Does a Ketogenic Diet Causes Ketosis in Patients on Intensive Care?

Does a Ketogenic Diet Reduce Delirium in Intensive Care? Part 1: - A Feasibility Study to Test if a Ketogenic Diet Causes Ketosis in Patients on Intensive Care

The purpose of this study is to assess if an enteral ketogenic feed will cause a ketotic state in critically ill patients on intensive care.

This pilot study is a prospective, single-centre, unblinded, parallel-group, randomised controlled, Phase IIb trial comparing standard enteral nutrition with an enteral ketogenic feed. The trial has a simple, pragmatic design and will be analysed on an intention-to-treat basis. It aims to recruit 10 patients from a single University teaching hospital adult general ICU. The anticipated recruitment period is 4 weeks. Adult patients admitted to intensive care and expected to require enteral feed via a nasogastric tube for at least 5 days and who fulfil other eligibility criteria will be allocated at random to receive either standard feed (Nutrison Protein Plus Multi Fibre) or a ketogenic enteral feed (Nutrison KetoCal 4:1). The primary endpoint will be increase in ketone body concentration in serum. Secondary endpoints will include, time taken to achieve a ketotic state, ketone levels in critical care patients who are not absorbing enteral feed, glucose levels in patients on a ketone feed, triglyceride and cholesterol levels, creatinine kinase levels and development of a metabolic acidosis. Adult ICU patients will be eligible to be included in this study if they are expected to require enteral feed via a nasogastric or nasojejunal tube or established percutaneous jejunostomy for at least 5 days. Practically, this will be achieved by screening ventilated patients as they will require enteral feeding Major exclusion criteria include contraindications to ketogenic feeds, contraindications to enteral feeding, a new (< 5 days) percutaneous jejunostomy. The intervention will continue until 14 days if the patient still requires enteral nutrition or until able to commence a normal diet orally.

A low-carbohydrate, high-fat enteral feed (Nutrison KetoCal 4:1) containing 0.4g of carbohydrate and 10g of fat per 100kcal. Given as a continuous feed via a naso-gastric tube as per standard feeding protocol.

Standard enteral feed (Nutrison ProteinPlus MF 1.28) containing 11.1g of carbohydrate and 3.8g of fat per 100kcal. Given as a continuous feed via a naso-gastric tube as per standard feeding protocol.

Serum ketone levels (mmol/L) will be recorded 4-hourly in each group. The median serum ketone level (mmol/L) will be calculated.

Time taken (hours) to achieve a clinically relevant ketosis (serum ketone > 0.3mmol/L) from introduction of an enteral ketogenic feed.

Inclusion Criteria: Adults who require mechanical ventilation within 72 hours of admission to intensive care Exclusion Criteria: Known intolerance to the ketogenic diet Contraindication to standard protocolised enteral feeding Pregnancy Severe liver disease (known decompensated liver cirrhosis, previous liver transplant, acute hepatitis (bilirubin >100, ALT >500) Severe metabolic acidosis (pH < 7.2, HCO3 < 15mmol/L) that has not been corrected prior to enrolment in the study Patients predicted to stay less than 24 hours on intensive care