32: Gastric and Transpyloric Intubation

INTRODUCTION

In gastric intubation, a gastric tube is inserted through the nose (NG) or mouth (OG) to the stomach. In transpyloric intubation, a transpyloric tube is inserted through the nose or mouth through the pylorus into the duodenum or jejunum.

GASTRIC INTUBATION

I. INDICATIONS

1. Enteric feeding in the following situations:

   1. High respiratory rate. Enteric feedings are used at some centers if the respiratory rate is >60 breaths/min to decrease the risk of aspiration pneumonia (controversial).

   2. Neurologic disease. If it impairs the sucking reflex or the infant's ability to feed. An abnormal gag reflex is an indication for a gastric tube.

   3. Premature infants. May have immature sucking and swallow mechanisms that normally develop after 32 weeks. Preemies have immaturity of motor function and tire before they can take in enough calories to maintain growth.

   4. Insufficient oral intake.

2. Gastric decompression. In infants with necrotizing enterocolitis (NEC), bowel obstruction, or ileus.

3. Administration of medications.

4. When a transpyloric tube is placed, a gastric tube is needed to empty gastric contents and administer medications.

5. Analysis of gastric contents.

II. EQUIPMENT

Infant feeding tube (3.5 or 5F if <1000 g or 5–8F if ≥1000 g), for decompression dual-lumen vented Replogle tube (6, 8, 10F) (Note: tubes come with and without stylets), stethoscope, sterile water (to lubricate the tube), syringes (10–20 mL), 1/2-inch adhesive tape, benzoin, gloves, suctioning equipment, cardiac monitor, stethoscope, pH paper, and bag-and-mask ventilation with 100% oxygen (in case of emergency). Recommended: colorimetric device (eg, CO2nfirm Now CO₂ detector [Covidian, Mansfield, MA] or capnograph) to help confirm the position of the tube by absence of CO₂ within the tube.

III. PROCEDURE

1. Monitor heart rate and respiratory function throughout the procedure. Place the infant in the supine position, with the head of the bed elevated. The infant can be swaddled to provide comfort.

2. There are 4 methods of estimating gastric tube insertion length:

   1. OG tube insertion. Table 32–1 provides OG guidelines for very low birthweight infants <1500 g.

   2. Age-related/height-based (ARHB) method

      1. Less than 1 month of age: NG only

         1. NG tube insertion length (cm) = 1.950 cm + 0.372 × (infant's length in centimeters)

      2. Greater than 1 month of age (if greater than 44.5 cm in length)

         1. OG tube insertion distance = 13.3 cm + 0.19 × (infant's length in centimeters)

         2. NG tube insertion distance =14.8 cm + 0.19 × (infant's length in centimeters)

   3. NEMU (nose/ear/mid-umbilicus) for NG/OG tubes. Measure the distance from the tip of the nose to the bottom of the ear (earlobe) to the midpoint between the xiphoid and the umbilicus. This measurement proved to be the most accurate in one study.

   4. NEX (nose/ear/xiphoid). Distance from the tip of the nose to the bottom of the ear to the xiphoid (controversial). This technique gave an insertion distance ...