Objective: To assess the feasibility of using a new helmet interface for CPAP, designated ELMO, to treat COVID-19-related acute hypoxemic respiratory failure (AHRF) outside the ICU. Methods: This was a proof-of-concept study involving patients with moderate to severe AHRF secondary to COVID-19 admitted to the general ward of a public hospital. The intervention consisted of applying CPAP via the ELMO interface integrated with oxygen and compressed air flow meters (30 L/min each) and a PEEP valve (CPAP levels = 8-10 cmH2O), forming the ELMOcpap system. The patients were monitored for cardiorespiratory parameters, adverse events, and comfort. Results: Ten patients completed the study protocol. The ELMOcpap system was well tolerated, with no relevant adverse effects. Its use was feasible outside the ICU for a prolonged amount of time and was shown to be successful in 60% of the patients. A CPAP of 10 cmH2O with a total gas flow of 56-60 L/min improved oxygenation after 30-to 60-min ELMOcpap sessions, allowing a significant decrease in estimated FIO2 (p = 0.014) and an increase in estimated PaO2/FIO2 ratio (p = 0.008) within the first hour without CO2 rebreathing. Conclusions: The use of ELMOcpap has proven to be feasible and effective in delivering high-flow CPAP to patients with COVID-19-related AHRF outside the ICU. There were no major adverse effects, and ELMO was considered comfortable. ELMOcpap sessions significantly improved oxygenation, reducing FIO2 without CO2 rebreathing. The overall success rate was 60% in this pilot study, and further clinical trials should be carried out in the future. (ClinicalTrials.gov identifier: NCT04470258 [http://www.clinicaltrials.gov/])

Keywords: Pneumonia; SARS-CoV-2; COVID-19; Respiratory protective devices; Continuous positive airway pressure; Noninvasive ventilation.

Objective: This study aimed to describe the outcomes and explore predictors of intubation and mortality in patients with ARDS due to COVID-19 treated with CPAP delivered via a helmet interface and light sedation. Methods: This was a retrospective cohort study involving patients with COVID-19-related ARDS who received CPAP using a helmet developed in Brazil (ELMOT), associated with a light sedation protocol in a pulmonology ward. Demographic, clinical, imaging, and laboratory data, as well as the duration and response to the ELMO-CPAP sessions, were analyzed. Results: The sample comprised 180 patients. The intubation avoidance rate was 72.8%. The lack of necessity for intubation was positively correlated with younger age, > 24-h continuous HELMET-CPAP use in the first session, < 75% pulmonary involvement on CT, and ROX index > 4.88 in the second hour. The overall in-hospital mortality rate was 18.9%, whereas those in the nonintubated and intubated groups were 3.0% and 61.2%, respectively. Advanced age increased the mortality risk by 2.8 times, escalating to 13 times post-intubation. Conclusions: ELMO-CPAP with light sedation in a pulmonology ward was successful in > 70% of patients with moderate to severe ARDS due to COVID-19. Younger age, pulmonary involvement, ROX index, and prolonged first Helmet-CPAP session duration were associated with no need for intubation. Older age and intubation are associated with mortality.

Keywords: Respiratory distress syndrome; COVID-19; Continuous positive airway pressure; helmets ; Dexmedetomidine.

Objective: To assess whether the use of ELMO, a helmet for noninvasive ventilation created in Brazil, had a positive impact on the prognosis of patients with hypoxemic respiratory failure caused by severe COVID-19. Methods: This is a retrospective study of 50 critically ill COVID-19 patients. Epidemiological, clinical, and laboratory data were collected on ICU admission, as well as before, during, and after ELMO use. Patients were divided into two groups (success and failure) according to the outcome. Results: ELMO use improved oxygenation parameters such as Pao2, Fio2, and the Pao2/Fio2 ratio, and this contributed to a gradual reduction in Fio2, without an increase in CO2, as determined by arterial blood gas analysis. Patients in the success group had significantly longer survival (p < 0.001), as determined by the Kaplan-Meier analysis, less need for intubation (p < 0.001), fewer days of hospitalization, and a lower incidence of acute kidney injury in comparison with those in the failure group. Conclusions: The significant improvement in oxygenation parameters, the longer survival, as reflected by the reduced need for intubation and by the mortality rate, and the absence of acute kidney injury suggest that the ELMO CPAP system is a promising tool for treating ARDS and similar clinical conditions.

Keywords: Respiratory distress syndrome; COVID-19; Noninvasive ventilation; Intensive care units.

Herein, we report an instance of occupational exposure to food preservatives and resultant acute respiratory failure in three workers. The toxicological analysis revealed that mixing the particular food preservatives involved, a procedure that was performed by the three workers involved, produced NO2, the inhalation of which caused the pulmonary edema and respiratory failure. With time, the pulmonary damage was completely reversed in all three individuals. Accompanying this case report is a brief review of the literature regarding acute pulmonary injury resulting from occupational exposure to chemicals. We emphasize the importance of training, as well as of the use of protective gear, for workers who handle chemical substances.

Keywords: Respiratory insufficiency; Occupational exposure; Occupational diseases; Case report

Objective: To present the pulmonary histopathological alterations found in the autopsies of patients with acute respiratory failure (ARF) and determine whether underlying diseases and certain associated risk factors increase the incidence of these histopathological patterns. Methods: Final autopsy reports were reviewed, and 3030 autopsies of patients > 1 year of age with an underlying disease and associated risk factors were selected. All had developed diffuse infiltrates and died of ARF-related pulmonary alterations. Results: The principal pulmonary histopathological alterations resulting in immediate death were diffuse alveolar damage (DAD), pulmonary edema, lymphocytic interstitial pneumonia (LIP) and alveolar hemorrhage. The principal underlying diseases were AIDS, bronchopneumonia, sepsis, liver cirrhosis, pulmonary thromboembolism, acute myocardial infarction (AMI), cerebrovascular accident, tuberculosis, cancer, chronic kidney failure and leukemia. The principal associated risk factors were as follows: age ≥ 50 years; arterial hypertension; congestive heart failure; chronic obstructive pulmonary disease; and diabetes mellitus. These risk factors and AIDS correlated with a high risk of developing LIP; these same risk factors, if concomitant with sepsis or liver cirrhosis, correlated with a risk of developing DAD; thromboembolism and these risk factors correlated with a risk of developing alveolar hemorrhage; these risk factors and AMI correlated with a risk of developing pulmonary edema. Conclusion: Pulmonary findings in patients who died of ARF presented four histopathological patterns: DAD, pulmonary edema, LIP and alveolar hemorrhage. Underlying diseases and certain associated risk factors correlated positively with specific histopathological findings on autopsy.

Keywords: Respiratory insufficiency; Autopsy; Lung diseases, interstitial; Pulmonary edema; Hemorrhage.

The goal of this paper is to review the use of CT scan in acute respiratory failure (ARF), acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). The most important papers studying CT in ARF, published in English language literature, were found in Medline. The use of CT in patients with ARF let allowed the authors to proceed to a qualitative evaluation of lung morphology looking for diffuse an/or localized hyperdensities, and for other concomitant abnormalities (pleural effusion, pneumothorax). It is also possible to evaluate lung density histograms and calculate the gas-tissue ratio within the lungs. Likewise, one can also calculate total and regional lung volumes (aerated, poorly-aerated, non-aerated, and overdistension volumes). Knowing those volumes it is possible to quantify alveolar recruitment and overdistension due to ventilatory strategies as the use of different positive end expiratory pressure (PEEP) levels.

Keywords: Acute lung injury. Acute respiratory distress syndrome.

Objective: To assess ICU patients with COPD, in terms of in-hospital characteristics, two-year mortality and two-year functional status of survivors. Methods: A prospective cohort study involving patients with acute exacerbation of COPD admitted to the ICUs of two hospitals in the city of Porto Alegre, Brazil, between July of 2005 and July of 2006. At two years after discharge, survivors were interviewed by telephone in order to determine Karnofsky scores and scores on a scale regarding activities of daily living (ADL). Results: The sample comprised 231 patients. In-hospital mortality was 37.7%, and two-year post-discharge mortality was 30.3%. Of the 74 survivors, 66 were interviewed (89%). The mean age at ICU admission was 74 ± 10 years, and the mean Acute Physiology and Chronic Health Evaluation II score was 18 ± 7. Two or more comorbidities were present in 87.8% of the patients. Of the 66 interviewees, 57 (86.3%) lived at home, 58 (87.8%) were self-sufficient, 12 (18.1%) required oxygen therapy, and 4 (6.1%) still required ventilatory support. There was a significant reduction in the quality of life and autonomy of the survivors, as evidenced by the Karnofsky scores (85 ± 9 vs. 79 ± 11, p = 0.03) and ADL scale scores (29 ± 5 vs. 25 ± 7; p = 0.01), respectively. Conclusions: In this patient sample, two-year mortality was quite high. Although there was a noticeable reduction in the functional status of the survivors, they remained self-sufficient.

Keywords: Pulmonary disease, chronic obstructive/mortality; Quality of life; Intensive care units.

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.

The goal of this paper is to review the use of pressure-volume (P-V) curves or compliance curves in patients with acute respiratory failure (ARF) - acute lung injury (ALI), and acute respiratory distress syndrome (ARDS). The most important papers published in English language literature concerning P-V curves in ARF were found in Medline and reviewed. Ideally, recommendation is made to calculate P-V curves in all patients with ARF in order to achieve adequate monitoring and management considering data obtained from the curves, such as lower inflexion point, upper inflexion point, and static compliance. The methods used to obtain P-V curves are supersyringe, multiple inspiratory occlusions and continuous flow. All of them are similar if low continuous flow is used and if care is taken to allow lung emptying and to avoid intrinsic PEEP (positive end expiratory pressure) before accomplishing the curves. In this way continuous flow can be a simple, inexpensive, secure and reliable method to be carried out at bedside in order to obtain P-V curves that allow for a better monitoring and management of patients with ARF.

Keywords: Acute lung injury. Acute respiratory distress syndrome. Pressure-volume curves.

Objective: To determine the impact that open lung biopsy findings have on decisions regarding changes in the treatment strategies employed for critically ill patients presenting diffuse pulmonary infiltrates and suffering from refractory acute respiratory failure, as well as on their clinical improvement. Methods: This study involved 12 mechanically ventilated patients with acute respiratory failure who were subjected to open lung biopsy (by thoracotomy) after not presenting a clinical response to standard treatment. Results: The single most common cause of the acute respiratory failure was viral infection, which was identified in 5 patients (40%). The pre-operative evaluation of the cause of respiratory failure was modified in 11 patients (91.6%), and a specific diagnosis was made in 100% of the cases. Regardless of changes in treatment regimen, the mortality rate was 50%. Six patients (50%) survived to be discharged from the hospital. All of the discharged patients survived for at least one year after the open lung biopsy, for an overall one-year survival rate of 50% among the 12 patients studied. For the patients who died in the hospital, the time of survival after open lung biopsy was 14 + 10.8 days. Conclusion: We conclude that open lung biopsy is a useful tool in the management of acute respiratory failure when there is no clinical improvement after standard treatment, since it can lead to a specific diagnosis that requires distinct treatment, which probably lowers the mortality rate among such patients.

Keywords: Respiratory distress syndrome, adult; Lung/pathology; Biposy; Acute respiratory syndrome

Objective: To evaluate the effects of non-invasive positive pressure ventilation (NIPPV) on acute respiratory failure and to identify the factors associated with its failure or success. Patients and methods: This open and prospective study analyzed 60 episodes of NIPPV use in 53 patients with respiratory failure. Results: In 37 occasions (62%), the patients were successfully ventilated with NIPPV (Success Group, SG) whereas in 23 episodes (38%) intubation was necessary (Failure Group, FG). FG patients showed a higher Apache II score (30.4 ± 9 versus 22.2 ± 8, p = 0.001). The use of NIPPV reduced respiratory rate after 2 hs. This reduction was less evident in FG (from 33 ± 9 to 30 ± 8 bpm, p = 0.094) than in SG (from 39 ± 11 to 28 ± 9 bpm, p < 0.001). PaO2 increased from 62 ± 22 to 101 ± 65 mmHg, (p < 0.001) with no differences between groups. Among patients with hypercapnia, PaCO2 level decreased in SG (from 76 ± 20 to 68 ± 21mmHg, p = 0.032) but not in FG (from 89 ± 23 to 93 ± 40mmHg, p = 0.54). Arterial pH increased in SG (from 7.25 ± 0.10 to 7.34 ± 0.11, p = 0.007) and not in FG (from 7.24 ± 0.07 to 7.21 ± 0.12, p = 0.48). NIPPV was used for longer in SG (3.4 ± 2.5 versus 2.3 ± 2 days, p = 0.003). Higher IPAP levels were used in SG (13.2 ± 3 versus 11 ± 4cmH2O, p = 0.02). The 10 patients (17%) who died, all belonged to FG. Skin lesions at the site of mask contact was the most common complication of NIPPV (5, 8%). NIPPV was efficient in treating acute respiratory failure in 2/3 of patients. The factors associated with failure were: greater severity of the illness, smaller reduction in the respiratory rate, no improvement of respiratory acidosis in 2 h and use of lower IPAP levels. The high mortality rate observed in FG (10, 43%) justifies efforts to optimize NIPPV implementation and to recognize its failure, as early as possible, in order to avoid delays in endotracheal intubation.

Keywords: Non-invasive positive pressure ventilation. Respiratory failure. Apache II. Hypercapnia.

Multidrug-resistant and extensively drug-resistant tuberculosis (MDR-TB and XDR-TB, respectively) continue to represent a challenge for clinicians and public health authorities. Unfortunately, although there have been encouraging reports of higher success rates, the overall rate of favorable outcomes of M/XDR-TB treatment is only 54%, or much lower when the spectrum of drug resistance is beyond that of XDR-TB. Treating M/XDR-TB continues to be a difficult task, because of the high incidence of adverse events, the long duration of treatment, the high cost of the regimens used, and the drain on health care resources. Various trials and studies have recently been undertaken (some already published and others ongoing), all aimed at improving outcomes of M/XDR-TB treatment by changing the overall approach, shortening treatment duration, and developing a universal regimen. The objective of this review was to summarize what has been achieved to date, as far as new and repurposed drugs are concerned, with a special focus on delamanid, bedaquiline, pretomanid, clofazimine, carbapenems, and linezolid. After more than 40 years of neglect, greater attention has recently been paid to the need for new drugs to fight the "white plague", and promising results are being reported.

Keywords: Tuberculosis/therapy; Tuberculosis, multidrug-resistant; Extensively drug-resistant tuberculosis; Antitubercular agents.

Objective: Bedside lung ultrasound (LUS) is a noninvasive, readily available imaging modality that can complement clinical evaluation. The Bedside Lung Ultrasound in Emergency (BLUE) protocol has demonstrated a high diagnostic accuracy in patients with acute respiratory failure (ARF). Recently, bedside LUS has been added to the medical training program of our ICU. The aim of this study was to investigate the accuracy of LUS based on the BLUE protocol, when performed by physicians who are not ultrasound experts, to guide the diagnosis of ARF. Methods: Over a one-year period, all spontaneously breathing adult patients consecutively admitted to the ICU for ARF were prospectively included. After training, 4 non-ultrasound experts performed LUS within 20 minutes of patient admission. They were blinded to patient medical history. LUS diagnosis was compared with the final clinical diagnosis made by the ICU team before patients were discharged from the ICU (gold standard). Results: Thirty-seven patients were included in the analysis (mean age, 73.2  14.7 years; APACHE II, 19.2  7.3). LUS diagnosis had a good agreement with the final diagnosis in 84% of patients (overall kappa, 0.81). The most common etiologies for ARF were pneumonia (n = 17) and hemodynamic lung edema (n = 15). The sensitivity and specificity of LUS as measured against the final diagnosis were, respectively, 88% and 90% for pneumonia and 86% and 87% for hemodynamic lung edema. Conclusions: LUS based on the BLUE protocol was reproducible by physicians who are not ultrasound experts and accurate for the diagnosis of pneumonia and hemodynamic lung edema.

Keywords: Ultrasonography, interventional; Respiratory insufficiency; Intensive care units.

Objective: To report data regarding COPD patients admitted to the ICU of a referral hospital for respiratory diseases, including outcomes and treatment evaluation. Methods: Study of a series of patients with respiratory failure and COPD admitted to the ICU of Nereu Ramos Hospital, located in the city of Florianópolis, Brazil, between October of 2006 and October of 2007. Data related to demographics, causes of hospitalization, pharmacological treatment, ventilatory support, length of hospital stay, in-hospital complications, ICU mortality, and 28-day mortality were obtained from the medical charts of the patients. Acute Physiology and Chronic Health Evaluation II (APACHE II) scores were calculated. Mortality at 18 months was assessed by subsequent telephone calls. Results: During the study period, 192 patients were admitted to the ICU, 24 (12.5%) of whom were diagnosed with respiratory failure and COPD. The mean length of ICU stay was 12.0 ± 11.1 days. Noninvasive ventilation was used in 10 of the 24 patients (41.66%) and failed in 5 of those 10. Invasive mechanical ventilation (IMV) was used in a total of 15 patients (62.5%). Overall ICU mortality and 28-day mortality were 20.83% and 33.33%, respectively. However, 18-month mortality was 62.5%. Conclusions: Respiratory failure associated with COPD was responsible for 12.5% of the ICU admissions. Orotracheal intubation and IMV were necessary in 62.5% of the cases. The ICU mortality rate was in accordance with that predicted by the APACHE II scores. However, late mortality was high.

Keywords: Epidemiology; Respiration, artificial; Respiratory insufficiency; Pulmonary disease, chronic obstructive; Intensive care units; Mortality.