Preoperative liquid fasting practices in twelve European countries: A prospective multicentre cohort study (Thirst study)

BACKGROUND: International guidelines recommend preoperative clear liquid fasting for 2 h before anaesthesia. However, excessive fasting times remain widespread, potentially contributing to patient discomfort and adverse clinical outcomes.

OBJECTIVE: To evaluate current preoperative liquid fasting practices among adults undergoing elective procedures across multiple European centres.

DESIGN: Prospective, observational, multicentre study.

SETTING: Forty-six centres in 12 European countries, conducted between November and December 2024.

PATIENTS: A total of 5100 adults undergoing elective surgery or interventional procedures under general anaesthesia, regional anaesthesia or sedation.

MAIN OUTCOME MEASURES: Self-reported duration of preoperative liquid fasting; incidence of prolonged fasting duration (defined as liquid fasting times of more than 4 h). Median [IQR] fasting time was calculated, with subgroup analyses by country and procedure type.

RESULTS: The median [IQR] preoperative liquid fasting time was 12 [10 to 14.6] h. Only 4% of patients consumed clear liquids within 2 to 4 h, and 0.8% within 2 h. Fasting durations were consistently prolonged across most countries and procedures, except for notably shorter times in Albania. Overall, 95% of patients fasted beyond 4 h.

CONCLUSIONS: Excessive preoperative liquid fasting remains highly prevalent across Europe, with poor implementation of established guidelines. These findings underscore the need for educational, institutional, and quality improvement interventions to align clinical practice with evidence-based recommendations and enhance patient-centred care.