Remote ischaemic preconditioning did not reduce mortality after non-cardiac surgery

Design

Systematic review and meta-analysis of 79 randomised trials

Population

9,340 adults undergoing non-cardiac surgery

Primary outcome

All-cause mortality at longest follow-up

Effect

OR 0.79 (95% CI 0.51–1.24); before-induction subgroup OR 0.37 (0.17–0.81)

This meta-analysis included 79 randomised trials with 9,340 adults having non-cardiac surgery, mostly abdominal and mostly single-centre. Preconditioning was usually delivered by inflating a blood pressure cuff on the upper arm.

Preconditioning was not associated with lower all-cause mortality (OR 0.79, 95% CI 0.51–1.24). In the subgroup that received it before induction, mortality was lower (OR 0.37, 0.17–0.81). Exploratory analyses suggested less stroke (OR 0.41, 0.22–0.78), a shorter stay by about 0.84 days, and lower peak NGAL, a kidney injury marker.

The primary answer is negative. The timing subgroup and exploratory outcomes are interesting enough to justify a trial but not to add cuff inflations to practice.

• Do not add remote ischaemic preconditioning to routine non-cardiac anaesthesia on this evidence
• Treat the before-induction finding as a hypothesis for trials
• Continue proven kidney and cardiac protection measures — blood pressure control, avoiding nephrotoxins

Why it matters

A cheap intervention with appealing biology again failed to show the survival benefit that would justify routine use.

Don't overread it

The before-induction mortality benefit is a subgroup finding and the stroke and length-of-stay results are exploratory.

The statistics, in plain English

The overall odds ratio of 0.79 has an interval from 0.51 to 1.24, which crosses 1.0, so no mortality effect can be claimed. Subgroup results in meta-analyses are often chance findings, particularly when the overall result is null.

Read the rest in the app

You have read your two free briefings this month. The app carries all 27 specialties, every morning, free — and this finding is waiting in it.

Get Daily Doctor — free

Scan to keep reading on your phone. No account needed to start.