Caffeine consumption and withdrawal among patients in the intensive care unit.

BACKGROUND: There is a lack of data surrounding the use of therapeutic caffeine among adults admitted to intensive care units (ICUs). OBJECTIVES: The objective of this study was to determine reported caffeine use and withdrawal symptoms among patients admitted to the ICU to inform future prospective interventional trials. METHODS: This study used a cross-sectional survey design, where a survey was conducted by a registered dietitian among 100 adult patients admitted to an ICU in Brisbane, Australia. RESULTS: The median age of patients was 59.8 y (interquartile range: 44.0-70.0), and 68% were male. Ninety-nine percent of patients had daily consumption of caffeine with a median 338 mg (interquartile range: 162-504). Caffeine consumption was self-reported in 89% of patients and was uncovered by detailed identification in 10%. Almost one-third (29%) reported caffeine withdrawal symptoms while admitted to intensive care. Common withdrawal symptoms reported were headaches, irritability, fatigue, anxiety, and constipation. Eighty-eight percent of patients reported willingness to participate in future studies of therapeutic caffeine if they were admitted to the ICU. Preferred methods of parenteral and enteral routes of administration varied by patient and illness characteristics. CONCLUSIONS: Patients admitted to this ICU were ubiquitous consumers of caffeine before admission, and one-tenth were unaware. Patients viewed trials of therapeutic caffeine as highly acceptable. The results provide important baseline information for future prospective studies.