This is a single-center retrospective observational study. The study aimed to look at the enteral feed interruptions in patients who were intubated and ventilated in an oncology intensive care unit. We collected data of the first 60 interruptions in the adult Oncology ICU from 12/12/2022 to 15/10/2023. We only included intubated and ventilated adult patients more than 18 years of age who had nasogastric tube feeding commenced. The data was collected from the electronic patient records. Data collected included demographics, total interruption time per episode of interruption, the reason for the delay, whether the delay could have been avoided, total calories lost, and percentage of calories lost.

Introduction Intensive Care Unit (ICU) patients are often intubated and ventilated. These patients cannot feed themselves orally, so enteral or parenteral nutrition becomes important. Various studies have suggested that meeting their nutritional demand is associated with their short and long-term outcomes. There is also ample evidence that in general ICU's, patients often do not meet their nutritional demands. (1,2) The ICU may often differ in the nature of the patients catered for and also may have very different systems of delivering healthcare provisions. This could have an impact on the patient care provided.

There are several studies suggesting that EN interruptions happen frequently in the ICU. (3,4,5) It is estimated that the EN interruption occurs in more than 85% of the patients for an average of 8-20% of the infusion time. Out of this, it is thought that 23% are avoidable in planned procedures and 65% on all occasions. (6) There is very little data on the duration of the interruptions and those associated with diagnostic procedures.

In this single-centre study, we aim to understand the prevalence of instances of missed feeding within an oncology-focused ICU in intubated patients. We looked at the reason for the delay and estimated the calorie deficit, the duration of the delay and the proportion of patients who met at least 60% of the calorie requirement. This is an important step in developing a feeding protocol to minimize such instances.

Methods This study included all intubated patients admitted to the Intensive Care Unit at the King Faisal Specialist Hospital and Research Centre from December 2022 to November 2023. The inclusion criteria were defined as adult patients above the age of 18 who were intubated and ventilated and started on enteral feeding via nasogastric tube. All patients who were not intubated and under 18 years of age were excluded.

Data will be collected from the electronic patient records. The data collected will be demographics, diagnosis, time the feed was started and stopped, delay in restarting the feed, estimated daily calorie requirement, and calorie deficit. The daily calorie requirement will be estimated using the quick calorie method using kilocalories per kilogram Table1. To estimate the actual calorie intake of the patient, the enteral feeding flowsheet of each patient was monitored, and the total intake will be calculated (mL/hr) for the whole day and based on the type of feed (High calorie, standard etc) it will be multiplied to the total intake to get the actual calorie intake.

Energy requirements Based on Kilocalories per kilogram of body weight condition Energy requirement (kcal/kg) Normal 25-30 (kcal/kg) Obese, critically ill, (BMI>30) 11-14 (actual body weight) or 22-25 (ideal body weight) Mild stress 30-35 (kcal/kg) Moderate to severe 35-45 (kcal/kg)

Table1. The formula used for estimating calorie requirement. The calorie deficit was calculated from this. The percentage of lost calories will be tabulated, and the number of instances where patients received >60% or <60% of the daily requirement will be computed.

The local Research Ethics Committee approved the study. As the study was a non-interventional observational study, a consent waiver was requested and was approved by the ethics committee.

Statistical analysis Demographics will be analyzed for the frequency of distribution. The incidence of feed interruption will be calculated and expressed as median, mean and percentage. The proportion of lost calories and calorie deficit will be calculated in numbers and percentages. The commonest reason for delay, avoidable and unavoidable reasons for feed interruption and the proportion of patients who missed more than 60% of the estimated daily requirement will be estimated using frequencies. Spearmen's correlation rank test will be used to examine the relation between the delay in restarting feed and the lost calories.

Inclusion Criteria:

- Adult patients above the age of 18 who were intubated and ventilated and started on enteral feeding via nasogastric tube

Exclusion Criteria:

• Patients less than the age of 18
• Patients not intubated and ventilated
• Patients not critically ill

-All adult patients who were intubated and ventilated in an adult oncology ICU

As of now there is no ethical approval and reason to share individual patient details. However, the team will be able to share anonymized dataset if deemed necessary