Hypotension Prediction Index was not superior to treating at MAP 73 mmHg

Design

Two-centre, open-label, parallel-group randomised trial

Population

100 adults undergoing major non-cardiac surgery with invasive arterial monitoring

Primary outcome

Time-weighted average hypotension (MAP <65 mmHg)

Effect

Median 0.07 vs 0.16 mmHg (P = 0.119); no difference in noradrenaline, stay or 30-day mortality

Earlier trials suggested that the Hypotension Prediction Index, an algorithm that warns of impending hypotension, reduces intraoperative hypotension. Those trials were open-label and compared it with treating at the conventional 65 mmHg threshold. This two-centre randomised trial, published in Anesthesiology on 29 September 2026, compared it instead with a proactive higher trigger.

One hundred adults having major non-cardiac surgery with arterial lines were randomised to treatment when the index reached 85 or when MAP fell to 73 mmHg or below, both using the same protocol. Median time-weighted average hypotension (MAP below 65) was 0.07 mmHg with the index and 0.16 mmHg with the higher MAP target (P = 0.119). Hypertension burden, noradrenaline dose, length of stay and 30-day mortality did not differ.

The trial was small and designed to test superiority, so it shows the index was not proven better rather than proven equivalent. It supports the view that much of the index's benefit comes from acting earlier. Where the monitoring platform is unavailable or unaffordable, as in many Indian theatres, treating at a slightly higher MAP threshold with an arterial line is a reasonable way to reduce hypotension.

• Consider a proactive treatment trigger around MAP 73 mmHg in major non-cardiac surgery
• Treat hypotension early with a predefined protocol whatever the monitoring platform
• Do not assume a proprietary prediction index is necessary to reduce hypotension
• Watch for hypertension with any higher-target strategy

Why it matters

It suggests the benefit attributed to an expensive monitoring algorithm may be achievable by acting at a higher pressure.

Don't overread it

A small superiority trial; it does not prove the two strategies are equivalent.

The statistics, in plain English

Time-weighted average hypotension combines how deep and how long MAP stays below 65 mmHg, averaged over the operation. Both groups had very low values, and a P value of 0.119 means the difference could easily be chance in a trial of 100 patients.

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