This is an open label randomized controlled trial with two parallel groups to compare the
effects of early initiation of oral diet to reduce the post-operative fasting time in adult
patients undergoing cardiac surgery. Assuming a incidence rate of post-operative nausea and
vomiting of 40% in cardiac surgery (Sawatzky et al., 2014), and an anticipated incidence of
clinically significant PONV using the simplified PONV impact scale of 20% (Myles et al.,
2012), with a presumed 50% risk reduction with early feeding, a power of 80%, and alpha of
0.05, the minimum effective sample size would be 164 subjects (82 per arm). Assuming a drop
out of 20%, the sample size was increased to 196 subjects (98 per arm).
Adult patients' status post-operative cardiac surgery in CTICU of Heart Hospital, after
extubation, meeting inclusion criteria will be included in the study.
They will be divided into early and conventional diet groups. and randomized using web-based
randomization to early diet (intervention arm) versus conventional diet (control arm) in 1:1
ratio. The patients of early group will be examined for water swallowing test (WST) at
bedside after extubation. Before performing the WST, the patient must be evaluated for
readiness including Awake, alert, cooperative, able to follow command, vital signs are
stable, able to maintain at least 75-degree.
in upright position, the patient can cough effectively, the patient can stick out tongue and
move to the left and right, the patient can breathe comfortable.
The patient's mouth will be cleaned, and the patient will be asked to drink each 5 ml of
water (1 teaspoon) 3 times respectively. If the patient shows any abnormal signs, the test
will be discontinued. If all steps are passed, then the patient will continue to drink the
entire 90 ml of water from a cup or with a straw in sequential slowly and steadily swallowing
without stopping (cup or straw can be held by clinician or patient). (Phothikun N, 2022).
If the patient fails in water swallow test, early diet will not be resumed. The finding will
be intimated to the physician in charge of the patient for further management.
For the early group if they pass water swallow test oral diet will be resumed after 2 hours
of extubation with water, followed by clear liquid diet after 4 hours and gradually laddered
to solid diet as patient prefers/tolerates. For the conventional diet group, the existing
standard feeding protocol will be followed, that is patient will be given only sips of water
on the day of surgery and the diet will be resumed on the next day after surgery.
The simplified post-operative nausea -vomiting impact score every 4th hourly for 24 hours,
time of first bowel movement, the length of ICU stays in days and patient satisfaction level
about timing of resuming oral diet using Visual analogue scale at the time of discharge from
hospital (VAS) (Appendix 3) will be collected. Participants will be provided with VAS with a
statement explaining what the scale was intended to measure that is the level of satisfaction
on resuming diet early. Other signs of regaining gut functions like bowel sounds and flatus
is not considered in this study because assessment of bowel sounds is not a reliable sign of
gut function (Deane et.al,2021) and chances for ambiguity are high while the assessment of
bowel sounds. Most of the patients after major surgery with general anaesthesia may not
recognize the first flatus in immediate post-operative period. For the patient who is not
tolerating the oral diet resumption with any signs of aspiration or clinically significant
vomiting or paralytic ileus or patient dissatisfaction with oral diet resumption, early diet
trial will be discontinued and reported accordingly.
The study will be conducted at a single center and the patients will be followed for 5 days
after surgery. The favorable circumstances enhance safety of early resumption of oral diet in
adult cardiac surgery are as follows. The short acting Propofol is used as the major sedation
after surgery to prevent prolonged sedative effect. Multimodal analgesia is used to reduce
the use of narcotics. Patient controlled analgesia of low dose morphine or fentanyl is used
along with intravenous paracetamol and non-pharmacological interventions like massage,
changing positions and early mobilization out of bed. Sedation score is assessed every hour
by the intensive care nurses using Ramsay Sedation scale. All patients are routinely placed
on intravenous metoclopramide injections as prokinetic and antiemetic which may help to
enhance peristalsis. Patients are also given oral mucosal massage with flavored glycerin swab
sticks to enhance their appetite.
All data will be analyzed using SPSS 24.0 statistical package. Descriptive statistics will be
used to describe and compare socio-demographic data on participants between the intervention
and control group. Continuous variables that follow a normal distribution will be expressed
as means and standard deviations, whereas categorical variables will be presented as
frequency counts and percentages. We will estimate simplified PONV (post-operative nausea
vomiting) impact score for early and conventional diet groups. Quantitative data between the
intervention and control groups will be analyzed using unpaired t or Mann Whitney U test as
appropriate. Categorical data will be summarized using frequencies and proportions.
Associations between two or more qualitative data variables will be assessed using Chi-square
(χ2) test or Fisher Exact test as appropriate. Univariate and multiple regression analysis
will be used to control and adjust for potential predictors and confounders such as type of
age, gender, nationality and presence of comorbidities and motion sickness. Generalized
estimating equation will be used to see the change over the post-operative nausea- vomiting
impact score in both the groups over 24 hours. All tests will be two sided and p value
considered <0.05 as significant.
No adverse events are expected in either of the groups. Any accidental adverse event will be
reported immediately to the physician and the details of the event, harm and treatments will
be notified to MRC. And the instructions by MRC will be followed. A record of such events
will be maintained for further reference. This is to state that this study will be conducted
in full conformance with principles of the "Declaration of Helsinki", Good Clinical Practice
(GCP) and within the laws and regulations of MoPH in Qatar. The participants will be able to
withdraw from the study anytime without any liabilities during the research process.