Objective: To compare pre-extubation physiological characteristics and ultrasound variables between patients intubated for COVID-19 compared to a clinical population and those intubated for other reasons. Methods: This was a secondary analysis of a prospective cohort study of patients undergoing invasive mechanical ventilation (IMV) for more than 48 h. Patients were divided into two groups: those intubated for COVID-19-induced ARDS and those intubated for other clinical reasons. Ultrasound assessment of lung and diaphragm function was performed before extubation. The results were compared between the two groups of patients. Results: In comparison with the patients without COVID-19, those with the disease were younger (a median age of 58 [46-76] years vs. a median age of 75 [69-85] years; p = 0.01), had fewer comorbidities (a median Charlson Comorbidity Index of 2 [1-4] vs. a median Charlson Comorbidity Index of 5 [4-6]; p < 0.01), and were less severely ill at admission (a median APACHE II score of 9 [8-14] vs. a median APACHE II score of 18 [13-22]; p < 0.01). In addition, the median duration of IMV was longer in the COVID-19 patients (11 [9-23] days vs. 6 [3-8] days; p < 0.01). Although extubation success rates were similar between the COVID-19 and non-COVID-19 groups (22 [71%] vs. 35 [77.8%]), median lung ultrasound score differed between the two groups (23 [18-25] vs. 15 [11-18]; p < 0.01), as did median diaphragmatic excursion (2.1 [1.7-2.4] vs. 1.7 [1.2-2.0]; p < 0.01). Conclusions: Although patients with COVID-19 requiring ventilatory support are younger and have fewer comorbidities than those intubated for other clinical reasons, they experience longer hospital stays. Although lung ultrasound score can differ between patients with and without COVID-19, these differences do not significantly translate into extubation success rates. Therefore, the utility of ultrasound scores in weaning COVID-19 patients from IMV needs further study.

Keywords: COVID-19; Ventilator weaning; Diaphragm; Ultrasound/diagnosis; Lung.

Objective: To investigate the applicability of ultrasound imaging of the diaphragm in interstitial lung disease (ILD). Methods: Using ultrasound, we compared ILD patients and healthy volunteers (controls) in terms of diaphragmatic mobility during quiet and deep breathing; diaphragm thickness at functional residual capacity (FRC) and at total lung capacity (TLC); and the thickening fraction (TF, proportional diaphragm thickening from FRC to TLC). We also evaluated correlations between diaphragmatic dysfunction and lung function variables. Results: Between the ILD patients (n = 40) and the controls (n = 16), mean diaphragmatic mobility was comparable during quiet breathing, although it was significantly lower in the patients during deep breathing (4.5 ± 1.7 cm vs. 7.6 ± 1.4 cm; p < 0.01). The patients showed greater diaphragm thickness at FRC (p = 0.05), although, due to lower diaphragm thickness at TLC, they also showed a lower TF (p < 0.01). The FVC as a percentage of the predicted value (FVC%) correlated with diaphragmatic mobility (r = 0.73; p < 0.01), and an FVC% cut-off value of < 60% presented high sensitivity (92%) and specificity (81%) for indentifying decreased diaphragmatic mobility. Conclusions: Using ultrasound, we were able to show that diaphragmatic mobility and the TF were lower in ILD patients than in healthy controls, despite the greater diaphragm thickness at FRC in the former. Diaphragmatic mobility correlated with ILD functional severity, and an FVC% cut-off value of < 60% was found to be highly accurate for indentifying diaphragmatic dysfunction on ultrasound.

Keywords: Diaphragm/ultrasonography; Lung diseases, interstitial; Respiratory muscles; Respiratory function tests.

Objective: The aim of this study was to describe practices for weaning from mechanical ventilation (MV), in terms of the use of protocols, methods, and criteria, in pediatric ICUs (PICUs), neonatal ICUs (NICUs), and mixed neonatal/pediatric ICUs (NPICUs) in Brazil. Methods: This was a cross-sectional survey carried out by sending an electronic questionnaire to a total of 298 NICUs, PICUs, and NPICUs throughout Brazil. Results: Completed questionnaires were assessed for 146 hospitals, NICUs accounting for 49.3% of the questionnaires received, whereas PICUs and NPICUs accounted for 35.6% and 15.1%, respectively. Weaning protocols were applied in 57.5% of the units. In the NICUs and NPICUs that used weaning protocols, the method of MV weaning most commonly employed (in 60.5% and 50.0%, respectively) was standardized gradual withdrawal from ventilatory support, whereas that employed in most (53.0%) of the PICUs was spontaneous breathing trial (SBT). During the SBTs, the most common ventilation mode, in all ICUs, was pressure-support ventilation (10.03 ± 3.15 cmH2O) with positive end-expiratory pressure. The mean SBT duration was 35.76 ± 29.03 min in the NICUs, compared with 76.42 ± 41.09 min in the PICUs. The SBT parameters, weaning ventilation modes, and time frame considered for extubation failure were not found to be dependent on the age profile of the ICU population. The findings of the clinical evaluation and arterial blood gas analysis are frequently used as criteria to assess readiness for extubation, regardless of the age group served by the ICU. Conclusions: In Brazil, the clinical practices for weaning from MV and extubation appear to vary depending on the age group served by the ICU. It seems that weaning protocols and SBTs are used mainly in PICUs, whereas gradual withdrawal from ventilatory support is more widely used in NICUs and NPICUs.

Keywords: Ventilator weaning/methods; Respiration, artificial; Airway extubation/methods; Intensive care units, pediatric/standards; Intensive care units, neonatal/standards.

Objective: Ventilator-associated pneumonia (VAP) is a serious complication of mechanical ventilation (MV). However, data on VAP in patients on prolonged MV (PMV) are scarce. We aimed to describe the characteristics of VAP patients on PMV and to identify factors associated with mortality. Methods: This was a retrospective cohort study including VAP patients on PMV. We recorded baseline characteristics, as well as 30-day and 90-day mortality rates. Variables associated with mortality were determined by Kaplan-Meier survival analysis and Cox regression model. Results: We identified 80 episodes of VAP in 62 subjects on PMV. The medians for age, Charlson Comorbidity Index, SOFA score, and days on MV were, respectively, 69.5 years, 5, 4, and 56 days. Episodes of VAP occurred between days 21 and 50 of MV in 28 patients (45.2%) and, by day 90 of MV, in 48 patients (77.4%). The 30-day and 90-day mortality rates were 30.0% and 63.7%, respectively. There were associations of 30-day mortality with the SOFA score (hazard ratio [HR] = 1.30; 95% CI: 1.12-1.52; p < 0.001) and use of vasoactive agents (HR = 4.0; 95% CI: 1.2-12.9; p = 0.02), whereas 90-day mortality was associated with age (HR = 1.03; 95% CI: 1.00-1.05; p = 0.003), SOFA score (HR = 1.20; 95% CI: 1.07-1.34; p = 0.001), use of vasoactive agents (HR = 4.07; 95% CI: 1.93-8.55; p < 0.001), and COPD (HR = 3.35; 95% CI: 1.71-6.60; p < 0.001). Conclusions: Mortality rates in VAP patients on PMV are considerably high. The onset of VAP can occur various days after MV initiation. The SOFA score is useful for predicting fatal outcomes. The factors associated with mortality could help guide therapeutic decisions and determine prognosis.

Keywords: Pneumonia, ventilator-associated; Critical care; Ventilators, mechanical.

Objective: To evaluate the role of intrapleural positioning of a pleural catheter in early lung expansion and pleurodesis success in patients with recurrent malignant pleural effusion (RMPE). Methods: This was a retrospective study nested into a larger prospective cohort study including patients with RMPE recruited from a tertiary university teaching hospital between June of 2009 and September of 2014. The patients underwent pleural catheter insertion followed by bedside pleurodesis. Chest CT scans were performed twice: immediately before pleurodesis (iCT) and 30 days after pleurodesis (CT30). Catheter positioning was categorized based on iCT scans as posterolateral, anterior, fissural, and subpulmonary. We used the pleural volume on iCT scans to estimate early lung expansion and the difference between the pleural volumes on CT30 and iCT scans to evaluate radiological success of pleurodesis. Clinical pleurodesis success was defined as no need for any other pleural procedure. Results: Of the 131 eligible patients from the original study, 85 were included in this nested study (64 women; mean age: 60.74 years). Catheter tip positioning was subpulmonary in 35 patients (41%), anterior in 23 (27%), posterolateral in 17 (20%), and fissural in 10 (12%). No significant differences were found among the groups regarding early lung expansion (median residual pleural cavity = 377 mL; interquartile range: 171-722 mL; p = 0.645), radiological success of pleurodesis (median volume = 33 mL; interquartile range: −225 to 257 mL; p = 0.923), and clinical success of pleurodesis (85.8%; p = 0.676). Conclusions: Our results suggest that the position of the tip of the pleural catheter influences neither early lung expansion nor bedside pleurodesis success in patients with RMPE.

Keywords: Pleurodesis; Pleural effusion, malignant; Tomography; Catheters.

Objective: To identify factors associated with prolonged weaning and mortality in critically ill COVID-19 patients admitted to ICUs and under invasive mechanical ventilation. Methods: Between March of 2020 and July of 2021, we retrospectively recorded clinical and ventilatory characteristics of critically ill COVID-19 patients from the day of intubation to the outcome. We classified the patients regarding the weaning period in accordance with established criteria. A logistic regression analysis was performed to identify variables associated with prolonged weaning and mortality. Results: The study involved 303 patients, 100 of whom (33.0%) had a prolonged weaning period. Most of the patients were male (69.6%), 136 (44.8%) had more than 50% of pulmonary involvement on chest CT, and 93 (30.6%) had severe ARDS. Within the prolonged weaning group, 62% died within 60 days. Multivariate analysis revealed that lung involvement greater than 50% on CT and delay from intubation to the first separation attempt from mechanical ventilation were significantly associated with prolonged weaning, whereas age and prolonged weaning were significantly associated with mortality. Conclusions: Prolonged weaning can be used as a milestone in predicting mortality in critically ill COVID-19 patients. Lung involvement greater than 50% on CT and delay from intubation to the first separation attempt from mechanical ventilation were identified as significant predictors of prolonged weaning. These results might provide valuable information for healthcare professionals when making clinical decisions regarding the management of critically ill COVID-19 patients who are on mechanical ventilation.

Keywords: COVID-19; Pneumonia, viral; Respiratory distress syndrome; Respiration, artificial; Ventilator weaning; Cohort studies; Hospital mortality; Patient outcome assessment.

The evaluation of critically ill patients using lung ultrasound, even if performed by nonspecialists, has recently garnered greater interest. Because lung ultrasound is based on the fact that every acute illness reduces lung aeration, it can provide information that complements the physical examination and clinical impression, the main advantage being that it is a bedside tool. The objective of this review was to evaluate the clinical applications of lung ultrasound by searching the PubMed and the Brazilian Virtual Library of Health databases. We used the following search terms (in Portuguese and English): ultrasound; lung; and critical care. In addition to the most relevant articles, we also reviewed specialized textbooks. The data show that lung ultrasound is useful in the differential diagnosis of pulmonary infiltrates, having good accuracy in identifying consolidations and interstitial syndrome. In addition, lung ultrasound has been widely used in the evaluation and treatment of pleural effusions, as well as in the identification of pneumothorax. This technique can also be useful in the immediate evaluation of patients with dyspnea or acute respiratory failure. Other described applications include monitoring treatment response and increasing the safety of invasive procedures. Although specific criteria regarding training and certification are still lacking, lung ultrasound is a fast, inexpensive, and widely available tool. This technique should progressively come to be more widely incorporated into the care of critically ill patients.

Keywords: Ultrasonography; Lung; Critical care; Intensive care units.

Objective: To evaluate the performance of lung ultrasound to determine short-term outcomes of patients with COVID-19 admitted to the intensive care unit. Methods: This is a Prospective, observational study. Between July and November 2020, 59 patients were included and underwent at least two LUS assessments using LUS score (range 0-42) on day of admission, day 5th, and 10th of admission. Results: Age was 66.5±15 years, APACHE II was 8.3±3.9, 12 (20%) patients had malignancy, 46 (78%) patients had a non-invasive ventilation/high-flow nasal cannula and 38 (64%) patients required mechanical ventilation. The median stay in ICU was 12 days (IQR 8.5-20.5 days). ICU or hospital mortality was 54%. On admission, the LUS score was 20.8±6.1; on day 5th and day 10th of admission, scores were 27.6±5.5 and 29.4±5.3, respectively (P=0.007). As clinical condition deteriorated the LUS score increased, with a positive correlation of 0.52, P <0.001. Patients with worse LUS on day 5th versus better score had a mortality of 76% versus 33% (OR 6.29, 95%CI 2.01-19.65, p. 0.003); a similar difference was observed on day 10. LUS score of 5th day of admission had an area under the curve of 0.80, best cut-point of 27, sensitivity and specificity of 0.75 and 0.78 respectively. Conclusion: These findings position LUS as a simple and reproducible method to predict the course of COVID-19 patients.

Keywords: Lund diseases; COVID-19; Ultrasonography.

The use of predictive parameters for weaning from mechanical ventilation is a rather polemic topic, and the results of studies on this topic are divergent. Regardless of the use of these predictive parameters, the spontaneous breathing trial (SBT) is recommended. The objective of the present study was to review the utility of predictive parameters for weaning in adults. To that end, we searched the Medline, LILACS, and PubMed databases in order to review articles published between 1991 and 2009, in English or in Portuguese, using the following search terms: weaning/desmame, extubation/extubação, and weaning indexes/indices de desmame. The use of clinical impression is an inexact means of predicting weaning outcomes. The most widely used weaning parameter is the RR/tidal volume (VT) ratio, although this parameter presents heterogeneous results in terms of accuracy. Other relevant parameters are MIP, airway occlusion pressure (P0.1), the P0.1/MIP ratio, RR, VT, minute volume, and the index based on compliance, RR, oxygenation, and MIP. An index created in Brazil, the integrative weaning index, has shown high accuracy. Although recommended, the SBT is inaccurate, approximately 15% of extubation failures going unidentified in SBTs. The main limitations of the weaning indexes are related to their use in specific populations, the cut-off points selected, and variations in the types of measurement. Since the SBT and the clinical impression are not 100% accurate, the weaning parameters can be useful, especially in situations in which the decision as to weaning is difficult.

Keywords: Weaning; Intensive care units; Ventilators, mechanical; Respiration, artificial.

Background: Open lung biopsy is regarded as the gold standard for the diagnosis of diffuse pulmonary infiltrates. Objective: To determine the diagnostic yield, therapeutic changes, complications and mortality attributed to open lung biopsy in patients with diffuse pulmonary infiltrates and on mechanical ventilation. Method: We reviewed, retrospectively, the charts of 24 patients, ranging from 26 to 89 years of age, admitted to the intensive care units of two private hospitals and submitted to open lung biopsy. Results: Diagnostic positivity was found in 100% of patients, resulting in an alteration in the treatment regimen in 75%. Postoperative complications occurred in five patients (20.8%). There were no biopsy-related deaths, although global mortality was 45.8%. Conclusion: Open lung biopsy is a safe and high yield procedure for diagnosing diffuse pulmonary infiltrate in patients on mechanical ventilation. Despite the fact that no mortality impact factor has been assigned to such patients, data in the literature regarding prognosis must be taken into consideration.

Keywords: Biopsy. Respiratory insufficiency. Respiration artificial.

Objective: To determine whether the predictive accuracy of clinical judgment alone can be improved by supplementing it with an objective weaning protocol as a decision support tool. Methods: This was a multicenter prospective cohort study carried out at three medical/surgical ICUs. The study involved all consecutive difficult-to-wean ICU patients (failure in the first spontaneous breathing trial [SBT]), on mechanical ventilation (MV) for more than 48 h, admitted between January of 2002 and December of 2005. The patients in the protocol group (PG) were extubated after a T-piece weaning trial and were compared with patients who were otherwise extubated (non-protocol group, NPG). The primary outcome measure was reintubation within 48 h after extubation. Results: We included 731 patients-533 (72.9%) and 198 (27.1%) in the PG and NPG, respectively. The overall reintubation rate was 17.9%. The extubation success rates in the PG and NPG were 86.7% and 69.6%, respectively (p < 0.001). There were no significant differences between the groups in terms of age, gender, severity score, or pre-inclusion time on MV. However, COPD was more common in the NPG than in the PG (44.4% vs. 17.6%; p < 0.001), whereas sepsis and being a post-operative patient were more common in the PG (23.8% vs. 11.6% and 42.4% vs. 26.4%, respectively; p < 0.001 for both). The time on MV after the failure in the first SBT was higher in the PG than in the NPG (9 ± 5 days vs. 7 ± 2 days; p < 0.001). Conclusions: In this sample of difficult-to-wean patients, the use of a weaning protocol improved the decision-making process, decreasing the possibility of extubation failure.

Keywords: Ventilator weaning; Ventilation; Ventilators, mechanical.

Objective: To identify factors that lead to a positive oxygenation response and predictive factors of mortality after prone positioning. Methods: This was a retrospective, multicenter, cohort study involving seven hospitals in Brazil. Inclusion criteria were being > 18 years of age with a suspected or confirmed diagnosis of COVID-19, being on invasive mechanical ventilation, having a PaO2/FIO2 ratio < 150 mmHg, and being submitted to prone positioning. After the first prone positioning session, a 20 mmHg improvement in the PaO2/FIO2 ratio was defined as a positive response. Results: The study involved 574 patients, 412 (72%) of whom responded positively to the first prone positioning session. Multiple logistic regression showed that responders had lower Simplified Acute Physiology Score III (SAPS III)/SOFA scores and lower D-dimer levels (p = 0.01; p = 0.04; and p = 0.04, respectively). It was suggested that initial SAPS III and initial PaO2/FIO2 were predictors of oxygenation response. The mortality rate was 69.3%. Increased risk of mortality was associated with age (OR = 1.04 [95 CI: 1.01-1.06]), time to first prone positioning session (OR = 1.18 [95 CI: 1.06-1.31]), number of sessions (OR = 1.31 [95% CI: 1.00-1.72]), proportion of pulmonary impairment (OR = 1.55 [95% CI: 1.02-2.35]), and immunosuppression (OR = 3.83 [95% CI: 1.35-10.86]). Conclusions: Our results show that most patients in our sample had a positive oxygenation response after the first prone positioning session. However, the mortality rate was high, probably due to the health status and the number of comorbidities of the patients, as well as the severity of their disease. Our results also suggest that SAPS III and the initial PaO2/FIO2 predict the oxygenation response; in addition, age, time to first prone positioning, number of sessions, pulmonary impairment, and immunosuppression can predict mortality.

Keywords: Respiratory distress syndrome; Coronavirus infections; Pulmonary medicine; COVID-19; Prone position; SARS-CoV-2.

Objective: To assess, using ultrasound, the effects that changes in body position have on diaphragmatic mobility in healthy subjects during spontaneous breathing. Methods: The study involved seven healthy female volunteers, all of whom were nonsmokers, well nourished, and free of any cardiopulmonary disease. They were submitted to pulmonary function testing and ultrasound evaluation of the mobility of the right diaphragm by the craniocaudal displacement of the left branch of the portal vein using an ultrasound device in mode B. The mobility of the right diaphragm was evaluated in right decubitus and in left decubitus. The order of evaluation was previously determined in a random drawing. Results: The average mobility of the right diaphragm in right decubitus (51.30 ± 9.69 mm) was significantly higher (p = 0.03) than that observed in left decubitus (45.93 ± 10.37 mm). Conclusion: The results suggest that, during spontaneous ventilation, the dependent portion of the diaphragm presents greater mobility than does the nondependent portion, and that the technique used was sufficiently sensitive to detect variations in diaphragmatic mobility related to changes in posture.

Keywords: Diaphragm; Ultrasonography; Respiratory function tests; Posture.

Studies published by Brochard et al. and by Esteban et al. came to different conclusions about the best technique of weaning from mechanical ventilation. Although the association of synchronized intermittent mandatory ventilation (SIMV) with pressure support ventilation (PSV) is frequently used and considered as a physiologic form of weaning, no prospective randomized study compared this technique to synchronized intermittent mandatory ventilation or to pressure support ventilation used singly. The authors compared these three weaning methods to determine the one that is associated with the shortest weaning time and the smallest frequency of unfavorable outcome. Methods: The authors analyzed prospectively 72 consecutive patients submitted to mechanical ventilation for at least 24 hours and that had clinical, gasometric, and respiratory criteria for weaning. The patients were randomized in three groups (SIMV, PSV, SIMV+PSV). Stringent criteria were used in the application of each technique to define success or failure of the procedure. Results: The groups (SIMV = 21, PSV = 25 and SIMV+PSV = 26 patients) were similar with respect to age, score APACHE III and diseases. Mean duration of weaning was 1.7 ± 1.2 days with SIMV, 2.5 ± 1.6 days with PSV, and 2.1 ± 1.5 days with SIMV+PSV. Four (19.0 %) patients failled to wean in the SIMV group, nine (36.0%) in PSV and two (7.7%) in SIMV+PSV. Conclusions: This study shows a good performance of SIMV+PSV for weaning patients from mechanical ventilation and unfavorable results with support ventilation that can not be attributed to homogeneity between the groups, nor to the methodologies or equipments used.

Keywords: Weaning. Synchronized intermittent mandatory ventilation. Pressure support ventilation.

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.