Primary prevention

Measures to identify oropharyngeal dysphagia and reduce oropharyngeal load of pathogenic organisms, particularly in patients with neurological disease, patients with comorbidities, and those who are intubated, can potentially help to reduce aspiration, and associated complications such as aspiration pneumonia.[43] Speech and language therapy can strengthen the pharyngolaryngeal musculature and may improve swallowing although few trials have demonstrated clear benefits.[44]

Aspiration of gastric content during anaesthesia can be prevented by adhering to national anaesthesiology societies' guidelines. Water and other clear liquids (e.g., tea, coffee, soda water, apple juice, pulp-free orange juice) are allowed up to 2 hours before anaesthesia in otherwise healthy adults (including pregnant women not in labour) and children (not covered in this topic) who are scheduled for elective surgery.[38][45] The fasting period after intake of solids should not be less than 6 hours.

Glucagon-like peptide-1 (GLP-1) receptor agonists and dual glucose-dependent insulinotropic polypeptide (GIP)/GLP-1 receptor agonists are known to delay gastric emptying, and because of retained gastric contents, their use is a risk factor for aspiration during procedures requiring general anaesthesia or deep sedation.[21][22][23][24]​ Anaesthetists should be aware that there may be residual gastric contents despite routine recommended fasting in patients taking a GLP-1 or dual GIP/GLP-1 receptor agonists. Management in preventing or minimising the risk of aspiration may be required.[24]

A nasogastric tube is commonly inserted prophylactically in patients at high risk for aspiration during general anaesthesia.[5]

Keeping the head of the patient's bed higher than 30° to 45° reduces the risk of aspiration, especially in critically ill or mechanically ventilated patients.[46]​ Other potentially useful measures to prevent aspiration in critically ill patients include:​​

  • Oral decontamination with antiseptic solutions

  • A chin-down position while feeding for patients with dysphagia

  • Percutaneous endoscopic gastrostomy tube or percutaneous endoscopic jejunostomy tube for feeding chronically debilitated patients

  • Feeding by hand rather than inserting feeding tubes for geriatric patients

  • Feeding a soft mechanical diet and thickened liquids

  • Using ACE inhibitors and capsaicin to sensitise the gag reflex​[47]

  • Suctioning subglottic secretions in patients with endotracheal tubes

  • Suppressing gastric acid with drugs; minimising use of sedative drugs

  • Placing a post-pyloric feeding tube​[16]

Radiologists should try to avoid barium entering the tracheobronchial tree by assessing the likelihood of aspiration in patients at risk before starting the examination.[13] Patients at high risk should swallow a contrast medium such as iopydol that is less likely to harm the lungs. Gastrografin can cause pulmonary oedema and should be avoided if aspiration is suspected.[14]​ Postural techniques during barium studies can reduce or eliminate the risk of aspiration when small volumes of barium sulfate are used.[48]

Secondary prevention

Involve the multidisciplinary team early for any patient following acute aspiration with suspected dysphagia and organise a swallowing assessment. Always involve the patient and/or carer in decision-making where possible.[62][63]​ See Assessment of dysphagia.

  • An initial screen of swallowing function should be completed by an appropriately trained healthcare professional.​[7][64] Screening questions that may be used are:[65]

    • Do you cough and/or choke when you eat and drink?

    • Do you ever feel like food or drink goes down ‘the wrong way?’

    • Does it take you longer to eat your meals than it used to?

    • Have you changed the type of food that you eat?

    • Does your voice change after eating/drinking?

  • Discuss keeping the patient ‘nil by mouth’ with a senior colleague or speech and language therapist if the initial swallowing assessment indicates dysphagia.

  • In addition, organise a specialist swallowing assessment (e.g., by a speech and language therapist).[62][64] See  Screening.

  • Give food, fluids, and medication in a form that is appropriate for your patient once they have had a swallowing assessment.[62][64]

    • Consider alternative feeding strategies if the patient is unable to take adequate food, fluids, and medication orally.[64] Tube feeding (e.g., nasogastric tube, gastrostomy, or nasal bridle tube) may be appropriate to provide temporary nutritional support for patients with non-progressive causes of dysphagia such as stroke.[64]

      • The Feed or Ordinary Diet (FOOD) study, a three-part randomised controlled trial, found no significant benefit from nutritional supplements in patients with stroke.[89][90] Early nutrition within the first week decreased mortality. In this study, percutaneous endoscopic gastrostomy tubes, when compared with nasogastric tubes, were associated with higher mortality or adverse outcomes at 6 months. The data available on the optimal type of feeding tube are conflicting. Postpyloric placement of feeding tubes has been shown to decrease pneumonia risk in small, single-centre studies, though no difference has been shown in other outcomes such as the duration of mechanical ventilation, vomiting, or mortality.[91][92][93][94][95] 

    • Ensure the patient is screened for malnutrition and dehydration and involve a dietitian to optimally address the patient’s nutritional needs.[62][64]

    • Discuss feeding strategies carefully with the patient and/or family because the risk of aspiration may be outweighed by the patient’s quality-of-life needs, especially in progressive disease. It may be preferable for the patient to eat and drink (while accepting it is unsafe) rather than using a modified diet, feeding tube, or ‘nil by mouth’ regimens.[63] This strategy is also known as ‘risk feeding’.[80] Be aware that thickened fluids can alter the pharmacokinetics of the patient’s medication by reducing the bioavailability.[81] Seek advice from a senior colleague or pharmacist. 

  • Other management strategies include swallowing rehabilitation, education, careful positioning when feeding, and referral to an oral hygienist/dentist.[62]

Anaesthesia-related aspiration of gastric contents can be prevented by identifying patients susceptible to vomiting, minimising gastric contents before surgery, minimising emetic stimuli, and avoiding complete loss of protective reflexes from over-sedation.[16] 

However, in the emergency procedural setting (when the opportunity to use preventative strategies may not be available), there are no data to suggest that the risk of aspiration is increased due to lack of fasting.[96] 

  • Use of perioperative H2 antagonists may maintain gastric pH >2.5 in patients who are not fasted, providing a theoretical benefit in preventing lung injury from aspiration.[82][83][97] However, no data exist that demonstrate improvement in outcome with this approach. A meta-analysis comparing the effectiveness of H2 antagonists with proton-pump inhibitors (PPIs) concluded that a single oral dose of an H2 antagonist before surgery is more effective than a PPI. However, when given as two oral doses preoperatively or using the intravenous route, both classes are equally effective.[98]

  • Pregnant patients requiring anaesthesia should receive a H2 antagonist preoperatively to increase gastric pH, and undergo early intubation with cricoid pressure.[27]

  • Routine preoperative use of H2 antagonists, PPIs, antacids, anti-emetics, or anticholinergics is not recommended for patients with no apparent increased risk for pulmonary aspiration.[38] 

Patients already in hospital with risk factors for aspiration should have the head of the bed raised at 30° to 45°.[99] Patients with ≥2 risk factors or with documented aspiration, persistent feeding intolerance, or both can be treated with a prokinetic drug and/or fed with tubes placed with the tip at or below the ligament of Treitz (suspensory ligament of the duodenum).[41][91][100]​ Relatively small, single-centre trials have suggested reduction in pneumonia with both metoclopramide and postpyloric feeding.[91][100]​ These findings need to be confirmed in larger randomised controlled studies. Improved oral hygiene may also decrease the risk of aspiration pneumonia.[101] 

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