What adverse effects can increased gastric air cause?

Adverse Effects of Increased Gastric Air

Increased gastric air can cause multiple adverse effects including gastroesophageal reflux, regurgitation, aspiration, impaired ventilation, abdominal distention, bloating, and in severe cases, decreased mesenteric blood flow and abdominal compartment syndrome. 1

Respiratory Complications

• Impaired Ventilation: Excessive gastric air can interfere with effective ventilation by pushing against the diaphragm, reducing lung capacity 1
• Aspiration Risk: Gastric air increases the risk of regurgitation and aspiration of stomach contents, which can lead to aspiration pneumonia 1
• Increased Airway Pressure: During mechanical ventilation, gastric distention can increase airway pressures and decrease compliance 1

Gastrointestinal Complications

• Belching and Eructation: The most common manifestation of increased gastric air, occurring as a physiological response to vent excessive air 1, 2
• Gastroesophageal Reflux: Gastric distention can promote reflux of gastric contents into the esophagus 1
• Bloating and Abdominal Distention: Excessive air can cause uncomfortable abdominal distention and bloating 1, 3
• Impaired Gastric Motility: Both respiratory and metabolic acidosis associated with gastric air have been linked to impaired gastric motility 1

Circulatory Complications

• Decreased Gastric Blood Flow: Hyperchloremic acidosis resulting from fluid management in patients with gastric distention has been shown to reduce gastric blood flow and decrease gastric intramucosal pH 1
• Splanchnic Edema: In severe cases, fluid overload combined with gastric distention can cause splanchnic edema 1
• Decreased Mesenteric Blood Flow: Significant gastric and intestinal distention can lead to decreased mesenteric blood flow 1

Severe Complications

• Abdominal Compartment Syndrome: In extreme cases, severe gastric distention combined with fluid overload can contribute to increased abdominal pressure and even abdominal compartment syndrome 1
• Intestinal Failure: Prolonged gastric distention can increase gut permeability and potentially lead to intestinal failure 1
• Anastomotic Dehiscence: In post-surgical patients, gastric distention can increase pressure on surgical anastomoses, potentially leading to dehiscence 1
• Gastric Pneumatosis: Though rare, severe vomiting with increased gastric pressure can lead to air within the stomach wall (gastric pneumatosis) 4

Populations at Increased Risk

• Patients Receiving Mechanical Ventilation: Particularly vulnerable to gastric inflation during bag-mask ventilation 1
• Post-surgical Patients: At risk for impaired gastrointestinal function and ileus 1
• Patients with Functional GI Disorders: More susceptible to symptoms from even normal amounts of gastric air due to visceral hypersensitivity 1, 5

Prevention Strategies

• During Mechanical Ventilation:

  • Avoid excessive peak inspiratory pressures by ventilating slowly
  • Give only enough tidal volume to achieve visible chest rise
  • Consider applying cricoid pressure in unresponsive patients
  • Pass a nasogastric or orogastric tube to relieve gastric inflation when necessary 1

• In General Medical Care:

  • Avoid carbonated beverages and drinking through straws
  • Consider low-FODMAP diet for patients with persistent symptoms
  • Implement behavioral therapies for those with aerophagia 3, 6

Treatment Approaches

• Decompression: Nasogastric tube placement for acute gastric distention 1
• Behavioral Therapy: For chronic belching due to aerophagia, open-mouth diaphragmatic breathing techniques and minimized swallowing can be effective 6
• Dietary Modifications: Low-flatulogenic diet for patients with excessive gas 7
• Pharmacological Options: Simethicone can reduce gas bubbles and provide relief from pressure and bloating 3

Understanding the source of increased gastric air (whether from aerophagia, supragastric belching, or other causes) is crucial for effective management and prevention of these adverse effects.