Background Severe abdominal pain is a hallmark of acute pancreatitis (AP). A control pain is often difficult. Transversus Abdominis Plane (TAP) block has been used in pain control in patients with exacerbation of chronic pancreatitis.

Objectives To evaluate the effect of Bilateral Blockade of the Abdominal Transverse Muscle Plane (TAP Block) in the analgesic control of patients with acute pancreatitis; compared to standard intravenous analgesia.

Methods A randomized controlled trial of parallel groups will be conducted. The Study will have a multicenter development. Study population: Adult patients admitted for episode of AP, with uncontrolled pain (visual analogue scale (VAS) equal to or greater than 5 after the administration of standard analgesia. Randomization Groups: Group A: Patients who will undergo TAP block as analgesic procedure added to standard analgesia. Group B: Patients to whom morphine 2 mg / ev will be administered as analgesic procedure added to standard analgesia.

Timing of pain determination (Visual Analogue Scale, VAS):

• Before conventional analgesia
• Immediately before Randomization
• 15 minutes after the administration of the analgesic treatment object of the study.
• One hour after the procedure.
• Every 8 hours, during the next 4 days or until discharge of the patient.
• Whenever the patient needs a dose of supplemental rescue analgesia. Analysis of data All results will be evaluated according to the initial "intention to treat". There will be a blinded assessment of the results after the last patient in the trial has completed the follow-up. The results will be presented as relative risks with their corresponding confidence intervals. P <0.05 will be considered statistically significant. In case of imbalance between the two treatment groups, a multivariate logistic regression is used to correct possible confounding factors.

Inclusion Criteria:

• Diagnosis of acute pancreatitis according to modified Atlanta criteria .
• Patients with the ability to understand the VAS scale and express their level of pain.
• Patients over 18 years old.
• Uncontrolled pain, with VAS ≥ 5 after the administration of standard analgesia.
• Material and technical possibility of performing the TAP technique immediately after randomization.
• Informed consent of the participating patients for inclusion in the study.
• Informed consent of the participating patients for the administration of TAP.
• Normality of coagulation levels

Exclusion Criteria:

• Patients with American Society of Anaesthesia (ASA) levels IV and V
• Patients with chronic pancreatitis
• Pregnancy
• Patients with chronic treatment with morphic medication