Regional anesthesia is the cornerstone of modern postoperative analgesia, but concerns remain about possible adverse effects and complication.

RICALOR Group Investigators developed a national registry to register the incidence of regional anesthesia-associated complications and to identify possible risk factors.

The project has been advertised through direct contact with relevant organizations in anaesthesia and pain management. Any other center willing to participate is provided with all the documents to receive its local Institutional Review Board (IRB) approval, and a 'local responsible' (LR) is nominated to co-ordinate the project and to be responsible of data collection locally.

Centers receiving IRB approval collect data about different types of procedure (adult major and minor surgery, pediatric surgery, obstetric anesthesia, pain management). Data are collected on a specifically designed form, and every center quarterly sent the promoter centre a report including general data and a specific report for every occurred complication.

Eligibility criteria

Investigators collect the total number of intervention and the number of regional anesthesia(RA) techniques performed . Patients recorded as "case" and "controls" had to sign a specifical informed consent. For pediatric patients and patients not able to sign for any reason, a specific form is included in the document, to be signed by parents or any legally-established tutor, as required for every clinical procedure or scientific trial in our country.

General data

Total number of interventions, the number of central neuraxial block (CNBs), peripheral nerve blocks (PNBs) and continuous PNBs (CPNBs) performed. CNBs are classified as epidurals, combined spinal-epidurals (CSEs), subarachnoid. PNBs and cPNBs are divided into ultrasound-guided, nerve stimulation-guided and blind techniques.

Specific data - report for complications

For each complication a specific report is sent for data analysis, including data concerning cases (patient with complication) and controls (the two following patients undergoing the same type of loco-regional technique).

Reports are slightly different for CNBs and (c)PNBs. For every patient, the investigators register demographic data (age, ASA-American Society of Anesthesiologists- status, height and weight), data regarding surgical technique (type of surgery, open/video-laparoscopic/robotic approach, election/emergency surgery) and data regarding anti-thromboembolic therapy (drugs, timing of suspension before/after blockade).

A second part of the report is strictly dedicated to the technique and to the type of complication occurred (and, hence, different in central and peripheral blocks).

Statistical analysis

Study population is estimated basing on previous studies of major complications after CNBs, which indicate an incidence of major adverse effects of 4.2 on 100.000 patients. Estimating an incidence of 1:25.000, a number of 25.000 procedures was calculated to be needed for the study, with a confidence interval of 95%. The primary endpoint was to assess cumulative incidence of adverse effects, while a following case-control analysis will be performed to identify possible risk factors.

Inclusion Criteria:

• M/F
• undergoing surgery or procedures needing regional anesthesia
• signed informed consent for data treatment

Exclusion Criteria:

• no informed consent

All patients undergoing surgery with regional anesthesia during study period will be considered for complications' incidence calculation .