Table 1 Definition of the primary and secondary endpoints

IAH

A sustained or repeated pathological elevation in IAP ≥ 12 mmHg

IAH grade

Grade I, IAP 12–15 mmHg

Grade II, IAP 16–20 mmHg

Grade III, IAP 21–25 mmHg

Grade IV, IAP > 25 mmHg

ACS

A sustained IAP > 20 mmHg (with or without an APP < 60 mmHg) that is associated with new organ dysfunction/failure

Increase in stool volume

Increase in 24 h stool volume on a designated day (day 1, day 2, day 3, day 5, and day 7) after randomization above the baseline 24 h stool volume before randomization

New-onset ACS

ACS occurring after randomization (not present at any time before it), assessed for up to 4 weeks

Deterioration of IAH

IAP that rebounds ≥ 5 mmHg or increases to ≥ 20 mmHg within 7 days after randomization

New-onset organ failure

Organ failure occurring after randomization (not present at any time before randomization)

Multiple-organ failure

Failure of two or more organs

Respiratory failure

PaO₂/FiO₂ ≤ 300, or requirement for mechanical ventilation

Circulatory failure

Circulatory systolic blood pressure < 90 mmHg, despite adequate fluid resuscitation, or requirement for inotropic catecholamine support

Renal failure

Creatinine level > 177 μmol/L after rehydration or new need for haemofiltration or hemodialysis

Timing of EN

Time from randomization to the initiation of tolerated EN

Intra-abdominal bleeding

Intra-abdominal bleeding that requires surgical, radiologic, or endoscopic intervention

Enterocutaneous or enteric fistula

Secretion of fecal material from a percutaneous drain or inflow into a necrotic cavity, either from small or large bowel, confirmed by endoscopy, imaging, or during surgery

Adverse event

The following events occurred during the use of neostigmine: drug eruption, ataxia, convulsions, coma, slurred speech, anxiety, fear, cardiac arrest, or other untoward events not characteristic of or expected from AP; diarrhea was excluded as this was part of the therapeutic effect to reduce IAP