclusively-as well as to compare this new criterion with the classical criterion in terms of diagnostic yield. Methods: This was an observational, cross-sectional study with a within-subject design, comprising 181 patients with pleural effusion treated at two university hospitals in the state of Rio de Janeiro, Brazil, between 2003 and 2006. The diagnostic parameters included in the classical criterion were identified, as were those included in the new criterion. Results: Of the 181 patients, 152 and 29 were diagnosed with pleural exudates and pleural transudates, respectively. For the classical criterion, the sensitivity, specificity, and accuracy for the diagnosis of pleural exudates were, respectively, 99.8%, 68.6%, and 94.5%, whereas the corresponding values for the diagnosis of pleural transudates were 76.1%, 90.1%, and 87.6%. For the new criterion (cut-off points set at 3.4 g/dL for TP-PF and 328.0 U/L for LDH-PF), the sensitivity, specificity, and accuracy for the diagnosis of exudates were, respectively, 99.4%, 72.6%, and 99.2%, whereas the corresponding values for the diagnosis of transudates were 98.5%, 83.4%, and 90.0%. The accuracy of the new criterion for the diagnosis of pleural exudates was significantly greater than was that of the classical criterion (p = 0.0022). Conclusions: The diagnostic yield was comparable between the two criteria studied. Therefore, the new classification criterion can be used in daily practice.

Keywords: Pleural effusion/diagnosis; Pleural effusion/classification; Exudates and transudates.