Abstract

Choking, suffocation and strangulation are important causes of unintentional injury and death in young children. Choking on food and toys, suffocation from plastic bags and strangulation from strings on children's items are common causes of mechanical airway obstruction. An effective prevention plan must include education, product labeling, and product and container modification. Health care providers can play an important role in the dissemination of prevention information to caregivers and manufacturers in order to reduce the incidence of these injuries in young children.

In the United States, mechanical airway obstruction from choking, suffocation and strangulation is the leading cause of unintentional injury that results in death of children less than 1 year. It ranks fourth as a cause of death in children 1 to 9 years, surpassed only by motor vehicle injuries, drowning/submersion, and fire/burns.¹ Many of these deaths are preventable. Prevention of death from mechanical airway obstruction has long been a concern of health care providers, whose role may involve education of parents, other caregivers and manufacturers about the risks and the prevention of choking, suffocation and strangulation in children.

Choking is the interruption of respiration by internal obstruction of the airway, usually by food or small toys in young children. Suffocation is obstruction of the airway from an external object that blocks the nose and mouth, such as a plastic bag. Strangulation also results from external compression of the airway from an object, such as a string that becomes caught around the neck.

Epidemiology

Children less than 3 years of age are at greatest risk for mechanical airway obstruction. According to the Centers for Disease Control and Prevention (CDC), the death rate for unintentional suffocation (including inhalation or ingestion of food, objects and accidental mechanical suffocation) from 1981-1998 was 2.96 per 100,000 for children age 0-4 years as compared to 0.36 per 100,000 for those 5-9 years.¹ Suffocation is a leading cause of morbidity in young Wisconsin children, as shown in Table 1.

Furthermore, death from airway obstruction is most common in the first year of life. Injury from unintentional suffocation is more common in males than in females.1 Some progress in the prevention of deaths from unintentional suffocation has been made through federal regulation and public education; the death rate from unintentional suffocation for children 0-4 years has fallen from 3.46 in 1981 to 2.78 per 100,000 in 1998.¹

Foods, coins and small toys are common causes of choking in young children. Foods, such as hot dogs, hard candy, nuts and grapes (Table 2), account for a substantial proportion of deaths from choking.

Children are likely to choke on small, round, pliable objects that conform to the shape of the airway.² Coins are a common cause of foreign body ingestions. Among toys, rubber balloons are the leading cause of suffocation, according to Consumer Product Safety Commission (CPSC) injury data. More than 110 children have died as a result of suffocation involving rubber balloons since 1973.³ In addition, balls, marbles and other small toys intended for use by older children lead to many unfortunate deaths. During a 1-year period, the CPSC received reports of 7 deaths of young children from small balls.³ Furthermore, any small household items including jewelry, arts and crafts items, small pieces of hardware, paper clips, and ballpoint pen caps are potential dangers (Table 2). Small button-type batteries are a particular concern as they may produce corrosive injury.

Unintentional strangulation often results from strings on clothing or pacifiers that catch on a household piece (e.g., crib posts, furniture or doorknobs) or playground equipment and tightly wrap around the child's neck. According to the CPSC, two to three children under 2 years of age are strangled each year due to strings, cords, ribbons or necklaces around their necks.3 Window blind and drapery cords as well as wall and crib decorations also have caused strangulation. From 1981-1995, 183 deaths resulted from strangulation by window cords, resulting in a mortality rate of 0.14 per 100,000 for children less than 3 years old.⁴ Furthermore, children can be strangled when a heavy hinged toy chest lid catches their necks.

Suffocation of children can occur in an unsafe sleeping or play environment. Approximately 25 children per year suffocate due to plastic bags.3 Most are dry-cleaning bags or plastic garbage bags used for storage or protection of furniture and bedding. The children suffocate when the plastic bags block the nose and mouth, impairing breathing. Unsafe crib environments and improper sleeping surfaces can also result in suffocation. Between 1985 and 1990, 250 infants suffocated on adult or youth beds.3 Entrapment and suffocation can also occur in household items, such as refrigerators, ice chests, toy boxes and dryers.

Risk Factors

The likelihood that a child will choke depends on the following: the child's anatomy, the developmental stage, the type of food being eaten, the type of objects available and environmental factors.

As described above, children less than 3 years of age are at highest risk for death and injury from mechanical airway obstruction. This is due to their immature anatomy and developmental stage. Young children do not have a fully developed set of teeth for thorough chewing. Children's airways have a smaller diameter, and their swallowing mechanism remains immature and ineffective. Children lack the experience and cognitive skills to avoid choking. They forget to eat slowly and chew well. In addition, young children have a natural tendency to put everything in their mouths. The immature anatomy and lack of sound judgment place children at an increased risk for choking.

Inappropriate foods and other objects in the surroundings also increase the risk of choking. As detailed above, foods that are round or cylindrical and pliable or compressible most effectively form an airplug.2 These danger foods should not be fed to children less than 4 years of age. Of all children's play products, rubber balloons, small balls and marbles are the leading cause of suffocation death. In addition, small household items may be choking hazards.

Environmental factors, such as distractions during eating, can contribute to the risk of choking. Children who eat while rushed, walking, running or laughing may choke. Also, poor parental supervision may contribute. Children need to be reminded to take small bites and chew thoroughly. Children are more likely to choke when fed by a sibling, as food may not be properly cut or inappropriate foods may be given to the younger child. The presence of older siblings in the household increases the risk for choking, since toys with small parts may be more easily accessible.

Prevention Strategies

Many deaths from mechanical airway obstruction are preventable. Information regarding the morbidity, mortality, trends and risk factors for choking, strangulation and suffocation can be used by health care providers to reduce the incidence of death and injury. A comprehensive prevention plan includes education, product labeling and product modification.

Education - Information regarding childhood risks for choking, strangulation and suffocation should be distributed not only to parents but also to other caregivers, including day care providers and babysitters. Parents are most easily educated at health supervision visits, according to the child's developmental stage. The Injury Prevention Program (TIPP) of the American Academy of Pediatrics (AAP) provides age-related safety sheets that may facilitate the provider's safety discussion with parents.⁵ In addition, community programs can distribute safety information to other child caregivers.

At the newborn and 2-week-old visit, the provider should advocate a safe crib environment. To reduce the risk of suffocation and SIDS, infants should be placed to sleep on their backs. Cribs should conform to the safety standards of the CPSC and American Society for Testing and Materials. Cribs should have a firm, tight-fitting mattress, no missing or defective hardware, properly spaced slats (no more than 2 3/8 inches between slats), and no corner posts or decorative headboard cutouts. Infants should not be placed to sleep on soft bedding, including pillows, quilts, comforters, or sheepskins. Wall decorations, including ribbons and streamers, should be kept away from the sleeping area. Parents should not use makeshift pacifiers or rattles that could break apart and lead to choking. Bibs and other clothing with strings should be removed before placing the child in the crib. Pacifiers, necklaces, toys or other items should not be tied around a child's neck. At the 4- to 6-month-old visit, choking on foods and household products should be discussed with the parents. Parents should be reminded that infants are beginning to bring objects to their mouths at this developmental stage. Parents should be encouraged to "childproof" their homes by safely storing away small household products and toys that may belong to older siblings. In particular, special emphasis should be given to small balls, marbles, toys with small parts, balloons, pen caps and batteries. Small balls and marbles are commonly found in older children's games, vending machines and as restaurant prizes. Due to their small size, they can easily become lodged in a child's airway. Balls smaller than 1.75 cm should not be available to children less than 3 years old. In general, toys smaller than 3.17 cm x 5.71cm (that fit through a toilet paper tube) should be kept away from young children.⁶ Parents can be referred to the AAP handout, "Toy Safety: Guideline for Parents."⁵

Safe foods should also be discussed at the 6-month visit, as finger foods are being introduced into the infant's diet. In general, parents should be advised to not feed infants small, round, firm or pliable foods that may lodge in the airway but rather soft foods that dissolve easily or tiny pieces that do not require chewing. Examples of dangerous foods should be discussed. As listed in the AAP handout "Choking Prevention and First Aid for Infants and Children," dangerous foods include hot dogs, nuts, chunks of meat, grapes, hard candy, popcorn and raw carrots.⁵ Furthermore, parents should be reminded that children should eat only while sitting. Food should be cut into small pieces, and parents or another adult caregiver should supervise mealtimes, since some episodes of choking occur when an older sibling is feeding the young child.

Parents and caregivers should be encouraged to learn emergency first aid for the choking infant. Cardiopulmonary resuscitation (CPR) may be lifesaving when initiated immediately by the caregivers of the infant. The AAP recommends parental participation in the American Heart Association's Pediatric Basic Life Support course (800-242-8721) or the American Red Cross's Infant and Child CPR Course (AAP).⁷

At the 9- to 12-month visit, parents should be reminded of the infant's emerging mobility. Infants begin to pull to stand at the side of toy chests with heavy lids and may be strangulated if the lid falls onto them. Lids should be removed or new, safer toy chests should be purchased. More importantly, parents should be warned about the dangers of looped drapery and window-blind cords. Children have reached up and placed the cords around their necks, resulting in strangulation. In 1995, the Window Covering Safety Council announced voluntary industry wide standards that eliminated the loop in the pull cord. Window coverings are now produced with two cords with individual tassels or a single break-apart tassel. For existing cords, the industry recommends cutting the loop and replacing with two tassels. Drapery cords should be tied down to pull cords tight or anchored high out of reach; strangulation from non-loop single cords has been reported. Free consumer brochures and modification kits for looped window coverings are available from the Window Covering Safety Council, (800) 506-4636.

During the toddler and preschool years, providers should continue to counsel parents on the choking risks described above, as appropriate for the developmental stage of the child. Parents should be warned about the suffocation risk from uninflated balloons and pieces of broken balloons. Children can suck a balloon into the mouth and throat while attempting to inflate it and can also suffocate when balloon pieces on which they are chewing are pulled back into the throat. Because of this danger, the CPSC recommends that children under the age of 8 years should not play with balloons without supervision. Children should never be allowed to chew on balloons or their pieces; broken balloons should be disposed of immediately.

Product Labeling - Physicians have long been interested in the prevention of choking, strangulation and suffocation. Child safety acts have been an integral part of this effort. In 1979, the Federal Hazardous Substances Act banned any toy or article intended for children under 3 years of age that presented a choking, aspiration or ingestion hazard because of small parts. The Small Parts Standard of January 1980 stated that toys for use by children under 3 years must meet minimal size requirements. This standard uses a device called the small parts test fixture (SPTF), a cylinder with a 1 1/4 inch (3.17cm) diameter and a sloping floor, giving a depth between 1 inch and 2 1/4 inches (2.54-5.71cm). Any toy that fully fits inside the fixture must be labeled for use by children older than 3 years.⁶

Use of this fixture has been effective in identifying toys with small parts that may lead to injury. A recent study of approximately 140 injury-causing foreign bodies revealed that more than 99% of identifiable foreign bodies fit within the cylinder.8 However, the SPTF may not be as effective in preventing deaths from choking. An analysis of the types, shapes and sizes of objects causing choking or asphyxiation deaths concluded that 14 of 101 (14%) deaths could have been prevented if the SPTF had been 4.44 cm in diameter and 7.62cm in length.²

The Child Safety Protection Act of January 1995 fixed some of these problems. It stated that any small ball, with a diameter less than 1 3/4 inches (4.44cm) must contain the following label: (to view label, see December 2000 issue of WMJ)

Despite toy labeling efforts, concern has arisen that parents do not understand the intention of labels. The label does not explain why the toy is inappropriate, therefore, parents assume that labeling is informational, and relates to the child's educational level. In a study of 199 toy buyers, 44% said that they would buy a toy for a child between 2 and 3 years old if it was labeled "Recommended for 3 and up," but only 5% would buy it if it was labeled "Not recommended for below 3-small parts."⁹ Therefore, more detailed labeling may reduce the purchase of inappropriate toys for children less than 3 years.

Toy-related deaths also occur in children over age 3. Of 449 deaths from aspirated foreign bodies in children 14 years old or younger recorded by the CPSC between January 1972 and January 1992, 35% occurred in children over 3 years of age.² (Perhaps toy regulation standards should be extended to children 3-6 years old.)

Unfortunately, actions comparable to those initiated with toys have not been taken with food. As described above, a significant proportion of morbidity and mortality from choking is due to foods. (Perhaps warning labels should be put on foods that pose a significant choking hazard to young children.)

Product Modification - As a result of federal regulation standards, many products intended for use by children have been modified to reduce the likelihood of choking, strangulation and suffocation. For example, cribs now have narrowly-spaced slats and tightly fitting mattresses. Fewer toys with small detachable parts are available. Window blinds now are available with tassels and without loops. Children's clothing is no longer manufactured with drawstrings. Toy boxes are made with safer lids and with air holes for the trapped child. However, further need for product modification remains. Hot dogs could be reengineered in a different shape and consistency that reduce their likelihood to become a plug in the airway. Mylar balloons should be used in place of rubber.

Summary