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The nurse alerts you that a gastric aspirate has been obtained in an infant. Gastric aspiration before feeding is a procedure by which the stomach is aspirated with an oral or nasogastric tube. The procedure is usually performed before each feeding to determine whether the feedings are being tolerated and digested. The amount of residual is measured and recorded (gastric residual). Gastric residuals indicate the rapidity of gastric emptying and can be an indicator of feeding intolerance, infection, or other diseases such as bowel obstruction/perforation if the gastric aspirate volume or color is abnormal. Isolated gastric aspirates in very low birthweight infants can reflect delayed gut maturation and motility and may not signify a gastrointestinal (GI) problem, especially if no other warning signs exist.
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II. IMMEDIATE QUESTIONS
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What is the volume of the aspirate? A volume of >20–30% of the total formula given at the last feeding may be abnormal and usually requires evaluation. A gastric aspirate of >10–15 mL is considered excessive. A prefeed gastric aspirate of >20% may predict (with other factors) late-onset sepsis.
What is the color and characteristic of the aspirate (eg, bilious, nonbilious, nonyellow, bloody, yellow aspirate)? This is important in the differential diagnosis (see Section III.A–D). Some neonatal intensive care units (NICUs) are introducing color charts to help identify bilious aspirates.
Are the vital signs normal? Abnormal vital signs may indicate a pathologic process, possibly an intra-abdominal process.
Is the abdomen soft, with good bowel sounds, or distended, with visible bowel loops? Has the abdominal girth increased >2 cm? Absence of bowel sounds, distention, tenderness, and erythema are all abnormal signs and may indicate a pathologic process. Absence of bowel sounds suggests an ileus. An increase in abdominal girth >2 cm is considered abnormal. Palpation of the abdomen may reveal a pyloric “olive” (pyloric stenosis).
When was the last stool passed? Constipation resulting in abdominal distention may cause feeding intolerance and increased gastric aspirates.
What medications is the infant on? Theophylline delays gastric emptying in very low birthweight infants. Cisapride (not available in United States) use increases the daily total gastric aspirate volume. Doxapram can cause gastric residuals.
Is the infant premature? Delayed gastric emptying and feeding intolerance is common in premature infants. They have decreased duodenal motor activity, gastrointestinal dysmotility, and slower intestinal transit time. Feeding intolerance is less common in term infants; therefore, if there is a bilious or bile-stained aspirate, a workup needs to be done.
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III. DIFFERENTIAL DIAGNOSIS
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The characteristics of the aspirate can provide important clinical clues to the cause of the problem and are outlined next. It is important to be able to identify bilious aspirates. A bilious aspirate is an aspirate that is light to dark green but can be bright yellow in the initial phases. Colostrum may appear yellow in color. Remember, overidentification of bilious aspirates can lead ...