Inclusion Criteria:  AGI are diagnosed according to the diagnostic criteria proposed by European Society Intensive Care Medicine (ESICM) in 2012 and the AGI grade great than or equal to II. Age 18-80 years. Expected length of stay longer than 3 days.  Exclusion Criteria:  Mean arterial pressure is still less than 65 millimeter of Mercury (mmHg) treated with rehydration and vasoactive agents, or with the dosage of norepinephrine more than 0.5ug/kg/min. Heart rates are less than 50 beats per minute or moderate and severe atrioventricular block without pacemaker. Primary gastrointestinal disease such as mechanical intestinal obstruction, massive hemorrhage of gastrointestinal tract and gastrointestinal perforation. Severe trauma of chest, abdomen or back. gastrointestinal tract surgery history. Neuromuscular disorders. Drug addiction, alcohol abuse, opioid or amphetamine dependence, or mental disorders. Pregnancy. Brain dead. Malignant tumor, or end-stage cachexia. With contraindications of the erector spinae plane block (ESPB), such as local infection, Spinal diseases or immobilization. Allergy to local anesthetics. Significant abnormalities in blood coagulation parameters. Without written informed consent.