NEET SS Anesthesia: Improve-multi Trial and MAP Targets Explained.

NEET SS Anesthesia: What the IMPROVE-multi Trial Means for Perioperative MAP Targets

A structured review of the IMPROVE-multi RCT (JAMA, December 2025) and its companion trials, built for NEET SS and INI SS anesthesia aspirants preparing for MD or DNB Anesthesia.

1. Why This Trial Matters for NEET SS Anesthesia Preparation

Intraoperative hypotension is one of those topics that comes back again and again in NEET SS, INI SS, and MD or DNB anesthesia vivas. IMPROVE-multi is the largest trial so far to test whether individualized MAP targets protect organs better than a fixed threshold after major abdominal surgery. This blog by Surgtest aims to address this.

Exam takeaway: if a viva question asks whether 65 mm Hg is still the right MAP floor for everyone, this is the trial to cite.

2. The Background Question

Current guidelines recommend keeping intraoperative MAP above 60 to 65 mm Hg during noncardiac surgery. This comes from observational data linking a sustained MAP below 65 mm Hg with acute kidney injury, myocardial injury, and death.

But a fixed threshold ignores individual variation. Roughly half of surgical patients have chronic hypertension, and baseline blood pressure varies widely between individuals. That raises an open question worth remembering for exams: do patients with a higher baseline BP need a higher intraoperative target to maintain organ perfusion?

Key baseline facts to remember

Intraoperative MAP below 65 mm Hg for 10 minutes or more: AKI risk rises by around 60%, myocardial injury risk by around 30%, and mortality risk by around 4% (Wesselink et al., a 42-study systematic review).

About 50% of elective major noncardiac surgery patients have chronic arterial hypertension at baseline.

3. IMPROVE-multi: Trial Design at a Glance

Parameter

Detail

Design

Multicenter, randomized, single-blind superiority trial across 15 German university hospitals

Population

Age 45 or older, elective major abdominal surgery, general anesthesia lasting 90 minutes or more, plus at least one high-risk criterion (n = 1134 in the primary analysis

None of the 22 secondary outcomes reached significance. A mixed-effects model adjusting for center gave a similarly null result (adjusted OR 1.16, 95% CI 0.90 to 1.49). Subgroups based on the degree of preoperative hypertension also showed no benefit.

Patients on the individualized target ran a higher median MAP throughout surgery, with a smaller area under 65 mm Hg. In other words, the intervention worked physiologically.

They received more norepinephrine (94.5% versus 87.3% of patients) to hit the higher targets.

Fluid volumes were similar between groups, so the difference was vasopressor-driven rather than fluid-driven.

Exam takeaway: the protocol worked as designed and MAP did go up. It just didn’t reduce organ injury. This is a negative outcome trial, not a failed intervention, and that distinction is worth remembering.

What actually changed at the bedside

Patients on the individualized target ran a higher median MAP throughout surgery, with a smaller area under 65 mm Hg. In other words, the intervention worked physiologically.

They received more norepinephrine (94.5% versus 87.3% of patients) to hit the higher targets.

Fluid volumes were similar between groups, so the difference was vasopressor-driven rather than fluid-driven.

Exam takeaway: the protocol worked as designed and MAP did go up. It just didn’t reduce organ injury. This is a negative outcome trial, not a failed intervention, and that distinction is worth remembering.