Critical incidents in anesthesia is one of the most valuable methods to assess the safety of anesthesia practice among different types of patients. Most of the studies in this regards are retrospective with many drawbacks and pitfalls like absence of information in the records of the patients.

In the investigators' study, the investigators will follow the critical incidents among patients who underwent surgery under anesthesia whether regional or general over the next two years from 2016 to 2018, by examining the patients records from the hospital database and recording the events that occur to the patients.

Over the forthcoming two years, the investigators will study in details critical incidences that may occur to patients in the perioperative period like; acute hypoxic event, acute major hemorrhage, acute airway obstruction and others that may endanger the life or one of the patient organs and whether the patient survive the acute event or die.

These critical incidences will be collected and all information about it will be known in order to be studied and to know were was the defect and eventually to improve the safety of practice of anesthesia and surgery.

Inclusion Criteria:

• patients who undergo anesthesia and surgery
• patients who are exposed to a critical incidence

Exclusion Criteria:

• patients who undergo anesthesia and surgery and do not expose to critical incidents.

patients who undergo anesthesia and surgery and be exposed to a critical incidence.