Types of feeding tubes
After deciding to feed a patient enterally and determining the anticipated duration of enteral support, the next decision is to determine the most appropriate location of feeding delivery: into the stomach or the small bowel. Gastric feeding is advantageous most commonly because of its increased capacity, allowing for larger volumes to be delivered over shorter durations. However, in the setting of postsurgical anatomy, gastroparesis, or obstructing tumors/pancreatic inflammation, distal delivery of tube feeds may be required into the jejunum. Additionally, percutaneous tubes placed into the stomach can have extenders into the small bowel (GJ tubes) to allow for feeding into the small bowel and decompression or delivery of medications into the stomach.
Dr. John C. Fang
In general, gastric feeding is preferred over small bowel feeding as PEG tubes are more stable and have fewer complications than either PEG-J or direct PEJ tubes. Gastrostomy tubes are generally shorter and larger in diameter making them less likely to clog. PEG-J tubes have separate lumens for gastric and small intestinal access, but the smaller-bore jejunal extension tubes are more likely to clog or become dislodged. While direct PEJ is shown to have higher rates of tube patency and decreased rates of endoscopic re-intervention, compared with PEG-J,7 one limitation of a direct PEJ is difficulty in placement and site selection, which can be performed with a pediatric colonoscope or balloon enteroscopy system. Most commonly, this procedure is performed under general anesthesia.
In the case of a critically ill patient in the ICU, it is recommended to start enteral nutrition within 24-48 hours of arrival to avoid complications of prolonged calorie deficits. Nasally inserted feeding tubes (e.g., Cortrak, Avanos Medical Devices, Alpharetta, Ga.) are most commonly used at the bedside and can be placed blindly using electromagnetic image guidance, radiographically, or endoscopy. However, the small caliber of nasoenteric tubes comes with the common complication of clogging, which can be overcome with slightly larger bore gastric feeding tubes. If gastric feeding is not tolerated (e.g., in the case of vomiting, witnessed aspiration), small bowel feeding should be initiated and can be a more durable form of enteral feeding with fewer interruptions as feedings do not need to be held for procedures or symptomatic gastric intolerance. In clinical areas of question, or if there is a concern for intolerance of enteral feeding, a short trial with nasogastric or nasojejunal tube placement should be performed before a more definitive percutaneous placement.
With respect to percutaneous tubes, important characteristics to choose are the size (diameter in French units), type of internal retention device, and external appearance of the tube (standard or low profile). All percutaneous tubes contain an external retention device (i.e., bumper) that fits against the skin and an internal retention device that is either a balloon or plastic dome or funnel that prevents the tube from becoming dislodged. Balloon retention tubes require replacement every 3-6 months, while nonballoon tubes generally require replacement annually in order to prevent the plastic from cracking, which can make removal complicated. Low-profile tubes have an external cap, which, when opened, allows for extension tubing to be securely attached while in use and detached while not in use. Low-profile tubes are often preferred among younger, active patients and those with adequate dexterity to allow for attachment of the external extension tubing. These tubes are most often inserted as a replacement for an initially endoscopically placed tube, although one-step systems for initial placement are available. The size of the low-profile tube is chosen based on the size of the existing PEG tube and by measuring the length of the stoma tract using specialized measuring devices.8 Patients and caregivers can also be trained to replace balloon-type tubes on their own to limit complications of displaced or cracked tubes. Low-profile tubes are commercially available for both gastric placement and gastric placement with extension into the small bowel, which often requires fluoroscopy for secure placement.
All percutaneous enteral tubes are being transitioned to the ENfit connector system, which prevents connections from the enteral system to nonenteral systems (namely intravenous lines, chest tubes) and vice versa. Tubing misconnections have been rarely reported, and the EnFIT system is designed to prevent such misadventures that have resulted in serious complications and even mortality.9 Adapter devices are available that may be required for patients with feeding tubes who have not been transitioned yet. Most commonly with new tube placements and replacements, patients and providers will have to become familiar with the new syringes and feeding bags required with EnFIT connectors.
Gastrostomy placement can be considered a higher-risk endoscopic procedure. One complicating factor is the increased use of antiplatelet and anticoagulant therapies in individuals with a history of neurologic insults. The American Society for Gastrointestinal Endoscopy (ASGE) guidelines recommend that coumadin be held 5 days before the procedure and bridged with heparin if the patient is at high risk of thromboembolic complications. For patients on dual anti-platelet therapy, thienopyridines like clopidogrel are often stopped 5-7 days prior to procedure with continuation of aspirin,10 but there are more recent data that PEG insertion is safe with continued use of DAPT.11 Direct-acting anticoagulants (DOACs) are often stopped 24-48 hours prior to procedure and then restarted 48 hours after tube placement, but this is dependent on the half-life of the specific DOAC and the patient’s renal function. Patients with decreased creatinine clearance may need to hold the DOAC up to 3-4 days prior to the procedure. In this situation, referring to ASGE guidelines and consultation with a hematologist or managing anti-coagulation clinic is advised.10
