Age-related variation in malignant cytology rates of thyroid nodules: insights from a retrospective observational study assessing the ACR TI-RADS.

OBJECTIVE: The influence of age on the malignant cytology rate of thyroid nodules remains uncertain. The American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) is currently used to guide subsequent investigations of thyroid nodules, regardless of clinical variables. This study aimed to investigate the impact of age on the malignant cytology rates of thyroid nodules and the diagnostic performance of ACR TI-RADS across different age groups. DESIGN: A retrospective, single-center, observational study. METHODS: Patients aged ≥ 20 years with thyroid nodules, who underwent fine-needle aspiration biopsy between 2012 and 2019 were evaluated. Ultrasound images were used to obtain the TI-RADS data. Malignancy was determined based on suspicious for malignancy (Bethesda V) and malignant (Bethesda VI) cytology results or malignancy in cell block analysis. RESULTS: A total of 1023 nodules from 921 patients (88.2% female) were analyzed. The median age was 58.5 (interquartile range [IQR], 41.1-66.6) years, and the median nodule size was 2.4 (IQR, 1.7-3.6) cm. Stratification by age revealed a decreasing prevalence of malignant cytology across subgroups of 20-39, 40-59, and ≥60 years (10.7%, 8.5%, and 3.7%, respectively; P = .002). After adjusting for sex, multinodularity, nodule size, and ACR TI-RADS category, we observed that each year of age reduced the OR for malignant cytology by 3.0% (95% CI: 0.7%-5.3%; P = .011). When comparing the subgroups of 20-39 and ≥60 years, the malignant cytology rate decreased by half in TI-RADS 4 (from 21.4% to 10.4%) and two-thirds in TI-RADS 5 (from 64.7% to 22.6%). CONCLUSIONS: Our study demonstrated that as patient age increased, the rate of malignant cytology in thyroid nodules decreased. Moreover, age significantly influences the malignancy rates of thyroid nodules classified according to the ACR TI-RADS.

Enhancing Cushing's disease diagnosis: exploring the impact of desmopressin on ACTH gradient during BIPSS.

Introduction: The differential diagnosis between Cushing's disease (CD) and ectopic ACTH syndrome (EAS) is complex, and bilateral inferior petrosal sinus sampling (BIPSS) is considered the gold-standard test. However, BIPSS with corticotropin-releasing hormone (CRH) stimulation is rarely available. Objective: This retrospective cohort study aimed to assess the accuracy of the inferior petrosal sinus to peripheral ACTH gradient (IPS:P) before and after desmopressin stimulation for the differential diagnosis of ACTH-dependent Cushing's syndrome (CS), applying different cutoff values. Methods: A total of 50 patients (48 with CD and 2 with EAS) who underwent BIPSS were included in this study. The sensitivity and specificity of IPS:P in BIPSS before and after desmopressin stimulation were evaluated. Various cutoff values for IPS:P were examined to determine their diagnostic accuracy. Results: Using the traditional IPS:P cutoff, the sensitivity was 85.1% before stimulation, 89.6% after stimulation, and a combined sensitivity of 91.7%. Applying cutoff values of IPS:P >1.4 before and >2.8 after stimulation, the sensitivity was 87.2% and 89.6%, respectively, with a combined sensitivity of 91.7%. Receiver operating characteristic (ROC) curve analysis determined optimal cutoff values of 1.2 before stimulation and 1.57 after stimulation, resulting in a sensitivity of 93.6% and 93.8%, respectively, with a combined sensitivity of 97.9%. Specificity remained at 100% throughout all analyses. Among the 43 patients who responded positively to stimulation, 42 (97.7%) did so within the first three minutes, and all 43 (100%) did so within the first five minutes. None of the assessed clinical variables predicted the ACTH response to stimulation in BIPSS with statistical significance. Discussion: ACTH stimulation with desmopressin during BIPSS improves the accuracy of IPS:P, making it a valuable tool for investigating ACTH-dependent Cushing's syndrome. Considering the low risk of complications, we recommend the use of desmopressin stimulation during BIPSS for the differential diagnosis of ACTH-dependent CS.

Percutaneous ethanol injection is an acceptable bridging therapy to hepatocellular carcinoma prior to liver transplantation.

PURPOSE: Locoregional therapies (LRT) are employed for bridging patients with hepatocellular carcinoma (HCC) awaiting orthotopic liver transplantation (OLT). Although the main LRT options include transarterial chemoembolization (TACE) and radiofrequency ablation (RFA), percutaneous ethanol injection (PEI) is an alternative with considerably lower costs. This study is a pioneering evaluation of the natural history of PEI bridging to OLT as compared to TACE. METHODS: All consecutive cirrhotic patients with HCC enlisted for OLT (2011-2020) at a single center were analyzed. Patients were divided into three LRT modality groups: PEI, TACE, and PEI+TACE. The primary study outcome was waitlist dropout due to tumor progression beyond Milan criteria. A comparison of post-transplant outcomes of patients as stratified by LRT modality also was performed. RESULTS: One hundred twenty-nine patients were included (PEI=56, TACE=43, PEI+TACE=30). The dropout rate due to tumor progression was not different among the three groups: PEI=8.9%, TACE=14%, PEI+TACE=16.7% (p=0.54). Thirteen (76.4%) patients underwent OLT after successful downstaging (3 [75%] in the PEI group, 5 [83.3%] in the TACE group, and 5 [71.4%] in the PEI+TACE group). For the 96 patients undergoing OLT, 5-year post-transplant recurrence-free survival was PEI=55.6% vs. TACE=55.1% vs. PEI+TACE=71.4% (p=0.42). Complete/near-complete pathological response rate was similar among groups (p=0.82). CONCLUSION: Dropout rates and post-transplant recurrence-free survivals related to PEI were comparable to those of TACE. This study supports the use of PEI alone or in combination with TACE for HCC patients awaiting OLT whenever RFA is not an option.

Active Surveillance of Differentiated Thyroid Cancer Metastatic Cervical Lymph Nodes: A Retrospective Single-Center Cohort Study.

Background: The most frequent site of recurrence of differentiated thyroid cancer (DTC) is cervical lymph nodes (LNs), which often necessitates repeated surgical interventions and morbidity in a generally indolent disease. Data on active surveillance (AS) of small cervical nodal metastasis are still scarce, particularly in real-world clinical settings. In this study, we evaluated the DTC outcomes of AS of metastatic cervical LNs and explored factors associated with disease progression. Methods: We conducted a retrospective cohort study, including DTC patients with biopsy-proven metastatic cervical LNs, who were followed on AS in a tertiary care, university-based institution in Brazil. The inclusion criteria were cervical metastasis ≤2.0 cm and an AS duration of at least 6 months. We excluded lesions with aggressive histology, those in close proximity to or invading local structures. The primary outcome was disease progression (enlargement ≥3 mm in any diameter or a new cervical metastasis). Results: Data from 40 patients were analyzed. Most were female (77.5%) and had papillary thyroid cancer (97.5%). The mean age was 47.0 (± standard deviation 15.8) years. The 8th edition of the tumor, node, metastasis stage (TNM8) staging for DTC was as follows: 29 in stage I (74.4%), 8 in stage II (20.5%), and 2 in stage IV (5.0%). The median maximum LN diameter was 0.9 (interquartile range [IQR], 0.8-1.3) cm, and the median AS follow-up duration was 27.5 (IQR, 16.5-47.3) months. Disease progression occurred in 14 (35%) patients: 7 (17.5%) due to enlargement ≥3 mm, and 7 (17.5%) had new cervical metastasis. The cervical progression-free survival was 51.0 (confidence interval, 47.0-55.0) months. No demographic, oncological, or biochemical factors were associated with disease progression. Of the 14 patients with disease progression, 8 were referred for surgery. No permanent surgical complications were reported. Of the six patients who remained on AS despite disease progression, five showed no further progression during subsequent follow-up (range 6-40 months). Conclusions: We observed that most small metastatic cervical LNs remained stable and were safely managed with AS. Nevertheless, these observations are limited by the retrospective design, small sample size, and short follow-up. Further prospective and long-term studies are warranted.

Translation and validation of the drooling impact scale questionnaire into Brazilian Portuguese / Tradução e validação do questionário da drooling impact scale para o português do Brasil

Abstract Introduction Inadequate drooling can cause serious clinical, functional and social problems. Validated questionnaires to evaluate drooling impact on quality of life are lacking in Brazilian Portuguese. Objectives To translate and validate the drooling impact scale to Brazilian Portuguese. Methods The drooling impact scale was translated to Brazilian Portuguese and back- translated to English to assess potential conceptual differences. Brazilian Portuguese version of drooling impact scale was applied to a 40 patients' sample of sialorrhea presenting pediatric patients (up to 20 years of age). Chronbach's alpha, exploratory factorial analysis and confirmatory factorial analysis were then proceeded with data collected. Results The mean drooling impact scale value for the whole population was 51.77 (SD = 16.13). The internal consistency obtained with Cronbach's alpha indicated a value of 0.72 for the entire sample. The Bartlett's test of sphericity was significant (p< 0.0001), confirming correlation among variables tested. Kaiser-Meyer-Olkin measure of sampling adequacy revealed a value of 0.72, indicating that the correlation matrix was reasonably suitable for factor analysis. Regarding exploratory factorial analysis, parallel analysis suggested a two-factor solution that was used for confirmatory factorial analysis. The first factor was responsible for 33.78% of the variance with an Eigenvalue of 3.38. The second factor explained 16.1% of the variance with an Eigenvalue of 1.61. At confirmatory factorial analysis, the two-factor model showed consistently better adjustments parameters than the one-factor model. Conclusion The drooling impact scale has been successfully translated to Brazilian Portuguese language, showing adequate internal validity. Validation of this instrument allows physicians and other personnel involved in the care of these patients to perform a better management of patients experiencing drooling. With this tool, we are now able to guide routines and provide guidelines both before and after the different kinds of treatments in order to improve the general well-being of the patient and his family.

Resumo Introdução A produção inadequada de saliva pode causar sérios problemas clínicos, funcionais e sociais. Questionários validados para avaliar o impacto da salivação na qualidade de vida em português do Brasil são necessários. Objetivos Traduzir e validar a Drooling Impact Scale para o português do Brasil. Método A Drooling Impact Scale foi traduzida para português do Brasil e retrotraduzida para o inglês para avaliar possíveis diferenças conceituais. A versão em português do Brasil da Drooling Impact Scale foi aplicada a uma amostra de 40 pacientes pediátricos que apresentavam sialorreia (até 20 anos). Alfa de Cronbach, análise fatorial exploratória e análise fatorial confirmatória foram então feitos com os dados coletados. Resultados O valor médio da Drooling Impact Scale para toda a população foi de 51,77 (DP = 16,13). A consistência interna obtida com o alfa de Cronbach indicou um valor de 0,72 para toda a amostra. O teste de esfericidade de Bartlett foi significante (p < 0,0001), confirmou a correlação entre as variáveis testadas. A medida de adequação da amostra de Kaiser-Meyer-Olkin revelou um valor de 0,72, indicou que a matriz de correlação era razoavelmente adequada para a análise fatorial. Em relação à análise fatorial exploratória, a análise paralela sugeriu uma solução de dois fatores, que foi usada para a análise fatorial confirmatória. O primeiro fator foi responsável por 33,78% da variância com um autovalor de 3,38. O segundo fator explicou 16,1% da variância com um autovalor de 1,61. Na análise fatorial confirmatória, o modelo de dois fatores mostrou parâmetros de ajustes consistentemente melhores do que o modelo de um fator. Conclusão A Drooling Impact Scale foi traduzida com sucesso para o português do Brasil, apresentou validade interna adequada. A validação desse instrumento permite que médicos e outras pessoas envolvidas no cuidado desses pacientes façam um melhor manejo dos pacientes com sialorreia. Com essa ferramenta, agora somos capazes de orientar rotinas e fornecer orientações antes e depois dos diferentes tipos de tratamentos, a fim de melhorar o bem-estar geral do paciente e de sua família.

Using an ultrasonography risk stratification system to enhance the thyroid fine needle aspiration performance.

PURPOUSE: The American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) is a risk stratification system for thyroid nodules based on their ultrasonography (US) characteristics. Here, we aimed to assess TI-RADS on fine needle aspiration biopsy (FNAB) recommendations and performance in thyroid nodules. METHODS: We performed a retrospective study in a single center. All patients with thyroid nodules who underwent FNAB between 2012 and 2019 were included. TI-RADS data were extracted from medical records. Malignancy rates were defined based on cytological exams. RESULTS: A total of 1,044 nodules (938 patients) were evaluated. TI-RADS classification was as follows: 13 TI-RADS 1, 524 TI-RADS 2, 273 TI-RADS 3, 148 TI-RADS 4, and 85 TI-RADS 5. TI-RADS classification showed a sensitivity of 75% (95 %CI: 63-84.7), a negative predictive value of 97.6% (95 %CI: 96.5-98.5), and accuracy of 73.1% (95 %CI: 70.3-75.8). According to TI-RADS FNAB criteria, only 314 (30%) nodules would have undergone FNAB. Of them, 157 (50%) were classified as benign (Bethesda II), 45 (14.3%) as undetermined (Bethesda III or IV), and 51 (16.2%) as malignant (Bethesda V or VI). Of the remaining 729 nodules that did not meet FNAB criteria, 17 (2.3%) had Bethesda V or VI and underwent surgery. Of them, four (23%) were <1 cm in size (microcarcinomas), and eight (47.0%) remain in follow-up according to the TI-RADS criteria. Seven malignant cases would be missed (0.9%). CONCLUSION: ACR TI-RADS allows a significant decrease in the number of FNAB, increasing its diagnostic accuracy.

Translation and validation of the drooling impact scale questionnaire into Brazilian Portuguese.

INTRODUCTION: Inadequate drooling can cause serious clinical, functional and social problems. Validated questionnaires to evaluate drooling impact on quality of life are lacking in Brazilian Portuguese. OBJECTIVES: To translate and validate the drooling impact scale to Brazilian Portuguese. METHODS: The drooling impact scale was translated to Brazilian Portuguese and back- translated to English to assess potential conceptual differences. Brazilian Portuguese version of drooling impact scale was applied to a 40 patients' sample of sialorrhea presenting pediatric patients (up to 20 years of age). Chronbach's alpha, exploratory factorial analysis and confirmatory factorial analysis were then proceeded with data collected. RESULTS: The mean drooling impact scale value for the whole population was 51.77 (SD = 16.13). The internal consistency obtained with Cronbach's alpha indicated a value of 0.72 for the entire sample. The Bartlett's test of sphericity was significant (p <  0.0001), confirming correlation among variables tested. Kaiser-Meyer-Olkin measure of sampling adequacy revealed a value of 0.72, indicating that the correlation matrix was reasonably suitable for factor analysis. Regarding exploratory factorial analysis, parallel analysis suggested a two-factor solution that was used for confirmatory factorial analysis. The first factor was responsible for 33.78% of the variance with an Eigenvalue of 3.38. The second factor explained 16.1% of the variance with an Eigenvalue of 1.61. At confirmatory factorial analysis, the two-factor model showed consistently better adjustments parameters than the one-factor model. CONCLUSION: The drooling impact scale has been successfully translated to Brazilian Portuguese language, showing adequate internal validity. Validation of this instrument allows physicians and other personnel involved in the care of these patients to perform a better management of patients experiencing drooling. With this tool, we are now able to guide routines and provide guidelines both before and after the different kinds of treatments in order to improve the general well-being of the patient and his family.

Treatment strategies for locally advanced hepatocellular carcinoma.

Liver cancer ranks fifth in incidence and fourth in overall cancer-related mortality, with approximately 854,000 new cases and 810,000 deaths per year worldwide. Hepatocellular carcinoma (HCC) accounts for 90% of these cases, and, over time, both the incidence and mortality of this cancer have been rising in many regions. Several staging systems are used to assess the extent of primary tumor, presence of metastasis, and underlying liver disease, and thereby aid in the definition of treatment strategies and prognosis for these patients. The consequence of this heterogeneity in HCC staging is that no consensual definition of advanced disease exists, and there is still ongoing debate on the optimal treatment for these patients. Patients with advanced tumors can be candidates for multiple therapies, ranging from potentially curative options such as transplantation and resection-to locoregional and systemic treatments; these should be evaluated on an individual basis by a multidisciplinary team. This paper provides an overview of treatment options for advanced stage HCC, based on a review of the latest relevant literature and the personal experience of the authors.

Comparação entre as complicações da lipoabdominoplastia sem preservação da fáscia de Scarpa com abdominoplastia clássica: um estudo prospectivo cego / Complications of lipoabdominoplasty without Scarpa fascia preservation versus classic abdominoplasty: a prospective blind study

Introdução: Abdominoplastia é um dos procedimentos cirúrgicos estéticos mais realizados. Seroma é a complicação local mais comum associada com abdominoplastia, com uma incidência média de 10%. A maior incidência de seroma pós-operatório (PO) ocorre no décimo primeiro dia PO. Ecografia abdominal é o método de escolha para o diagnóstico de seroma após abdominoplastia. Novas técnicas surgiram ao longo dos anos na tentativa de trazer melhores resultados estéticos com menos complicações, como lipoabdominoplastia descrita por Saldanha. Porém, estudos anatômicos recentes questionam a necessidade da manutenção da fáscia de Scarpa descrita na técnica de lipoabdominoplastia, descrevendo que em torno de 90% do sistema linfático abdominal está no plano subdérmico e 10% em um sistema linfático profundo justa-aponeurose abdominal. O objetivo é comparar a incidência de seroma na lipoabdominoplastia sem preservação da fáscia de Scarpa com a abdominoplastia clássica. Métodos: Coorte prospectiva, cega na qual serão analisados 40 pacientes consecutivos que realizaram abdominoplastia sem lipoaspiração associada (n = 20) ou lipoabdominoplastia (n = 20) no Hospital de Clínicas de Porto Alegre entre abril de 2016 e maio de 2017. Todos foram submetidos à ecografia de parede abdominal no 10o dia PO. Resultados: A incidência de seroma foi de 5% (n = 1) no grupo de abdominoplastia clássica e de 10% (n = 2) no grupo de lipoabdominoplastia, sem diferença estatística. Conclusão: Estes resultados, neste grupo de pacientes, mostram que não houve diferença estatística entre os dois grupos.

Introduction: Abdominoplasty is among the most commonly performed surgical procedures. Seroma is the most common local complication associated with abdominoplasty, with an average incidence of 10%. The highest incidence of postoperative (PO) seroma occurs on the eleventh postoperative day (POD). Abdominal ultrasound is the method of choice for diagnosing seroma after abdominoplasty. New techniques have emerged aiming to improve aesthetic results with fewer complications, such as lipoabdominoplasty described by Saldanha. However, recent anatomical studies have questioned the need for Scarpa fascia preservation recommended in the lipoabdominoplasty technique, describing that around 90% of the abdominal lymphatic system is in the subdermal plane, while the other 10% is in a deep lymphatic system near the abdominal aponeurosis. The objective is to compare the incidence of seroma in lipoabdominoplasty without Scarpa fascia preservation to that in classic abdominoplasty. Methods: Prospective blinded cohort in which 40 consecutive patients who underwent abdominoplasty without associated liposuction (n = 20) or lipoabdominoplasty (n = 20) at the Hospital de Clínicas of Porto Alegre between April 2016 and May 2017 were analyzed. All patients underwent abdominal wall ultrasonography on the tenth POD. Results: The incidence of seroma was 5% (n = 1) in the classic abdominoplasty group and 10% (n = 2) in the lipoabdominoplasty group, with no statistical difference. Conclusion: These results showed no statistically significant intergroup difference in seroma development.

Serum TSH levels as a predictor of malignancy in thyroid nodules: A prospective study.

BACKGROUND: The role of serum TSH concentrations as a predictor of malignancy of thyroid nodule remains unclear. OBJECTIVE: To prospectively evaluate the usefulness of serum TSH levels as a predictor of malignancy in thyroid nodules. METHODS: Patients with thyroid nodule(s) who underwent fine-needle aspiration biopsy under ultrasonographic guidance in a tertiary, university-based hospital were consecutively evaluated. Patients with known thyroid cancer and/or patients receiving thyroid medication were excluded. Serum TSH levels were measured by two differents methodologies, chemiluminescent (CLIA) and electrochemiluminscent immunoassay (ECLIA). Anatomopathological exam of tissue samples obtained at thyroidectomy was considered the gold standard for the diagnosis of thyroid cancer. RESULTS: A total of 615 patients participated in the study. The mean age was 55.9±14.7 years, and 544(88.5%) were female. The median TSH values were 1.48 and 1.55 µU/mL, using CLIA and ECLIA, respectively. One-hundred-sixty patients underwent thyroidectomy and the final diagnoses were malignant in 47(29.4%) patients. TSH levels were higher in patients with malignant than in those with benign nodules in both TSH assays: 2.25 vs. 1.50; P = 0.04 (CLIA) and 2.33 vs. 1.27; P = 0.03 (ECLIA). Further analysis using binary logistic regression identified elevated TSH levels, a family history of thyroid cancer, the presence of microcalcifications, and solitary nodule on US as independent risk factors for malignancy in patients with thyroid nodules. Additional analyses using TSH levels as a categorical variable, defined by ROC curve analysis, showed that the risk of malignancy was approximately 3-fold higher in patients with TSH levels ≥2.26 µU/mL than in patients with lower TSH levels (P = 0.00). CONCLUSIONS: Higher serum TSH levels are associated with an increased risk of thyroid cancer in patients with thyroid nodules. Using TSH levels as an adjunctive diagnostic test for stratifying the risk of malignancy associated with a thyroid nodule may help on defining the best therapeutic approaches.

Mechanical ventilation in patients in the intensive care unit of a general university hospital in southern Brazil: an epidemiological study.

OBJECTIVES: To determine the characteristics, the frequency and the mortality rates of patients needing mechanical ventilation and to identify the risk factors associated with mortality in the intensive care unit (ICU) of a general university hospital in southern Brazil. METHOD: Prospective cohort study in patients admitted to the ICU who needed mechanical ventilation for at least 24 hours between March 2004 and April 2007. RESULTS: A total of 1,115 patients admitted to the ICU needed mechanical ventilation. The mortality rate was 51%. The mean age (± standard deviation) was 57±18 years, and the mean Acute Physiology and Chronic Health Evaluation II (APACHE II) score was 22.6±8.3. The variables independently associated with mortality were (i) conditions present at the beginning of mechanical ventilation, age (hazard ratio: 1.01; p<0.001); the APACHE II score (hazard ratio: 1.01; p<0.005); acute lung injury/acute respiratory distress syndrome (hazard ratio: 1.38; p=0.009), sepsis (hazard ratio: 1.33; p=0.003), chronic obstructive pulmonary disease (hazard ratio: 0.58; p=0.042), and pneumonia (hazard ratio: 0.78; p=0.013) as causes of mechanical ventilation; and renal (hazard ratio: 1.29; p=0.011) and neurological (hazard ratio: 1.25; p=0.024) failure, and (ii) conditions occurring during the course of mechanical ventilation, acute lung injuri/acute respiratory distress syndrome (hazard ratio: 1.31; p<0.010); sepsis (hazard ratio: 1.53; p<0.001); and renal (hazard ratio: 1.75; p<0.001), cardiovascular (hazard ratio: 1.32; p≤0.009), and hepatic (hazard ratio: 1.67; p≤0.001) failure. CONCLUSIONS: This large cohort study provides a comprehensive profile of mechanical ventilation patients in South America. The mortality rate of patients who required mechanical ventilation was higher, which may have been related to the severity of illness of the patients admitted to our ICU. Risk factors for hospital mortality included conditions present at the start of mechanical ventilation conditions that occurred during mechanical support.

Mechanical ventilation in patients in the intensive care unit of a general university hospital in southern Brazil: an epidemiological study

OBJECTIVES: To determine the characteristics, the frequency and the mortality rates of patients needing mechanical ventilation and to identify the risk factors associated with mortality in the intensive care unit (ICU) of a general university hospital in southern Brazil. METHOD: Prospective cohort study in patients admitted to the ICU who needed mechanical ventilation for at least 24 hours between March 2004 and April 2007. RESULTS: A total of 1,115 patients admitted to the ICU needed mechanical ventilation. The mortality rate was 51%. The mean age (± standard deviation) was 57±18 years, and the mean Acute Physiology and Chronic Health Evaluation II (APACHE II) score was 22.6±8.3. The variables independently associated with mortality were (i) conditions present at the beginning of mechanical ventilation, age (hazard ratio: 1.01; p<0.001); the APACHE II score (hazard ratio: 1.01; p<0.005); acute lung injury/acute respiratory distress syndrome (hazard ratio: 1.38; p=0.009), sepsis (hazard ratio: 1.33; p=0.003), chronic obstructive pulmonary disease (hazard ratio: 0.58; p=0.042), and pneumonia (hazard ratio: 0.78; p=0.013) as causes of mechanical ventilation; and renal (hazard ratio: 1.29; p=0.011) and neurological (hazard ratio: 1.25; p=0.024) failure, and (ii) conditions occurring during the course of mechanical ventilation, acute lung injuri/acute respiratory distress syndrome (hazard ratio: 1.31; p<0.010); sepsis (hazard ratio: 1.53; p<0.001); and renal (hazard ratio: 1.75; p<0.001), cardiovascular (hazard ratio: 1.32; p≤0.009), and hepatic (hazard ratio: 1.67; p≤0.001) failure. CONCLUSIONS: This large cohort study provides a comprehensive profile of mechanical ventilation patients in South America. The mortality rate of patients who required mechanical ventilation was higher, which may have been related to the severity of illness of the patients admitted to our ICU. Risk factors for hospital mortality included conditions present at the start of mechanical ventilation conditions that occurred during mechanical support.