Feed and Stop after Twenty hours for Four hours –

INTERVENTION: Intervention group (20 hour protocol) participants will receive prescribed amounts of enteral nutrition following a revised protocol that includes compensatory increase in feeding rates over a set period of 20 hours a day and then fasted for a set period of 4‐hours each day. The prescribed amount given is based on the individual's nutritional assessment and estimation of of the energy and protein requirements . These requirements are calculated using predictive equations as is the common practice by dietitians The overall duration is a maximum of 12 days or till patient is discharged from the ICU whichever is sooner. The 20 hour feeding protocol (Intervention group) involves running the prescribed amount for each patient as a continuous infusion for 20 hours per day followed by 4 hours of fasting Example : If a patient's requirements are 1800 calories and the amount prescribed is 1800 ml formula over 24 hours , the infusion will run at a rate of 90 ml /hour (90 ml x 20 = 1800 ml per day) CONDITION: Critically ill, mechanically ventilated patients PRIMARY OUTCOME: Acceptability and safety of the revised feeding protocol ; Staff satisfaction survey ; A questionnaire will be distributed to the nurses, doctors and dietitians The secondary outcome of this pilot study is the feasibility of the new feeding protocol as judged by a questionnaire that evaluates their opinion of its safety and acceptability. The acceptability of each the novel parts of the feeding protocol and the overall protocol uses a scale where 1 = totally unacceptable and 10 = totally acceptable. This evaluation questionnaire will be administered to all bedside nurse involved in caring for study patients at the end of each nursing shift during the study period and to all medical staff. A minmum of 50 % response rate is anticipated. ; ; Safety endpoints that will be measured are 1. Episodes of reflux, regurgitation or vomiting documented on nursing charts Frequency of diarrhoea (Stools > 300ml liquid per 24 hours), Episodes of high gastric residual volumes ( > 250 ml per 4 hours Ventilator associated pneumonia documented by medical staff, patient positioning daily: measured by researcher daily on rounds, ; Management of risk factors or events ; ; All critically ill patients are at risk of developing the above signs and symptoms while on Enteral Nutrition . ICU Standard protocols are followed to manage these conditions for ALL patients. The same protocols will be followed for the study patients. ; SECONDARY OUTCOME: Clinical indicator( Length of ICU stay , length of mechanical ventilation , discharge status from ICU, length of hospital stay, discharge status from hospital,60‐day mortality, ) Nutritional indicator:( Body Mass Index Subjective Global Assessment ) Participants will undergo: Quality of Life assessment with a validated EuorQol 5D (EQ5D) The EQ‐5D is a global quality‐of‐life questionnaire that assesses five domains: mobility, self‐care, usual activities, pain/discomfort and anxiety/depression. Each dimension has three levels of severity; no problem to severe problems. The second part of the EQ‐5D consists of a vertical visual analogue scale (VAS), where 0 represents the worst imaginable health status and 100 represents the best imaginable health status. ; In addition, two physicians independently will review the charts of all enrolled patients to determine whether episodes of vomiting, regurgitation, macroaspiration (visually noted gastric secretions when suctioning the endotracheal tube), and ventilator‐associated pneumonia had occurred. Pneumonia is defined using a definition and process that is standard practice for the ICU doctors .This would determine if there were any undetected serious adverse events related to the nutritional management of the patient and whether the prescription hourly target rates was appropriate and this will be checked off on the data forms. At the discretion of the two physicians and /or the medical team the patient may be discontinued from the study Adequacy of enteral nutrition (Amount of calories and protein received by patients versus amounts prescribed per day by the dietitian), received from enteral nutrition over the first 12 ICU days (or lesser if length of stay <12 days) INCLUSION CRITERIA: Adult patients (>18 years), expected length of stay (LOS) > 72 hrs; mechanically ventilated within 48 hours of admission to the ICU and indicated for enteral nutrition (presence and accessibility of functioning gut and inability to use the oral route for nutrition)