Preoperative fasting was initiated as a measure to decrease the risk of pulmonary aspiration of gastric contents during induction of anesthesia, with an 8-hour preoperative fasting or ‘Nil-per-Oral (NPO) after midnight’ as an initial recommendation [1]. However, it is now widely known that prolonged fasting negatively contributes to insulin resistance, exacerbates the metabolic response to surgical stress and correlates with increased incidences of adverse effects such as dehydration, nausea, vomiting, hunger, thirst, and anxiety. Several studies and guidelines have noted that preoperative carbohydrate-rich drinks up to 2 hours and restriction of fasting for light solid foods to 6 hours before surgery are associated with decreased insulin resistance in the perioperative period, decreased length of hospital stay, and improvement in perioperative metabolic, cardiac, psychosomatic status of the patient and increased healthcare expenditures [2-5].

In spite of all gathered evidence of the positive impact of modern guidelines which has been widely adopted over nearly two decades, implementation of such in clinical practice remains challenging. Various reasons contribute to this deviation, including scheduling disparities, socioeconomic and cultural factors, logistical challenges, the entrenched practice of midnight fasting, lack of fasting guidelines and professional beliefs that may differ from empirical evidence [6-7].

In this context, the present audit aimed to identify the evident gaps in the implementation of our hospital guidelines for preoperative fasting. The primary objective was to assess the compliance of the hospital NPO fasting guidelines. Secondary objectives were to identify the influence of factors like age, sex, and surgical specialties with fasting status at our institution.

After obtaining approval from the Department Management Board, preoperative fasting status of 109 patients were included in this observational cross sectional audit conducted at Khoula Hospital, in the month of October 2023. All these patients were directly interviewed on the day of their surgery by one of the audit data collectors and details of their Nil-per-oral (NPO) status recorded. Patients of all ages undergoing elective surgical procedures in the main operation theatre, their American Society of Anesthesiologists (ASA) status and nature of surgery and type of anesthesia that included both general and local anesthesia were recorded.

Study design: All 109 patients gave their verbal consent for being included in this audit. They were met on the day of their surgery in the holding area in the main operative theaters, and a questionnaire was filled directly from them or the next of kin if a patient was less than 18 years of age. The questionnaire included: age, weight, gender, surgical specialty, and hours of fasting in total and last clear fluids taken.

Data have been expressed in tables as numbers and percentages.

A cohort of 109 patients were included in our study, 62.4% of which were males and 37.6% females. Mean age and weight of the patients were 36.6 yr and 63.1 kg respectively (Table I). Patient’s ASA grades ranged from I-III. 22.9% of patients had surgeries in the afternoon.

Table 1 showing demographic details of the 109 patients.

All 109 patients underwent operative procedures under various surgical specialties that included orthopedic, plastic, neuro, hand and general surgery. Majority of the patients in this study underwent orthopedic procedures (57/109, 52.3%). Patients were administered either general or local anesthesia with general anesthesia being the predominant procedure (Table II).

Table 2 showing the surgical specialty to which the patient belonged in this audit.

Looking at the duration of fasting, the average was 9.66 hr, taken into account that the majority of the cohort were assigned for operative procedures before 8 AM. Only 26.4% of patients were fasting for the recommended 8-hr period. 50 patients (45.8%) were noted to be fasting between 9-10 hr. Overall, a total of 72.4% of patients exceeded the recommended 6-8 hr preoperative fasting (Table III).

Table 3 shows the number of patients and their fasting duration in hours.

Further data analysis showed that age is the most associated factor with fasting hours, as younger patients fasted for less hours irrespective of type of operation and anesthesia (Graph I). 

Graph I showing fasting hours across age groups

An interesting finding of this audit was that only pediatric patients were drinking clear fluids

up to allowable 2-hr preoperatively. Other demographic factors did not show any significant difference with outcomes.

The primary findings of this audit demonstrated a significant deviation from established preoperative fasting guidelines, with only 26.6% of patients adhering to the recommended 6-8-hour fasting period.

The minimum, maximum, and mean fasting hours in an study by Gebremedhn and Nagaratnam in 2014 were 5, 19, and 12.72, respectively [6]. More than 95 % of their patients fasted from fluid longer than the recommended preoperative fasting times of the ASA [5]. Prolonged fasting hours have also been noted by other studies as well [8,9].

Despite the latest guidelines recommending shorter fasting periods, our audit revealed an average fasting span of 9.8 hours, with 44.9% of participants fasting over 10 hours. This indicates a significant lapse from our hospital’s preoperative fasting guideline that conforms to the ASA standard guideline [5].

We noted that surgeries scheduled in the afternoon were associated with longer fasting times compared to surgical procedures planned for morning surgeries. The age group of 60-80 years exhibited the longest average fasting durations.

Similar findings were reported in the BIGFAST study, encompassing 3715 patients [10], and a study [11], both highlighting prolonged fasting durations despite the adoption of ERAS protocols. The BIGFAST study noted a significant difference in median fasting times between traditional and modern fasting protocols. 

Furthermore, a 2023 update by the American Society of Anesthesiologists endorsed guidelines allowing clear liquids up to 2 hours preoperatively for healthy adults. However, our study and others displayed that even institutions following updated fasting protocols still record average fasting times exceeding recommendations, emphasizing real-world challenges in guideline implementation.

Studies exploring pediatric populations also indicated variations in fasting practices. An update from the European Society of Anaesthesiology recommended reduced fasting durations for clear caloric solutions in pediatric patients, emphasizing positive patient outcomes and the potential role of ultrasound in assessing gastric contents.

In conclusion, despite evolving guidelines advocating for shorter fasting periods, our study alongside similar studies revealed persistent challenges in translating these guidelines into routine practice. Factors contributing to prolonged fasting include afternoon surgeries, unpredictable schedules, patient diversity, and communication gaps among healthcare professionals. Further research is needed to understand the underlying causes of prolonged fasting and to develop strategies for effective guideline adherence.

There is a pressing need for healthcare professionals to enhance their familiarity with contemporary fasting guidelines and prioritize comprehensive education for both patients and the healthcare team. Future research initiatives should focus on developing effective strategies to address prolonged fasting instances.

The authors declare that they have no conflict of interest

No funding sources

The study was approved by the Khoula Hospital Muscat.

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