A 2016 guideline presented evidence-based recommendations for nutrition therapy in hospitalized adults, including the management of complications associated with enteral feeding. Specifically, for the management of a clogged enteral tube, the guideline recommended an initial attempt to declog the tube by instilling warm water via syringe with agitated back-and-forth motion. In cases where this is unsuccessful, the guideline suggested crushing a nonenteric-coated pancreatic enzyme tablet (e.g., Viokase) and a 650 mg sodium bicarbonate tablet together in warm water. This mixture should then be instilled into the g-tube using a similar agitated motion with a syringe. The guideline further noted that the use of a carbonated soft drink represents an acceptable alternative approach. [1]
A 2011 review described appropriate methods for dissolving pancreatic enzyme preparations for administration via enteral tube feed. Recommendations for preparation solely focused on use of enteric-coated microspheres. When pancreatic enzymes are to be given into a gastrically placed enteral feeding tube, the microspheres should be left whole so that the enteric coating can protect the enzyme activity from gastric acid. Giving the microspheres as a slurry in water, however, allows them to clump in the feeding tube, causing a blockage. Clumping may be avoided using a mildly thickened or “nectar”-consistency fruit juice as it can help maintain the enteric coating and keep the microspheres suspended. Adequate flushing with water, before and after administration, is necessary to prevent interaction with the acidic juice and the feed formula. Of note, Viokase is only available as a non-enteric coated tablet formulation. Thus, it is unknown if these same preparation/administration techniques can be utilized for Viokase for enzyme supplementation. [2]
Additionally, a 2015 study evaluated the administration of pancreatic enzyme preparations in bicarbonate solution via enteral feeding tubes. Four delayed-release pancrelipase products were evaluated (Creon, Pancreaze, Ultresa, and Zenpep). Each of these formulations are available in capsules that contain multiple enteric coated granules. The intact contents of each dose of pancrelipase product was added to 20 mL of 8.4% sodium bicarbonate injection in a 50-mL polypropylene conical tube. Only one dose of Creon completely dissolved in sodium bicarbonate at 30 minutes (24,000 lipase units). No doses of Pancreaze and only the lowest dose of Ultresa (23,000 lipase units) were completely dissolved at 30 minutes. Zenpep doses of 20,000 and 40,000 lipase units were completely dissolved in 30 minutes. The baseline pH of the solvent decreased slightly once pancrelipase was added, but returned towards baseline after granule dissolution. Relative particle count increased over time and with increasing doses. Osmolality varied across pancrelipase products and times. As this study was primarily a stability study, it did not evaluate the effects on the patient following enteral tube administration. Results of this study are likely not generalizable to Viokace dissolved in sodium bicarbonate, as Viokace is in the form of a tablet, and the preparations evaluated within this study are in the form of delayed-release enteric coated granules. [3]
Viokace is considered the best choice of pancrelipase to use for clogged feeding tubes, as other preparations (i.e., Creon, Zenpep) are enteric-coated. To unclog with Viokace, the authors recommend crushing one tablet and dissolve with one non-enteric-coated tablet of sodium bicarbonate (324 mg) or ⅛ teaspoon of baking soda in 5 mL of water. The sodium bicarbonate creates an alkaline pH for clog dissolving. Allow this enzyme solution to soak in the tube before flushing with 30-60 mL of water. [4]
The use of Viokase tablets combined with sodium bicarbonate was a previously effective protocol for declogging feeding tubes, showing a high efficacy rate of 71.9% in a clinical trial. This method involved crushing a Viokase tablet with a sodium bicarbonate tablet, dissolving them in warm water, and instilling the solution into occluded tubes. The effectiveness increased to a remarkable 95.8% when excluding clogs unrelated to the feeding formula, such as mechanical issues. However, Viokase was removed from the US market in 2010 due to its status as an unapproved drug, leading to changes in clinical practice. Subsequent to the removal of Viokase, the protocol was adapted to use Creon delayed-release capsules, despite limited published efficacy data. Creon, which contains pancreatic enzymes in enteric-coated beads designed for delayed release, was combined with a higher dose of sodium bicarbonate in attempts to clear feeding tube obstructions. However, in a 2014 retrospective study, the modified protocol using Creon demonstrated significantly lower success, with only 48.2% of tubes being cleared. Despite its efficacy, the clearance rate observed was substantially lower than the 95.8% success rate previously documented using an alkalinized Viokase-based protocol. This is notably less effective compared to the previous Viokase-based method. [5]
A 2021 retrospective, quality assurance study compared a Viokace-based alkalinized pancreatic enzyme protocol to a Creon-based alkalinized solution using historical data (Table 1). The Viokace protocol successfully cleared 176 of the 277 (63.5%) occluded enteral feeding tubes, which appeared to have a significantly higher success rate than the previous protocol using Creon delayed-release pancreatic enzyme capsules (p= 0.0056); however, interpretations from indirect comparison must be made cautiously. Therefore, while the Viokase and bicarbonate combination was once recommended, the change to Creon has not retained the same level of effectiveness, highlighting a gap in highly effective options for declogging feeding tubes. [5], [6]