Educating the patient is the responsibility of the nursing, which is one of the most important aspects
of patient post cardiac surgery. Fatigue is recognized as one of the most common and distressing
complications post cardiac surgery. Educational guidelines are providing general information about
fatigue and introduce new concepts regarding cardiac surgery, self-care, and confrontation
techniques. The aim was to determine the effect of instructional guidelines on knowledge, practice,
and fatigue level among post-cardiac surgery patients. Subjects and method: Design: A quasi
experimental research design was utilized to fulfill the aim of this study. Setting: the research was
applied in the Cardiothoracic Surgery Department at the Fayoum University Hospital. Subjects: A
purposive sample of 60 adult patients who are undergoing cardiac surgery was included. Four tools
were used: Tool (I) a structured interview questionnaire, Tool (II) patients' knowledge regarding
cardiac surgery, Tool (III) patients' practice regarding cardiac surgery (pre/post), and Tool (IV)
Fatigue assessment scale. Results: The results revealed that there was a positive significant
correlation (P=0.001) between patients' knowledge scores and their practice post-two months of
instructional guidelines implementation. There were highly significant improvements in patients'
knowledge and practice regarding cardiac surgery post instructional guidelines implementation
(P=0.005). Statistical highly significant differences and reduction were detected between fatigue
mean scores post-one-month of instructional guidelines implementation. Conclusion: The
instructional guidelines implementation had a highly significant positive effect on reducing fatigue
levels among patients undergoing cardiac surgery. Recommendations: The instructional guidelines
regarding cardiac surgery should be conducted, discussed, integrated into the rehabilitation
programs, and taught to the patients using the booklet and illustrated pamphlets for each one to
improve their information and reduce their fatigue level and replication of the current study with a
larger sample of patients undergoing cardiac surgery in different settings is required for generalizing
the results.