Weaning from mechanical ventilation in intensive care units across 50 countries (WEAN SAFE): a multicentre, prospective, observational cohort study

BACKGROUND

Current management practices and outcomes in weaning from invasive mechanical ventilation are poorly understood. We aimed to describe the epidemiology, management, timings, risk for failure, and outcomes of weaning in patients requiring at least 2 days of invasive mechanical ventilation.

METHODS

WEAN SAFE was an international, multicentre, prospective, observational cohort study done in 481 intensive care units in 50 countries. Eligible participants were older than 16 years, admitted to a participating intensive care unit, and receiving mechanical ventilation for 2 calendar days or longer. We defined weaning initiation as the first attempt to separate a patient from the ventilator, successful weaning as no reintubation or death within 7 days of extubation, and weaning eligibility criteria based on positive end-expiratory pressure, fractional concentration of oxygen in inspired air, and vasopressors. The primary outcome was the proportion of patients successfully weaned at 90 days. Key secondary outcomes included weaning duration, timing of weaning events, factors associated with weaning delay and weaning failure, and hospital outcomes. This study is registered with ClinicalTrials.gov, NCT03255109.

FINDINGS

Between Oct 4, 2017, and June 25, 2018, 10 232 patients were screened for eligibility, of whom 5869 were enrolled. 4523 (77·1%) patients underwent at least one separation attempt and 3817 (65·0%) patients were successfully weaned from ventilation at day 90. 237 (4·0%) patients were transferred before any separation attempt, 153 (2·6%) were transferred after at least one separation attempt and not successfully weaned, and 1662 (28·3%) died while invasively ventilated. The median time from fulfilling weaning eligibility criteria to first separation attempt was 1 day (IQR 0-4), and 1013 (22·4%) patients had a delay in initiating first separation of 5 or more days. Of the 4523 (77·1%) patients with separation attempts, 2927 (64·7%) had a short wean (≤1 day), 457 (10·1%) had intermediate weaning (2-6 days), 433 (9·6%) required prolonged weaning (≥7 days), and 706 (15·6%) had weaning failure. Higher sedation scores were independently associated with delayed initiation of weaning. Delayed initiation of weaning and higher sedation scores were independently associated with weaning failure. 1742 (31·8%) of 5479 patients died in the intensive care unit and 2095 (38·3%) of 5465 patients died in hospital.

INTERPRETATION

In critically ill patients receiving at least 2 days of invasive mechanical ventilation, only 65% were weaned at 90 days. A better understanding of factors that delay the weaning process, such as delays in weaning initiation or excessive sedation levels, might improve weaning success rates.

FUNDING

European Society of Intensive Care Medicine, European Respiratory Society.

Hepatitis C and lipid metabolism, hepatic steatosis, and NAFLD: still important in the era of direct acting antiviral therapy?

Chronic hepatitis C (CHC) and nonalcoholic fatty liver disease (NAFLD) have an individual prevalence of 1.8-3% and at least 30%, respectively, in the United States. It is therefore not surprising that there is overlap between these two common chronic liver diseases, although the relationship appears to go beyond isolated co-existence. Hepatic steatosis is a common feature of CHC infection and can be related to both metabolic and viral specific factors. Steatosis in the setting of nongenotype 3 CHC has been predictive of response to therapy prior to the advent of the direct acting antiviral medications (DAAs). Similarly, lipid metabolism appears important in response to CHC treatment. The pathways for both lipid homeostasis and NAFLD as it pertains to CHC infection as well as the utilization of statin therapy in CHC infection will be reviewed with a focus on the relevance of these topics in the era of DAA therapy.

Nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is fast becoming the most common chronic liver condition in many parts of the world. It is a heterogeneous disease encompassing a broad spectrum of histologic states characterized universally by macrovesicular hepatic steatosis. NAFLD is now recognized as the hepatic manifestation of the metabolic syndrome and is a major cause of liver-related morbidity and mortality. The prevalence of the disease is increasing, tied closely to the increased prevalence of insulin resistance in industrialized countries. Risk factors for NAFLD include obesity, diabetes, insulin resistance, and hypertriglyceridemia. The clinical course of NAFLD depends upon the histologic subtype. Patients with simple hepatic steatosis generally are thought to have a benign long-term prognosis. However, nonalcoholic steatohepatitis can progress to cirrhosis and may have a similar prognosis as cirrhosis from other liver disease with progression to end stage liver disease and hepatocellular carcinoma. The decision to obtain a biopsy is determined by weighing the risks of the biopsy against the information obtained from the biopsy. No standardized therapeutic approach exists although many promising modalities are under investigation. This paper presents an overview of the incidence and prevalence of disease, diagnosis, histologic spectrum, natural history, pathogenesis, clinical course, and current treatment of nonalcoholic fatty liver disease.

Ascaris-Trichuris association and malnutrition in Brazilian children

This work was designed to evaluate the role of intestinal parasites on nutritional status in three rural areas of Brazil. A total of 520 children aged 1-12 years were studied through a questionnaire concerning housing, socio-economic conditions and a 24-h food intake recall. Measurements of weight and height were also performed, and three stool samples were collected on consecutive days for parasitological analysis. Scores of the standard deviation (z-scores) for the weight-for-height and height-for-age were used to characterise the growth profile. A high prevalence of intestinal parasites was detected, with Giardia lamblia (44%), Endolimax nana (43%), Ascaris lumbricoides (41%) and Trichuris trichiura (40%) being the most prevalent. Eleven per cent of the children were classified as showing stunting. Inadequate daily caloric intake was observed in 78% of the population and the proportion of those with inadequate protein intake was 34%. Logistic regression analysis was employed for the multivariate study. Stunting was significantly associated with estimators of low economic income, inadequate protein intake and polyparasitism, especially the association between Ascaris lumbricoides and Trichuris trichiura.

Human infection by Phagicola sp. (Trematoda, Heterophyidae) in the municipality of Registro, São Paulo State, Brazil

In 1988, nine cases of human parasitism by Phagicola sp. were diagnosed in the municipality of Registro (São Paulo State, Brazil) by stool examinations, in patients who ate raw mullet (Mugil sp.). Six (66%) of the nine patients suffered from flatulence and four (44%) had diarrhoeal episodes; six (66%) showed slight eosinophilia. On the same occasion, 61 dogs and 11 cats from Registro were also submitted to stool examination. Only one dog (1.6%) showed Phagicola eggs in the stool. All patients were treated with a single dose of praziquantel (50 mg kg-1 body weight) and control stool tests performed on the 15th, 30th and 60th days post-treatment showed no trematode eggs.

[Cryptosporidium parasitism in children with acute diarrhea]

During the period from August 1987 to July 1990, 241 fecal samples collected from 1 to 48 months old children with acute diarrhea and examined in the Child's Institute of Hospital das Clínicas of Faculdade de Medicina da Universidade de São Paulo, were submitted to parasitological tests in the Enteroparasitosis Section of the Instituto Adolfo Lutz. Fourty two (17.43%) fecal samples showed Cryptosporidium sp. oocysts by carbol-fucsin stain. Parasitism by Cryptosporidium sp. was more frequent during the period comprised from March to May, in the studied three years. The authors discussed the Cryptosporidium sp. in association with other agents.

[Occurrence of Strongyloides stercoralis in patients with acquired immunodeficiency syndrome (AIDS)]

A comparative study on the occurrence of Strongyloides stercoralis larvae in 554 patients with AIDS and in 142 patients suffering from infectious diseases other than AIDS was conducted during the period from January 1987 to December 1988. The two groups was constituted by male individuals in-patients at Emílio Ribas Hospital--São Paulo. Faeces samples from 696 patients were submitted to spontaneous sedimentation method and Rugai method. The data obtained from the present investigation demonstrated a similar prevalence of Strongyloides stercoralis in both groups (p > 0.05) indicating no significant statistical differences.

[Occurrence of Taenia sp. in the population seen at the Central Laboratory of the Adolfo Lutz Institute, São Paulo, SP, Brazil (1960/1989)]

Monthly and yearly reports of the Seção de Enteroparasitoses of the Instituto Adolfo Lutz (São Paulo, SP, Brazil) from 1960 to 1989 with 1,519,730 parasitological stool examinations were studied. There were also 355 identifications of Taenia sp. proglottids. Using Hoffman, Pons & Janer's method, 7,663 (0.5%) cases of taeniasis were diagnosed, and 311 (87.60%) of the 355 proglottids were on easy terms to be specified, 273 (87.80%) of them were from Taenia saginata.

[Giardiasis in nurseries supported by the São Paulo Municipal Prefecture, 1982/1983]

Parasitological analysis was carried out during 1982 and 1983 in 3,076 children aged under 7 years, who were enrolled in 52 day nurseries supported by Municipal Prefecture of São Paulo and 50 food handlers (cooking employees) working at 18 day nurseries. The prevalence of Giardia lamblia infection was studied according to sex, age group and seasonal variations, and attained 32.80% among children and 4.0% among adult population. The occurrence of giardiasis was most frequent in age group corresponding to 1-4 years old. The study of seasonal variations showed that, in 1982, the prevalence of G. lamblia was high in the autumn and in the spring and, in 1983, giardiasis was more prevalent in the autumn and in the summer. Statistical analysis indicated non association between sex and prevalence for Giardia infection, and there was also no significative difference on the distribution of G. lamblia prevalence in the four regions analysed in the present study (p > 0.05). The most probable mode of acquisition of Giardia infection, in the nurseries analysed in the present study was person-to-person, as factors, like environmental contamination and others, associated with the spreading of giardiasis through water, reported in other countries, are unlike from those verified in our Municipality. On the other hand, there is evidence of no significant role of food handlers in Giardia transmission, because of the rate of infection in this group was very low.

Human parasitism by Phagicola sp (Trematoda, Heterophyidae) in Cananéia, São Paulo state, Brazil

We report one case of parasitism by Phagicola sp. (Trematoda, Heterophyidae) in a 31 year-old woman who, in 1987, travelled and stayed several months in the municipality of Cananéia (SP), where she ingested, in various occasions, raw mullet (Mugil sp.). The patient referred mild intestinal pain and laboratory examinations showed eggs of Phagicola sp. in the stools and a slight increase in eosinophil blood levels (8%). After treatment with praziquantel (75 mg/kg per day for three days) all the symptoms and signs disappeared. This is, certainly, the first record of human infection by Phagicola sp. in Brazil and, perhaps, in countries other than the U.S.A. where unclear references to a few human cases were reported in the South-eastern region.

[Infection by Clonorchis sinensis in Asian immigrants in Brazil. Treatment with praziquantel]

Fifteen adult patients with assymptomatic infection due to Clonorchis sinensis, diagnosed by coprological examination, were studied. They all came from Asia (twelve from Taiwan, two from South Korea and one from Hong Kong) and were examined at the Adolfo Lutz Institute and the Department of Infectious Diseases, School of Medicine, University of São Paulo, in São Paulo, Brazil. Six patients were women and nine men. All studied patients were admitted to hospital and treated with praziquantel (60 mg/kg). Previous to treatment and on the 15th, 30th and 60th days after praziquantel administration, patients were submitted to quantitative stool examinations, according to Kato-Katz's technique and to hematological and biochemical serum analysis. After a 60 day follow-up nine patients (60%) were negative for C. sinensis eggs in stools. Those not cured after praziquantel administration (six patients, 40%) revealed a sharp decline in faecal elimination of C. sinensis eggs.

[Headache in childhood: diagnosis and therapy. A prospective study of 77 cases]

Seventy seven cases of migraine in children were studied. Age average was 9 years +/- 2; there were any sex differences. The frontal localization was found in roughly 49% of cases, whereas hemicrania was just found in 9% of cases. The most frequent factors associated were nausea, vomiting and dizziness. The most common triggering factor was the stress. Family history of migraine occurred in 76.5%. Out of 36 patients suffering migraine, 31 underwent a prophylactic treatment with pizotifen or propranolol. There was satisfactory clinical responses in roughly 90% of cases.

Cryptosporidiosis among patients with acquired immunodeficiency syndrome (AIDS) in the county of São Paulo, Brazil

Stool samples of 157 patients with AIDS, living in the county of São Paulo, were submitted to several techniques in the search for Cryptosporidium sp.. Among the various techniques tested for slide preparation (direct smear, spontaneous sedimentation method, and formol-ether concentration), the latter, formol-ether concentration, offered the best results, clearly outdoing all the others. Nineteen samples out of 157 prepared by this technique, after dyeing by the Kinyoun method or by carbol fuchsin dimethyl sulfoxide, were found to be positive for Cryptosporidium sp..

[Health conditions of children of the municipality of São Paulo (Brazil), 1984/1985. VII--Intestinal parasitosis]

Como parte de estudo populacional sobre condições de saúde na infância, uma amostra representativa das crianças menores de cinco anos residentes no Município de São Paulo, SP (Brasil) (n=695) foi submetida a exames parasitológicos de fezes. Os exames foram realizados através da técnica de sedimentação e, quando as fezes tinham consistência amolecida ou liquefeita, também pela técnica do exame direto. A prevalência de enteroparasitoses em geral foi de 30,9%, sendo de 16,4%, 14,5% e 12,5% as prevalências específicas da ascaridíase, giardíase e tricuríase. Prevalências inferiores foram assinaladas para os enteroparasitas E. histolytica, H. nana e S. stercoralis, respectivamente 2,0%, 0,9% e 0,3%. Em apenas uma criança foram encontrados ovos de ancilostomídeos e em nenhuma delas ovos de Schistosoma mansoni. Das crianças examinadas, 13,1% apresentaram duas ou mais espécies de enteroparasitas e 4,8% três ou mais. As prevalências atuais, comparadas às prevalências encontradas em 1973/74 por outro inquérito populacional realizado no município, indicam queda expressiva da ascaridíase e tricuríase, mas não da giardíase. A estratificação das prevalências segundo faixa etária revelou aumento significativo com a idade da criança, chamando atenção o aumento que ocorre do primeiro para o segundo ano de vida. As enteroparasitoses aumentam também significativamente sua freqüência à medida que piora o nível socioeconômico, chegando a ser de nove vezes a diferença de prevalência existente entre os estratos socioeconômicos extremos da população. No caso específico da giardíase o gradiente socioeconômico foi consideravelmente menor do que o encontrado para as demais enteroparasitoses, o que confirma a maior complexidade epidemiológica do problema.