A Percutaneous Endoscopic Gastrostomy (PEG) tube is a feeding tube inserted through the skin directly into the stomach. This medical device provides nutrition, fluids, and medications to individuals who cannot safely swallow or consume enough food by mouth. The tube creates an opening, often called a stoma, allowing direct access to the stomach while bypassing the mouth and esophagus. Digestion and absorption processes continue normally within the gastrointestinal tract, similar to consuming food orally.
What is Gastric Residual Volume?
Gastric residual volume (GRV) refers to the amount of liquid remaining in the stomach after enteral feeding has been administered. This liquid consists of the nutritional formula, water, and gastric juices. Healthcare providers check GRV to assess stomach emptying, monitor feeding tolerance, and help prevent complications like aspiration. The procedure involves attaching a syringe to the PEG tube and gently withdrawing stomach contents. This measurement is a routine part of PEG tube care.
Recognizing Excessive Residual Volume
Determining an “excessive” gastric residual volume varies, as there is no single universal threshold; clinical judgment guides decisions. Historically, guidelines for holding tube feedings ranged from 100 mL to 500 mL, with some older practices suggesting holding feeds for GRVs as low as 30 mL. Current recommendations from organizations like ASPEN suggest enteral nutrition should not be stopped for GRVs less than 500 mL if there are no other signs of feeding intolerance. Some institutions may use a lower threshold, such as 200-250 mL.
High GRV is a concern because it suggests delayed gastric emptying, increasing the risk of complications. When the stomach retains a large volume of fluid, there is a greater potential for regurgitation and vomiting. If stomach contents are inhaled into the lungs, it can lead to aspiration pneumonia, a complication. Signs of feeding intolerance that accompany elevated GRV, such as abdominal distension, nausea, or discomfort, are important indicators.
Common Causes of Elevated Residuals
Several factors can contribute to an elevated gastric residual volume, indicating slower stomach emptying. Administering tube feedings too rapidly can overwhelm the stomach’s capacity to empty, leading to a buildup of fluid. Certain medications are also known to slow gastric motility, including opioid analgesics and anticholinergic agents. Some diabetic medications can also delay gastric emptying.
Underlying medical conditions play a role in delayed gastric emptying. Conditions such as gastroparesis, poorly controlled diabetes mellitus, or critical illness can impair the stomach’s ability to move contents into the small intestine. Electrolyte imbalances, recent stomach or intestinal surgery, and the patient’s position during feeding can influence stomach emptying and contribute to higher residual volumes.
Managing High Gastric Residuals
When an excessive gastric residual volume is identified, immediate steps include pausing or slowing the feeding. After a short period, the residual volume should be re-checked to see if it has decreased. Most or all of the aspirated fluid should be returned to the stomach, as it contains important electrolytes and nutrients. If high residuals persist or are accompanied by signs of distress like nausea, vomiting, abdominal distension, coughing, or fever, contacting a healthcare professional is necessary.
A healthcare provider may adjust management for persistent high gastric residuals. These adjustments may include changing the feeding formula, adjusting the feeding rate or schedule, or modifying medications that could be contributing to slow gastric emptying. Prokinetic medications may be prescribed to stimulate gastric motility and accelerate stomach emptying. Further diagnostic evaluation may also be pursued to identify underlying causes of delayed gastric emptying.