Aspiration of Gastric Contents, Acute

Key Features

• Pulmonary response depends on the characteristics and amount of gastric contents aspirated

• One of the most common causes of acute respiratory distress syndrome

• May be catastrophic

• Sometimes referred to as Mendelson syndrome

Clinical Findings

• Abrupt onset of respiratory distress, with cough, wheezing, fever, and tachypnea

• Crackles may be audible at the bases of the lungs

• Hypoxemia may be noted immediately after aspiration occurs

• Fever and leukocytosis are common even in the absence of infection

• Patchy alveolar opacities in dependent lung zones, appear within a few hours

• Radiographic features of bronchial obstruction may be observed if particulate food matter has been aspirated along with gastric acid

• Hypotension secondary to alveolar capillary membrane injury and intravascular volume depletion is common

Diagnosis

• The more acidic the material, the greater the degree of chemical pneumonitis

• Aspiration of pure gastric acid (pH < 2.5) causes

  • Extensive desquamation of the bronchial epithelium

  • Bronchiolitis

  • Hemorrhage

  • Pulmonary edema

Treatment

• Supplemental oxygen

• Measures to maintain airway

• Management of acute respiratory failure

• Administration of intravenous fluids or vasopressors or both for hypotension or shock secondary to alveolar capillary membrane injury and intravascular volume depletion

• No evidence supports routine use of corticosteroids or prophylactic antibiotics

• Management of secondary pulmonary infection depends on observed flora of tracheobronchial tree