Supplemental Parenteral Nutrition in Critically Ill Adults: A Pilot Randomised Controlled Trial

The principal objectives are:

• To determine whether the supplemental Parenteral Nutrition (PN) strategy leads to the delivery of increased amounts of total nutrition (measured as energy delivered), and is safe in regards to adverse effects.
• To measure the clinical outcomes in patients receiving both study strategies to provide information to assist design of a larger randomized controlled trial.

Secondary objectives in a sub-set of patients are:

• To determine whether the supplemental PN strategy leads to improved nitrogen balance.
• To determine both the nutritional requirements and nutritional intake of critically ill patients during the period of hospitalization after transfer from the Intensive Care Unit (ICU).

Inclusion criteria

Patients in intensive care who meet all of the following:

• Admitted to intensive care between 48 hours and 72 hours previously
• Mechanically ventilated at the time of enrollment and expected to remain ventilated until the day after tomorrow
• At least 16 years of age
• Have central venous access suitable for PN solution administration
• Have 1 or more organ system failure (respiratory, cardiovascular or renal) related to their acute illness defined as:

• Partial pressure of oxygen (PaO2) / Fraction of Inspired oxygen (FiO2) ratio ≤ 300 mmHg
• Currently on 1 or more continuous vasopressor infusion which were started at least 4 hours ago at a minimum dose of :

• Dopamine greater than 5 mcg/kg/min
• Noradrenaline ≥ 0.1mcg/kg/min
• Adrenaline ≥ 0.1 mcg/kg/min
• Any dose of total vasopressin
• Milrinone >0.25mcg/kg/min)
• Renal dysfunction defined as

In patients without known renal disease:

• serum creatinine > 171 mmol/l OR
• Currently receiving renal replacement therapy

In patients with known renal disease:

• an absolute increase of > 50% in creatinine from baseline OR
• Currently receiving renal replacement therapy
• Currently has an intracranial pressure monitor or ventricular drain in situ
• Currently receiving extracorporeal membrane oxygenation
• Currently has a ventricular assist device

Exclusion criteria

• Both EN and PN cannot be delivered at enrollment (i.e. either an enteral tube or a central venous catheter cannot be placed or clinicians feel that EN or PN cannot be safely administered due to any other reason).
• Currently receiving PN
• Standard PN solutions cannot be delivered at enrolment (i.e. clinicians believe that a patient definitely needs a specific parenteral nutrition formulation (e.g. glutamine-supplementation or specific lipid formulation).
• Death is imminent or deemed highly likely in the next 96 hours.
• There is a current treatment limitation in place or the patient is unlikely to survive to 6 months due to underlying illness
• More than 80% of energy requirements have been satisfactorily delivered via the enteral route in the last 24 hours.
• Are known to be pregnant