Delirium is a complication characterized by fluctuations in orientation, memory, thinking, or behavior, with a sudden onset of these changes. Increased mortality and prolonged hospital stay have been identified in patients diagnosed with delirium. Advanced age, underlying urinary or respiratory tract infection, and existing cognitive impairment increase the risk of delirium development. Studies have shown that pharmacological agents are the most significant risk factors for delirium in intensive care units. However, environmental factors such as sound, continuous light, odors, invasive and non-invasive interventions, sensory overload, lack of meaningful verbal and cognitive stimuli, social isolation, immobilization, sleep disorders, temperature, drafts, and absence of windows in the environment are also indicated to contribute to delirium development. The presence of tubes, urinary catheters, invasive procedures, mechanical ventilation, and retention in the patient also increases the risk. In treatment, early detection and prevention of risk factors are prioritized. In case of development, efforts are made to prevent delirium-related complications and reduce its duration through pharmacological and non-pharmacological interventions. However, although many studies have been conducted on the prevention of delirium development with numerous pharmacological agents, a clear conclusion has not yet been reached. Pharmacological agents are generally used to alleviate symptoms. In recent years, the impact of non-pharmacological interventions in preventing delirium development has started to be discussed. Non-pharmacological interventions used in delirium prevention, as published by the National Institute for Health and Care Excellence (NICE), are itemized as pain management, prevention of dehydration, early mobilization, infection control, regulation of medications, sleep hygiene, and patient orientation. NICE also emphasizes the necessity of using a validated tool for assessing delirium.

A meta-analysis study has been published examining non-pharmacological interventions aimed at reducing the incidence of delirium, with a total of 26 studies included. According to this study, the methods that reduce the incidence are, respectively; family involvement, exercise program, multiple interventions (occupational therapy, reorientation, sleep therapy, music, etc.), ensuring cerebral hemodynamics, arranging the physical environment, and applying a sedation protocol. When the studies are examined, it is seen that efforts focus on ensuring sleep hygiene, maintaining patient orientation, and eliminating factors in the physical environment that may disrupt patient comfort. Evidence suggests strategies such as optimizing the environment, controlling light and noise, grouping patient care activities, and taking appropriate measures to preserve patients' sleep cycles to promote sleep regulation in adult ICU patients (Evidence: +1C). In the literature, studies have been conducted on the use of earplugs to protect ICU patients from noise and using eye masks to reduce exposure to light to ensure sleep hygiene. Delirium prevention strategies to be implemented should be compatible with clinical workflow. The method to be used should be easily adapted by all team members and patient relatives, and should be encouraged for use in clinical protocol. Collaboration between physicians, nurses, and patient relatives is essential in preventing delirium development. The pharmacological dimension of preventive interventions can be carried out by physicians, while non-pharmacological interventions can be implemented through collaboration between nurses and patient relatives. In this study, we aimed to determine the effect of guideline usage and team collaboration on the frequency of delirium development.