Which finding in a client receiving enteral feedings via nasogastric tube indicates possible aspiration?

Aspiration is a major risk of enteral feeding. Signs of aspiration: new-onset cough during or after feeding; increased respiratory rate; decreased oxygen saturation; fever (often delayed); abnormal lung sounds (crackles, decreased breath sounds, especially in dependent areas); change in mental status. Prevention strategies: (1) Verify tube placement before each feeding (radiographic confirmation initially, then mark position and check for migration; pH testing of aspirate is also used — gastric pH should be acidic, less than 5); (2) Keep the head of bed elevated at least 30-45 degrees during feeding and for 30-60 minutes after; (3) Check residual volume per facility policy (typically before each intermittent feeding or every 4 hours for continuous feedings); withhold and notify provider if high residuals (definitions vary, often >250 mL or per provider order); (4) Use small bowel placement (post-pyloric tube) for high-risk clients; (5) Assess swallow function before resuming oral intake. Suspected aspiration: stop the feeding, suction airway, elevate head, assess vital signs, notify provider, anticipate chest x-ray and possibly antibiotics.