Major intraoperative events including bronchospasm, thromboembolic events, arrhythmias, tension pneumothorax, cardiac tamponade, respiratory and cardiac arrest, hypovolaemia, distributive, cardiogenic, and obstructive shock, acute myocardial ischaemia, acute pulmonary oedema, aortic dissection, aspiration of gastric contents, massive haemoptysis, coma, prolonged seizures, anaphylaxis, and fat and air embolism.