Background: It is questionable whether pressure-controlled ventilation (PCV) has advantages over volume-cycled ventilation (VCV). Objectives: To compare PCV to VCV with decelerating flow profile during assisted and controlled modes in an acute lung injury experimental model. Methods: Severe acute lung injury (PaO2/FIO2 < 100 mmHg) was induced by oleic acid IV infusion (0.05 mg/kg) in seven dogs. The animals were submitted to PCV and VCV in a randomized sequence. After 40 minutes in the assisted mode, ventilation was changed to the controlled mode after neuromuscular blockade. The tidal volume and the inspiratory time were kept constant throughout the experiment. Results: There were no differences in gas exchange (PaO2 and PaCO2), cardiac output or oxygen delivery (DO2) between VCV and PCV. The same was observed regarding maximum airway and plateau pressures, and also to the static compliance. Oxygen consumption (VO2) after neuromuscular blockade was 124 ± 48 in VCV versus 143 ± 50 ml/min in PCV, p = 0.42. In the assisted mode, there was a statistical trend of a higher VO2 in PCV (219 ± 72 versus 154 ± 67 ml/min in VCV, p = 0.06), that was associated with a statistical trend of a higher oxygen cost of breathing (OCB) during assisted PCV, although without statistical significance (31 ± 77 in VCV versus 75 ± 96 ml/min in PCV, p = 0.23), and also in a lower PvO2 (34 ± 7 in PCV versus 42 ± 6 ml/min in VCV, p = 0.02). These occurred despite a higher maximum inspiratory flow in the assisted mode in PCV (58 ± 9 versus 48 ± 4 L/min in VCV, p = 0.01). In both VCV and PCV the institution of controlled ventilation reduced cardiac debit and DO2 in as much as 20% relative to the assisted mode. Conclusions: The implementation of controlled ventilation improved the oxygen delivery/consumption relationship in this severe and with high OCB acute lung injury model. The PCV offered no additional benefits to VCV and it was associated with a higher OCB during the assisted mode.

Keywords: Artificial respiration. Pulmonary gas exchange. Tidal volume.

Objective: To investigate the effects of N-acetylcysteine (NAC) and pentoxifylline in a model of remote organ injury after hind-limb ischemia/reperfusion (I/R) in rats, the lungs being the remote organ system. Methods: Thirty-five male Wistar rats were assigned to one of five conditions (n = 7/group), as follows: sham operation (control group); hind-limb ischemia, induced by clamping the left femoral artery, for 2 h, followed by 24 h of reperfusion (I/R group); and hind-limb ischemia, as above, followed by intraperitoneal injection (prior to reperfusion) of 150 mg/kg of NAC (I/R+NAC group), 40 mg/kg of pentoxifylline (I/R+PTX group), or both (I/R+NAC+PTX group). At the end of the trial, lung tissues were removed for histological analysis and assessment of oxidative stress. Results: In comparison with the rats in the other groups, those in the I/R group showed lower superoxide dismutase activity and glutathione levels, together with higher malondialdehyde levels and lung injury scores (p < 0.05 for all). Interstitial inflammatory cell infiltration of the lungs was also markedly greater in the I/R group than in the other groups. In addition, I/R group rats showed various signs of interstitial edema and hemorrhage. In the I/R+NAC, I/R+PTX, and I/R+NAC+PTX groups, superoxide dismutase activity, glutathione levels, malondialdehyde levels, and lung injury scores were preserved (p < 0.05 for all). The differences between the administration of NAC or pentoxifylline alone and the administration of the two together were not significant for any of those parameters (p > 0.05 for all). Conclusions: Our results suggest that NAC and pentoxifylline both protect lung tissue from the effects of skeletal muscle I/R. However, their combined use does not appear to increase the level of that protection.

Keywords: Skeletal muscle; Ischemia; Reperfusion injury; Lung injury; Acetylcysteine; Pentoxifylline.

Objective: To evaluate systematically the effects of continuous positive airway pressure (CPAP) on blood pressure in patients with resistant hypertension and obstructive sleep apnea (OSA). Methods: The Cochrane Library, PubMed, ScienceDirect, and the Web of Science were searched for studies investigating the effects of CPAP on blood pressure in patients with resistant hypertension and OSA. The selected studies underwent quality assessment and meta-analysis, as well as being tested for heterogeneity. Results: Six randomized controlled trials were included in the meta-analysis. The pooled estimates of the changes in mean systolic blood pressure and mean diastolic blood pressure (as assessed by 24-h ambulatory blood pressure monitoring) were −5.40 mmHg (95% CI: −9.17 to −1.64; p = 0.001; I2 = 74%) and −3.86 mmHg (95% CI: −6.41 to −1.30; p = 0.00001; I2 = 79%), respectively. Conclusions: CPAP therapy can significantly reduce blood pressure in patients with resistant hypertension and OSA.

Keywords: Continuous positive airway pressure; Sleep apnea, obstructive; Hypertension; Meta-analysis.

Objective: To determine the efficacy of chest compression accompanied by a 10-cmH2O increase in baseline inspiratory pressure on pressure support ventilation, in comparison with that of aspiration alone, in removing secretions, normalizing hemodynamics, and improving respiratory mechanics in patients on mechanical ventilation. Methods: This was a randomized crossover clinical trial involving patients on mechanical ventilation for more than 48 h in the ICU of the Porto Alegre Hospital de Clínicas, in the city of Porto Alegre, Brazil. Patients were randomized to receive aspiration alone (control group) or compression accompanied by a 10-cmH2O increase in baseline inspiratory pressure on pressure support ventilation (intervention group). We measured hemodynamic parameters, respiratory mechanics parameters, and the amount of secretions collected. Results: We included 34 patients. The mean age was 64.2  14.6 years. In comparison with the control group, the intervention group showed a higher median amount of secretions collected (1.9 g vs. 2.3 g; p = 0.004), a greater increase in mean expiratory tidal volume (16  69 mL vs. 56  69 mL; p = 0.018), and a greater increase in mean dynamic compliance (0.1  4.9 cmH2O vs. 2.8  4.5 cmH2O; p = 0.005). Conclusions: In this sample, chest compression accompanied by an increase in pressure support significantly increased the amount of secretions removed, the expiratory tidal volume, and dynamic compliance. (ClinicalTrials.gov Identifier:NCT01155648 [http://www.clinicaltrials.gov/])

Keywords: Physical therapy modalities; Respiration, Artificial; Intensive care units; Respiratory therapy.

Lung retrieval following cardio-circulatory arrest has been studied experimentally, however severe ischemia/reperfusion injury requires improved methods of graft preservation. Allograft perfusion with crystalloid solution delivered via pulmonary artery (antegrade perfusion) remains the standard procedure, however it does not provide adequate washout of the blood retained within the bronchial circulation which may trigger reperfusion injury. This has led the authors to test the impact of antegrade versus retrograde (via left atrium) perfusion of lung grafts submitted to 3 hours of warm ischemia after cardio-circulatory arrest in a dog model of left lung allotransplantation. Twelve donor dogs were sacrificed with thiopental sodium and kept under mechanical ventilation at room temperature for 3 hours. They were randomized and the heart-lung blocks harvested after being perfused in a retrograde (group I, n = 6) or antegrade (group II, n = 6) fashion with modified Euro-Collins solution. Twelve recipient animals were submitted to a left lung transplant receiving the grafts from both groups and the assessment was performed during 6 hours. Hemodynamic parameters were similar for animals in both groups. The gas exchange (arterial PaO2 and PaCO2) in recipients of group I (retrograde perfusion) was significantly better when compared to recipients of grafts perfused via pulmonary artery. Intracellular ATP did not show difference between the groups, however there was a measurable drop in its values when samples obtained upon extraction were compared to those measured after reperfusion and at the end of the assessment. The authors concluded that retrograde perfusion yields better pulmonary function after 6 hours of reperfusion in this animal model of left lung allotransplantation following 3 hours of normothermic ischemia under mechanical ventilation.

Keywords: Lung. Ischemia. Preservation. Retrograde perfusion. ATP.

Objective: To compare the effects that prone and supine positioning during high-frequency oscillatory ventilation (HFOV) have on oxygenation and lung inflammation, histological injury, and oxidative stress in a rabbit model of acute lung injury (ALI). Methods: Thirty male Norfolk white rabbits were induced to ALI by tracheal saline lavage (30 mL/kg, 38°C). The injury was induced during conventional mechanical ventilation, and ALI was considered confirmed when a PaO2/FiO2 ratio < 100 mmHg was reached. Rabbits were randomly divided into two groups: HFOV in the supine position (SP group, n = 15); and HFOV with prone positioning (PP group, n = 15). For HFOV, the mean airway pressure was initially set at 16 cmH2O. At 30, 60, and 90 min after the start of the HFOV protocol, the mean airway pressure was reduced to 14, 12, and 10 cmH2O, respectively. At 120 min, the animals were returned to or remained in the supine position for an extra 30 min. We evaluated oxygenation indices and histological lung injury scores, as well as TNF-α levels in BAL fluid and lung tissue. Results: After ALI induction, all of the animals showed significant hypoxemia, decreased respiratory system compliance, decreased oxygenation, and increased mean airway pressure in comparison with the baseline values. There were no statistically significant differences between the two groups, at any of the time points evaluated, in terms of the PaO2 or oxygenation index. However, TNF-α levels in BAL fluid were significantly lower in the PP group than in the SP group, as were histological lung injury scores. Conclusions: Prone positioning appears to attenuate inflammatory and histological lung injury during HFOV in rabbits with ALI.

Keywords: Respiration, artificial/adverse effects; Prone position; Lung/physiopathology; Pneumonia; Respiratory distress syndrome, adult; Acute lung injury; Disease models, animal; Rabbits.

Objective: To compare the effects of a home-based pulmonary rehabilitation (PR) program with and without telecoaching on health-related outcomes in COVID-19 survivors. Methods: A total of 42 COVID-19 patients who completed medical treatment were randomly divided into two groups: the study (telecoaching) group (n = 21) and the control (no telecoaching) group (n = 21). Both groups participated in an 8-week home-based PR program including education, breathing exercises, strength training, and regular walking. The study group received phone calls from a physiotherapist once a week. Both groups of patients were assessed before and after the program by means of the following: pulmonary function tests; the modified Medical Research Council dyspnea scale; the six-minute walk test; extremity muscle strength measurement; the Saint George's Respiratory Questionnaire (to assess disease-related quality of life); the Medical Outcomes Study 36-item Short-Form Health Survey (SF-36, to assess overall quality of life); and the Hospital Anxiety and Depression Scale. Results: In both groups, there were significant improvements in the following: FVC; the six-minute walk distance; right and left deltoid muscle strength; Saint George's Respiratory Questionnaire activity domain, impact domain, and total scores; and SF-36 social functioning, role-physical, role-emotional, and bodily pain domain scores (p < 0.05). Decreases in daily-life dyspnea, exertional dyspnea, and exertional fatigue were significant in the study group (p < 0.05), and the improvement in SF-36 social functioning domain scores was greater in the study group (p < 0.05). Conclusions: A home-based PR program with telecoaching increases social functioning and decreases daily-life dyspnea, exertional dyspnea, and exertional fatigue in COVID-19 survivors in comparison with a home-based PR program without telecoaching.

Keywords: COVID-19; Exercise; Telerehabilitation; Dyspnea; Fatigue.

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: To compare the expiratory flow increase technique (EFIT) and vibration accompanied by postural drainage (PD) in terms of their effects on the heart rate (HR), respiratory rate (RR) and SpO2 of infants with acute viral bronchiolitis (AVB). Methods: Infants with clinical and radiological diagnosis of AVB were analyzed. The HR, RR and SpO2 were registered at four time points: prior to the procedure; and at 10, 30 and 60 min after the procedure. The patients were divided into three groups: submitted to the EFIT; submitted to vibration/PD; and control. Results: We included 81 infants, 27 per group, with a mean age of 4.52 years and a mean weight of 6.56 kg. Using ANOVA, we found that the EFIT and vibration/PD groups presented no significant differences in relation to the control group in terms of the mean values for HR, RR or SpO2 (p > 0.05). Considering only the four time points evaluated, the mean RR was significantly lower in the EFIT and vibration/PD groups than in the control group (p < 0.05). Conclusions: In terms of overall improvement of cardiorespiratory parameters, neither the EFIT nor vibration/PD provided any benefit to infants with BVA. However, over time, respiratory physical therapy seems to contribute to decreasing the RR in these patients.

Keywords: Bronchiolitis, viral; Physical therapy modalities; Infant.

Objective: To investigate the effects of manual chest compression (MCC) on the expiratory flow bias during the positive end-expiratory pressure-zero end-expiratory pressure (PEEP-ZEEP) airway clearance maneuver applied in patients on mechanical ventilation. The flow bias, which influences pulmonary secretion removal, is evaluated by the ratio and difference between the peak expiratory flow (PEF) and the peak inspiratory flow (PIF). Methods: This was a crossover randomized study involving 10 patients. The PEEP-ZEEP maneuver was applied at four time points, one without MCC and the other three with MCC, which were performed by three different respiratory therapists. Respiratory mechanics data were obtained with a specific monitor. Results: The PEEP-ZEEP maneuver without MCC was enough to exceed the threshold that is considered necessary to move secretion toward the glottis (PEF − PIF difference > 33 L/min): a mean PEF − PIF difference of 49.1 ± 9.4 L/min was achieved. The mean PEF/PIF ratio achieved was 3.3 ± 0.7. Using MCC with PEEP-ZEEP increased the mean PEF − PIF difference by 6.7 ± 3.4 L/min. We found a moderate correlation between respiratory therapist hand grip strength and the flow bias generated with MCC. No adverse hemodynamic or respiratory effects were found. Conclusions: The PEEP-ZEEP maneuver, without MCC, resulted in an expiratory flow bias superior to that necessary to facilitate pulmonary secretion removal. Combining MCC with the PEEP-ZEEP maneuver increased the expiratory flow bias, which increases the potential of the maneuver to remove secretions.

Keywords: Physical therapy modalities; Critical care; Respiration, artificial; Bodily secretions.

Objective: To compare the influence of two different ventilation strategies-volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV)-on the functional performance of lung grafts in a canine model of unilateral left lung transplantation using donor lungs harvested after three hours of normothermic cardiocirculatory arrest under mechanical ventilation. Methods: The study comprised 40 mongrel dogs, randomized into two groups: VCV and PCV. Of the 20 recipients, 5 did not survive the transplant, and 5 died before the end of the post-transplant assessment period. The remaining 10 survivors (5 in each group) were evaluated for 360 min after lung transplantation. The functional performance of the grafts was evaluated regarding respiratory mechanics, gas exchange, and lung graft histology. Results: There were no significant differences between the groups regarding respiratory mechanics (peak inspiratory pressure, plateau pressure, mean airway pressure, dynamic compliance, and static compliance) or gas exchange variables (PaO2, venous oxygen tension, PaCO2, venous carbon dioxide tension, and the arterial-venous oxygen content difference). The histopathological findings were consistent with nonspecific acute lung injury and did not differ between the groups. Conclusions: This model of lung transplantation showed that the functional performance of lung grafts was not influenced by the ventilation strategy employed during the first six hours after reperfusion.

Keywords: Pulmonary ventilation; Respiration, artificial; Lung transplantation; Dogs; Organ preservation.

Objective: This study aimed to investigate acute and chronic effects of varenicline on lung tissue in an experimental study. Methods: A total of 34 rats were randomly allocated into study (varenicline) and control groups. The rats were divided into two groups (i) control group, (ii) varenicline group. Then, the rats in the each group were sub‑divided equally in turn as acute (C1; V1) and chronic (C2; V2) ; all rats of acute and chronic groups were sacrificed under the anesthesia on the 45th day for acute group [C1 (n=5) and V1 (n=12)] and the 90th day for chronic group [C2 (n=5) and V2 (n=12)], respectively. Thus, biochemical and histopathological analysis were carried out. Results: Thirty four rats completed the study, 24 were in varenicline group and 10 were in control group. In chronic exposure to varenicline, oxidant levels comprising of malondialdehyde (MDA), and myeloperoxidase (MPO) increased and superoxide dismutase (SOD), catalase (CAT), glutathione (GSH) and glutathione peroxidase (GPx) levels, named as antioxidants, decreased significantly when compared to the control group. MDA and MPO levels were also significantly higher and SOD, CAT, GPx, GSH levels were also significantly lower in chronic varenicline group when compared to acute varenicline group. These findings were also supported by histopathological observations. Conclusion: This is the first study, which evaluated pulmonary effects of varenicline experimentally on an animal model. It was observed that chronic varenicline treatments cause inflammation and lung cell injury.

Keywords: Varenicline; Lung tissue; Oxidative stress; Pulmonary toxicity.

Objective: To clarify whether, in healthy individuals, practicing yoga can modify maximal inspiratory pressure and spirometric indices when compared with the practice of aerobic exercise. Methods: A controlled clinical trial. A total of 31 healthy volunteers were allocated to practice aerobic exercise (n = 15) or to practice yoga (n = 16). Those in the first group served as controls and engaged in aerobic exercise for 45-60 minutes, twice a week for three months. Those in the second group practiced selected yogic techniques, also in sessions of 45-60 minutes, twice a week for three months. Forced vital capacity, forced expiratory volume in one second and maximal inspiratory pressure were measured before and after the three months of training. Results: No significant alterations were seen in the spirometric indices. A slight, although not significant, improvement in maximal inspiratory pressure was seen in both groups. However, there was a significant difference, seen in both genders, between the absolute delta (final value minus baseline value) of maximal inspiratory pressure for the group practicing yoga and that obtained for the group engaging in aerobic exercise (males: 19.5 cm H2O versus 2.8 cm H2O, p = 0.05; females: 20 cm H2O versus 3.9 cm H2O, p = 0.01). Conclusion: Neither yoga nor aerobic exercise provided a statistically significant improvement in maximal inspiratory pressure after three months. However, the absolute variation in maximal inspiratory pressure was greater among those practicing yoga.

Keywords: Yoga; Exercise; Respiratory muscles; Respiratory function tests; Maximal voluntary ventilation; Spirometry; Inspiratory capacity/physiology

Recent studies suggest that non-invasive positive pressure ventilation (NPPV) improves clinical signs and gas exchange, apart from avoiding the need for endotracheal intubation in selected patients with acute respiratory failure. In this prospective, open trial in the Intensive Care Unit (Hospital Universitário da Universidade Federal de Juiz de Fora), the authors evaluated the efficacy and security of using NPPV in patients with acute respiratory failure. Twenty-five patients with clinical or gasometric diagnosis of acute respiratory failure (respiratory rate > 25 breaths/min, accessory muscle use, PaO2 < 60 mmHg, PaCO2 > 50 mmHg after supplemental oxygen) received NPPV. Fifteen patients (60%) were successfully ventilated with NPPV, avoiding the tracheal intubation. After two hours with NPPV, the respiratory rate was reduced (from 36 ± 2 breaths/min to 26 ± 1 breaths/min, p < 0.01) and the PaO2 increased (from 76 ± 6 mmHg to 100 ± 12 mmHg, p < 0.05). Among the patients with hypercapnia, after two hours, the PaCO2 decreased (from 60 ± 2 mmHg to 49 ± 3 mmHg, p < 0.05). Four patients (16%) presented complications with facial skin necrosis, but only one had the NPPV stopped. Among the patients who did not respond to the method, three did not adapt to the NPPV and seven had it interrupted because of clinical deterioration. The authors conclude that NPPV is a safe option that can be used to treat selected patients with acute 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 assess possible alterations in the tidal volume and peak inspiratory pressure delivered by seven models of manually operated self-inflating resuscitation bags as a function of the oxygen supply rate used. Methods: The resuscitation bags tested were the following: Oxigel, models A and B; CE Reanimadores; ProtecSolutions; Missouri; Axmed; and Narcosul. For the measurements, a wall oxygen flow meter, a flow meter/respirometer, a resuscitation bag, a sensor (Tracer 5 unit), and a test lung were connected. In addition, the Tracer 5 unit was connected to a notebook computer. Oxygen supply rates of 1, 5, 10, and 15 L/min were used. Results: The tidal volume delivered by the Oxigel model A resuscitation bag when receiving oxygen at a rate of 15 L/min was approximately 99% greater than that delivered when receiving oxygen at a rate of 1 L/min. Similarly, peak inspiratory pressure was approximately 155% greater. Under the same conditions, the tidal volume delivered by the Narcosul resuscitation bag was 48% greater, and peak inspiratory pressure was 105% greater. The remaining resuscitation bags tested showed no significant alterations in the tidal volume or peak inspiratory pressure delivered. Conclusions: Under the resistance and compliance conditions used, the resuscitation bags in which the oxygen inflow is directed to the interior of the bag had the patient valve stuck at the inspiratory position when receiving oxygen at a rate ≥ 5 L/min, significantly increasing the tidal volume and peak inspiratory pressure delivered. This did not occur with the resuscitation bags in which the oxygen inflow is directed to the exterior of the bag.

Keywords: Oxygen/administration & dosage; Resuscitation; Equipment and supplies; Pulmonary ventilation; Intensive care.

Objective: Brain death (BD) triggers important hemodynamic and inflammatory alterations, compromising the viability of organs suitable for transplantation. To better understand the mi-crocirculatory alterations in donor lungs caused by BD. The present study investigated the pul-monary microcirculation in a rodent model of BD via intravital microscopy. Methods: Male Wistar rats were anaesthetized and mechanically ventilated. They were trepanned and BD was induced through the increase in intracranial pressure. As control group, sham-operated (SH) rats were trepanned only. In both groups, expiratory O2 and CO2 were monitored and after three hours, a thoracotomy was performed, and a window was created to observe the lung surface using an epi-fluorescence intravital microscopy. Lung expression of intercellular adhesion molecule (ICAM)-1 and endothelial nitric oxide synthase (eNOS) was evaluated by immunohistochemistry, and cytokines were measured in lung samples. Results: Three hours after the surgical proce-dures, pulmonary perfusion was 73% in the SH group. On the other hand, BD animals showed an important decrease in organ perfusion to 28% (p = 0.036). Lung microcirculatory compromise after BD induction was associated with an augmentation of the number of leukocytes recruited to lung tissue, and with a reduction in eNOS expression and an increase in ICAM-1 expression on lung endothelial cells. BD rats showed higher values of expiratory O2 and lower values of CO2 in comparison with SH animals after three hours of monitoring. Conclusion: Data presented showed that BD triggers an important hypoperfusion and inflammation in the lungs, compromis-ing the donor pulmonary microcirculation

Keywords: Brain death; Inflammation; Intravital microscopy; Lung microcirculation.

Objective: To investigate the effects of quercetin in a model of bleomycin-induced pulmonary inflammation and fibrosis. Methods: Seventynine adult male hamsters were randomized to receive intratracheal (IT) instillations and intraperitoneal (IP) injections in four configurations: IP vehicle/IT saline (VS group, n = 16); IP quercetin/IT saline (QS group, n = 16); IP vehicle/IT bleomycin (VB group, n = 27); and IP quercetin/ IT bleomycin (QB group, n = 20). Quercetin and bleomycin were administered at 30 mg/kg/day and 10 U/kg, respectively. Quercetin was started/discontinued 3 days before/14 days after the IT instillations. Results: The mortality rate was significantly higher in the VB group than in the other groups (44% vs. VS: 0%; QS: 0%; and QB: 15%). Lung levels of thiobarbituric acid reactive substances (× 10−2 nmol/mg) were significantly higher in the VB group (6.6 ± 1.3 vs. VS: 5.5 ± 0.8; QS: 2.5 ± 0.6; and QB: 5.8 ± 0.6). Lung levels of reduced glutathione (× 10−2 nmol/mg) were significantly lower in the VB/QB groups than in the VS/QS groups (28.9 ± 13.8/28.6 ± 14.8 vs. 43.9 ± 16.0/51.1 ± 20.3), whereas those of hydroxyproline (mg/g) were significantly higher (201.6 ± 37.3/177.6 ± 20.3 vs. 109.6 ± 26.1/117.5 ± 32.0).Mean lung septal thickness (μm) was greatest in the VB group (16.9 ± 3.2 vs. VS: 3.0 ± 0.3; QS: 3.3 ± 0.2; and QB: 5.2 ± 1.1). Conclusions: In a hamster model of lung injury, quercetin exhibited anti-inflammatory effects that are related, at least in part, to its antioxidant properties.

Keywords: Pulmonary fibrosis; Bleomycin; Flavonoids; Lipid peroxidation.

Objective: To evaluate the stability of hemodynamic, respiratory and gas exchange variables in an animal model of oleic acid-induced acute lung injury. Methods: This was an experimental study involving 10 mongrel dogs. The variables were measured at baseline, as well as at 30, 60, 90 and 120 min after the administration of oleic acid. In order to analyze repeated measurements, linear and quadratic effects were tested. Mixed linear models with diversified variance and covariance structures were used, depending on the variable studied. Results: We found that mean arterial blood pressure stabilized at 30 min, as did heart rate, pulmonary arterial pressure and pulmonary capillary pressure at 60 min. Respiratory rate, tidal volume, minute volume and respiratory work stabilized at 30 min. Regarding gas exchange variables, PaO2, PaO2/FiO2 ratio and pulmonary shunt fraction stabilized at 30 min. The remaining variables maintained a continuous rise or fall. Conclusions: This oleic acid-induced acute lung injury model is stable for some of the variables tested, although stabilization occurs at different times. The respiratory and gas exchange variables stabilized at 30 min, whereas the hemodynamic variables stabilized at 60 min.

Keywords: Respiratory distress syndrome, adult; Models, animal; Statistical analysis.

Objective: To determine the occurrence of cardiorespiratory alterations and to identify adverse events during the intrahospital transport of patients on invasive ventilation. Methods: A prospective observational non-randomized study was conducted at two tertiary hospitals between April of 2005 and December of 2006. We included patients on invasive ventilation who required intrahospital transport during the study period. Exclusion criteria were as follows: being under suspicion of brain death; being submitted to alternate periods of mechanical ventilation/nebulization via a T-piece; and being transported to the operating room. Prior to and after transport, we evaluated blood gas analysis results, vital signs, use of medications by means of a continuous infusion pump, parameters regarding the mechanical ventilator, duration of transport, transport distance and number of professionals involved. Results: We included 48 patients in a total of 58 intrahospital transports. Relevant cardiorespiratory alterations were identified in 39 transports, totaling 86 episodes, as well as 16 adverse events related to equipment or personnel failure, such as problems related to batteries and to miscommunication. Conclusions: During the intrahospital transport of patients on invasive ventilation, cardiorespiratory alterations were common (67.2%), and adverse events occurred in 75.7% of the transports.

Keywords: Patient transfer; Intensive care; Respiration, artificial; Ventilators, mechanical.