Choking and Foreign Body Airway Obstruction (FBAO)

Choking is the physiological response to sudden airways obstruction. Obstruction may be partial or complete. Foreign body airway obstruction (FBAO) causes asphyxia and is a terrifying condition, occurring very acutely, with the patient often unable to explain what is happening to them and with rapid loss of consciousness and death if first aid is not undertaken quickly and successfully. Immediate recognition and response is of the utmost importance. It can occur to anyone - even mighty world leaders have been brought low by such as the humble pretzel.¹

Incidence

Choking is a risk whenever food is consumed. A US study suggests an incidence of death due to FBAO of 0.66 per 100,000 population.² An Australian study looking at incidence of foreign body asphyxia admission rate in the under 15s shows a rate of 15.1 per 100,000 per annum, peaking in the under ones and then gradually declining to low levels by 3 years old.³

Risk factors

In one Austrian autopsy series, certain risk factors were identified:⁴

• Old age
• Poor dentition
• Alcohol consumption
• Chronic disease
• Sedation
• Eating risky foods

In less than 10% of cases where help was summoned, was FBAO correctly diagnosed during resuscitation attempts.
The elderly are a particularly vulnerable group and FBAO is associated with:⁵

• A higher risk with soft/slick foods
• Agomphiasis (absence of teeth)
• Neurological impairment

Children, in particular mobile babies and toddlers who orally explore their environments, are at risk from FBAO from non-food objects. Carers need to maintain vigilance for objects such as:^6,7

• Coins
• Balloons
• Marbles

Risky foods in childhood tend to be round in shape and include:^3,8,9

• Sausages and hotdogs
• Improperly chewed meat
• Sweets
• Nuts
• Carrots
• Apples
• Grapes

Choking due to inhalation of a foreign body usually occurs whilst eating - it need not have been a formal 'sit-down' meal, a snack eaten 'on-the-go' or chewing gum can also be inhaled.

History

Beware the so-called 'cafe coronary' - consider the diagnosis where a patient collapses during or shortly after a meal or snack.¹⁰Events unfold almost instantaneously:

• The victim may clutch his neck, appearing extremely distressed and may even turn cyanosed as you watch.
• He may struggle to cough or for breath.
• Ask the victim directly, "Are you choking?" Speech is difficult or impossible and so he may utter, "Yes" in a muffled voice or simply nod his head.
• If the event has not been witnessed, you may simply find someone unconscious without obvious cause.

Examination

Assess the severity of the situation:

• Is he able to speak, cough and breath?
• His breath may sound wheezy.
• There may be silent attempts at coughing.
• There may be loss of consciousness.

Rapid evaluation is key: swiftly consider other conditions that may cause sudden respiratory distress, cyanosis or loss of consciousness such as:

• Anaphylaxis
• Syncope
• Myocardial infarct
• Seizure

In adults¹¹

Action depends upon the severity of the situation and the adequacy of the cough. It may be classified as:

1. Mild
2. Severe but conscious
3. Severe and unconscious

In mild airways obstruction encourage him to keep coughing but more dramatic action is unnecessary.

If there is severe airways obstruction but he is conscious, give 5 blows to the back:

• Stand to the side and slightly behind the victim, preferably to the left if you are right handed and the right if you are left handed.
• Support the chest with one hand and lean the victim well forwards so that when the obstructing object is dislodged it comes out of the mouth rather than goes further down the airway.
• Give a sharp blows between the scapulae with the heel of the hand.
• After each blow, reassess the patient to see if the foreign body has moved.

If the airways are still obstructed, repeat the blow and re-assess until 5 blows have been delivered. If this does not work, use the Heimlich manoeuvre (or abdominal thrust).

CPR in airways obstruction

If the patient becomes unconscious, start CPR whilst someone else calls an ambulance. The aim is still the basic intention to support the circulation and to ventilate the lungs.

• Resus UK suggests starting with chest compression but others recommend giving a couple of rescue breaths first.
• Kneel beside the patient and place the "heel" of one hand in the centre of the sternum and the other over it. Interlock the fingers of both hands and ensure that pressure is not applied over the patient's ribs. Do not apply force over the upper abdomen or the xiphisternum.
• Position yourself vertically above the patient's chest and, with your arms straight, press down on the sternum 4 or 5 cm.
• After each compression, relax but do not loose contact between the hands and the patient's chest. Compression and relaxation should be about equal in duration and at a rate of around 100 a minute.
• If there are 2 rescuers, one should attend to cardiac output whilst the other ventilates the lungs. A single rescuer should stop every 30 compressions and perform 2 breaths.
• Use the head tilt and chin lift. Pinch the nose below the cartilage to close it, using the index finger and thumb of your hand on his forehead. Allow his mouth to open, but maintain chin lift.
• Take a breath and place your lips around his mouth, making sure there is a good seal. Blow steadily into the mouth whilst watching for the chest to rise. Take about one second to make his chest rise as in normal breathing. This is an effective rescue breath.
• Maintaining head tilt and chin lift, whilst you remove your mouth from the patient and watch for his chest to fall with expiration.
• Repeat this to give a second rescue breath and then return at once to compressions.
• Continue this routine until help arrives, stopping only if breathing return spontaneously.
• If the chest does not rise the Heimlich manoeuvre may be used to try to clear the obstruction.

In children

Airways obstruction is suggested by the sudden onset of respiratory distress with coughing, gagging or stridor. Similar signs and symptoms will occur with other causes of airway obstruction such as laryngitis or epiglottitis, but suspect a foreign body if:

• There is very sudden onset.
• There are no other features of illness.
• The child may has been eating or playing with small items.

With an effective cough there is crying or reply to questions. The child is able to take a deep breath before making a loud cough and is fully responsive. A spontaneous cough is likely to be more effective and safer than any manoeuvre a rescuer might perform. With an inadequate cough response:

• The child cannot speak.
• The cough is quiet.
• The child may be cyanosed.
• There is a decreasing level of consciousness.

If the situation is deteriorating, shout for urgent help.
In a child who is conscious but has an inadequate cough, give blows to the back as for an adult.
If this does not work use abdominal thrusts for children and chest thrusts for infants.

For infants (<1 year old)

• In a seated position, support the infant in a head-downwards, prone position to let gravity to aid removal of the foreign body.
• Support the head by placing the thumb of one hand at the angle of the lower jaw, and one or two fingers from the same hand at the same point on the other side of the jaw. Do not compress the soft tissues under the jaw, as this will aggravate the airway obstruction.
• After each blow assess to see if the foreign body has been dislodged and if not repeat the manoeuvre up to 5 times.
• After 5 unsuccessful back blows, use chest thrusts (do not use the Heimlich manoeuvre): turn the infant into a head-downwards supine position by placing your free arm along the infant's back and encircling the occiput with your hand. Support the infant down your arm, which is placed down (or across) your thigh. Identify the landmark for chest compression. This is the lower sternum about a finger's breadth above the xiphisternum. Deliver 5 chest thrusts. These are similar to chest compressions for CPR, but sharper in nature and delivered at a slower rate.
• Where CPR is instituted:
  • Use thumbs for compression to a 1/3-1/2 chest depth compression.
  • Use a rate of 100/min.
  • Place the head in the neutral position.

For children (1 year old to puberty)

• Blows to the back are more effective if the child is positioned head down. A small child can be placed across the lap as with an infant. If this is not possible, support the child in a forward-leaning position and deliver the back blows from behind.
• After 5 unsuccessful back blows the Heimlich manoeuvre may be used in children over 1 year old.

If the child becomes unconscious, place him on a flat, firm surface, shouting for help if none has arrived, and begin CPR as for paediatric basic life support:

• Open the mouth and look for any obvious object. If one is seen and it is easily accessible, remove it with care. Do not attempt a blind sweep as this may impact the body back into the pharynx or damage the mucosa which may bleed and compound the airway compromise.
• Open the airway and attempt 5 rescue breaths. Each time, check that the breath makes the chest rise. Reposition the head before making the next attempt. After 5 rescue breaths, if there is no response, move immediately to chest compression even if the breaths were unsuccessful. When the airway is opened for attempted delivery of rescue breaths, look to see if the foreign body can be seen in the mouth and if easily accessible, remove it with care.
• Use 1 hand for compressions (not 2 as for adults).
• If 2 rescuers are present, use 15:1 compressions:breaths.
• If the procedure is effective and the child regains consciousness, place him in the recovery position.

• Inhaled foreign body: After successful treatment for choking, foreign material may still be present in the upper or lower airways and cause complications such as bronchiectasis or lung abscess later.⁹ Anyone with a persistent cough, difficulty swallowing, or with the sensation of an object being still stuck in the throat should therefore be referred to A&E. CXR may show an opacity that requires removal at bronchoscopy or atelectasis. In children, clinical features and radiological findings may have a poor correlation with findings at bronchoscopy.¹³ If a foreign body is suspected, bronchoscopy should be performed at an early stage for best results.¹⁴
• Iatrogenic: Abdominal thrusts can cause serious injuries (e.g. gastric and splenic rupture)¹⁵ and all victims receiving abdominal thrusts require examination of the abdomen with a particular view to visceral injuries.
• Hypoxic brain injury and death

Tragedy due to FBAO is unpredictable. In our risk-averse society, we can try to iron out some elements of increased risk such as:

• Not eating whilst exercising.
• Remembering to chew food properly.
• Avoiding drunkenness.
• Cutting up grapes and not giving peanuts to small children.

We can also increase public awareness of choking and confidence at initiating first-aid. The Heimlich manoeuvre used in the pre-hospital setting on adults has a good rate of success (86.5%).¹⁶ Given the speed with which individuals lose consciousness and die in a complete airway obstruction and the fact that survival often requires obstructions to have been cleared prior to the arrival of paramedics,¹⁷ these skills should be widely taught and practiced.