Comparison of Gastric Volume After 6-hour and 8-hour Fasting in Patient Scheduled for Elective Surgery
Condition: Gastric Volume; Ultrasonography
Study type: Observational

Summary: 
      Preoperative fasting was a common practice to decrease perioperative aspiration risk.
      Duration of fasting was proportional to gastric volume. Short fasting duration may increase
      aspiration risk. However, prolonged perioperative fasting duration may lead to dehydration
      and hypoglycemia.

      The objective of this study was to analyze gastric volume after 6-hour and 8-hour duration of
      fasting after consumption of solid meal on patients scheduled for elective surgery.

      This was a cohort study recruiting 37 subjects from January to February 2019. Subjects were
      patients scheduled for elective non-digestive surgery in Cipto Mangunkusumo Hospital,
      Jakarta, Indonesia. Before fasting, all subjects consumed standard Cipto Mangunkusumo meal
      and was later assessed for gastric volume using ultrasound at 6 and 8 hour after meal was
      consumed.
    

Detailed description: 
      Background. Preoperative fasting was a common practice to decrease perioperative aspiration
      risk. Duration of fasting was proportional to gastric volume. Short fasting duration may
      increase aspiration risk. However, prolonged perioperative fasting duration may lead to
      dehydration and hypoglycemia. The protocols of 8 hours preoperative fasting was recommended
      by American Society of Anesthesiologist (ASA) after a full meal. The meal recognized by ASA
      to make this guidelines were Western diet that contains more fat. South East Asian (SEA)
      standard solid meal mainly contains rice and less protein and fats. We hypothesized 6-hours
      compared with 8-hours fasting was sufficient to provide ideal gastric volume for preoperative
      fasting after SEA standard solid meal. The objective of this study was to analyze gastric
      volume after 6-hour and 8-hour of fasting after consumption of SEA standard solid meal on
      patients scheduled for elective surgery.

      Methods This was a cohort study recruiting 37 subjects from January to February 2019.
      Subjects were patients scheduled for elective non-digestive surgery in Cipto Mangunkusumo
      Hospital, Jakarta, Indonesia. Inclusion criteria were age between 18 to 60 years old, have no
      nutritional status disorder, and ASA physical status of 1 or 2. The exclusion criteria were
      patients with diabetes mellitus, pregnancy, abdominal distention, history of dyspepsia, and
      intestinal motility disturbances.

      Subjects agreed to take part in the research, will be initial examined for obtaining
      demographic data: age, weight and height, type of surgery to be performed, and preoperative
      examinations. The subject will start 8 hours of fasting before the surgical planning time.
      Before fasting, the subjects were given Cipto Mangunkusumo Hospital food standardized
      nutritional levels. Subjects were given 1 hour to consume the food. Six hours after the
      standard meal is consumed, an ultrasound examination will be performed in the right lateral
      decubitus position to obtain ultrasound imaging of the antrum. After that, the subject
      continued fasting until 8 hours after meal and ultrasound examination was performed using the
      same technique to obtain images of ultrasound imaging of the antrum. Imaging pictures are
      taken at the time relaxation of the antrum, between two contractions. The results of this
      imaging are stored and assessments of antrum craniocaudal (CC) and anteroposterior (AP)
      diameters were performed by research assistants who don't know when the image was taken.
      These measurements were used to calculate Cross Sectional Area (CSA) using the formula of
      CSA=(π×CC×AP)/4. The Gastric Volume (GV) was then calculated with the formula
      GV=27.0+(14.6×CSA)-(1.28×age).

      The primary data obtained was the result of repeated examinations. The analysis was adjusted
      using the Bonferonni correction factor. Categorical data was analyzed using the McNemar test.
      The results of data processing are displayed in tabular form. The gastric volume was grouped
      into sufficient and insufficient with a border value of 1.5ml/kg.
    

Intervention name(s): Fasting for elective surgery
Intervention type(s): Behavioral
Intervention description(s): 6-hours and 8-hours fasting before elective surgery
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        This was a cohort study for 37 subjects from January to February 2019. Subjects were
        patients scheduled for elective non-digestive surgery in Cipto Mangunkusumo Hospital
      
Keywords: Gastric volume; preoperative fasting; ultrasonography.