Background: Nurses work in complex environments with high numbers of alarms, including nuisance alarms 
and other factors. Alarm-related adverse events are common. Aim: Evaluate the effect of implementing safety 
bundle regarding alarm fatigue on nurses‘ perception and practices in cardiac care units. Design: A quasiexperimental design used in this study. Setting: The study carried out at the Cardiac Care Units (CCU) at Tanta 
University Hospital. Subjects and Method: Subjects: All nurses (50) of both sex working at CCU at Tanta 
University Hospital. Tools: Three tools were utilized. Tool I: Critical Care Nurses‘ Questionnaire. Tool II: 
Nurse s‘ Alarm Fatigue Level Questionnaire. Tool III: Nurses‘ Alarm Fatigue Management Observational 
Checklist. Results: There was statistically significant positive correlation between perception of clinical alarms, 
alarm fatigue level and alarm fatigue management pre and post implementation of alarm safety bundle. 
Conclusion: It was concluded that there were statistically significant differences between nurses' perception and 
practices categories indicating good knowledge and practice after the nurses implementing safety bundle 
regarding alarm fatigue, compared with poor perception and practice pre- implementing safety bundle regarding 
alarm fatigue p value (0.005*). Recommendation: It is recommended to develop a standardized tool that 
assesses nurses‘ perception of clinical alarms and alarm management guidelines. In service training 
implementing safety bundle regarding alarm fatigue should be conducted be conducted for nurses regarding 
alarm management and increase nurses‘ awareness of the presence of alarm fatigue. Future study should be 
made to implement fundamental universal alarm management guidelines all across the world.