Inclusion Criteria:  planned surgical intervention postoperative intensive medical and therapeutic treatment expected duration of ventilation > 48 hours age ≥ 18 years preoperative informed consent by the patients in the study weight >45 kg and <135 kg body height >1.50 m and <1.95 m  Exclusion Criteria:  patient refusal to participate in the study unable to give consent chronically bedridden before inclusion clinical Frailty Scale ≥ 7 chronic ventilation (over 24h) before ICU admission increased intracranial pressure / risk for increased intracranial pressure / recent cerebral hemorrhage pregnancy pre-existing neuromuscular disease resulting in chronic limitation of strength and efficiency sternotomy / sternectomy during surgical procedure