Three ways to fail weaning, and the first attempt decides which

Design

secondary analysis of a worldwide prospective observational cohort with phenotype derivation

Population

5,664 patients receiving invasive mechanical ventilation; 664 failing to wean by day 90

Primary outcome

ICU mortality

Effect

78% in failed-wean vs 2% in successful-wean; three phenotypes by separation attempt count and withdrawal timing

WEAN SAFE followed 5,664 patients on invasive ventilation worldwide. Of these, 1,270 (22.4%) never reached a separation attempt at all. Among the 4,394 who did, 3,730 (65.9%) weaned successfully and 664 (15.1%) had still not weaned at day 90.

The gap in outcome is extreme: ICU mortality was 78% in the failed-wean group against 2% in those who weaned. Failed-wean patients had the longest ventilation and the longest ICU stay, underwent more separation attempts but fewer attempted extubations, and had more reintubations and tracheostomies. Three phenotypes emerged, distinguished by how many separation attempts were made and when life-sustaining treatment was withdrawn: a single attempt followed by withdrawal, a single attempt without withdrawal, and more than one attempt. A failed first separation attempt was strongly associated with the subsequent withdrawal decision.

That last association is where the analysis becomes uncomfortable rather than merely descriptive. A failed first attempt might mark a patient who was always going to die, or it might be the moment a team's expectations change - and this dataset cannot tell the two apart. The practical consequence is not a new protocol. It is to notice that the first separation attempt carries weight in the room beyond its physiological information, and to say explicitly, when one fails, whether the plan is a second attempt or a change of direction. That is a decision worth making out loud rather than by drift.

• State explicitly after a failed first separation attempt whether the plan is another attempt or a change of goals.
• Almost a quarter of ventilated patients never reached a separation attempt at all.
• Failed-wean patients had more separation attempts but fewer attempted extubations - the gap is worth auditing.
• ICU mortality was 78% in those who failed to wean by day 90.
• A failed attempt is information about today's physiology, not a prognosis on its own.

Why it matters

It raises the possibility that the first separation attempt is doing work as a prognostic signal to the team, not only as a test of the patient.

Don't overread it

Observational phenotypes from a secondary analysis - a failed first attempt is not established as a reason to change goals of care.

The statistics, in plain English

The association between a failed first attempt, withdrawal of treatment and death is the kind that cannot be untangled observationally: the decision to withdraw both follows from prognosis and determines the outcome. A 78% mortality in the failed-wean group therefore describes a group defined partly by decisions already made about them, which is why the authors call for investigation rather than drawing a causal conclusion.

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