ABSTRACT Objective: To evaluate how ventilatory support, the duration of invasive ventilatory support use and lung mechanics are related to barotrauma development in patients who are severely infected with COVID-19 and who are admitted to the intensive care unit and develop pulmonary barotrauma. Methods: Retrospective cohort study of patients who were severely infected with COVID-19 and who developed pulmonary barotrauma secondary to mechanical ventilation. Results: This study included 60 patients with lung barotrauma who were divided into two groups: 37 with early barotrauma and 23 with late barotrauma. The early barotrauma group included more individuals who needed noninvasive ventilation (62.2% versus 26.1%, p = 0.01). The tidal volume/kg of predicted body weight on the day of barotrauma was measured, and 24 hours later, it was significantly greater in the late barotrauma group than in the early barotrauma group. During the day, barotrauma was accompanied by plateau pressure and driving pressure accompanied by tidal volume, which significantly increased in the late barotrauma group. According to the SAPS 3, patients in the early barotrauma group had more pulmonary thromboembolism and more severe illness. However, the intensive care unit mortality rates did not significantly differ between the two groups (66.7% for early barotrauma versus 76.9% for late barotrauma). Conclusion: We investigated the effect of respiratory mechanics on barotrauma in patients with severe COVID-19 and found that 25% of patients were on nonprotective ventilation parameters when they developed barotrauma. However, 50% of patients were on protective ventilation parameters, suggesting that other nonventilatory factors may contribute to barotrauma. Objective COVID19 COVID 19 COVID-1 Methods Results 6 3 2 62.2% 622 62 (62.2 261 26 1 26.1% 0.01. 001 0.01 . 0 01 0.01) volumekg volume kg measured later illness However 66.7% 667 66 7 (66.7 769 76 9 76.9 barotrauma) Conclusion 25 50 COVID1 COVID- 62.2 (62. 26.1 00 0.0 66.7 (66. 76. 5 62. (62 26. 0. 66. (66 (6 (

RESUMO Objetivo: Avaliar como o suporte ventilatório, o tempo de uso do suporte ventilatório invasivo e a mecânica pulmonar estão relacionados ao desenvolvimento de barotrauma em pacientes com infecção grave pela COVID-19 admitidos na unidade de terapia intensiva. Métodos: Trata-se de estudo de coorte retrospectivo de pacientes com infecção grave pela COVID-19 que desenvolveram barotrauma pulmonar secundário à ventilação mecânica. Resultados: Este estudo incluiu 60 pacientes com barotrauma pulmonar divididos em dois grupos: 37 com barotrauma precoce e 23 com barotrauma tardio. O grupo com barotrauma precoce incluiu mais indivíduos que precisaram de ventilação não invasiva (62,2% versus 26,1%, p = 0,01). O volume corrente/kg de peso corporal previsto no dia do barotrauma foi medido e, 24 horas depois, foi significativamente maior no grupo com barotrauma tardio do que no grupo com barotrauma precoce. Durante o dia, o barotrauma foi acompanhado pela pressão de platô e pela pressão de distensão acompanhada do volume corrente, o qual aumentou significativamente no grupo com barotrauma tardio. De acordo com o SAPS 3, os pacientes do grupo com barotrauma precoce apresentaram mais tromboembolia pulmonar e doença mais grave. Entretanto, as taxas de mortalidade na unidade de terapia intensiva não diferiram significativamente entre os dois grupos (66,7% para barotrauma precoce versus 76,9% para barotrauma tardio). Conclusão: Investigamos o efeito da mecânica respiratória no barotrauma em pacientes com COVID-19 graves e descobrimos que um quarto dos pacientes estava em parâmetros de ventilação não protetores quando desenvolveram barotrauma. No entanto, 50% dos pacientes estavam em parâmetros de ventilação protetora, sugerindo que outros fatores não ventilatórios podem contribuir para o barotrauma. Objetivo COVID19 COVID 19 COVID-1 Métodos Tratase Trata se Resultados 6 3 2 62,2% 622 62 (62,2 261 26 1 26,1% 0,01. 001 0,01 . 0 01 0,01) correntekg corrente kg depois Entretanto 66,7% 667 66 7 (66,7 769 76 9 76,9 tardio) Conclusão entanto 50 protetora COVID1 COVID- 62,2 (62, 26,1 00 0,0 66,7 (66, 76, 5 62, (62 26, 0, 66, (66 (6 (

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.

OBJECTIVE: Studies suggest an association between vitamin D deficiency and morbidity/mortality in critically ill patients. Several issues remain unexplained, including which vitamin D levels are related to morbidity and mortality and the relevance of vitamin D kinetics to clinical outcomes. We conducted this study to address the association of baseline vitamin D levels and vitamin D kinetics with morbidity and mortality in critically ill patients. METHOD: In 135 intensive care unit (ICU) patients, vitamin D was prospectively measured on admission and weekly until discharge from the ICU. The following outcomes of interest were analyzed: 28-day mortality, mechanical ventilation, length of stay, infection rate, and culture positivity. RESULTS: Mortality rates were higher among patients with vitamin D levels <12 ng/mL (versus vitamin D levels >12 ng/mL) (32.2% vs. 13.2%), with an adjusted relative risk of 2.2 (95% CI 1.07-4.54; p< 0.05). There were no differences in the length of stay, ventilation requirements, infection rate, or culture positivity. CONCLUSIONS: This study suggests that low vitamin D levels on ICU admission are an independent risk factor for mortality in critically ill patients. Low vitamin D levels at ICU admission may have a causal relationship with mortality and may serve as an indicator for vitamin D replacement among critically ill patients.