Residual Gastric Volume After the Ingestion of Supplements Containing Carbohydrates and Whey Protein
Condition: Fasting; Gastric Stasis; Perioperative Complication; Safety Issues
MeSH terms: Gastroparesis
Study type: Interventional

Summary: 
      Oral supplements (OS) containing carbohydrates are being used 2h before anesthesia. The
      addition of a nitrogen source would improve these drinks designed for the abbreviation of
      preoperative fasting. The gastric emptying of an oral supplement containing whey protein in
      addition to carbohydrates was investigated. This is a randomized crossover study including
      six healthy young volunteers who were submitted to abdominal MRI in 3 phases: 1) after a
      overnight fast, 2) after drank 200 mL of an OS containing whey protein and carbohydrates (no
      lipids), and 3) 3h after ingestion of the mentioned OS. The gastric residual volume (GRV)
      will be evaluate by MRI. The overall findings would allow us to conclude whether the GRV,
      assessed by MRI, in healthy young volunteers after three hours of the ingestion of 200 ml of
      an oral supplement containing carbohydrates associated with whey proteins is similar to the
      GRV found after an overnight fast. This pilot study will add important information to allow
      future randomized trials including an arm with patients undergoing elective surgical
      procedures with a 3h fasting after the ingestion of an OS containing whey protein and
      carbohydrates.
    

Detailed description: 
      One of most important prescription of enhanced recovery after surgery protocols is the
      reduction of preoperative fasting time in opposition to the traditional recommendation of
      overnight fast. This changing from prolonged fast to only 2-3h after the ingestion of 200-400
      mL of carbohydrate (CHO)-enriched drinks in not only safe but recommended by various
      societies of anesthesia and nutrition. A long list of beneficial effects associated with the
      abbreviation of the preoperative fasting time with CHO beverages is reported ranging from
      alleviation of thirst, hunger and stress of the patient to metabolic benefits such as the
      improvement of insulin resistance. However, new formulas for preoperative beverages continue
      to evolve during the last years aiming to achieve better results. The addition of glutamine,
      anti-oxidants e recently whey protein to CHO-enriched formula has been tested and associated
      with a better reduction of insulin resistance, decrease of acute phase inflammatory response,
      and increasing production of glutathione. The effect of whey protein-enriched preoperative
      drinks on the postoperative functional capacity of patients are awaited. Nevertheless, only a
      few studies have tested the gastric emptying of drinks containing whey protein in addition to
      CHO Thus, the aim of this study is to investigate in healthy volunteers the gastric residual
      volume (GRV) 3h after ingesting a formula containing CHO and whey protein.

      Methods This is an experimental pilot crossover clinical trial design.The data will be
      collected in three phases. Firstly, after a fasting period of eight hours, the participants
      attended the Radiology Service of the Hospital de Cancer, Cuiaba, Brazil to perform MRI
      images of the upper abdomen with the objective of measuring the fasting GRV (phase 1). In
      this phase, adequate stomach motility will be observed to exclude cases of possible
      gastroparesis that could interfere with gastric emptying and expected results. GRV (cmˆ3)
      will be measured in the fasting state as explained below. In phase 2, each participant while
      still inside the MRI exam room will ingest 200mL of the study drink described below. The
      individual will be immediately positioned in the supine position and another MRI scan will be
      carried out. In this second phase, GRV will be evaluated by tracking the same region of
      interest (ROI) in each slice, forming a volume by the sum of all ROIs. Finally, in phase 3 a
      third MRI scan of the upper abdomen to measure again the GRV as previously described will be
      done after a 3-hour pause.

      Intervention oral supplement The oral supplement used as intervention for the study will be
      Nutren Fresh (Nestle, São Paulo, Brazil). This oral non-residual supplement (clear fluid) has
      100% whey protein isolated from total proteins, with various vitamins (B1, B6, C, D, niacin
      and folic acid) with "lemon tea" flavor. In addition, the formula contains no lactose or
      lipids; is formulated with a volume of 200ml, with a caloric density of 1.28kcal/ml; protein:
      10g in 200ml of product (100% whey protein isolate); and carbohydrate: 54g in 200ml of
      product (74% glucose syrup and 26% maltodextrin).

      MRI Protocol All exams will be performed using the same MRI equipment which was a Magnetom
      Essenza 1.5T device; Siemens Healthcare, Brazil. Each volunteer will be placed in a supine
      position, with a body coil (Body Matrix) to capture the signal. Cross-sectional acquisitions
      with 40 slices (perpendicular to the longitudinal axis of the body) were performed in HASTE
      (echo-planar fast spin echo) sequences with a slice width of 4.0 mm at 3.0 mm intervals. This
      STEM sequence (TR [repetition time] 774 msec, TE [echo time] 92 msec) visualizes fluids with
      hypersignal as opposed to low signal from adjacent organs. Each acquisition of a set of
      images was performed during 15 seconds of apnea. The images will be captured by an industry
      technician with MRI experience and reviewed by a radiologist to confirm that the images
      covered the entire stomach. The GRV will be assessed by tracking the region of interest (ROI)
      in each slice, forming a volume by the sum of all ROIs. GRV measurements in cmˆ3 will be
      performed manually by tracing regions of interest on each slice using Osirix MD ANVISA
      v.12.0.3 software and summing the slices to determine total gastric volume and the results
      entered into an ExcelR data sheet for statistical analysis.
    

Intervention name(s): Gastric emptying after an oral supplement containing carbohydrates and whey protein; Overnight Fast
Intervention type(s): Dietary Supplement; Dietary Supplement
Intervention description(s): Ingestion of an oral supplement containing carbohydrates and whey protein; Residual Gastric Volume assessed by MRI after overnight fast (8h)
Allocation: Non-Randomized
Intervention model: Crossover Assignment
Intervention model description: The data will be collected in three phases. Firstly, after a fasting period of eight hours, the participants will attend the Radiology Service of the Hospital de Cancer, Cuiaba, Brazil to perform MRI images of the upper abdomen with the objective of measuring the fasting GRV (phase 1). In this phase, adequate stomach motility will be observed to exclude cases of possible gastroparesis. GRV (cmˆ3) will be measured in the fasting state by MRI tracking the region of interest (ROI) in each slice, forming a volume by the sum of all ROIs. In phase 2, each participant while still inside the MRI exam room will ingest 200 mL of the study drink described below. The individual will be immediately positioned in the supine position and another MRI scan will be carried out. Finally, phase 3 will be performed after a 3-hour pause and a third MRI scan will be done to measure again the GRV.
Masking: Double (Investigator, Outcomes Assessor)
Primary purpose: Other
Keywords: Preoperative care; Preoperative fasting; Whey protein; Gastric residual volume; Oral nutritional supplement