- Email: [email protected]
Foreign body asphyxia
Foreign Body Asphyxia A Preventable Cause of Death in the Elderly Andrea M. Berzlanovich, MD, Barbara Fazeny-Do¨rner, MD, Thomas Waldhoer, PhD, Peter Fasching, MD, Wolfgang Keil, MD Background: To assess the prevalence of food/foreign body asphyxia in the elderly Viennese population in order to reduce the incidence of these fatal events. Methods:
This is an autopsy-based, retrospective study in Vienna, Austria. Participants included all nonhospitalized (n ⫽200) cases of choking in 1984 to 2001, from a total 42,745 consecutive autopsies performed at the Institute of Forensic Medicine. In addition, data from hospitalized adult cases of fatal choking (n ⫽73) in 1984 to 2001, from the mortality registrar of Vienna, were included.
Results:
The nonhospitalized choking victims were analyzed according to age (18 to 64 vs ⱖ65 years), sex, circumstances of death, and predisposing factors. Hospitalized cases were analyzed according to age, sex, and whether an autopsy was already performed by pathologists at the institution where they died. In the study period, 273 adults died of food/foreign body asphyxia, 73% of them out of the hospital and 27% in hospitals. Food/foreign body asphyxia in the elderly was characterized by a significantly higher asphyxiation of soft/slick foods (p ⬍0.007) with agomphiasis (p ⬍0.002), occurring most frequently during lunch (49%), and in 2.5% during feeding of neurologically impaired. In contrast, younger individuals choked significantly more often on large pieces of foreign material (p ⬍0.002) and showed a significantly higher rate of blood alcohol concentration (p ⬍0.001).
Conclusions: This study demonstrates that semisolid foods are the cause of a large number of asphyxiations, especially among the elderly. Knowledge of the fact that semisolid foods are a high-risk factor in elderly individuals should be distributed in public and private healthcare systems, and awareness could be a first step in reducing the incidence of food/foreign body asphyxia. (Am J Prev Med 2005;28(1):65– 69) © 2005 American Journal of Preventive Medicine
Introduction
F
ood/foreign body asphyxia is well known to forensic pathologists. The description of the “cafe coronary,” a term coined by Haugen in 1963,1 enhanced awareness of the causes, prevention, and emergency treatment of food asphyxiation. However, even today, 40 years later, people observing sudden attacks— especially in the elderly— often do not suspect choking, and erroneously attribute death to coronary artery disease. A recent autopsy study of food/foreign body asphyxia at the Viennese Institute of
From the Institute of Forensic Medicine (Berzlanovich), Department of Internal Medicine I (Fazeny-Do¨rner), and Department of Epidemiology, Institute of Cancer Research (Waldhoer), University of Vienna Vienna, Austria; Geriatric Center Baumgarten (Fasching), Vienna, Austria; and Institute of Forensic Medicine, University of Munich (Keil), Munich, Germany Address correspondence and reprint requests to: Andrea M, Berzlanovich, MD, Institute of Forensic Medicine, University of Vienna, Sensengasse 2, A-1090 Vienna, Austria. E-mail: andrea. [email protected].
Forensic Medicine revealed that observers were present in 63% of the choking events. The fatal incident was correctly identified in only 8% of cases by emergency personnel. Common misdiagnoses were cardiovascular failure; epileptic seizures; and intoxication from medication, drugs, or alcohol.2 However, the special aspect of food/foreign body asphyxia in the elderly is rarely mentioned in current medical textbooks or journals, and remains largely uninvestigated. The fatal event of food/foreign body asphyxia may be preventable. Prevention depends on understanding the nature and frequency of food/foreign body asphyxia and its specific causes. Valuable data for community education could be obtained from medical examiners who catalog all sudden and unexpected deaths, in concert with an investigation at the scene of occurrence that is performed by a competent forensic pathologist. The current study had three purposes: (1) present results of an analysis of 18 years of autopsy data reporting food asphyxiation in a nonhospitalized pop-
Am J Prev Med 2005;28(1) © 2005 American Journal of Preventive Medicine • Published by Elsevier Inc.
0749-3797/05/$–see front matter doi:10.1016/j.amepre.2004.04.002
65
ulation; (2) identify risk factors influencing food asphyxiation, especially in elderly individuals; and (3) suggest preventive as well as effective accident control strategies that can be used to minimize the risk of food asphyxiation among the elderly.
Methods The Viennese Institute of Forensic Medicine is the unique institution in Vienna responsible for determining the cause and manner of death in all cases of unexpected deaths occurring out of hospitals. Its geographic jurisdiction encompasses the greater Vienna area, with a population base of 1.6 million people. At present, approximately 53% of Vienna residents are female. Although the proportion of the population aged ⬎60 years has been declining since 1971, Vienna still has the largest share of elderly people (20.7%) compared to Austria’s other provinces. Women account for 64% of the population aged ⬎60 and 72% of those aged ⬎75.3 Approximately 18% of Vienna’s resident population are foreign nationals, most of whom emigrated from Yugoslavia and its successor states and Turkey. Austrian law requires the use of an autopsy to detail and ascertain the cause of each death of people who died outside of hospitals when the cause is uncertain and in cases in which a physician has not been consulted within 10 days before death. Thus, all unexpected out-of-hospital deaths in Vienna are investigated at the Viennese Institute of Forensic Medicine.
Subjects Inclusion criteria for this study were adult non-hospitalized and hospitalized victims aged ⬎18 years, fulfilling the working definition of deaths from asphyxia by foreign objects as defined by the ICD-9 code: “Foreign body in pharynx and larynx,” which includes “pharynx, nasopharynx and throat not otherwise specified” (933.0), and larynx “asphyxia due to foreign body” and “choking” due to “food (regurgitated) or phlegm” (933.1). The data from the adult hospitalized individuals who had choked (n ⫽73) and the sex of the deceased from 1984 to 2001 were provided from the mortality registrar of Vienna.3 For all nonhospitalized individuals who died of food/ foreign body asphyxia, records were gathered of 42,745 autopsies performed at the Institute of Forensic Medicine. The autopsy reports and medical histories of the individuals were evaluated with regard to age, sex, circumstances of death, type and consistency of the obstructing foreign material, and consumption of alcohol or sedative and hypnotic drugs. Furthermore, the characteristics associated with food/ foreign body asphyxia were analyzed according to age (18 to 64 versus ⱖ65 years). All autopsies were performed by eight physicians specialized in forensic medicine. The number of all hospitalized individuals during the study period was provided by the mortality registrar of Vienna, from which the sample of choking victims was drawn. For this group, the data were analyzed according to age, sex, and whether an autopsy was performed by local pathologists at the institution where the individuals died.
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Statistics Comparisons of continuous variables were made with the Mann–Whitney U test. Chi-square tests were used to calculate p values for comparisons in 2⫻2 contingency tables. Direct standardized rates (SRs) and 95% confidence intervals (CIs) were calculated. SAS (SAS Institute Inc., Cary NC, 2001) was used for performing all calculations. A p value of ⬍0.05 was considered statistically significant.
Results Incidence of Foreign Body Asphyxia, Age, Sex, and Autopsy Rate in Nonhospitalized and Hospitalized Individuals From 1984 through 2001, 273 nonhospitalized and hospitalized adults died of food/foreign body asphyxia in Vienna, resulting in an average of two victims per 100,000 population (men: SR⫽2.7, CI⫽2.4 –3.1; women: SR⫽1.3, CI⫽1.1–1.6; total: SR⫽2, CI⫽1.8 –2.2). The Viennese Institute of Forensic Medicine performed an autopsy on all 200 nonhospitalized choking victims, accounting for 0.5% of deaths out of 42,745 consecutive autopsies. The male-to-female ratio was 1.2:1. The median age was 65 (range, 27 to 91) years; 105 of 200 (53%) were aged ⱖ65 years and 95 (47%) were aged 18 to 64 years. A total of 272,594 hospitalized patients died during the study period in Vienna. Of this total, 73 died due to food/foreign body asphyxia, accounting for 0.03% of all deaths in hospitals; 49 of the latter (67%) underwent autopsy because the cause of death was not ascertained by the caregiver team. In these cases, food/foreign body asphyxia was not suspected at the time of death, but was identified by the autopsy. In the remaining 24 cases, an autopsy was not performed because the inferred cause of death was not questioned. The median age of the hospitalized individuals was 73 years (range, 45 to 96); the male-to-female ratio was 0.8:1.
Medical History of Nonhospitalized Individuals One third of the deceased were described as healthy at the time of death. Pre-existing conditions were present in the remaining and are depicted in Table 1. In 43% (45 of 105) of individuals aged ⱖ65, neurologic disorders including Parkinsonism, Alzheimer disease, and hemorrhagic stroke were evident.
Circumstances of Death of Nonhospitalized Individuals Sixty-nine percent of the fatal incidents occurred in private homes, 15% in restaurants, 9.5% in private nursing institutions, 5% in public areas, and 1.5% during transportation to a hospital. Five neurologically impaired victims (2.5%) choked during feeding. Of 137 eyewitnesses, 94 uniformly reported at least three of the
American Journal of Preventive Medicine, Volume 28, Number 1
Table 1. Medical history of 200 nonhospitalized adult victims of fatal foreign body asphyxia, by age Pre-existing conditions of deceased Without any symptoms, presumably healthy Neuropsychiatric diseases Cardiovascular disease Diabetes mellitus Oral/pharyngeal/ gastrointestinal disorders Total
Table 2. Type and consistency of asphyxiated foreign material in 200 nonhospitalized adult victims, by age
Age 18–64 years (n) 45
Age >65 years (n) 18
Total (n) 63
23
56
79
20
41
61
9 4
11 16
20 20
95
105
200
following: cessation of eating and talking, apnea, paleness, cyanosis, and collapse.
Time of Death of Nonhospitalized Individuals
18–64 years (n)
>65 years (n)
Asphyxiated material Meat, fish 57 43 Sausage 16 25 Bread, pizza, 9 15 cookies, pastries Fruit, vegetables 8 6 Noodles 1 4 Cheese, eggs 1 1 Denture 0 2 Not identified 3 9 Total 95 105 Consistency of asphyxiated material (nⴝ188) Solids 86 38 One piece of food/ 63 4 foreign material Two or more pieces 23 34 Semisolids 6 58
Total (n) 100 41 24 14 5 2 2 12 200 124 67 57 64
In 137 of 200 cases, the time of the event could be precisely determined. Fatal food/foreign body asphyxia occurred at breakfast for 44, at lunch for 50, and at dinner for 17, and with snacks for 26 cases. Thirty-seven of the 50 individuals who died at lunch were ⬎65 years, representing 49% of the elderly with determined time of death (n ⫽ 75). All elderly (n ⫽10) who had received a sedative the night before, choked in the early morning.
bolus size ranged from a plum (up to 3 cm in diameter) to an apricot (up to 5 cm in diameter). The largest obstructing foodstuff encountered at autopsy was a meat chunk with a weight of 50 g, measuring 11⫻7⫻2 cm. The location of the obstructing material was the supraglottic region or within the glottis itself in 74%, presumably within reach of fingers, whereas the bolus was lodged in the infraglottic area in 26%. In 24% the first morsel of food was lethal; in the remaining 76% of cases the stomach contained undigested food.
Asphyxiated Food/Foreign Material in Nonhospitalized Individuals
Dentition of Nonhospitalized Individuals
In 188 of 200 individuals, the obstructing bolus could be identified at autopsy. The foreign material that caused asphyxia were common foods in Vienna, such as meat, fish, sausage, bread, pizza, cookies, and pastries (Table 2). It was a solid in 124 cases and semisolid in 64 cases. The obstructing foods were chunks of meat/fish in 50%, and a chunk of sausage in 20%. A bolus consisting of bread, pizza, cookies, or pastries was noted in 12%, while fruit or vegetables accounted for another 7%. A displaced denture was determined to be the cause of asphyxia in two cases. A single chunk of food created an obstruction in 68% of individuals aged 18 to 64 years, and in only 4% of individuals aged ⱖ65 years (p ⬍0.002). Thirty-five percent of the elderly choked on more complex boluses (sausages on a bun, sandwiches, meatballs, meat and vegetables/noodles), and 61% on semisolids (puree, ground meat, mashed fruits), as compared to a combined total of 7% among the 18- to 64-year-olds (p ⬍0.007). A large mass of food was found in the mouths of 46% of all patients aged ⱖ65 years. The
Only 10% of victims had intact dentition (closed alignment with a minimum of 24 teeth), 32% had partial or complete dentures, 31% had defective or partial dentition without dental prostheses, and 27% were edentulous at the time of death (Table 3). Agomphiasis (being edentulous) correlated with age (p ⬍0.002). Table 3. Dentition in 200 nonhospitalized adult victims, by age Age Dentition Intact dentition Partial/complete dentures Edentulous Defective/partial dentition without dental protheses Total
18–64 years (n)
>65 years (n)
Total (n)
p value
15 20
5 44
20 64
0.079 0.215
18 42
35 21
53 63
0.002 0.253
95
105
200
Am J Prev Med 2005;28(1)
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Alcohol and Toxicologic Analysis in Nonhospitalized Individuals Blood alcohol concentration and blood levels for sedative and/or hypnotic drugs were analyzed in all 200 cases. At the time of death, 50% of the victims were sober. The remaining had blood alcohol levels ranging from 0.1% to 4.4%. Blood alcohol concentration was significantly higher in individuals aged 18 to 64 years compared to those aged ⱖ65 years (p ⬍0.001). Positive blood levels for sedative and/or hypnotic drugs were found in 12 cases (6%).
Medical Interventions in Nonhospitalized Individuals In 68% (n ⫽137) of cases, other people were in the vicinity of the victim, so emergency services were called and cardiopulmonary resuscitation started. Resuscitation attempts at the scene included artificial respiration, mouth-to-mouth resuscitation, and, in two instances, the Heimlich maneuver. Physicians’ reports revealed that in 125 of 137 cases the choking event, being the initial cause for emergency intervention, was not subsequently recognized as asphyxiation. Before autopsy, death caused by food/foreign body asphyxia was correctly identified in 4 of the 75 (5%) cases of individuals aged ⱖ65 years, and in 8 of the 62 (13%) cases aged 18 to 64 years.
Discussion This study demonstrates old age, poor dentition, neurologic disorders, certain types of foods, and the intake of sedatives as risk factors for food/foreign body asphyxia. Prevention of these fatal events requires neither special diagnostic facilities nor highly sophisticated knowledge, but merely a simple awareness of predisposing factors. In this data set, fatal food/foreign body asphyxia increased with age, from 0.1 per 100,000 adults aged 18 to 64 years to 0.7 for individuals aged ⱖ65 years, which is consistent with the literature.4 – 6 It is remarkable that half of the elderly choked during lunch. Elderly individuals are known to devote more time processing food in the mouth and to require solids of a smaller particle size before the food can be swallowed.7,8 Thus, rapid feeding rates may overload marginally functional deglutition, resulting in life-threatening bolus misdirection into the airway. In addition, this study revealed semisolid dysphagia diets to significantly increase the risk of fatal food/ foreign body asphyxia in the elderly. Paradoxically, the commonly propagated semisolid dysphagia diets have been shown to significantly increase the risk of asphyxiation in this data set. The risk of death is further elevated because semisolids cannot be removed easily 68
by resuscitation interventions. For these two reasons, semisolid diets should not be commonly prescribed. The literature suggests that for dysphagic patients, food should not be semisolid, but instead limited to a particle size of 1 cm2 combined with careful patient monitoring at mealtimes.9 In the present study, neurologic disorders such as Parkinsonism, Alzheimer disease, or hemorrhagic stroke were prevalent in 43% of the choking victims aged ⱖ65 years. These neurologic conditions are known to be related to difficulties in mastication and motor coordination,10,11 which lead to oral-stage dysfunction12; 2.5% of the elderly who choked during feeding were neurologically impaired. Furthermore, all elderly individuals in the study who choked at breakfast had received a sedative the night before. High dosages of drugs with antidopaminergic or anticholinergic activity have been reported to increase the risk of choking.5,10,13 Another striking feature of this study was that intact dentition was evident in only 10%. Dentition in the elderly choking victims was markedly poor—all edentulous elderly were asphyxiated on semisolid, slick food. Statistically, alcohol was less a risk factor in the elderly population than in choking individuals aged 18 to 64 years. Nevertheless, 32% of the elderly victims had an elevated blood alcohol concentration at the time of death. With this data set, the risk factors of fatal food/ foreign body asphyxia could be successfully identified, demonstrating that the high autopsy rate in Vienna provided an excellent opportunity for detection of these fatal events, and may elucidate a potentially higher number of unknown cases. The identified risk factors— old age, poor dentition, semisolid foods, neurologic impairment, and intake of sedatives— could easily be incorporated into care guidelines presented in education programs. Based on the literature14 of childhood asphyxiation by food, another helpful tool might be the establishment of asphyxiation risk scores for adults and the definition of risky foods based on these scores. Education about food/foreign body asphyxia risk factors should not be limited to healthcare workers, but should be extended to the entire population, and especially people aged ⱖ65. For example, the preventive aspect of adequate dentition care and reconstruction must be started in adolescence and individual responsibility must be more heavily emphasized. As in many matters of preventive health, the prevention of choking deaths may be achieved by simple behavior changes and by the encouragement of healthy habits before and after the onset of old age. The contributing factor of poor dental health to food asphyxiation is yet another reason for the rigorous promotion of proper dental care.
American Journal of Preventive Medicine, Volume 28, Number 1
What This Study Adds . . . Foreign body asphyxia in the elderly was characterized by a significantly higher asphyxiation on soft/slick foods, with agomphiasis occurring most frequently during lunch and during feeding of the neurologically impaired. Especially among the elderly, semisolid foods are the cause of a large proportion of asphyxiations. A greater awareness of this risk factor among healthcare workers, as well among the general public, may help to reduce the incidence of this fatal event.
In cases of food/foreign body asphyxia where observers were present at the time of the fatal incident and with food lodged in the glottis and supraglottic region, application of the Heimlich maneuver15,16 might have been life saving. The obstructing material could have been removed by the simple insertion of fingers or by the use of a specially designed curved plastic forceps that is inserted into the mouth and hypopharynx.4,17 Administration of oxygen or mouth-to-mouth resuscitation before removal of the obstruction is obviously futile.17 However, the choking event was correctly identified during cardiopulmonary resuscitation in only 5% of the elderly study population and in 13% of the younger ones. Thus, lack of awareness on the part of first responders seems to be another crucial factor in the occurrence of fatal asphyxiation. In summary, this study demonstrates that in addition to the well-known risk factors, semisolid foods are, especially in the elderly, responsible for a large number of asphyxiations. The incidence of these fatal events could be easily reduced, but require understanding of circumstances and predisposing factors and their inclusion into care guidelines. Thorough education of
healthcare workers as well as raising awareness of the risk factors among the general populace, and especially the elderly, may also greatly enhance the prevention of food/foreign body asphyxia. We are grateful to John Leake for editing the manuscript version. The authors reported no financial conflict of interest.
References 1. Haugen RK. The cafe coronary—sudden deaths in restaurants. JAMA 1963;186:142–3. 2. Berzlanovich A, Muhm M, Sim E, Bauer G. Food/foreign body asphyxia—an autopsy study. Am J Med 1999;107:351–5. 3. Statistics Austria. Mortality records 1984 –2001. Vienna: Statistics Austria 2002 (data set). 4. Mittlemann RE, Wetli C. The fatal cafe coronary: foreign-body airway obstruction. JAMA 1982;247:1285–8. 5. Irwin RS, Ashba JK, Braman SS, Lee HY, Corrao WM. Food asphyxiation in hospitalized patients. JAMA 1977;237:2744 –5. 6. Gelperin A. Sudden death in the elderly population from aspiration of food. J Am Geriatr Soc 1974;22:135–6. 7. Hu T, Huang L, Cartwrigth WS. Evaluation of the costs of caring for the senile demented elderly: a pilot study. Gerontologist 1986;26:158 –62. 8. Fioritti A, Giaccotto L, Melega V. Choking incidents among psychiatric patients: retrospective analysis of thirty-one cases from the west Bologna psychiatric wards. Can J Psychiatry 1997;42:515–20. 9. Finestone HM, Foley NC, Woodbury MG, Greene-Finestone L. Quantifying fluid intake in dysphagic stroke patients: a preliminary comparison of oral and nonoral strategies. Arch Phys Med Rehabil 2001;82:1744 –6. 10. Pontoppidan H, Beecher HK. Progressive loss of protective reflexes in the airway with the advance of age. JAMA 1960;174:77–81. 11. Kendall KA, Leonard RJ. Bolus transit and airway protection coordination in older dysphagic patients. Laryngoscope 2001;111:2017–21. 12. Feinberg MJ, Ekberg O. Deglutination after near-fatal choking episode: radiologic evaluation. Radiology 1990;176:637–40. 13. Hsieh HH, Bhatia SC, Andersen JM, Cheng SC. Psychotropic medication and nonfatal cafe coronary. J Clin Psychopharmacol 1986;6:101–2. 14. Stallings Harris C, Baker SP, Smith GA, Harris RM. Childhood asphyxiation by food—a national analysis and overview. JAMA 1984;251:2231–5. 15. Heimlich HJ. A life-saving maneuver to prevent food-choking. JAMA 1975;234:398 –401. 16. Heimlich HJ, Patrick EA. Best technique for saving any choking victim’s life. Postgrad Med 1990;87:38 –48. 17. Eller WC, Haugen RK. Food asphyxiation—restaurant rescue. New Engl J Med 1973;289:81–82.
Am J Prev Med 2005;28(1)
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This is an autopsy-based, retrospective study in Vienna, Austria. Participants included all nonhospitalized (n ⫽200) cases of choking in 1984 to 2001, from a total 42,745 consecutive autopsies performed at the Institute of Forensic Medicine. In addition, data from hospitalized adult cases of fatal choking (n ⫽73) in 1984 to 2001, from the mortality registrar of Vienna, were included.
Results:
The nonhospitalized choking victims were analyzed according to age (18 to 64 vs ⱖ65 years), sex, circumstances of death, and predisposing factors. Hospitalized cases were analyzed according to age, sex, and whether an autopsy was already performed by pathologists at the institution where they died. In the study period, 273 adults died of food/foreign body asphyxia, 73% of them out of the hospital and 27% in hospitals. Food/foreign body asphyxia in the elderly was characterized by a significantly higher asphyxiation of soft/slick foods (p ⬍0.007) with agomphiasis (p ⬍0.002), occurring most frequently during lunch (49%), and in 2.5% during feeding of neurologically impaired. In contrast, younger individuals choked significantly more often on large pieces of foreign material (p ⬍0.002) and showed a significantly higher rate of blood alcohol concentration (p ⬍0.001).
Conclusions: This study demonstrates that semisolid foods are the cause of a large number of asphyxiations, especially among the elderly. Knowledge of the fact that semisolid foods are a high-risk factor in elderly individuals should be distributed in public and private healthcare systems, and awareness could be a first step in reducing the incidence of food/foreign body asphyxia. (Am J Prev Med 2005;28(1):65– 69) © 2005 American Journal of Preventive Medicine
Introduction
F
ood/foreign body asphyxia is well known to forensic pathologists. The description of the “cafe coronary,” a term coined by Haugen in 1963,1 enhanced awareness of the causes, prevention, and emergency treatment of food asphyxiation. However, even today, 40 years later, people observing sudden attacks— especially in the elderly— often do not suspect choking, and erroneously attribute death to coronary artery disease. A recent autopsy study of food/foreign body asphyxia at the Viennese Institute of
From the Institute of Forensic Medicine (Berzlanovich), Department of Internal Medicine I (Fazeny-Do¨rner), and Department of Epidemiology, Institute of Cancer Research (Waldhoer), University of Vienna Vienna, Austria; Geriatric Center Baumgarten (Fasching), Vienna, Austria; and Institute of Forensic Medicine, University of Munich (Keil), Munich, Germany Address correspondence and reprint requests to: Andrea M, Berzlanovich, MD, Institute of Forensic Medicine, University of Vienna, Sensengasse 2, A-1090 Vienna, Austria. E-mail: andrea. [email protected].
Forensic Medicine revealed that observers were present in 63% of the choking events. The fatal incident was correctly identified in only 8% of cases by emergency personnel. Common misdiagnoses were cardiovascular failure; epileptic seizures; and intoxication from medication, drugs, or alcohol.2 However, the special aspect of food/foreign body asphyxia in the elderly is rarely mentioned in current medical textbooks or journals, and remains largely uninvestigated. The fatal event of food/foreign body asphyxia may be preventable. Prevention depends on understanding the nature and frequency of food/foreign body asphyxia and its specific causes. Valuable data for community education could be obtained from medical examiners who catalog all sudden and unexpected deaths, in concert with an investigation at the scene of occurrence that is performed by a competent forensic pathologist. The current study had three purposes: (1) present results of an analysis of 18 years of autopsy data reporting food asphyxiation in a nonhospitalized pop-
Am J Prev Med 2005;28(1) © 2005 American Journal of Preventive Medicine • Published by Elsevier Inc.
0749-3797/05/$–see front matter doi:10.1016/j.amepre.2004.04.002
65
ulation; (2) identify risk factors influencing food asphyxiation, especially in elderly individuals; and (3) suggest preventive as well as effective accident control strategies that can be used to minimize the risk of food asphyxiation among the elderly.
Methods The Viennese Institute of Forensic Medicine is the unique institution in Vienna responsible for determining the cause and manner of death in all cases of unexpected deaths occurring out of hospitals. Its geographic jurisdiction encompasses the greater Vienna area, with a population base of 1.6 million people. At present, approximately 53% of Vienna residents are female. Although the proportion of the population aged ⬎60 years has been declining since 1971, Vienna still has the largest share of elderly people (20.7%) compared to Austria’s other provinces. Women account for 64% of the population aged ⬎60 and 72% of those aged ⬎75.3 Approximately 18% of Vienna’s resident population are foreign nationals, most of whom emigrated from Yugoslavia and its successor states and Turkey. Austrian law requires the use of an autopsy to detail and ascertain the cause of each death of people who died outside of hospitals when the cause is uncertain and in cases in which a physician has not been consulted within 10 days before death. Thus, all unexpected out-of-hospital deaths in Vienna are investigated at the Viennese Institute of Forensic Medicine.
Subjects Inclusion criteria for this study were adult non-hospitalized and hospitalized victims aged ⬎18 years, fulfilling the working definition of deaths from asphyxia by foreign objects as defined by the ICD-9 code: “Foreign body in pharynx and larynx,” which includes “pharynx, nasopharynx and throat not otherwise specified” (933.0), and larynx “asphyxia due to foreign body” and “choking” due to “food (regurgitated) or phlegm” (933.1). The data from the adult hospitalized individuals who had choked (n ⫽73) and the sex of the deceased from 1984 to 2001 were provided from the mortality registrar of Vienna.3 For all nonhospitalized individuals who died of food/ foreign body asphyxia, records were gathered of 42,745 autopsies performed at the Institute of Forensic Medicine. The autopsy reports and medical histories of the individuals were evaluated with regard to age, sex, circumstances of death, type and consistency of the obstructing foreign material, and consumption of alcohol or sedative and hypnotic drugs. Furthermore, the characteristics associated with food/ foreign body asphyxia were analyzed according to age (18 to 64 versus ⱖ65 years). All autopsies were performed by eight physicians specialized in forensic medicine. The number of all hospitalized individuals during the study period was provided by the mortality registrar of Vienna, from which the sample of choking victims was drawn. For this group, the data were analyzed according to age, sex, and whether an autopsy was performed by local pathologists at the institution where the individuals died.
66
Statistics Comparisons of continuous variables were made with the Mann–Whitney U test. Chi-square tests were used to calculate p values for comparisons in 2⫻2 contingency tables. Direct standardized rates (SRs) and 95% confidence intervals (CIs) were calculated. SAS (SAS Institute Inc., Cary NC, 2001) was used for performing all calculations. A p value of ⬍0.05 was considered statistically significant.
Results Incidence of Foreign Body Asphyxia, Age, Sex, and Autopsy Rate in Nonhospitalized and Hospitalized Individuals From 1984 through 2001, 273 nonhospitalized and hospitalized adults died of food/foreign body asphyxia in Vienna, resulting in an average of two victims per 100,000 population (men: SR⫽2.7, CI⫽2.4 –3.1; women: SR⫽1.3, CI⫽1.1–1.6; total: SR⫽2, CI⫽1.8 –2.2). The Viennese Institute of Forensic Medicine performed an autopsy on all 200 nonhospitalized choking victims, accounting for 0.5% of deaths out of 42,745 consecutive autopsies. The male-to-female ratio was 1.2:1. The median age was 65 (range, 27 to 91) years; 105 of 200 (53%) were aged ⱖ65 years and 95 (47%) were aged 18 to 64 years. A total of 272,594 hospitalized patients died during the study period in Vienna. Of this total, 73 died due to food/foreign body asphyxia, accounting for 0.03% of all deaths in hospitals; 49 of the latter (67%) underwent autopsy because the cause of death was not ascertained by the caregiver team. In these cases, food/foreign body asphyxia was not suspected at the time of death, but was identified by the autopsy. In the remaining 24 cases, an autopsy was not performed because the inferred cause of death was not questioned. The median age of the hospitalized individuals was 73 years (range, 45 to 96); the male-to-female ratio was 0.8:1.
Medical History of Nonhospitalized Individuals One third of the deceased were described as healthy at the time of death. Pre-existing conditions were present in the remaining and are depicted in Table 1. In 43% (45 of 105) of individuals aged ⱖ65, neurologic disorders including Parkinsonism, Alzheimer disease, and hemorrhagic stroke were evident.
Circumstances of Death of Nonhospitalized Individuals Sixty-nine percent of the fatal incidents occurred in private homes, 15% in restaurants, 9.5% in private nursing institutions, 5% in public areas, and 1.5% during transportation to a hospital. Five neurologically impaired victims (2.5%) choked during feeding. Of 137 eyewitnesses, 94 uniformly reported at least three of the
American Journal of Preventive Medicine, Volume 28, Number 1
Table 1. Medical history of 200 nonhospitalized adult victims of fatal foreign body asphyxia, by age Pre-existing conditions of deceased Without any symptoms, presumably healthy Neuropsychiatric diseases Cardiovascular disease Diabetes mellitus Oral/pharyngeal/ gastrointestinal disorders Total
Table 2. Type and consistency of asphyxiated foreign material in 200 nonhospitalized adult victims, by age
Age 18–64 years (n) 45
Age >65 years (n) 18
Total (n) 63
23
56
79
20
41
61
9 4
11 16
20 20
95
105
200
following: cessation of eating and talking, apnea, paleness, cyanosis, and collapse.
Time of Death of Nonhospitalized Individuals
18–64 years (n)
>65 years (n)
Asphyxiated material Meat, fish 57 43 Sausage 16 25 Bread, pizza, 9 15 cookies, pastries Fruit, vegetables 8 6 Noodles 1 4 Cheese, eggs 1 1 Denture 0 2 Not identified 3 9 Total 95 105 Consistency of asphyxiated material (nⴝ188) Solids 86 38 One piece of food/ 63 4 foreign material Two or more pieces 23 34 Semisolids 6 58
Total (n) 100 41 24 14 5 2 2 12 200 124 67 57 64
In 137 of 200 cases, the time of the event could be precisely determined. Fatal food/foreign body asphyxia occurred at breakfast for 44, at lunch for 50, and at dinner for 17, and with snacks for 26 cases. Thirty-seven of the 50 individuals who died at lunch were ⬎65 years, representing 49% of the elderly with determined time of death (n ⫽ 75). All elderly (n ⫽10) who had received a sedative the night before, choked in the early morning.
bolus size ranged from a plum (up to 3 cm in diameter) to an apricot (up to 5 cm in diameter). The largest obstructing foodstuff encountered at autopsy was a meat chunk with a weight of 50 g, measuring 11⫻7⫻2 cm. The location of the obstructing material was the supraglottic region or within the glottis itself in 74%, presumably within reach of fingers, whereas the bolus was lodged in the infraglottic area in 26%. In 24% the first morsel of food was lethal; in the remaining 76% of cases the stomach contained undigested food.
Asphyxiated Food/Foreign Material in Nonhospitalized Individuals
Dentition of Nonhospitalized Individuals
In 188 of 200 individuals, the obstructing bolus could be identified at autopsy. The foreign material that caused asphyxia were common foods in Vienna, such as meat, fish, sausage, bread, pizza, cookies, and pastries (Table 2). It was a solid in 124 cases and semisolid in 64 cases. The obstructing foods were chunks of meat/fish in 50%, and a chunk of sausage in 20%. A bolus consisting of bread, pizza, cookies, or pastries was noted in 12%, while fruit or vegetables accounted for another 7%. A displaced denture was determined to be the cause of asphyxia in two cases. A single chunk of food created an obstruction in 68% of individuals aged 18 to 64 years, and in only 4% of individuals aged ⱖ65 years (p ⬍0.002). Thirty-five percent of the elderly choked on more complex boluses (sausages on a bun, sandwiches, meatballs, meat and vegetables/noodles), and 61% on semisolids (puree, ground meat, mashed fruits), as compared to a combined total of 7% among the 18- to 64-year-olds (p ⬍0.007). A large mass of food was found in the mouths of 46% of all patients aged ⱖ65 years. The
Only 10% of victims had intact dentition (closed alignment with a minimum of 24 teeth), 32% had partial or complete dentures, 31% had defective or partial dentition without dental prostheses, and 27% were edentulous at the time of death (Table 3). Agomphiasis (being edentulous) correlated with age (p ⬍0.002). Table 3. Dentition in 200 nonhospitalized adult victims, by age Age Dentition Intact dentition Partial/complete dentures Edentulous Defective/partial dentition without dental protheses Total
18–64 years (n)
>65 years (n)
Total (n)
p value
15 20
5 44
20 64
0.079 0.215
18 42
35 21
53 63
0.002 0.253
95
105
200
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Alcohol and Toxicologic Analysis in Nonhospitalized Individuals Blood alcohol concentration and blood levels for sedative and/or hypnotic drugs were analyzed in all 200 cases. At the time of death, 50% of the victims were sober. The remaining had blood alcohol levels ranging from 0.1% to 4.4%. Blood alcohol concentration was significantly higher in individuals aged 18 to 64 years compared to those aged ⱖ65 years (p ⬍0.001). Positive blood levels for sedative and/or hypnotic drugs were found in 12 cases (6%).
Medical Interventions in Nonhospitalized Individuals In 68% (n ⫽137) of cases, other people were in the vicinity of the victim, so emergency services were called and cardiopulmonary resuscitation started. Resuscitation attempts at the scene included artificial respiration, mouth-to-mouth resuscitation, and, in two instances, the Heimlich maneuver. Physicians’ reports revealed that in 125 of 137 cases the choking event, being the initial cause for emergency intervention, was not subsequently recognized as asphyxiation. Before autopsy, death caused by food/foreign body asphyxia was correctly identified in 4 of the 75 (5%) cases of individuals aged ⱖ65 years, and in 8 of the 62 (13%) cases aged 18 to 64 years.
Discussion This study demonstrates old age, poor dentition, neurologic disorders, certain types of foods, and the intake of sedatives as risk factors for food/foreign body asphyxia. Prevention of these fatal events requires neither special diagnostic facilities nor highly sophisticated knowledge, but merely a simple awareness of predisposing factors. In this data set, fatal food/foreign body asphyxia increased with age, from 0.1 per 100,000 adults aged 18 to 64 years to 0.7 for individuals aged ⱖ65 years, which is consistent with the literature.4 – 6 It is remarkable that half of the elderly choked during lunch. Elderly individuals are known to devote more time processing food in the mouth and to require solids of a smaller particle size before the food can be swallowed.7,8 Thus, rapid feeding rates may overload marginally functional deglutition, resulting in life-threatening bolus misdirection into the airway. In addition, this study revealed semisolid dysphagia diets to significantly increase the risk of fatal food/ foreign body asphyxia in the elderly. Paradoxically, the commonly propagated semisolid dysphagia diets have been shown to significantly increase the risk of asphyxiation in this data set. The risk of death is further elevated because semisolids cannot be removed easily 68
by resuscitation interventions. For these two reasons, semisolid diets should not be commonly prescribed. The literature suggests that for dysphagic patients, food should not be semisolid, but instead limited to a particle size of 1 cm2 combined with careful patient monitoring at mealtimes.9 In the present study, neurologic disorders such as Parkinsonism, Alzheimer disease, or hemorrhagic stroke were prevalent in 43% of the choking victims aged ⱖ65 years. These neurologic conditions are known to be related to difficulties in mastication and motor coordination,10,11 which lead to oral-stage dysfunction12; 2.5% of the elderly who choked during feeding were neurologically impaired. Furthermore, all elderly individuals in the study who choked at breakfast had received a sedative the night before. High dosages of drugs with antidopaminergic or anticholinergic activity have been reported to increase the risk of choking.5,10,13 Another striking feature of this study was that intact dentition was evident in only 10%. Dentition in the elderly choking victims was markedly poor—all edentulous elderly were asphyxiated on semisolid, slick food. Statistically, alcohol was less a risk factor in the elderly population than in choking individuals aged 18 to 64 years. Nevertheless, 32% of the elderly victims had an elevated blood alcohol concentration at the time of death. With this data set, the risk factors of fatal food/ foreign body asphyxia could be successfully identified, demonstrating that the high autopsy rate in Vienna provided an excellent opportunity for detection of these fatal events, and may elucidate a potentially higher number of unknown cases. The identified risk factors— old age, poor dentition, semisolid foods, neurologic impairment, and intake of sedatives— could easily be incorporated into care guidelines presented in education programs. Based on the literature14 of childhood asphyxiation by food, another helpful tool might be the establishment of asphyxiation risk scores for adults and the definition of risky foods based on these scores. Education about food/foreign body asphyxia risk factors should not be limited to healthcare workers, but should be extended to the entire population, and especially people aged ⱖ65. For example, the preventive aspect of adequate dentition care and reconstruction must be started in adolescence and individual responsibility must be more heavily emphasized. As in many matters of preventive health, the prevention of choking deaths may be achieved by simple behavior changes and by the encouragement of healthy habits before and after the onset of old age. The contributing factor of poor dental health to food asphyxiation is yet another reason for the rigorous promotion of proper dental care.
American Journal of Preventive Medicine, Volume 28, Number 1
What This Study Adds . . . Foreign body asphyxia in the elderly was characterized by a significantly higher asphyxiation on soft/slick foods, with agomphiasis occurring most frequently during lunch and during feeding of the neurologically impaired. Especially among the elderly, semisolid foods are the cause of a large proportion of asphyxiations. A greater awareness of this risk factor among healthcare workers, as well among the general public, may help to reduce the incidence of this fatal event.
In cases of food/foreign body asphyxia where observers were present at the time of the fatal incident and with food lodged in the glottis and supraglottic region, application of the Heimlich maneuver15,16 might have been life saving. The obstructing material could have been removed by the simple insertion of fingers or by the use of a specially designed curved plastic forceps that is inserted into the mouth and hypopharynx.4,17 Administration of oxygen or mouth-to-mouth resuscitation before removal of the obstruction is obviously futile.17 However, the choking event was correctly identified during cardiopulmonary resuscitation in only 5% of the elderly study population and in 13% of the younger ones. Thus, lack of awareness on the part of first responders seems to be another crucial factor in the occurrence of fatal asphyxiation. In summary, this study demonstrates that in addition to the well-known risk factors, semisolid foods are, especially in the elderly, responsible for a large number of asphyxiations. The incidence of these fatal events could be easily reduced, but require understanding of circumstances and predisposing factors and their inclusion into care guidelines. Thorough education of
healthcare workers as well as raising awareness of the risk factors among the general populace, and especially the elderly, may also greatly enhance the prevention of food/foreign body asphyxia. We are grateful to John Leake for editing the manuscript version. The authors reported no financial conflict of interest.
References 1. Haugen RK. The cafe coronary—sudden deaths in restaurants. JAMA 1963;186:142–3. 2. Berzlanovich A, Muhm M, Sim E, Bauer G. Food/foreign body asphyxia—an autopsy study. Am J Med 1999;107:351–5. 3. Statistics Austria. Mortality records 1984 –2001. Vienna: Statistics Austria 2002 (data set). 4. Mittlemann RE, Wetli C. The fatal cafe coronary: foreign-body airway obstruction. JAMA 1982;247:1285–8. 5. Irwin RS, Ashba JK, Braman SS, Lee HY, Corrao WM. Food asphyxiation in hospitalized patients. JAMA 1977;237:2744 –5. 6. Gelperin A. Sudden death in the elderly population from aspiration of food. J Am Geriatr Soc 1974;22:135–6. 7. Hu T, Huang L, Cartwrigth WS. Evaluation of the costs of caring for the senile demented elderly: a pilot study. Gerontologist 1986;26:158 –62. 8. Fioritti A, Giaccotto L, Melega V. Choking incidents among psychiatric patients: retrospective analysis of thirty-one cases from the west Bologna psychiatric wards. Can J Psychiatry 1997;42:515–20. 9. Finestone HM, Foley NC, Woodbury MG, Greene-Finestone L. Quantifying fluid intake in dysphagic stroke patients: a preliminary comparison of oral and nonoral strategies. Arch Phys Med Rehabil 2001;82:1744 –6. 10. Pontoppidan H, Beecher HK. Progressive loss of protective reflexes in the airway with the advance of age. JAMA 1960;174:77–81. 11. Kendall KA, Leonard RJ. Bolus transit and airway protection coordination in older dysphagic patients. Laryngoscope 2001;111:2017–21. 12. Feinberg MJ, Ekberg O. Deglutination after near-fatal choking episode: radiologic evaluation. Radiology 1990;176:637–40. 13. Hsieh HH, Bhatia SC, Andersen JM, Cheng SC. Psychotropic medication and nonfatal cafe coronary. J Clin Psychopharmacol 1986;6:101–2. 14. Stallings Harris C, Baker SP, Smith GA, Harris RM. Childhood asphyxiation by food—a national analysis and overview. JAMA 1984;251:2231–5. 15. Heimlich HJ. A life-saving maneuver to prevent food-choking. JAMA 1975;234:398 –401. 16. Heimlich HJ, Patrick EA. Best technique for saving any choking victim’s life. Postgrad Med 1990;87:38 –48. 17. Eller WC, Haugen RK. Food asphyxiation—restaurant rescue. New Engl J Med 1973;289:81–82.
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