Objective: To evaluate the use of reflex cough PEF as a predictor of successful extubation in neurological patients who were candidates for weaning from mechanical ventilation. Methods: This was a cross-sectional study of 135 patients receiving mechanical ventilation for more than 24 h in the ICU of Cristo Redentor Hospital, in the city of Porto Alegre, Brazil. Reflex cough PEF, the rapid shallow breathing index, MIP, and MEP were measured, as were ventilatory, hemodynamic, and clinical parameters. Results: The mean age of the patients was 47.8 ± 17 years. The extubation failure rate was 33.3%. A reflex cough PEF of < 80 L/min showed a relative risk of 3.6 (95% CI: 2.0-6.7), and the final Glasgow Coma Scale score showed a relative risk of 0.64 (95% CI: 0.51-0.83). For every 1-point increase in a Glasgow Coma Scale score of 8, there was a 36% reduction in the risk of extubation failure. Conclusions: Reflex cough PEF and the Glasgow Coma Scale score are independent predictors of extubation failure in neurological patients admitted to the ICU.

Keywords: Weaning; Intensive care units; Cough.

Objective: To evaluate the usefulness of simple motor tasks such as hand grasping and tongue protrusion as predictors of extubation failure in critically ill neurological patients. Methods: This was a prospective cohort study conducted in the neurological ICU of a tertiary care hospital in the city of Porto Alegre, Brazil. Adult patients who had been intubated for neurological reasons and were eligible for weaning were included in the study. The ability of patients to perform simple motor tasks such as hand grasping and tongue protrusion was evaluated as a predictor of extubation failure. Data regarding duration of mechanical ventilation, length of ICU stay, length of hospital stay, mortality, and incidence of ventilator-associated pneumonia were collected. Results: A total of 132 intubated patients who had been receiving mechanical ventilation for at least 24 h and who passed a spontaneous breathing trial were included in the analysis. Logistic regression showed that patient inability to grasp the hand of the examiner (relative risk = 1.57; 95% CI: 1.01-2.44; p < 0.045) and protrude the tongue (relative risk = 6.84; 95% CI: 2.49-18.8; p < 0.001) were independent risk factors for extubation failure. Acute Physiology and Chronic Health Evaluation II scores (p = 0.02), Glasgow Coma Scale scores at extubation (p < 0.001), eye opening response (p = 0.001), MIP (p < 0.001), MEP (p = 0.006), and the rapid shallow breathing index (p = 0.03) were significantly different between the failed extubation and successful extubation groups. Conclusions: The inability to follow simple motor commands is predictive of extubation failure in critically ill neurological patients. Hand grasping and tongue protrusion on command might be quick and easy bedside tests to identify neurocritical care patients who are candidates for extubation.

Keywords: Ventilator weaning; Airway extubation/adverse effects; Critical care; Neurosurgery.

Objective: The use of the rapid shallow breathing index (RSBI) is recommended in ICUs, where it is used as a predictor of mechanical ventilation (MV) weaning success. The aim of this study was to compare the performance of the RSBI calculated by the traditional method (described in 1991) with that of the RSBI calculated directly from MV parameters. Methods: This was a prospective observational study involving patients who had been on MV for more than 24 h and were candidates for weaning. The RSBI was obtained by the same examiner using the two different methods (employing a spirometer and the parameters from the ventilator display) at random. In comparing the values obtained with the two methods, we used the Mann-Whitney test, Pearson's linear correlation test, and Bland-Altman plots. The performance of the methods was compared by evaluation of the areas under the ROC curves. Results: Of the 109 selected patients (60 males; mean age, 62 ± 20 years), 65 were successfully weaned, and 36 died. There were statistically significant differences between the two methods for respiratory rate, tidal volume, and RSBI (p < 0.001 for all). However, when the two methods were compared, the concordance and the intra-observer variation coefficient were 0.94 (0.92-0.96) and 11.16%, respectively. The area under the ROC curve was similar for both methods (0.81 ± 0.04 vs. 0.82 ± 0.04; p = 0.935), which is relevant in the context of this study. Conclusions: The satisfactory performance of the RSBI as a predictor of weaning success, regardless of the method employed, demonstrates the utility of the method using the mechanical ventilator.

Keywords: Respiration, artificial; Ventilator weaning; Spirometry.

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: This study sought to estimate body composition values by disease severity in patients recovered from COVID-19. Methods: This was an observational, analytical, prospective cross-sectional study involving patients recovered from COVID-19 and employing the following assessment methods: bioelectrical impedance analysis, dual-energy X-ray absorptiometry, and air displacement plethysmography. Results: A total of 210 volunteers were included. Demographic characteristics, comorbidities, and body composition values highlighted significant differences between men and women across disease severity levels. Conclusions: Sex differences influence the severity of COVID-19. Our results provide a cross-sectional analysis of the impact of body composition on COVID-19 patients, showing risk factors and parameters that can contribute to the treatment, health recovery, and quality of life of this population.

Keywords: COVID-19; Body composition; Risk factors; Quality of life.

Gastroesophageal reflux (GER) is a common cause of chest affections and symptoms, such as chronic cough, asthma, respiratory infections, pulmonary fibrosis and chest pain. Relief after medical or surgical antireflux therapy is variable. Twenty-four hour pH monitoring has been considered the gold standard for the diagnosis of gastroesophageal reflux disease (GERD). The use of 2 or more pH sensors in different locations within the esophagus is a reliable method for the diagnosis of more severe GER and enables aspiration of the airways and lungs. The purpose of this study was to determine whether the height at which reflux is detected within the esophagus is an indicator of surgical, as opposed to medical, antireflux therapy. In a series of 35 patients with cough as a sole presentation of GER the levels of reflux within the esophagus were correlated to the outcome after medical or surgical antireflux therapy. The studies and surgical procedures were performed in the affiliated hospitals of the Federal and Catholic Universities of Pelotas - RS. Chi-square and Mann-Whitney-U test were used to perform statistical analysis. The present study showed that gastroesophageal reflux into either the distal or the proximal esophagus can cause chronic cough. The height of reflux is an important predictor of response to antireflux therapy. Patients with proximal reflux treated medically do poorly. Surgical therapy is consistently associated with a good outcome, regardless of the height to which reflux occurs, particularly in patients with proximal reflux. Overall, surgical therapy provides the best outcome in all patients with chronic cough due to gastroesophageal reflux.

Keywords: Chronic cough. Gastroesophageal reflux disease. Esophageal pH monitoring.

Objective: To evaluate the association between extubation failure and outcomes (clinical and functional) in patients with traumatic brain injury (TBI). Methods: A prospective cohort study involving 311 consecutive patients with TBI. The patients were divided into two groups according to extubation outcome: extubation success; and extubation failure (defined as reintubation within 48 h after extubation). A multivariate model was developed in order to determine whether extubation failure was an independent predictor of in-hospital mortality. Results: The mean age was 35.7 ± 13.8 years. Males accounted for 92.3%. The incidence of extubation failure was 13.8%. In-hospital mortality was 4.5% and 20.9% in successfully extubated patients and in those with extubation failure, respectively (p = 0.001). Tracheostomy was more common in the extubation failure group (55.8% vs. 1.9%; p < 0.001). The median length of hospital stay was significantly greater in the extubation failure group than in the extubation success group (44 days vs. 27 days; p = 0.002). Functional status at discharge was worse among the patients in the extubation failure group. The multivariate analysis showed that extubation failure was an independent predictor of in-hospital mortality (OR = 4.96; 95% CI, 1.86-13.22). Conclusions: In patients with TBI, extubation failure appears to lengthen hospital stays; to increase the frequency of tracheostomy and of pulmonary complications; to worsen functional outcomes; and to increase mortality.

Keywords: Brain injuries; Ventilator weaning; Intensive care units; Glasgow outcome scale.

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.

Objective: To compare the reference values for PEF suggested by other authors in 1963, 1989 and 2001 (for populations in the USA, England and Cuba, respectively) with those obtained from a population sample in the city of São Carlos, Brazil, and to determine whether there is concordance among them. Methods: A total of 243 volunteers (123 females and 120 males; 20-70 years of age) participated in the study. The PEF measurements were performed with the volunteer standing, using a nose clip, by means of a portable peak flow meter. These measurements were compared with the reference values using the Friedman test and Dunn's post-hoc test (p < 0.05). Results: Significant differences were found in all age groups from both genders regarding the values predicted in 1989; the same occurred in the 20-30 and 31-40 age groups (both genders), as well as in the 61-70 age group (females only), regarding those predicted in 2001, as well as in the 20-30 age group (males only) regarding those predicted in 1963. Conclusions: The values predicted in 1963 are appropriate for a population of individuals with the same characteristics as the study sample, except for males in the 20-30 age group. Our study is relevant due to the fact that our sample was larger than that evaluated in the 1963 study. The majority of the values predicted in 1989 and 2001 overestimated the PEF values obtained in our study, proving to be inappropriate for the population studied.

Keywords: Reference values; Respiratory function tests; Airway obstruction; Peak expiratory flow rate.

Objective: To assess the routine use of barium swallow study in patients with chronic cough. Methods: Between October of 2011 and March of 2012, 95 consecutive patients submitted to chest X-ray due to chronic cough (duration > 8 weeks) were included in the study. For study purposes, additional images were obtained immediately after the oral administration of 5 mL of a 5% barium sulfate suspension. Two radiologists systematically evaluated all of the images in order to identify any pathological changes. Fisher's exact test and the chi-square test for categorical data were used in the comparisons. Results: The images taken immediately after barium swallow revealed significant pathological conditions that were potentially related to chronic cough in 12 (12.6%) of the 95 patients. These conditions, which included diaphragmatic hiatal hernia, esophageal neoplasm, achalasia, esophageal diverticulum, and abnormal esophageal dilatation, were not detected on the images taken without contrast. After appropriate treatment, the symptoms disappeared in 11 (91.6%) of the patients, whereas the treatment was ineffective in 1 (8.4%). We observed no complications related to barium swallow, such as contrast aspiration. Conclusions: Barium swallow improved the detection of significant radiographic findings related to chronic cough in 11.5% of patients. These initial findings suggest that the routine use of barium swallow can significantly increase the sensitivity of chest X-rays in the detection of chronic cough-related etiologies.

Keywords: Barium sulfate; Cough; Contrast media; Radiography, thoracic.

Objective: To evaluate cough efficiency using two manually-assisted cough techniques. Methods: We selected 28 patients with Duchenne muscular dystrophy. The patients were receiving noninvasive nocturnal ventilatory support and presented FVC values < 60% of predicted. Peak cough flow (PCF) was measured, with the patient seated, at four time points: at baseline, during a spontaneous maximal expiratory effort (MEE); during an MEE while receiving chest compression; during an MEE after air stacking with a manual resuscitation bag; and during an MEE with air stacking and compression (combined technique). The last three measurements were conducted in random order. The results were compared using Pearson's correlation test and ANOVA with repeated measures, followed by Tukey's post-hoc test (p < 0.05). Results: The mean age of the patients was 20 ± 4 years, and the mean FVC was 29 ± 12%. Mean PCF at baseline, with chest compression, after air stacking and with the use of the combined technique was 171 ± 67, 231 ± 81, 225 ± 80, and 292 ± 86 L/min, respectively. The results obtained with the use of the combined technique were significantly better than were those obtained with the use of either technique alone (F[3.69] = 67.07; p < 0.001). Conclusions: Both chest compression and air stacking techniques were efficient in increasing PCF. However, the combination of these two techniques had a significant additional effect (p < 0.0001).

Keywords: Muscular dystrophy, Duchenne; Intermittent positive-pressure ventilation; Cough; Insufflation;Peak expiratory flow rate.

Objective: To determine the diagnostic accuracy of positron emission tomography/computed tomography (PET/CT) using fluorine- 18‑deoxyglucose ([18F]-FDG) for the evaluation of a solitary pulmonary nodule (SPN). Methods: Prospective analysis of 53 consecutive patients submitted to PET/CT between March 2005 and May 2007 for the evaluation of an SPN. Of those, 32 met the criteria for inclusion in the present study. The lesions were evaluated for location, size, radiotracer uptake and maximum standardized uptake value (SUV). The FDG-PET/CT results were correlated with other predictors of malignancy (age, gender, smoking status, nodule size and nodule location). The definitive diagnosis was established through histopathology or through clinical/radiological follow-up for at least one year. Results: Fourteen malignant SPNs were found. Through analysis of the receiver operating characteristic curve, we established an SUV of 2.5 as the most appropriate cut-off point, since it correctly identified 13 of the 14 malignant SPNs. The results below that point revealed one false positive for neoplasia out of a total of 14. The semiquantitative method presented a sensitivity of 92.9%, specificity of 72.2%, positive predictive value of 72.2%, negative predictive value of 92.9% and accuracy of 81.2%. The multivariate analysis showed a statistically significant association with SPN malignancy only for nodule location in the upper lobes (p = 0.048) and SUV (p = 0.007). Conclusions: The results obtained suggest that the SUV of [18F]-FDG is a useful predictor of neoplasia in SPN, with a high negative predictive value, which allows malignancy to be safely ruled out, showing its relevance in the diagnostic approach to pulmonary nodules.

Keywords: Positron-emission tomography; Coin lesion, pulmonary; Lung neoplasms.

Objective: The aim of this study was to determine the factors associated with nocturnal, productive and dry cough among young adults in Nigeria. Methods: We evaluated 498 subjects, 20-44 years of age, in Ilorin, Nigeria, using the European Community Respiratory Health Survey (ECRHS) questionnaire, administered by trained interviewers. Results: Nocturnal cough was associated with asthma (OR = 10.87; p < 0.01), nasal allergy (OR = 6.33; p < 0.01), smoking (OR = 3.10; p < 0.01), skilled manual and non-manual work (OR = 2.86 and 2.10, respectively; p < 0.01 for both) and female gender (OR = 1.33; p = 0.17). Productive cough was associated with skilled manual and non-manual work (OR = 3.82 and 3.03, respectively; p < 0.01 for both), smoking (OR = 3.10; p < 0.01), asthma (OR = 3.27; p < 0.01) and nasal allergy (OR = 5.81; p < 0.01). Dry cough was associated with asthma (OR =5.18; p < 0.01) obesity (OR =1.88; p = 0.19), smoking (OR = 1.77; p = 1.44), nasal allergy (OR = 1.45; p = 0.26) and female gender (OR =1.36; p = 0.33). Age, gender, type of residence and obesity were not significantly associated with any type of cough (p > 0.05). Conclusions: Early prevention and treatment of conditions associated with cough, as well as the modification of social factors commonly associated with cough, are needed in order to reduce respiratory morbidity.

Keywords: Cough; Smoking; Asthma; Rhinitis; Nigeria.

Cough is the main physiological mechanism responsible for the clearance of secretions from airways, acting as an important defense mechanism. However, the presentation of chronic cough is one of the most important causes for patients to seek medical attention all over the world, thus the significance of the correct recognition of all the factors related to the process of cough. Among those factors, some are of extreme importance, since they may be present in almost 95% of the cases: post-nasal drip syndrome, asthma and gastroesophageal reflux disease. The main step for a successful therapy for chronic cough is a rational and progressive diagnostic approach, narrowing the list of possible diagnosis and allowing the institution of a treatment with a better cost-effectiveness. The proposal of an algorithm focusing on the most common causes of chronic cough may be helpful in this initial approach.

Keywords: Chronic cough. Diagnostic algorithm. Asthma. Postnasal drip syndrome. Gastroesophageal reflux disease.

Objective: To evaluate the diagnostic performance of the rapid shallow breathing index (RSBI) in predicting extubation failure among adult patients in the intensive care unit and to determine the appropriateness of the classical RSBI cut-off value. Methods: This was a prospective study conducted in the adult intensive care unit of the Botucatu School of Medicine Hospital das Clínicas. The RSBI was evaluated in 73 consecutive patients considered clinically ready for extubation. Results: The classical RSBI cut-off value (105 breaths/min/L) presented a sensitivity of 20% and a specificity of 95% (sum = 115%). Analysis of the receiver operator characteristic (ROC) curve revealed a better cut-off value (76.5 breaths/min/L), which presented a sensitivity of 66% and a specificity of 74% (sum = 140%). The area under the ROC curve for the RSBI was 0.78. Conclusions: The classical RSBI cut-off value proved inappropriate, predicting only 20% of the cases of extubation failure in our sample. The new cut-off value provided substantial improvement in sensitivity, with an acceptable loss of specificity. The area under the ROC curve indicated that the discriminative power of the RSBI is satisfactory, which justifies the validation of this index for use.

Keywords: Adult; Intensive care; ROC curve; Ventilator weaning; Diagnosis; Respiration, artificial.

Objective: To translate the Leicester Cough Questionnaire (LCQ) to Portuguese and adapt it for use in Brazil. Methods: Cross-cultural adaptation of a quality of life questionnaire requires a translated version that is conceptually equivalent to the original version and culturally acceptable in the target country. The protocol used consisted of the translation of the LCQ to Portuguese by three Brazilian translators who were fluent in English and its back-translation to English by another translator who was a native speaker of English and fluent in Portuguese. The back-translated version was evaluated by one of the authors of the original questionnaire in order to verify its equivalence. Later in the process, a provisional Portuguese-language version was thoroughly reviewed by an expert committee. In 10 patients with chronic cough, cognitive debriefing was carried out in order to test the understandability, clarity, and acceptability of the translated questionnaire in the target population. On that basis, the final Portuguese-language version of the LCQ was produced and approved by the committee. Results: Few items were questioned by the source author and revised by the committee of experts. During the cognitive debriefing phase, the Portuguese-language version of the LCQ proved to be well accepted and understood by all of the respondents, which demonstrates the robustness of the process of translation and cross-cultural adaptation. Conclusions: The final version of the LCQ adapted for use in Brazil was found to be easy to understand and easily applied.

Keywords: Quality of life; Translations; Questionnaires; Cough.