Study had to be put on hold after the outbreak of Covid-19 in the participating countries and was terminated in September 2020 since a date for re-starting was not foreseeable.

The main focus of the study is to show that SmofKabiven® extra Nitrogen, in a realistic clinical setting, enables to meet high protein requirements in patients during the first week after onset of critical illness, without risk of overfeeding with energy.

Inclusion Criteria:

1. Age ≥18 years and <90 years, male and female
2. Critically ill, medical or surgical ICU patient
3. Admitted to the ICU on the same day or the day before with a minimum expected ICU stay of 3 days
4. Central venous access available for continuous infusion of the study drugs
5. Sequential Organ Failure Assessment (SOFA) score ≥2
6. Contraindication against enteral nutrition or limited tolerance to enteral nutrition and it is planned that patient receives ≥80% of the total target caloric intake from parenteral nutrition during the first 3 nutritional treatment days
7. Written informed consent from the patient or the patient's legal representative or deferred written consent from the patient or patient's legal representative (deferred proxy consent)

Exclusion Criteria:

1. Contraindication against parenteral nutrition or inability to receive parenteral nutrition via central venous access
2. Received parenteral nutrition within 7 days before randomisation
3. It is planned that patient receives ≥20% of the total target caloric intake via enteral or oral nutrition and/or non-nutritional sources (glucose solution for drug dilution or lipids from propofol/clevidipine or citrate from continuous renal replacement therapy) during the first 3 nutritional treatment days
4. Body mass index (BMI) <18.5 kg/m2 or >35 kg/m2
5. Burn injury
6. Any severe, persistent blood coagulation disorder with uncontrolled bleeding
7. Any congenital errors of amino acid metabolism
8. Uncontrolled hyperglycaemia despite insulin treatment
9. Known hypersensitivity to fish, egg, soybean proteins, peanut proteins, or to any of the active substances or excipients contained in SmofKabiven® extra Nitrogen or Olimel N9E
10. Known hypersensitivity to milk protein or to any other substance contained in Fresubin® Original
11. Treatment-refractory cardiopulmonary or metabolic instability showing persistent or progressive worsening despite increased interventions, including severe pulmonary oedema, severe cardiac insufficiency, myocardial infarction, acute phase of circulatory shock, severe sepsis, embolism, haemodynamic instability, metabolic or respiratory acidosis, hypotonic dehydration, or hyperosmolar coma
12. Severe renal dysfunction, defined as serum creatinine ≥2.0 times baseline or urine output <0.5 mL/kg/h for ≥12 hours (Acute Kidney Injury stage ≥2; [KDIGO 2012]), and blood urea nitrogen (BUN) exceeding 2 x upper limit of normal (ULN)
13. Severe liver failure with encephalopathy, including intoxication (e.g. paracetamol, death cap, golden chain) and/or liver enzymes (aspartate aminotransferase [AST], alanine aminotransferase [ALT], gamma glutamyl transferase [GGT]) or bilirubin exceeding 5 x ULN
14. Oncologic disease with anticancer drug and/or radiation treatment incl. Hyperthermic Intraperitoneal Chemotherapy (HIPEC) during this Trial up to and including Study Day 28
15. Preceding transplantation causal for acute critical illness
16. Hemophagocytic syndrome
17. Pregnancy or lactation
18. Receiving end-of-life-care
19. Pathologically altered blood pH (arterial pH <7.0), oxygen saturation (SaO2 <80%), or carbon dioxide concentration (PaCO2 ≥80 mm Hg)
20. Hyperlipidaemia or any disorder of lipid metabolism characterised by hypertriglyceridaemia (serum triglyceride levels >4 mmol/L [>350 mg/dL])
21. Treatment-refractory, clinically significant major abnormality in the serum concentration of any electrolyte (sodium, potassium, magnesium, total calcium, chloride, inorganic phosphate)
22. Administration of growth hormone including teduglutide within the previous 4 weeks before randomisation
23. Invasive devices and procedures influencing metabolism and organ perfusion, e.g. extracorporeal membrane oxygenation (ECMO), continuous renal replacement therapy (CRRT), molecular absorbent recycling system (MARS), intra-aortic balloon pump (IABP)
24. Receipt of the last dose of study drug in another interventional clinical trial within the previous 4 weeks before randomisation into this clinical trial
25. Previous inclusion in the present study
26. Any other known reason that may prevent a patient to take part in the study in accordance with local requirements