BackgroundMultiple guidelines recommend that families be involved in the care of ICU patients, which has been widely used in ICU delirium management in recent years. Postoperative delirium (POD) occurs frequently after cardiac surgery and is associated with poor outcomes; however, the effects of family intervention on this group are rarely studied. ObjectivesThis study aimed to investigate the effects of family intervention on the incidence of POD and the ICU prognoses of patients undergoing cardiac valve surgery. MethodsThis was a two-group, single-blind, randomized controlled trial involving 80 patients undergoing cardiac valve surgery, with 40 patients in each group. The control group received routine ICU visits, and the experimental group implemented a family intervention that instructed family caregivers to participate in delirium management during ICU visits. The occurrence of POD, ICU stay, mechanical ventilation time of patients; as well as the anxiety, depression, and satisfaction levels of family caregivers were compared between the two groups. ResultsThe incidence of POD and ICU stay of patients were significantly lower in the experimental group compared to the control group (P < 0.05). The anxiety and depression incidence of family caregivers in the experimental group was lower than those of the control group (P < 0.05), and satisfaction scores were higher than those of the control group (P < 0.05). ConclusionsFamily intervention has the potential to reduce the incidence of POD in patients undergoing cardiac valve surgery, shorten ICU stays, reduce the incidence of anxiety and depression in family caregivers, and improve their satisfaction. These findings suggest that family intervention could be incorporated into routine nursing practice.