Inclusion Criteria:  Patients ≥ 80 or ≥18 - ≤40 years of age Informed consent Scheduled for elective surgery under general anaesthesia (expected duration of anaesthesia > 1 hour) with intubation and use of cisatracurium American Society of Anaesthesiologists (ASA) physical status classification I to III Can read and understand Danish  Exclusion Criteria:  Known allergy to cisatracurium Neuromuscular disease Indication for rapid sequence induction Surgery in the prone position