High versus low positive end-expiratory pressure (PEEP) levels for mechanically ventilated adult patients with acute lung injury and acute respiratory distress syndrome.

BACKGROUND: In patients with acute lung injury (ALI) and acute respiratory distress syndrome (ARDS), mortality remains high. These patients require mechanical ventilation, which has been associated with ventilator-induced lung injury. High levels of positive end-expiratory pressure (PEEP) could reduce this condition and improve patient survival. This is an updated version of the review first published in 2013. OBJECTIVES: To assess the benefits and harms of high versus low levels of PEEP in adults with ALI and ARDS. SEARCH METHODS: For our previous review, we searched databases from inception until 2013. For this updated review, we searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, LILACS, and the Web of Science from inception until May 2020. We also searched for ongoing trials (www.trialscentral.org; www.clinicaltrial.gov; www.controlled-trials.com), and we screened the reference lists of included studies. SELECTION CRITERIA: We included randomised controlled trials that compared high versus low levels of PEEP in ALI and ARDS participants who were intubated and mechanically ventilated in intensive care for at least 24 hours. DATA COLLECTION AND ANALYSIS: Two review authors assessed risk of bias and extracted data independently. We contacted investigators to identify additional published and unpublished studies. We used standard methodological procedures expected by Cochrane. MAIN RESULTS: We included four new studies (1343 participants) in this review update. In total, we included 10 studies (3851 participants). We found evidence of risk of bias in six studies, and the remaining studies fulfilled all criteria for low risk of bias. In eight studies (3703 participants), a comparison was made between high and low levels of PEEP, with the same tidal volume in both groups. In the remaining two studies (148 participants), the tidal volume was different between high- and low-level groups. In the main analysis, we assessed mortality occurring before hospital discharge only in studies that compared high versus low PEEP, with the same tidal volume in both groups. Evidence suggests that high PEEP may result in little to no difference in mortality compared to low PEEP (risk ratio (RR) 0.97, 95% confidence interval (CI) 0.90 to 1.04; I² = 15%; 7 studies, 3640 participants; moderate-certainty evidence). In addition, high PEEP may result in little to no difference in barotrauma (RR 1.00, 95% CI 0.64 to 1.57; I² = 63%; 9 studies, 3791 participants; low-certainty evidence). High PEEP may improve oxygenation in patients up to the first and third days of mechanical ventilation (first day: mean difference (MD) 51.03, 95% CI 35.86 to 66.20; I² = 85%; 6 studies, 2594 participants; low-certainty evidence; third day: MD 50.32, 95% CI 34.92 to 65.72; I² = 83%; 6 studies, 2309 participants; low-certainty evidence) and probably improves oxygenation up to the seventh day (MD 28.52, 95% CI 20.82 to 36.21; I² = 0%; 5 studies, 1611 participants; moderate-certainty evidence). Evidence suggests that high PEEP results in little to no difference in the number of ventilator-free days (MD 0.45, 95% CI -2.02 to 2.92; I² = 81%; 3 studies, 1654 participants; low-certainty evidence). Available data were insufficient to pool the evidence for length of stay in the intensive care unit. AUTHORS' CONCLUSIONS: Moderate-certainty evidence shows that high levels compared to low levels of PEEP do not reduce mortality before hospital discharge. Low-certainty evidence suggests that high levels of PEEP result in little to no difference in the risk of barotrauma. Low-certainty evidence also suggests that high levels of PEEP improve oxygenation up to the first and third days of mechanical ventilation, and moderate-certainty evidence indicates that high levels of PEEP improve oxygenation up to the seventh day of mechanical ventilation. As in our previous review, we found clinical heterogeneity - mainly within participant characteristics and methods of titrating PEEP - that does not allow us to draw definitive conclusions regarding the use of high levels of PEEP in patients with ALI and ARDS. Further studies should aim to determine the appropriate method of using high levels of PEEP and the advantages and disadvantages associated with high levels of PEEP in different ARDS and ALI patient populations.

Acute Respiratory Distress Syndrome: Mortality in a Single Center According to Different Definitions.

BACKGROUND: Mortality in acute lung injury (ALI) remains high, with outcome data arising mostly from multicenter studies. We undertook this investigation to determine hospital mortality in patients with ALI in a single center. METHODS: We studied patients admitted between 2005 and 2012 with ALI and acute respiratory distress syndrome (ARDS) according to the American European Consensus Conference (AECC) criteria and recorded clinical variables. Thereafter, patients were classified as subgroups according to the AECC and Berlin definition in order to compare the clinical characteristics and outcomes. RESULTS: In the 93 patients comprising the study, hospital mortality was 38%. Mortality at 28 days was 36%. Multivariate analysis associated hospital mortality with age and Pao2/Fio2 on day 1 ( P < .001). Differences resulted between the subgroups of AECC (ALI vs ARDS) and Berlin (mild vs moderate vs severe ARDS) in the lung injury score, Pao2/Fio2, Pao2/PAo2, PaCo2 on day 1, and hospital mortality. CONCLUSION: The overall hospital mortality (38%) was similar to that of other studies and according to the presence of ARDS (Pao2/Fio2 ≤ 200), we found significant differences between ALI and ARDS (AECC) and between mild and moderate or severe ARDS (Berlin) in baseline respiratory variables and mortality.

Lung function and organ dysfunctions in 178 patients requiring mechanical ventilation during the 2009 influenza A (H1N1) pandemic.

INTRODUCTION: Most cases of the 2009 influenza A (H1N1) infection are self-limited, but occasionally the disease evolves to a severe condition needing hospitalization. Here we describe the evolution of the respiratory compromise, ventilatory management and laboratory variables of patients with diffuse viral pneumonitis caused by pandemic 2009 influenza A (H1N1) admitted to the ICU. METHOD: This was a multicenter, prospective inception cohort study including adult patients with acute respiratory failure requiring mechanical ventilation (MV) admitted to 20 ICUs in Argentina between June and September of 2009 during the influenza A (H1N1) pandemic. In a standard case-report form, we collected epidemiological characteristics, results of real-time reverse-transcriptase--polymerase-chain-reaction viral diagnostic tests, oxygenation variables, acid-base status, respiratory mechanics, ventilation management and laboratory tests. Variables were recorded on ICU admission and at days 3, 7 and 10. RESULTS: During the study period 178 patients with diffuse viral pneumonitis requiring MV were admitted. They were 44 ± 15 years of age, with Acute Physiology And Chronic Health Evaluation II (APACHE II) scores of 18 ± 7, and most frequent comorbidities were obesity (26%), previous respiratory disease (24%) and immunosuppression (16%). Non-invasive ventilation (NIV) was applied in 49 (28%) patients on admission, but 94% were later intubated.Acute respiratory distress syndrome (ARDS) was present throughout the entire ICU stay in the whole group (mean PaO2/FIO2 170 ± 25). Tidal-volumes used were 7.8 to 8.1 ml/kg (ideal body weight), plateau pressures always remained < 30 cmH2O, without differences between survivors and non-survivors; and mean positive end-expiratory pressure (PEEP) levels used were between 8 to 12 cm H2O. Rescue therapies, like recruitment maneuvers (8 to 35%), prone positioning (12 to 24%) and tracheal gas insufflation (3%) were frequently applied. At all time points, pH, platelet count, lactate dehydrogenase assay (LDH) and Sequential Organ Failure Assessment (SOFA) differed significantly between survivors and non-survivors. Lack of recovery of platelet count and persistence of leukocytosis were characteristic of non-survivors. Mortality was high (46%); and length of MV was 10 (6 to 17) days. CONCLUSIONS: These patients had severe, hypoxemic respiratory failure compatible with ARDS that persisted over time, frequently requiring rescue therapies to support oxygenation. NIV use is not warranted, given its high failure rate. Death and evolution to prolonged mechanical ventilation were common outcomes. Persistence of thrombocytopenia, acidosis and leukocytosis, and high LDH levels found in non-survivors during the course of the disease might be novel prognostic findings.

Mortality in Critically Ill Elderly Individuals Receiving Mechanical Ventilation.

BACKGROUND: Previous studies that evaluated mortality in elderly subjects who received mechanical ventilation had conflicting results. The aim of this systematic review was to evaluate the effects of age on mortality. METHODS: A number of medical literature databases and the references listed (from 1974 to May 2015) were searched for studies that compared 2 different age groups. The primary outcome was mortality in subjects ages ≥ 65 y. The severity scores, ICU and hospital lengths of stay, and the presence of ventilator-associated pneumonia were secondary outcomes. Finally, mortality in the subjects with ARDS and of cutoff ages 70 and 80 y was assessed by subgroup analysis. Evidence quality was assessed by the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) criteria score. RESULTS: Of the 5,182 articles identified, 21 were included. Subjects ages ≥ 65 y had higher mortalities (odds ratio [OR] 1.80, 95% CI 1.56-2.08; I2 = 71%). APACHE (Acute Physiology and Chronic Health Evaluation) II revealed intergroup differences (mean difference 3.07, 95% CI 2.52-3.61; I2 = 0%), whereas neither the ICU nor hospital length of stay (mean difference 1.27, 95% CI -0.82 to 3.36, I2 = 82%, and mean difference 1.29, 95% CI -0.71 to 3.29, I2 = 0%, respectively) nor the groups in the 2 studies that assessed ventilator-associated pneumonia exhibited any difference. Subgroup analysis revealed a higher mortality in the older subjects, in the subjects with ARDS (OR 1.76, 95% CI 1.30-2.36; I2 = 0%) and in the subjects ages 70 and 80 y (OR 1.78, 95% CI 1.51-2.10, I2 = 71%; and OR 1.96, 95% CI 1.81-2.13, I2 = 0%, respectively). The quality of associated evidence was low or very low. CONCLUSIONS: Although low-quality evidence was available, we conclude that age is associated with a greater mortality in critical subjects who were receiving mechanical ventilation.

[Black esophagus due to acute necrotizing esophagitis: report of one case]. / Esófago negro secundario a esofagitis necrotizante aguda: Reporte de un caso clínico.

Acute esophageal necrosis, which presents as a black esophagus on endoscope, is an uncommon occurrence. It is defined as a dark pigmentation of the esophagus associated with histological mucosal necrosis. We report a 75-year-old man who developed black esophagus due to acute esophageal necrosis caused by septicemia. The patient had a favorable evolution.

[Thoracoabdominal periaortic lymphoma mimicking acute aortic syndrome. Report of one case]. / Linfoma periaórtico tóraco-abdominal, que simula un síndrome aórtico agudo y revisión de la literatura.

Systemic lymphoma that involves the aorta is called periaortic lymphoma, and may be misdiagnosed clinically or in CT sean, mimicking a thoracic aortic aneurysm, dissection, penetrating ulcer or an intramural hematoma. We report a 70 year-old woman in whom a systemic non-Hodgkin 's lymphoma ivas diagnosed after she presented with the clinical features of an acute aortic syndrome. A CT sean showed the presence of a large thoracoabdominal periaortic soft tissue mass without aneurism or dissection. Later, a biopsy of the mass ivasperformed which showed a non-Hodgkin's lymphoma. Chemotherapy with CHOP-R was effective, with complete initial resolution of the mass, developing in the follow up chylothorax, malnutrition and death.

Linfoma periaórtico tóraco-abdominal, que simula un síndrome aórtico agudo y revisión de la literatura / Thoracoabdominal periaortic lymphoma mimicking acule aortic syndrome. Report of one case

Systemic lymphoma that involves the aorta is called periaortic lymphoma, and may be misdiagnosed clinically or in CT sean, mimicking a thoracic aortic aneurysm, dissection, penetrating ulcer or an intramural hematoma. We report a 70 year-old woman in whom a systemic non-Hodgkin 's lymphoma ivas diagnosed after she presented with the clinical features of an acute aortic syndrome. A CT sean showed the presence of a large thoracoabdominal periaortic soft tissue mass without aneurism or dissection. Later, a biopsy of the mass was performed which showed a non-Hodgkin's lymphoma. Chemotherapy with CHOP-R was effective, with complete initial resolution of the mass, developing in the follow up chylothorax, malnutrition and death.

Esófago negro secundario a esofagitis necrotizante aguda: reporte de un caso clínico / Black esophagus due to acute necrotizing esophagitis: report of one case

Acute esophageal necrosis, which presents as a black esophagus on endoscope, is an uncommon occurrence. It is defined as a dark pigmentation of the esophagus associated with histological mucosal necrosis. We report a 75-year-old man who developed black esophagus due to acute esophageal necrosis caused by septicemia. The patient had a favorable evolution.

Hidratacion en la cetoacidosis diabetica. ¿Como influye la velocid de infusion / Hydration in diabetic ketoacidosis. How much influence does the rate of infusion have?

La cetoacidosis diabética (CAD) se acompaña de severa depleción hidroelectrolítica; aunque habitualmente se utiliza hidratación abundante, el ritmo de reposición de fluidos en esta patología continúa siendo controvertido. A fin de determinar la velocidad de infusión de líquidos adecuada en la CAD sin patología asociada, se realizó un estudio prospectivo, randomizado, en 27 pacientes sometidos a dos planes terapéuticos diferentes sólo en el ritmo del aporte de líquidos. Un grupo (14 pacientes) recibió solución salina al 0,9 por ciento a una velocidad de 1000 ml/h, y otro grupo (13 pacientes) a 500 ml/h; el flujo de reposición hidrosalina se redujo a la mitad después de 4 horas de tratamiento. Al ingreso y a las 2, 4, 8, 12 y 24 horas se realizaron determinaciones del estado ácido-base en sangre arterial, y de sodio, potasio y cloro en plasma. Ambos grupos fueron similares en las determinaciones bioquímicas al ingreso. Todos los pacientes corrigieron el cuadro de cetoacidosis y no se observó mortalidad ni complicaciones. No se hallaron diferencias significativas para ninguna de las variables metabólicas entre los grupos de tratamiento en ningún momento de la evolución. Se concluye que resulta igualmente efectivo utilizar una velocidad de reposición de líquidos de 500 ml/h que de 1000 ml/h, en cuanto a la morbimortalidad de los pacientes con CAD no asociada a severa depleción de volumen. El uso de cantidades modestas de fluidos para la hidratación en estos pacientes resultaría en menores costos.