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.

Association between Developmental Venous Anomalies and Cavernous Angiomas: a Retrospective MR Study

Developmental venous anomalies (DVA) are large veins usually arranged in a cluster around a collector vein draining directly into the superficial and deep venous systems. Since the introduction of magnetic resonance imaging DVA have been disclosed more frequently. Many studies suggested and then confirmed the association between cavernous angioma and developmental venous anomaly, described for the first time by Roberson in 1974. The aim of our study was a retrospective assessment of the case series at our institution, namely to determine the frequency of the association between developmental venous anomaly and cavernous and analyse the relation between the two lesions.

Three-Year Retrospective Study of Complications Arising during Interventional Procedures

SUMMARY

This retrospective study aimed to assess the percentage of complications arising in our daily practice of interventional procedures, comparing our findings with those of leading international reference centers and accepted guidelines for endovascular treatment. During the threeyear period considered (2000-2002), we performed 246 interventional procedures, divided into seven different pathological conditions: aneurysms, brain AVMs dural and carotid cavernous fistulae, spine-spinal cord tumours, headneck tumours, carotid stenosis and thrombolysis. Aneurysmal disease accounted for 45% of all endovascular procedures. In conclusion, four periprocedural complications arose in the course of 246 procedures resulting in one death and three cases of permanent neurological deficit (2%).

Analysis of ethereal extracts of wines and other alcoholic beverages by high-performance liquid chromatography with microbore columns

The ethereal extracts of wines, beer and vermouth were analysed by high-performance liquid chromatography. The following three characteristic peaks were first identified using GC-MS and then quantitatively determined: 5-hydroxy-methyl-2-furaldehyde, 2-(4-hydroxyphenyl)ethanol and 3-(2-hydroxyethyl)indole.

Magnetic resonance imaging

All of the data published in the literature show that MR is more sensitive than CT in diagnosing cerebral ischemic lesions. This greater sensitivity is due to its ability to detect even the minimal changes in tissue water content which occur in the early phases of the infarct. The literature concerning the use of MR in lacunar lesions is extremely limited but agrees with the general data regarding ischemia. However, there is some doubt that the thickness of the strata of CT and the interval between the strata of MR could have an influence on their ability to detect very small lesions. Modifications in the sensitivity of MR in detecting ischemic lesions are now well known: during the acute phase, the T2 images are more sensitive, while in the subacute and chronic phase both T1 and T2 have the same diagnostic capability.

The role of MR and CT in evaluating clival chordomas and chondrosarcomas

Sixteen chordomas and nine chondrosarcomas of the clivus were evaluated with CT and MR either before (22 cases) or after (three cases) treatment with proton beam irradiation. The ability of these imaging techniques to provide information necessary to direct patient treatment was studied. The tumor was detected and its gross margins were identified by both techniques in all instances. No reliable diagnostic features allowing differentiation between these two tumors were encountered. MR generally was superior in defining the exact position of the brainstem and optic chiasm relative to the tumor, and it frequently provided superior information about tumor extension into the nasopharynx and cavernous sinus. CT was always better than MR in demonstrating tumoral calcification and in defining the exact anatomy of bone destruction. MR was generally superior to CT in demonstrating the position of the cavernous internal carotid artery relative to the tumor and often provided superior visualization of the vertebral and basilar arteries. In cases in which bone-induced artifact obscured the interface between the neural axis and tumor in the CT image, or in which the tumor had suprasellar extension and was likely to compress the optic chiasm and tracts, MR was of great value in planning irradiation therapy. The high occurrence of clinically asymptomatic signal intensity alterations in the MR studies of previously treated patients appears to limit the differential diagnostic value of this information. Given its greater availability and lower cost, CT appears to be the technique of choice for routine follow-up of previously treated patients.