• Pregnancy increases the risk of pulmonary aspiration of gastric contents.

• Aspiration during pregnancy is most likely to occur due to impaired consciousness.

• Suction, oxygen and bronchodilators are the mainstay of treatment.

• Antibiotics and corticosteroids should not be used unless there is a specific indication.

• The patient should be cared for in an appropriate environment (if necessary: PACU, HDU, ITU)

This is a controlled document. If you are using a printed copy, check it against the guidelines site to ensure you are using the latest edition.

Abbreviations

Definition

Aspiration is the inhalation of material into the airway below the level of the true vocal cords. It occurs due to passive regurgitation or active vomiting of gastric contents in patients without sufficient protective airway reflexes.¹

Background

Pregnancy increases the risk of pulmonary aspiration of gastric contents. This is due to progesterone-induced relaxation of the oesophageal sphincter and delayed gastric emptying, especially during labour. There was one death related to aspiration in the last triennial report occurring during emergence from anaesthesia.²

In the obstetric setting, aspiration is most likely to occur in the patient with impaired consciousness:

• General anaesthesia (induction and emergence)

• High anaesthetic blocks

• Seizures (e.g., eclampsia)

• Drugs: opioids, sedatives, alcohol

• Acute stroke

The extent of pulmonary damage depends on the volume and acidity of the material aspirated, and whether it is liquid or particulate:

• Avoid general anaesthesia by using regional techniques.

• Rapid sequence induction of anaesthesia with cricoid pressure, and definitive airway with endotracheal intubation.

• Extubate only when airway reflexes have fully returned.

• Preoperative fasting or restricting oral intake in those at risk of surgery.

• Reducing gastric acidity in patients at risk (refer to guideline: Antacid Prophylaxis in Obstetric Patients).

• Be aware of risk of aspiration in patients who have had seizures and high regional blocks, and take precaution to avoid regurgitation and aspiration.

If cardio-respiratory arrest occurs, follow maternal collapse guidelines

Recognition

• The event may not have been witnessed.

• Presence of material in the upper airway (not always seen).

• Initial presentation is often bronchospasm, coughing, cyanosis and tachypnoea.

• Other suspicious signs include tachycardia and high inflation pressures (if ventilated).

Next steps

• Tilt the patient head down to limit pulmonary contamination.

• Clear the airway of particles and fluid with suction (+/- forceps).

• Summon help from the duty anaesthetist (if not present) to manage the airway and assess the need for ventilation.

• Give 100% oxygen.

• Obstetric SHO/Registrar should site a cannula and commence 1L of crystalloid.

• Obstetric SHO should order a portable chest X-ray. (This can be useful but in 25% of cases there are no changes initially).

• Treat symptomatic bronchospasm with bronchodilators.

• Ventilated patients should be transferred to ICU.

• The obstetric registrar should assess the patient and call the on-call obstetric consultant to inform them once the situation allows.

If the patient is intubated

• Tracheal suction should be performed.

• Early bronchoscopy is recommended if there is assumed to be particulate matter.

• If the aspiration has occurred intraoperatively and the patient has been stable enough to extubate, they should be observed in PACU for 2 hours.^1,3

Things NOT to do

• There is no evidence that bronchial lavage or instillation of sodium bicarbonate are of any immediate value.^1,3

• Corticosteroids should not be given prophylactically in the acute phase. They may even adversely affect mortality in critically ill patients.^1,3

• Antibiotics should not be given unless there is proven infection (20-30% of patients). Inappropriate administration has been linked to ventilator-associated pneumonia with virulent organisms.^1,3

A patient who remains asymptomatic at 2 hours can safely be managed on the ward. ^1,3

If any of the following occur, refer to critical care.^1,3

• New cough or wheeze

• Tachycardia, tachypnoea

• Oxygen saturation on air less than 95%

• New pathological changes on chest X-ray

Monitoring

• An incident form should be completed and a full explanation given to the mother.

• Cases of pulmonary aspiration of gastric contents will be reviewed by the risk management team when risk issues are identified.

Communication

If there are communication issues (e.g., English as a second language, learning difficulties, blindness/partial sightedness, deafness) staff will take appropriate measures to ensure the patient (and her partner, if appropriate) understand the actions and rationale behind them.

This policy has been subject to an Equality Impact Assessment.

1. Janda, M., Scheeren, T., Nöldge-Schomburg, G. (2006) ‘Management of pulmonary aspiration’, Best Practice & Research Clinical Anaesthesiology, 20(3), pp. 409-427.

2. Cantwell, R. et al. (2011) ‘Saving Mothers’ Lives: Reviewing maternal deaths to make motherhood safer: 2006-2008. The Eighth Report of the Confidential Enquiries into Maternal Deaths in the United Kingdom’, BJOG: An International Journal of Obstetrics & Gynaecology, 118(S1), pp. 1-203.

3. King, W. (2010) Pulmonary Aspiration of Gastric Contents. Available at: https://resources.wfsahq.org/atotw/pulmonary-aspiration-of-gastric-contents/ (Accessed: 13 April 2023).

This guideline has been registered with the trust. However, clinical guidelines are guidelines only. The interpretation and application of clinical guidelines will remain the responsibility of the individual clinician. If in doubt contact a senior colleague or expert. Caution is advised when using guidelines after the review date. This guideline is for use in Frimley Health Trust hospitals only. Any use outside this location will not be supported by the Trust and will be at the risk of the individual using it.

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