International multicenter observational study of a random-sample cohort of patients undergoing any in-hospital surgical procedure under general or regional anaesthesia during a continued 14-day period of recruitment.

Primary hypothesis of this study is that the use of muscle relaxants, their reversal agents, or neuromuscular monitoring increases the incidence of postoperative pulmonary complications. The secondary hypothesis is that the use of muscle relaxants increases in-hospital mortality.

Overall postoperative mortality for patients undergoing non-cardiac surgery in Europe is 4% (EUSOS study). Postoperative pulmonary complications are a major factor, which increase patient morbidity and mortality (PERISCOPE study). This study is designed to evaluate the effects of management of neuromuscular blockade on postoperative pulmonary complications in a general unrestricted anaesthetized population across Europe. The investigation will be a continuation of the European EUSOS and PERISCOPE studies. Based on a well-recognised body of surrogate data, it is hypothesized that incorrect approaches to the use, monitoring, and reversal of muscle relaxants will increase the incidence of in-hospital postoperative pulmonary complications and prolong hospital stay.

The investigators will not modify a participating centre's customary management of patients. Patients with postoperative pulmonary complications will be identified by postoperative assessment and consulting medical records for events that fulfil the definition of postoperative pulmonary complications.

Inclusion Criteria:

• Adult Patients undergoing any in-hospital surgical procedure under general or regional anaesthesia during the defined continued 14-day period of recruitment.

Exclusion Criteria:

1. Patients less than 18 years of age
2. Patients scheduled for local or regional anaesthesia only
3. Patient's anaesthetic procedure scheduled outside an operating room
4. Ambulatory patients = Patient planned to be discharged within 12 hours post anaesthesia
5. Patient with preoperatively intubated trachea
6. Patient from an intensive care unit (ICU)
7. Patient scheduled for additional surgical / anaesthetic procedure in the next 7 days
8. Patients who had a surgical / anaesthetic procedure within the past 7 days
9. Patient born outside the predetermined 'month(s)' allocated for the specific study centre.

Adult Patients undergoing any in-hospital surgical procedure under general or regional anaesthesia