Inhaled foreign body

01OverviewDefinition, clinical context and the essential points that orientate the chapter.

Foreign-body inhalation spans an immediately fatal laryngeal obstruction and a missed bronchial object causing chronic focal disease. Toddlers are vulnerable because of small airways, immature chewing and oral exploration; older adults, people with neurological swallowing impairment, intoxication, poor dentition or dental procedures have different risks.

The central decision is whether airflow is effective. Effective cough is protective and should be encouraged. An ineffective or absent cough demands age-specific manoeuvres. After immediate obstruction is relieved, the question becomes whether retained distal material remains and how to remove it in a controlled airway setting.

Organic material can swell and provoke inflammation; sharp fragments, button batteries and tablets can damage mucosa; bones or dental material may be radiopaque. Object type and duration affect urgency, but ongoing respiratory compromise always overrides radiological convenience.

Key points

A sudden choking event followed by inability to speak, ineffective cough, stridor, cyanosis or collapse is a clinical diagnosis requiring action before tests.
An effective cough and audible speech indicate airflow: encourage coughing, observe continuously and avoid manoeuvres that might convert partial obstruction to complete obstruction.
For a conscious adult with ineffective cough, give up to five back blows then up to five abdominal thrusts, repeating according to the current RCUK algorithm.
Use chest thrusts rather than abdominal thrusts in pregnancy or when the abdomen cannot be encircled; infants receive chest thrusts, never abdominal thrusts.
Do not perform blind finger sweeps. Remove material from the mouth only when it is clearly visible and readily accessible.
If the person becomes unresponsive, call or confirm 999, begin CPR and use an AED; trained clinicians may inspect with laryngoscopy during airway care.
A distal aspirated object may present later with unilateral wheeze, reduced air entry, persistent cough, air trapping, lobar collapse or recurrent same-site pneumonia.
Chest radiography may be normal because many objects are radiolucent; bronchoscopy remains definitive when the history and focal findings are convincing.
CT can refine selected stable uncertain cases, especially in adults, but must not delay retrieval in a child or adult with high clinical probability.
Anyone treated successfully with abdominal or chest thrusts should receive clinical assessment for retained material and manoeuvre-related injury.

02AetiologyUnderlying causes, associations and risk factors, with why each one matters.

Food or small objects

Nuts, food boluses, toy parts and other small items can enter the larynx or bronchi during eating or play, especially in young children.

Impaired airway protection

Neurological disease, intoxication, sedation, poor dentition and swallowing dysfunction increase aspiration risk in adolescents and adults.

Dental and procedural material

Teeth, dental appliances and instrument fragments may be aspirated during trauma, seizure, anaesthesia or dental work.

Risk-taking behaviour

Holding pins or objects in the mouth and hurried eating create preventable aspiration risk in otherwise healthy people.

03PathophysiologyThe causal sequence from the underlying abnormality to symptoms and harm.

1
Upper-airway obstruction
A large object at the larynx or trachea can abruptly prevent ventilation, speech and effective cough, causing rapid hypoxaemia.
2
Partial bronchial obstruction
A smaller object lodges distally and creates fixed narrowing or a ball-valve effect with unilateral air trapping.
3
Local inflammation
Retained organic material irritates mucosa, producing oedema, granulation tissue, mucus retention and secondary infection, with effects that increase as the pathological process progresses.
4
Distal lung damage
Persistent blockage causes atelectasis, obstructive pneumonia and eventually focal bronchiectasis or abscess, contributing to the resulting loss of respiratory reserve.

04Clinical features and red flagsSymptoms, examination findings, patterns of presentation and time-critical warnings.

Effective coughRed flag

The person can vocalise, breathe and cough forcefully despite distress. Encourage coughing and be ready to escalate immediately if the cough weakens, speech disappears or consciousness changes.

Severe obstructionRed flag

Inability to speak or cry, silent ineffective cough, minimal air movement, cyanosis and decreasing responsiveness indicate critical obstruction. A quiet chest is more dangerous than loud coughing.

Infant presentationRed flag

Abrupt coughing, gagging, wheeze, stridor or apnoea while feeding or playing may be witnessed, but the event can be missed. Infants need back blows and chest thrusts.

Distal bronchial objectRed flag

Persistent unilateral monophonic wheeze, asymmetric air entry, local hyperresonance or focal crackles after choking suggests bronchial lodgement, commonly on the right but possible anywhere.

Delayed retained object

Recurrent consolidation in one lobe, chronic cough, haemoptysis, bronchiectatic change or an asthma label that behaves atypically should prompt a renewed aspiration history.

High-risk objectRed flag

Button batteries, caustic tablets, sharp fragments, large objects and organic matter that absorbs water can cause necrosis, perforation, oedema or fragmentation and need immediate specialist planning.

05InvestigationsWhat to request, why it matters and how to interpret it.

Investigation order

Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.

01
Immediate airway and cough assessmentFirst step
Why
Separate effective airflow from life-threatening obstruction.
Interpretation and limitations
Speech or crying, cough strength, chest movement, stridor, colour and consciousness determine the choking algorithm. Pulse oximetry can lag and must not delay manoeuvres.
02
Chest and neck radiographs
Why
Identify radiopaque material and indirect obstruction signs in a stable patient.
Interpretation and limitations
Look for an object, unilateral hyperinflation, mediastinal shift, atelectasis or focal consolidation. Normal films do not exclude a radiolucent bronchial foreign body.
03
Inspiratory-expiratory or decubitus imaging
Why
Demonstrate asymmetric air trapping when standard films are inconclusive.
Interpretation and limitations
The affected side may remain lucent and expanded on expiration. Request only views the patient can perform safely and never postpone bronchoscopy for a convincing history.
04
Low-dose CT chest
Why
Localise a suspected distal object in selected stable uncertain cases.
Interpretation and limitations
CT may show the object, airway cut-off, air trapping and complications. Radiation and delay must be weighed carefully, particularly in children.
05
Rigid or flexible bronchoscopy
Why
Confirm and remove retained airway material.
Interpretation and limitations
Rigid bronchoscopy offers airway control and retrieval capacity, especially in children or central large objects; flexible bronchoscopy may suit selected adult peripheral objects. The airway team decides.
06
Post-removal chest assessment
Why
Detect retained fragments and procedural or aspiration complications.
Interpretation and limitations
Re-examine air entry and oxygenation, inspect the airway when indicated and image for pneumothorax, collapse or persistent infiltrate if symptoms or procedural findings warrant it.
07
Swallow and neurological assessment
Why
Identify why an adult aspirated and reduce recurrence.
Interpretation and limitations
Speech and language therapy, dental or neurological review is appropriate for dysphagia, poor dentition, sedation or recurrent events, not every isolated childhood accident.

06Differential diagnosisRealistic alternatives and the features that help distinguish them.

Acute asthma

Diffuse expiratory wheeze and established variable airflow disease favour asthma, while sudden choking and unilateral signs suggest a foreign body.

Anaphylaxis

Generalised urticaria, angio-oedema, hypotension or gastrointestinal symptoms indicate systemic allergy rather than mechanical obstruction, while chronology and directed testing distinguish the competing explanation.

Croup or epiglottitis

Fever, preceding infection, barking cough, drooling or toxic appearance suggests inflammatory upper-airway disease; minimising agitation and avoiding unsafe examination reduces the risk of deterioration.

Inducible laryngeal obstruction

Recurrent brief inspiratory symptoms with normal intervals and dynamic laryngeal closure differ from a persistent aspirated object.

Mucus plugging

Asthma, cystic fibrosis or postoperative retention can cause focal collapse and wheeze without an aspiration event, though bronchoscopy may still be needed.

07ManagementImmediate care, first-line treatment, alternatives and escalation.

01Adult chokingTreat ineffective cough immediatelyFirst stepA conscious adult cannot speak or cough effectively after a sudden choking event.

1Ask if they are choking, call for help and give up to five firm back blows, checking after each attempt.
2If obstruction persists, give up to five abdominal thrusts; use chest thrusts for pregnancy or when the abdomen cannot be encircled.
3Call 999 if not already done and alternate back blows with thrusts until relief or unresponsiveness; never sweep blindly inside the mouth.
4If unresponsive, lower them safely, start CPR, attach an AED and have trained airway clinicians inspect for visible removable material.

02Paediatric chokingUse infant and child sequences correctlyAn infant or child has an ineffective cough or cannot cry or breathe after suspected aspiration.

1Give up to five back blows while supporting a head-down infant securely or leaning an older child forward, checking after each blow.
2If ineffective, give up to five chest thrusts to an infant or abdominal thrusts to a child over one year, then alternate while conscious.
3Call 999 at the latest if consciousness is lost, begin paediatric CPR with five rescue breaths and inspect only for a clearly visible object.
4Arrange assessment after successful thrusts and urgent bronchoscopy review when focal signs or a high-risk object suggest retention.

03Retained objectInvestigate stable distal aspirationChoking history, focal signs or recurrent same-site infection without current complete obstruction.

1Keep the patient nil by mouth, monitor oxygenation, take an exact event and object history and contact the age-appropriate airway specialists.
2Obtain appropriate radiographs and consider CT only if stable and useful; do not let a normal radiograph close a high-probability case.
3Plan rigid or flexible bronchoscopic retrieval with rescue airway equipment and surgical backup matched to the object and anticipated difficulty.
4After removal, document completeness, assess mucosal injury and complications, and address dysphagia or safeguarding issues where relevant.

04Post-eventReview after apparent reliefThe object seems expelled after back blows, thrusts or CPR.

1Reassess voice, swallowing, breathing, chest symmetry, abdominal or chest pain and oxygenation; persistent focal signs may indicate fragments.
2EscalationEvaluate anyone who received abdominal thrusts or compressions for injury, escalating severe pain, haematemesis, chest pain or breathlessness.
3Give return advice for fever, wheeze, cough, haemoptysis, dyspnoea or recurrent choking and arrange preventive swallow review when appropriate.

Key medicines and prescribing safety4 treatments · regimens, roles and cautions

Support oxygenation while mechanical obstruction is relieved and definitive airway care proceeds.

High-concentration oxygen

Give the highest available concentration during critical hypoxaemia or resuscitation, then titrate to the appropriate saturation target once reliable.

Oxygen cannot pass a completely obstructed airway and must not delay choking manoeuvres, CPR or retrieval. Use controlled targets after stabilisation if hypercapnia is possible.

Treat a reversible bronchospastic component around a partial distal obstruction.

Inhaled salbutamol

Use the current acute wheeze protocol only when clinically important bronchospasm persists alongside definitive foreign-body assessment and removal.

Improved wheeze does not prove the object has passed. Tachycardia, tremor and lactate rise can occur, and bronchodilation must not replace bronchoscopy.

Treat post-obstructive bacterial pneumonia or another documented infective complication.

Antibiotic therapy

Prescribe according to the current local pneumonia protocol, cultures, allergy status, severity and age only when infection is established.

Do not give prophylactically after an uncomplicated aspiration. Antibiotics neither remove the object nor correct collapse; retrieval remains necessary.

Occasionally reduce marked swelling around a difficult object or after traumatic removal.

Corticosteroid

No routine dose is indicated; use only after airway-specialist advice for a specific important inflammatory or oedematous indication.

Evidence and protocols vary. Steroid may mask infection or delay definitive removal, so it must never be the sole treatment for retention.

08ComplicationsImportant consequences, why they occur and why they matter clinically.

Asphyxial arrest

Complete obstruction rapidly causes severe hypoxaemia, loss of consciousness and cardiac arrest unless airflow is restored.

Obstructive pneumonia

Retained secretions distal to an object support bacterial infection that may recur despite antibiotics, particularly when baseline cardiopulmonary reserve is limited.

Bronchiectasis

Chronic obstruction and infection permanently damage and dilate the affected bronchi, creating an additional need for recognition and targeted treatment.

Airway trauma

The object or retrieval procedure can tear mucosa, cause bleeding, oedema, perforation or displace material into a more dangerous position.

Pneumothorax or air leak

Ball-valve hyperinflation, perforation or positive-pressure ventilation can rupture distal lung and introduce pleural air, and increasing the burden of otherwise local respiratory disease.

09Monitoring and follow-upTreatment response, safety checks and longer-term review.

During choking, continuously reassess cough strength, speech or cry, air movement, colour and consciousness because partial obstruction can become complete without warning.
In hospital, monitor respiratory rate, work of breathing, SpO2, stridor, unilateral wheeze and capnography where an advanced airway or sedation is used.
After bronchoscopy, watch for laryngeal oedema, bronchospasm, bleeding, pneumothorax, fever, persistent collapse and recurrent oxygen requirement.
Confirm that the retrieved object is complete and correlate residual symptoms with repeat examination or imaging rather than assuming all fragments were removed.
For delayed aspiration, document resolution of post-obstructive change and investigate bronchiectasis or another cause if focal infection persists.
Where swallowing impairment contributed, track the speech and language therapy plan, feeding supervision and medication-form changes across settings.

10Special situationsVariants, exceptions and circumstances that change the usual approach.

Silence can mark deterioration

Loud cough and stridor attract attention, but sudden silence may mean airflow has ceased. Ability to speak or cry is a better immediate discriminator than saturation.

Radiographs show consequences

Most food is radiolucent. Air trapping, segmental collapse or recurrent focal consolidation may be the only clue, and a normal film cannot overrule a compelling history.

Either bronchus can trap

Right-sided lodgement is frequent, but objects occur in the left bronchus, larynx or trachea. Examine and image without anchoring to the expected side.

Organic material evolves

Nuts and vegetable matter absorb fluid, fragment and provoke oedema or granulation. A stable patient can become harder to ventilate or treat later.

Adult aspiration needs explanation

Dentures, intoxication, sedatives, stroke, Parkinson disease, oesophageal disease and dental procedures may contribute. Preventing recurrence requires more than retrieval.

11Common pitfallsFrequent interpretation and management errors.

01
Performing abdominal thrusts on an infant or pregnant person instead of the correct chest-thrust technique.
02
Using a blind finger sweep and pushing unseen material farther into the airway.
03
Giving back blows to someone who is coughing effectively and potentially worsening a partial obstruction.
04
Waiting for cyanosis or a low oximeter reading before acting on severe obstruction.
05
Excluding aspiration because the object is not visible on chest radiography.
06
Treating unilateral wheeze repeatedly as asthma without revisiting sudden onset or focal recurrent pneumonia.
07
Giving antibiotics or corticosteroid while leaving the obstructing object in place.
08
Discharging after thrusts without checking for retained material or thoracoabdominal injury.