To evaluate the effects of liberal transfusion strategy (trigger haemoglobin ≤90–100 g/L) compared with a restrictive strategy (trigger haemoglobin ≤70–80 g/L) on long-term neurological functional outcome in anaemic adult patients with acute acquired brain injury (ABI).

Systematic review and study-level meta-analysis of randomised controlled trials (RCTs).

MEDLINE, EMBASE, Cochrane from inception to 6 February 2025.

RCTs enrolling patients with acute ABI and anaemia (haemoglobin ≤100 g/L), comparing a liberal vs restrictive transfusion strategy.

Two reviewers independently identified eligible studies, extracted data and assessed risk of bias. We performed random-effects meta-analysis of RCTs and applied Grading of Recommendations, Assessment, Development and Evaluation methodology to assess the certainty of evidence. Our primary outcome was an unfavourable neurological functional outcome, using the Glasgow Outcome or modified Rankin scales.

Five trials enrolling 2364 patients with acute ABI and anaemia were included in the primary analysis. Liberal transfusion reduces the risk of unfavourable neurological outcome (risk ratio (RR)=0.89, 95% CI 0.84 to 0.95, high certainty). Liberal transfusion may reduce severe disability (RR=0.82, 95% CI 0.66 to 1.02, moderate certainty), and increase good recovery compared with restrictive transfusion (RR=1.29, 95% CI 0.95 to 1.76, low certainty). We found no difference in the risk of most adverse events, including death. Statistical heterogeneity was low (I²=0%–36%) for neurological outcomes.

In adults with acute ABI and anaemia, liberal transfusion reduces the risk of unfavourable outcome (high certainty) and possibly improves the chances of good recovery (low certainty) when compared with restrictive transfusion.

CRD42025628732.

Acute hypoxaemic respiratory failure is a common reason for intensive care unit (ICU) admission. Non-invasive respiratory support strategies such as high-flow nasal oxygen (HFNO) and helmet non-invasive ventilation may reduce the need for invasive mechanical ventilation and death. The High-flow nasal Oxygen with or without alternating helmet Non-invasive ventilation for Oxygenation sUpport in acute Respiratory failure pilot trial is designed to compare helmet non-invasive ventilation combined with HFNO vs HFNO alone in patients with acute hypoxaemic respiratory failure and to determine the feasibility of a larger randomised controlled trial.

This is a pragmatic, open-label, multicentre randomised controlled pilot trial enrolling 200 critically ill adults with acute hypoxaemic respiratory failure across 12 Canadian ICUs. Participants are randomised 1 to 1 to receive either helmet non-invasive ventilation plus HFNO or HFNO alone for at least 48 hours. The primary aim is to assess feasibility metrics including recruitment rate, protocol adherence and fidelity to pre-specified intubation criteria. Secondary outcomes include rates of intubation, all-cause mortality, ventilator-free days, ICU length of stay and quality of life at 6 months. Primary and secondary outcomes will be analysed using Bayesian methods.

Ethics approval has been obtained at all participating centres. Findings will inform the feasibility and design of a future full-scale trial and be disseminated through peer review publications and conference presentations.

ClinicalTrials.gov Identifier: NCT05078034.