Archives of Disease in Childhood 1995; 72: 6-10

ORIGINAL ARTICLES

Suffocation, choking, and strangulation inchildhood in England and Wales: epidemiologyand prevention

James W Nixon, Alison M Kemp, Sara Levene, J R Sibert

Department of ChildHealth, University ofWales College ofMedicine, UlandoughSpecial ChildrenCentre, Penarth,South GlamorganCF64 2XXJW NixonA M KempJ R Sibert

Child AccidentPrevention Trust,LondonS Levene

Correspondence to:Professor Sibert.Accepted 16 September1994

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AbstractThe causes, classification, and preven-tion of mechanical asphyxial death inchildren were examined. The Office ofPopulation Censuses and Surveys(OPCS) identified children, under 15years of age, who had died as a result ofchoking, suffocation, or strangulationin England and Wales during the years1990 and 1991. Cases in the InternationalClassification of Diseases (ICD) codesof E911-3, E953, E963, and E983 wereselected and case details from HMcoroners' records and the death certifi-cates were extracted.The OPCS identified 136 children (99

boys, 37 girls) in the two year period, 65%were under 3 years of age. The childrenwere classified as dying from choking (21cases), aspirating gastric contents (39cases), suffocation (29 cases), strangula-tion (11 cases), and hanging (36 cases).The strangulation cases could be furthersubdivided into a group of 12 youngerchildren who were suspended from liga-tures around the home and a group of 21boys (8-14 years) who died of self initi-ated hanging. Overall, 11 children weredeliberately killed and 31 children died inbeds or cots. Children whose deaths areclassified as being due to aspiration of

* E911 choking on food* E913 mechanical

suffocation* E912 choking on non-food items

IIi

YearChoking and mechanical suffocation 1972-89 (OPCS mortality statistics series DH4).

vomit appear to be cases of the suddeninfant death syndrome or backgroundmedical conditions.

This study suggests the need for adviceon maintaining a safe sleeping environ-ment. Only one child choked on a toyand European Standards for Toy Safetyappear to have been successful. Theprevention of hanging in the group ofolder boys needs further exploration.(Arch Dis Child 1995; 72: 6-10)

Keywords: choking, suffocation, strangulation.

The Office of Population Censuses andSurveys (OPCS) lists asphyxia (InternationalClassification of Diseases (ICD) 911-913),excluding drowning, as the third most com-mon cause of accidental death in childrenunder 15 years of age in England and Wales,'after road traffic accidents and thermal injury.Asphyxia is also a leading cause of accidentrelated death in children under 1 year of age.' 2We have analysed mortality statistics forchildren from the OPCS over the last 20 yearsand found there has been a steady fall inthe number of childhood deaths registered aschoking or mechanical suffocation (figure).This may be due to improved medical treat-ment of foreign body aspiration cases throughbronchoscopy, improved infant feedingpractices, modification of baby equipment,and 'small part' regulations through con-sumer safety standards. However, in theabsence of a comprehensive British study ofthe subject, we do not have an adequateexplanation.

Previous reports have identified food,plastic bags,2 dummies,3 water beds and softbedding,4 and toy balloons25 as agents ofchoking and suffocation. There are reports ofstrangulation by cords, furniture, clothes, andcollapsible washing lines.6 Hanging, whetheraccidental or suicidal7 is a rare cause of death,primarily in boys.8 Asphyxial injury in childrenmay be due to abuse both in the context ofdeliberate suffocation or strangulation. In thisstudy we have analysed deaths to childrenfrom mechanical asphyxia to determine the

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Suffocation, choking, and strangulation in childhood in England and Wales: epidemiology and prevention

Table 1 Deaths from choking, strangulation, and suffocation

MeanTotal age

Classification No Boys Girls (years)

Choking 21 14 7 2-3Foreign body 10 5 5 1-2Food 11 9 2 3-3Inhalation ofvomit 39 25 14 2-3Associated with medical conditions 19 14 5 2-9

Cerebral palsy 5 4 1 4-8Bronchopneumonia or bronchiolitis 6 5 1 0 9During a fit* 8 5 3 3-6Extreme prematurity 1 1 0 0-2

No predisposing cause (probable SIDS) 15 8 7 0 5Homicide 2 2 0 1-7Unknown 3 1 2 7-9Suffocation 29 22 7 2-2Suffocated in adult beds 12 6 6 0 7

Overlain 6 2 4 0 5Slipped gap between wall and bed 4 2 2 0 7Plastic bags 2 2 0 0 9

Suffocated in cot 5 4 1 '0.7Chest freezer 3 3 0 4.9Homicide 5 5 0 4-5Crushed 2 2 0 6-5Plastic bag 1 1 0 0 5Unknown 1 1 0 2-6Strangulation and hanging 47 38 9 4 5Strangulation 11 6 5 1-8Caught between mattress and cot 5 4 1 1-2Homicide 4 0 4 2-3Caught in frame of old pram 1 1 0 2-9Caught in bed frame 1 0 9

Accidental hanging 15 11 * 4 2Ligatures in cot (dummy cord, curtain cords) 6 5 1 1Loose cords (phone cable blind pull, etc) 7 6 1 2-3Necklace 1 0 1 7-8Clothing on pram 1 0 1 0-8

Self initiated hanging 21 21 0 12-3

*Including one child with cerebral palsy.

extent and nature of the problem, to investi-gate the appropriateness of the classificationof deaths, and to ascertain the potential forprevention.

MethodsThe OPCS identified for us children who haddied as a result of choking, suffocation, or

strangulation in England and Wales during theyears 1990 and 1991. We selected cases in theICD codes of E911 (inhalation of food); E9 12(inhalation of other object); E9 13 (accidentalmechanical suffocation); E953, E963, andE983 non-accidental strangulation and hang-ing. We did not include cases of asphyxiationfrom carbon monoxide or other toxic gases inthe study. We obtained additional informationfrom the inquest files of HM coroners. Weincluded children in the study if they were lessthan 15 years of age. We categorised the casesaccording to the mechanism of asphyxiation.We used the following categories and defini-tions:

* Choking: internal obstruction of an air-way by a foreign body or food.

* Aspiration of vomit: internal obstructionof airways secondary to inhalation of gastriccontents.* Suffocation: obstruction of the airway by

covering the nose and mouth or throughstarvation of oxygen through enclosure.

* Strangulation: the airway was obstructedby external pressure other than to the nose ormouth.

* Hanging: a form of strangulation bysuspension from a ligature.

ResultsWe identified 136 children less than 15 years ofage who died from mechanical asphyxia inEngland and Wales during the two year period1990 and 1991. We received death registrationforms forf all these cases and detailed HMcoroners' reports for 85%. We show the detailsof the children in table 1.There were 99 boys and 37 girls. The modal

age for girls was in the first year of life while forboys there were two modal peaks: at less than 1year of age and in the early teenage years. Theannual mean incidence was 0 7 per 100 000children under 15 years old' and 3-8 per100 000 children at risk under 1 year of age.Thirty one deaths occurred in a bed or a cot.Eleven children were deliberately killed. Theseincluded two children who aspirated vomit inassociation with severe non-accidental injuries,five children who were suffocated, and fourchildren who were strangled.

CHOKINGTwenty one children died from choking. Tentoddlers choked on a foreign body that theyhad picked up and put in their mouths. Theforeign bodies aspirated included a marble,conker, silver and tissue paper, a small toy, adummy, and a stone. Eleven older childrenchoked on food while eating. Two of thechildren who choked on food had Down'ssyndrome. The most common foods were fruitand the stones and pips from fruit (five cases).One child choked on a pea, two on bread, oneon a piece of sausage, and the remaining twoon unspecified food items.

ASPIRATION OF VOMITThirty nine children had a cause of deathrecorded as asphyxia secondary to inhalationof vomit. We did not consider that the deathsof most of these children were correctly classi-fied as an accident. In 19 cases there was a pre-existing medical condition such as cerebralpalsy, epilepsy (eight children aspirated vomitduring a fit), or bronchopneumonia. In 15cases we found no predisposing cause of theaspiration of vomit, which was a postmortemfinding. These children were infants all under14 months and 13 of them were younger than7 months of age. Two babies aspirated after afeed but in 13 cases the aspiration occurredduring sleep. Two children in this group hada cause of death recorded as inhalation ofvomit in association with sudden infant deathsyndrome (SIDS). We obtained details of thesleeping position in five cases and that wasprone.

SUFFOCATIONTwenty nine children suffocated. Twelvechildren under 1 year of age accidentally suffo-cated in adult beds. Six babies were recordedas overlain, one by a mother in diabetic coma,one by a mother incapacitated by alcohol, oneby a mother who was grossly obese, two werebabies less than 2 months of age, and one was

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Nixon, Kemp, Levene, Sibert

the youngest of seven children who were in bedtogether when it collapsed. Five childrenbetween 7 and 11 months old suffocated intheir cot. Three children suffocated in oneincident in a chest freezer. They had beenplaying and shut themselves in the freezer andwere unable to escape. Five children wereunlawfully killed. All the perpetrators wereclose family members: the father in threeinstances (two ofwhom themselves committedsuicide), a mother and uncle in the other cases.

STRANGULATION AND HANGINGForty seven children died from constrictionaround the neck: 11 were cases of strangula-tion and 36 of hanging. These included sevenchildren who were strangled in associationwith a product: five of these children had theirheads caught between the mattress and adefective cot side or wall. Two had similaraccidents involving a pram and wrought ironbed head. Four girls were deliberatelystrangled by a parent.The age distribution of the hanging cases

demonstrated two distinct age groups. Theyounger group (0-7 years) included 15 victimsof accidental hanging who were killed bycords, necklaces, or clothing around the house.The group of older boys over 8 years of agewere cases of self initiated hanging. In themajority of cases the boys were involved inplay that had gone badly wrong. In three casesthere had been an emotional disturbancebefore the event that was possible suicide andin one case there was evidence of autoeroticactivity.

DiscussionMechanical asphyxial deaths in children are asignificant problem in England and Wales.These cases of choking, suffocation, andstrangulation are predominantly accidental inorigin: however, they do include a number ofincidents of homicide9 10 (that reflect thespectrum of child killing and fatal child abuse)and cases where inhalation of vomit is thereported cause of death. When we excludedthe children who had been deliberately killedand those with inhalation of vomit, we classi-fied only 88 (65%) of the cases as trueaccidents. We therefore advise caution wheninterpreting accident statistics quoted directlyfrom ICD codes.1The cases classified as being due to aspira-

tion of vomit include some children withpre-existing medical conditions: such as casesof cerebral palsy, epilepsy, and chest infection.They also include a group of babies with unex-plained inhalation of vomit found at post-mortem examination: their age range coincideswith that of SIDS and the majority of casesdied in their sleep. Knight believes that, with-out clinical corroboration of aspiration ofgastric contents, the finding of such aspirationby necropsy only is to be regarded with reser-vation.11 He reports the presence of gastriccontents in 25% of cases of SIDS: most likelyresulting from agonal aspiration secondary

to the terminal event. We believe that themajority of the cases of babies in our study whowere classified as being due to inhalation ofvomit, without other cause, should be correctlyclassified as the SIDS.

Mechanical asphyxiation is distinctly aproblem in the baby and toddler age groupwith 65% of the children under 3 years ofage. Boys, who hang themselves, cause asecond peak in early teenage years. Otherstudies show a similar age pattern.12 13 The sexratio with male preponderance is a typicalfinding in most childhood accident statistics.1

There is a strong relationship between thelevel of the child's development and the acci-dent mechanism. Child victims of choking onforeign bodies are in the oral phase of develop-ment: they naturally put small objects straightto the mouth. We found no child younger than6 months when the ability to manipulate asmall object successfully into the mouth is notpresent. Young babies who asphyxiated in beddid so when they fell into a gap between bedand wall or between a faulty cot side. Theyneither had the strength nor motor agility torecover themselves. Older toddlers, however,succumbed while standing in the cot and theirhead became entangled in ligature near the cotor when clothing or dummy cords becamecaught on the cot side. This age group also hasthe manual dexterity to pull a plastic bag intothe cot. We can extend this developmentaltheme to include the older boys who, in play oranger, imitated behaviour portrayed in themedia and hung themselves with drastic conse-quences. This age and development specificityof the children who died indicate that preven-tion programmes should be directed atthose involved with children under 5 years, inparticular through the child surveillanceprogramme. We should aim education pro-grammes at raising awareness, so that parentscan make their child's environment as safe aspossible.

Effective measures aimed at the preventionof choking should also reduce the cases ofinhalation of foreign body admitted to hospitalfor bronchoscopy. Davies et al estimate thesecases amount to one in 14 000 children servedby a district general hospital in England.'4They carry a considerable morbidity and anestimated mortality rate of 7-5%.12 The caseswe describe in this study are only a fraction ofa very much larger problem.'2-15 Parents needto know about the dangers of small objects,which must be kept out of the reach oftoddlers, and the importance of supervisingchildren while eating. This is particularlythe case with children who have learningdifficulties. Education programmes act as aback up to environmental safety requirementssuch as the European Standards for ToySafety.The lack of a significant pattern of choking

incidents with non-food items (in particularcoins, toys, and pen caps) encouraged us. Theitems inhaled were similar to those reportedin other studies.2 1216 Coins are the mostcommonly aspirated or inhaled item seen incases referred to hospital.16 17 Toys caused

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Table 2 Advice on maintaining a safe sleepingenvironment

* A baby should never sleep in a faulty cot* Dummy cords and necklaces in bed should be discouraged* Cots should be positioned away from curtain cords, small

items, and plastic bags* Babies and toddlers should sleep in age appropriate cots* Cot safety standards should be maintained and extended to

retailed second hand equipment

only one choking death in our study. The toyinvolved had been purchased in 1980 and metthe standard for small parts of toys at thattime. Trading standards officers need to con-tinue to enforce the European Standards forToy Safety as they do appear to have beensuccessful. In the past children have diedfrom choking on pen caps. This resulted inwork on venting (pen caps manufactured witha hole to allow passage of air) and this hasbeen successful.

Beds and cots were implicated directly as themechanism of injury in more than a third ofaccidental deaths. There are similar reports inthe literature.4 Cot design is currently subjectto British Standard BS1753 1989. No deathcould be directly attributed to cot design butthe safety of equipment is highly dependent onits maintenance and correct usage. Cots areexpected to have a long life span and are fre-quently used across generations. There is alsoa market for second hand equipment. Thereneeds to be a mechanism to extend safetystandards to retailed second hand items. Weshould encourage facilities to service andmaintain baby equipment as part of safe com-munity programmes.18 We stress the import-ance of a child sleeping in an age appropriatecot or bed, of not using faulty cots and beds,positioning cots away from curtain cords andother potential ligatures and plastic bags. Weshould discourage children having 'dummycords' in bed or excess clothing. HM coronershave commented on the practice of placingcords or ribbons around a young child's neckfor any purpose. The danger of these cordsnear cots has been reported previously.19 20Safe sleeping practices could be stressed withinthe child surveillance programme by theprimary care team, in parent held records, andby national publicity (see table 2).

There were cases where a child was overlainby an adult in bed. We have previouslyreported a case of drowning in a baby wherethe mother suffered an epileptic fit.21 Thesetragic cases are fortunately rare but suggest thevalue of specialist advice to maximise safetyprovisions into the child's environment wherethe mother may be prone to periods of dimin-ished supervision. Historically, overlying wasregularly listed as a cause of death in youngbabies22; it is now a largely unrecognised entityand superseded by SIDS.Feldman and Simms reported strangula-

tions involving playground equipment.23Improvements in playground equipmentdesign over the past decade may have had aninfluence as only one case involving a bag anda slide occurred in this study.

Children who died from hanging came from

two clear groups. Prevention of accidentalhangings in the younger group relies on thevigilance of parents tying cords well out of thereach of toddlers and safe positioning of the cotin the bedroom. The older group of exclusivelyboys presents more challenges in the field ofprevention. Education programmes may nothave the desired effect on what is a recognisedbut infrequent event. Currently there is avogue for blaming the media for exposingchildren to detrimental forms of behaviour,there could be a place for blaming the media inthis case but there is no supportive evidence inour study. Cooke et al, however, describe acase of a child enacting a judicial hangingscene viewed on television.24 There is nosuggestion that these cases have increased inthe past 20 years25 or are any more prevalentin other parts of the world.8 24 Clark and hiscolleagues describe similar cases in the USAwith three cases of unequivocal suicide. Wefound three previously stable boys whoindulged in an impulsive form of behaviourafter an argument or household disharmony.Reports of children with strangulation associ-ated with autoerotic behaviour are rare.26 Wefound one case with supportive evidence ofpenile trauma.

Accidental mechanical asphyxia is a multi-faceted subject but clearly mainly a problem inthe preschool age group. It is difficult to seehow further legislative changes can be made toensure environmental safety in this field,although it is essential that strict safetystandards for cots, prams, and small parts oftoys are maintained within the EuropeanCommunity. Preventive education pro-grammes and home checks need to be offeredas part of health visitor component of the childsurveillance programme. Tertinger et al havepiloted a scheme specific to the reduction ofhousehold mechanical suffocation hazards inhigh risk families.27 This programme of house-hold checks and education feedback was suc-cessful in producing sustained change but itwas highly intensive and involved only sixfamilies. However, this provides a model andencouragement for the development of futureeducational preventive programmes.

We are very grateful to the Coroners Society and to all the HMcoroners who responded to our study. We are grateful to thehelp we have had from the OPCS and to the Catherine JenkinsTrust for financial support.

Dr Nixon is a visiting senior research fellow from theDepartment of Child Health, University of Queensland,Brisbane, Australia.

1 Office of Population Censuses and Surveys. OPCS MonitorPPI 93/1. London: OPCS, 1993.

2 Baker SP, Fisher RS. Childhood asphyxiation by choking orsuffocation. JAMA 1980; 244: 1343-6.

3 Barrett TG, Debelle GD, Cranston AJ. Minerva. BMJ1993; 306: 76.

4 Gilbert-Bamess E, Hegstrand L, Chandra S, et al. Hazardsof mattresses, beds and bedding in deaths of infants. Am 3fForensic Med Pathol 1991; 12: 27-32.

5 Ryan CA, Yacoub W, Paton T, Avard D. Childhooddeaths from toy balloons. Am _3 Dis Child 1990; 144:1221-4.

6 Roberton D, Rookwood K, Rutter N. Collapsible washinglines: a strangulation hazard. BMJ 1981; 282: 1664.

7 Dudley M, Waters B, Kelk N, Howard J. Youth suicide inNew South Wales: urban-rural trends. Med 3f Aust 1992;156: 83-9.

8 Clark MA, Feczko JD, Hawley DA, Pless JE, Tate LR,Fardal P. Asphyxial deaths due to hanging in children.3f Forensic Sci 1993; 38: 344-52.

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9 Meadow R. Suffocation, recurrent apnoea, and suddeninfant death. _J Pediatr 1990; 117: 351-7.

10 Pearn J, Wilkey I, Petrie G, Nixon JW. Neonaticide,infanticide and child homicide. Med Sci Law 1982; 22:31-5.

11 Knight BH. The significance of the post mortem discoveryof gastric contents in the air passages. Forensic Science1975; 6: 229-34.

12 Menendez AA, Cruz FG, Seda FJ, Velez W, Pinedo JT.Foreign body aspiration: experience at the universitypediatric hospital. Puerto Rico Health Sciences Journal1991; 10: 127-33.

13 Steen K, Zimmerman T. Tracheo-bronchial aspiration offoreign bodies in children: a study of 94 cases.Lanryngoscope 1990; 100: 525-9.

14 Davies H, Gordon I, Matthew DJ, et al. Long term followup of inhalation of foreign body. Arch Dis Child 1990; 65:619-21.

15 Al Hilou R. Inhalation of foreign bodies by children: reviewof experience with 74 cases from Dubai. J Laryngol Otol1991; 105: 466-70.

16 Reilly JS, Walter MA. Consumer product aspiration andingestion: analysis of emergency room reports to thenational electronic injury surveillance system. Ann OtolRhinol Laryngol 1992; 101: 739-42.

17 Consumer Safety Unit. Home accident surveillance system.Data. London: Department of Trade and Industry, 1991.

18 World Health Organisation. Manifesto for safe communities.

Stockholm: World Conference on Accident and InjuryPrevention, 1989.

19 Shepherd RT. Accidental self-strangulation in a young child- a case report and review. Med Sci Law 1990; 30:119-23.

20 Yee WH. Accidental strangulation by window-blind cords[letter]. Can Med Assoc _J 1990; 142: 436.

21 Kemp AM, Sibert JR. Epilepsy in children and the risks ofdrowning. Arch Dis Child 1993; 68: 684-5.

22 Templeman C. Two hundred and fifty eight cases ofsuffocation of infants. Edinburgh Medical J7ournal 1892:322-9.

23 Feldman KW, Simms RJ. Strangulation in childhood:epidemiology and clinical course. Pediatrics 1980; 65:1079-85.

24 Cooke CT, Cadden GA, Hilton JMN. Hanging deathsin children. Am _J Forensic Med Pathol 1989; 10:98-104.

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26 Herman SP. Recovery from hanging in an adolescent male.Clin Pediatr (Phila) 1974; 13: 854-60.

27 Tertinger DA, Green BF, Lutzker JR. Home safety:development and validation of one component ofan ecobehavioural treatment program for abusedand neglected children. J Appl Behav Anal 1984; 17:159-74.

Look what I can do with my shoulder

Some children are able to subluxate one or both shoulders. atwill and do so regularly to amuse or amaze their friends andcolleagues. Whether this practice does any harm or whethersurgical treatment to stop it is ever justified has not been known.In a Swiss orthopaedic clinic 26 children (13 boys and 13 girls)with this ability were seen over a period of 20 years and 25 ofthem were followed up for between six and 26 years (HarryHuber and Christian Gerber, Journal of Bone and Joint Surgery(British Volume) 1994; 76: 118-22). It had first been noticedat between 2 and 14 years of age. The instability affected onlyone shoulder in 12 of the 25 children and the direction ofsubluxation was most commonly posterior but some wentanteriorly or inferiorly and 10 children could do it in more thanone direction. In none was it the result of known trauma. Thejoints were all pain free at first but four children later developedpain on shoulder movement. Nobody in this series developedosteoarthritis of an affected shoulder. Eighteen children weresimply advised to stop the voluntary subluxation and were notsubjected to operation. They did well. The shoulder instabilitydid not cause any disability and did not appear to influence orrestrict their choice of occupation as adults. Seven eventually lostthe ability to subluxate their shoulder(s). Seven children wereoperated on and they did less well. Only three of them (five of 10operated shoulders) were considered to have had a satisfactoryresult; two shoulders were painful, one stiff, and two unstableafter operation.The authors conclude, reasonably, that these children should

not be submitted to operation.ARCHIVIST

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