• Lymphocytes:T4,T8,B,T,NK
• Cytokine secretion:IL-1、IL-2、IL-6、IL-8、IL-11、IL-18、OX40 ligand、G-CSF、FN-γ、TGF-β1、TNF-α.
• Clinical outcome:incidence of infections,length of ICU and hospital stay,ventilation,mortality

• Liver function(AST,ALT,bilirubin,ALP,rGT,albumin)
• renal function(BUN,creatinine)
• AC blood sugar
• coagulation(INR,aPTT)
• sodium
• potassium
• chloride
• calcium
• magnesium
• phosphate
• total white blood cell counts
• platelets
• haemoglobin
• haematoc

1. A prospective, controlled, randomized, study evaluating the clinical efficacy, including nutritional status, immune function and safety of Omegaven (ω-3 fish oil) supplemented parenteral nutrition in subjects of SICU.
2. Study patients are the critical ill patients in SICU of NTUH and the enrolled patients will be 30 subjects ,including 15 in each treatment group.
3. During parenteral nutrition, fat emulsions will be given separately from amino acid and glucose solutions. Infusion pump must be used.The recommended infusion duration of the daily lipid emulsion is 16 hours (0.0625 g fat/kg B.W./hour) from 8:00 am to 12:00 pm.
4. During the study the assessments of safety and efficacy are to be performed according to case report form. The assessment for safety variables including blood pressure、heat rate 、body temperature、liver function、renal function、coagulation、WBC、lipid profile etc. In addition，the assessments for efficacy variables including lymphocytes、cytokines(IL-1、IL-2、IL-6、IL-8、IL-11、IL-18、OX40 ligand、G-CSF、FN-γ、TGF-β1、TNF-α etc)、incidence of infections、 length of ICU and hospital stay、mortality etc.

1. A prospective, controlled, randomized, study evaluating the clinical efficacy, including nutritional status, immune function and safety of Omegaven (ω-3 fish oil) supplemented parenteral nutrition in subjects of SICU.
2. Study patients are the critical ill patients in SICU of NTUH and the enrolled patients will be 30 subjects ,including 15 in each treatment group.
3. During parenteral nutrition, fat emulsions will be given separately from amino acid and glucose solutions. Infusion pump must be used.The recommended infusion duration of the daily lipid emulsion is 16 hours (0.0625 g fat/kg B.W./hour) from 8:00 am to 12:00 pm.
4. During the study the assessments of safety and efficacy are to be performed according to case report form. The assessment for safety variables including blood pressure、heat rate 、body temperature、liver function、renal function、coagulation、WBC、lipid profile etc. In addition，the assessments for efficacy variables including lymphocytes、cytokines(IL-1、IL-2、IL-6、IL-8、IL-11、IL-18、OX40 ligand、G-CSF、FN-γ、TGF-β1、TNF-α etc)、incidence of infections、 length of ICU and hospital stay、mortality etc.

Inclusion Criteria:

• Male and female patients between 15 and 75 years of age
• Expected ICU stay and TPN support requirement > 7 days
• Hemodynamically stable
• Serum bilirubin < 2.5 mg/dl
• Serum creatinine < 1.4 mg/dl
• INR (international Normalized ratio of PT) < 1.4
• Written informed consent from the subject

Exclusion Criteria:

• Pregnant or lactating women. (Pre-menopause women, capable of bearing children will undergo pregnancy test)
• General contraindications of infusion therapy; acute pulmonary oedema,hyperhydration and decompensated cardiac insufficiency
• Known hypersensitivity to egg- or soy protein or any of the ingredients
• Severe blood coagulation disorders
• Shock necessitating acute resuscitation at the discretion of the investigator
• Diabetes mellitus with known ketoacidosis within 7 days of onset of study treatment
• APACHE II score > 25
• Renal insufficiency defined as serum creatinine value of >1.4 mg/dl
• Subjects with severe liver dysfunction which contraindicates the use of parenteral nutrition at the discretion of the investigator
• Known type IV hyperlipidemia, disturbances in lipid metabolism or hypertriglyceridemia (at the time of inclusion, a blood sample (fasting) for serum triglyceride assessment has to be taken. The sample has to be analysed before start of trial treatment. In case of fasting serum triglyceride value of >4 mmol/l (>354 mg/dl) the subject must be withdrawn.
• Unconscious or uncooperative patients
• Participation in a clinical study with an investigational drug or an investigational medical device within one month prior to start of study