Signa Vitae. 2022; 18(2): 71-77. doi: 10.22514/sv.2021.220
Original Research

Epidemiology and clinical outcomes of emergency medical events at an international airport

Dongjoon Yoo1, Jin Hui Paik1, Won Kyung Lee2, Areum Durey3, Soo Kang1, Seung Baik Han3, Ji Hye Kim3, Yu Jin Lee3,*,

1Department of Emergency Medicine, Inha University Hospital, 22332 Incheon, Republic of Korea

2Department of Prevention and Management, Inha University School of Medicine, 22212 Incheon, Republic of Korea

3Department of Emergency Medicine, Inha University School of Medicine, 22212 Incheon, Republic of Korea

*Corresponding Author(s):eyeblack99@gmail.com (Yu Jin Lee)

History Submitted: 11 July 2021 | Accepted: 05 August 2021 | Published: 08 March 2022
Copyright:  ©2022  The Author(s). Published by MRE Press.
This is an open access article under the CC BY 4.0 license (https://creativecommons.org/licenses/by/4.0/).

Collapse table of contents

Abstract

The use of airplanes is becoming increasingly frequent worldwide. However, although the number of flight passengers is steadily increasing, there is no comprehensive database that accurately reflects the frequency of emergency medical events that occur in airports. We evaluated the characteristics and treatment outcomes of patients who had emergency medical events at an airport. We retrospectively reviewed cases of patients who had emergency medical events at International Airport between May 2013 and April 2018. A comparative analysis was conducted on gender, age, disease, temperament, and average length of stay between patients visiting the airport and the general population visiting the emergency room (ED). Among the 258,823 patients who visited our ED during the study period. A total of 846 patients (0.3%) were transferred from the airport; the proportion of men was 59.3%, the mean age of the subjects was 43.7 ± 20.1 years. The admission and mortality rates of the patients in the airport group were relatively higher (35.1% and 2.6%, respectively) than that of those in the direct ED visit group (21.6% and 0.5%, respectively). Abdominal disease was the most common medical problem, and the most common causes of death were sudden cardiac arrest and acute myocardial infarction. Future prospective studies are necessary to affirm its findings.

Keywords:Epidemiology;Emergency;Airport
PDF(2.13 MB)|EndNote (RIS)|BibTeX|RefMan|RefWorks

Cite this article

Dongjoon Yoo, Jin Hui Paik, Won Kyung Lee, Areum Durey, Soo Kang, Seung Baik Han, Ji Hye Kim, Yu Jin Lee. Epidemiology and clinical outcomes of emergency medical events at an international airport. Signa Vitae. 2022; 18(2): 71-77. doi: 10.22514/sv.2021.220

1. Introduction

Air travel is becoming increasingly frequent worldwide. Before the outbreak of the coronavirus disease, the speed and comfort of air travel prompted 4.5 billion passengers to travel through commercial airlines annually [1]. It is estimated that more than half of all airplane passengers will be aged ≥50 years by 2030. Some previous literature have suggested that as the global population is getting older and number of aircraft passengers is gradually increasing, the frequency of urgent medical events during flights has gradually increased [2, 3].

Although aircrafts depart and return to terra firma, they generally cruise at an altitude of 10,000 m, which entails changes in environmental conditions, including hypoxia, low pressure level and humidity, and prolonged sitting, that might be stressful for special individuals [4, 5]. Extended exposure to these stressful conditions might lead to in-flight medical emergencies (IMEs) which while not common are not rare either. The prevalence of IMEs is 1 in every 604 flights [6].

Several studies have focused on the symptoms, prevalence, and in-flight emergency care aspects of IMEs [7, 8, 9, 10, 11, 12]. However, there have been no studies on the aspects of patients and treatment outcomes of emergency medical events that occur in airports, a special environment in which emergency medical systems are less accessible due to security and take-off and landing reasons.

In this study, we explored the characteristics and treatment outcomes of patients with various symptoms, who had emergency medical events at an airport.

2. Materials and methods

Our hospital is a tertiary academic hospital that is the primary and unique referral hospital for Incheon International Airport, the biggest airport in South Korea and 16th most frequently visited airport worldwide [13]. Clinics in Incheon airport are directly managed by our hospital, and most patients in need of emergency transfer are accommodated in our center.

2.1 Data collection and variables

This is a descriptive cross-sectional study using medical records. We reviewed all cases of patients who visited our emergency department (ED) for emergency medical events that occurred at Incheon International Airport between May 2013 and April 2018; which encompasses all severe IME cases transferred from airport clinic for further evaluation or emergency treatment and also cases occurred at the airport which not on flight. The sex distribution, age distribution, medical or other diseases (trauma, delivery, intoxication, and others), disposition, and mean length of stay (LOS) of the study subjects were analyzed and compared with those of the general population that visited our ED. The severity classification used Korean Triangle and Acuity Scale (KTAS). KTAS is a severity classification standard developed based on Canadian Triangle and Acuity Scale and currently being used [14, 15, 16]. According to the result of KTAS classification, level 1 was classified as serious, level 2 as severe, level 3 as moderate and level 4, 5 as slight.

2.2 Main outcomes

We conducted a retrospective comparative analysis of all patients who visited our hospital ED, including airport ED visits and direct ED visits, between May 2013 and April 2018. A demographic comparative analysis was conducted between the airport ED visits group and the direct ED visit groups. The clinical outcomes of the study subjects, including their disposition and LOS in the ED, were reviewed and all parameters were compared with those of the patients who visited the ED directly. Classification according to their disease entity and triage of their severity of the study group were carried out; a comparative analysis of incidence between 3 groups of age-children (age <15 years), adults (aged 15–65 years), elderly (aged >65 years) was done, apart. Dead patients among the study subjects were reviewed separately, including their age, sex, nationality, chief complaint and cause of death and their most common cause of death and chief complaints were identified.

2.3 Statistical analyses

Categorical variables are expressed as numbers and percentages, and continuous variables are presented as means and standard deviations in the description analysis. We performed a comparative analysis of the two groups using a Chi-square test for categorical variables and a Mann-Whitney U test for continuous variables because the sample size was extreme. Both Chi-Square and Mann-Whitney U tests are non-parametric tests and are robust when the sample sizes are not equal. All reported p values were two-sided. Statistical significance was set at p < 0.05. Stata software version 16 (StataCorp, College Station, TX, USA) was used for the analyses.

3. Results

During the study period, 258,823 patients visited the ED of our hospital. Of these, we excluded 2933 patients who visited the ED for simple medical records without consultations and 32 patients with unknown age and sex. A total of 255,858 cases were finally included in the analysis; of these, 846 (0.3%) were cases transferred from the airport, whereas 255,012 (99.7%) were direct ED visits (Fig. 1).

Patient flowchart. ED, emergency department.

Fig. 1.Patient flowchart. ED, emergency department.

3.1 Demographic characteristics

A comparative analysis of the demographic data showed differences between the two groups (Table 1). The male-to-female ratio in the airport group (59.3% vs. 40.7%) was higher than that in the direct ED visit group (53.8% vs. 46.2%) (p < 0.01). Of note, the proportion of children aged <15 years in the airport group was much lower than that in the direct ED visit group (8.2% vs. 33.5%). In contrast, the proportions of adults (aged 15–65 years) and elderly persons (aged >65 years) in the airport group were higher than those in the direct ED visit group (adult: 75.1% vs. 51.3%, elderly: 16.8% vs. 15.2%, respectively). The average age at the time of visit was significantly higher in the airport group than in the direct ED visit group (43.7 years vs. 33.4 years) (p < 0.01). Regarding types of disease, medical disease and injury accounted for 80.6% and 19.4% of all cases in the airport group, respectively, and 71.4% and 28.6% of all cases in the direct ED visit group, respectively. Thus, a significantly higher incidence of medical disease was noted in the airport group (p < 0.01).

Table 1.Demographic characteristics of the study participants.
VariablesTotalDirect ED visitVisit from airportp value
n%n%n%
Total255858100.025501299.78460.3
Sex<0.01
Male13778253.913728053.850259.3
Female11807646.111773246.234440.7
Age group<0.01
Child (age <15)8539633.48532733.5698.2
Adult (15 ≤ age <65)13143351.413079851.363575.1
Elderly (age ≥65)3902915.33888715.214216.8
Average (mean ± SD), year33.5 ± 26.533.4 ± 26.543.7 ± 20.1<0.01
Disease type<0.01
Medical disease18281571.518213371.468280.6
Injury7304328.57287928.616419.4
ED results<0.01
Admission5621022.05519321.629735.1
Transfer20660.820260.8404.7
Discharge19619476.719570776.748757.6
Death13880.513660.5222.6
ED LOS (mean ± SD), min148.4 ± 140.8147.9 ± 134.3297.1 ± 735.1<0.01
ED, emergency department; LOS, length of stay.

3.2 Treatment outcomes of the study participants

A comparative analysis of the treatment outcomes of patients transferred from the airport and those of patients not related to flights was performed. The admission rate in the airport group was 35.1%, which was much higher than the 21.6% in direct ED visit group. The rate of transfer to other hospitals was 4.7% in the airport group and 0.8% in the direct ED visit group. The rate of discharge was much lower in the airport group (57.6%) than in the direct ED visit group (76.7%). Regarding the rate of death, the patients in the airport group markedly passed away more than those in the direct ED visit group (2.6% vs. 0.5%). The mean LOS in the emergency department appeared to be significantly longer in the airport group than in the direct ED visit group (297.1 ± 735.1 min vs. 147.9 ± 134.3 min; p < 0.01) (Table 1).

3.3 Diagnoses and disease severity among patients transported from the airport

Among the 846 patients who needed emergency transfer from the airport to our hospital, the most common medical problem was acute abdominal pain (166 patients) (Fig. 2), followed by cerebrovascular problems (145 patients), injuries (138 patients), cardiovascular problems (120 patients, including 23 syncope patients), respiratory problems (55 patients), infectious problems (51 patients), gynecological problems (31 patients), psychiatric problems (29 patients), gastrointestinal (GI) bleeding and metabolic diseases (23 patients each), and other problems (intoxication and others) (38 patients).

Diagnosis and severity of diseases among patients transported from the airport. GI, gastrointestinal.

Fig. 2.Diagnosis and severity of diseases among patients transported from the airport. GI, gastrointestinal.

The analysis of disease severity demonstrated that disease severity was markedly higher in the GI bleeding group, with 60.86% of the cases being serious or severe (Fig. 2). Other medical problems that showed considerably high severity (serious and severe) included cardiovascular (42.50%), respiratory (41.82%), cerebrovascular (33.10%), metabolic (39.13%) and infectious (21.57%) problems.

To determine the age distribution according to disease, the patients were classified as children (aged <15 years), adults (aged 15–65 years), and elderly (aged >65 years). Except for gynecological problems, which were encountered only in a limited number of female patients of menstruating age, injuries (28 cases) and infectious diseases (17 cases) occurred most in the pediatric population. Abdominal (145 cases) and cerebrovascular (121 cases) problems were the most common medical problems in the adult population. Cardiovascular problems (27 cases), injuries (21 cases), and cerebrovascular (19 cases) problems were the most common in the elderly population (Fig. 3).

Age distribution according to disease diagnosis among patients from the airport. GI, gastrointestinal; DOA, dead on arrival.

Fig. 3.Age distribution according to disease diagnosis among patients from the airport. GI, gastrointestinal; DOA, dead on arrival.

3.4 Analysis of dead patients

We reviewed all dead patient cases and recorded the age, sex, and nationality of the patient, year of visit, chief complaints, cause of death, and whether the patient had the medical event before departure or after arrival (Table 2). In dead patients, the most common chief complaints were “no respiration”, and the most common causes of death were sudden cardiac arrest and acute myocardial infarction. Of the 36 patients who died, 22 died before arrival at the hospital or during emergency treatment, 14 died after admission to the intensive care unit. Regarding the nationality of the dead patients, 12 (33.33%) were South Korean, 11 (30.56%) were Chinese, 7 (19.44%) were American, 2 (5.56%) were Russian, 1 (2.78%) was Japanese, 1 (2.78%) was Senegalese, 1 (2.78%) was Indonesian, and 1 (2.78%) was Filipino. The number of male patients who died outweighed that of females (3.5-fold, 28 patients vs. 8 patients). The age of the dead patients ranged from 1 day to 83 years (53.5 ± 18.3 years). Ten patients were before departure, and 26 were after arrival at the airport.

Table 2.Chief complaint and cause of death of the dead patients.
NoYearArrival or departureChief complaintCause of death
12013ArrivalDeath on arrivalSudden cardiac arrest
22013DepartureAspiration of foodAsphyxia
32013ArrivalNo respirationSudden cardiac arrest
42013ArrivalNo respirationPulmonary embolism
52013ArrivalDyspneaMalignant melanoma
62014ArrivalMental changeIntracerebral hemorrhage
72014ArrivalMental changeAsphyxia
82014ArrivalDyspneaPulmonary embolism
92014ArrivalNo respirationSudden cardiac arrest
102014ArrivalDyspneaUpper gastrointestinal bleeding
112014ArrivalNo respirationSubarachnoid hemorrhage
122014ArrivalNo respirationSudden cardiac arrest
132014DepartureUnspecified chest painAcute myocardial infarction
142014ArrivalChest PainAcute myocardial infarction
152014ArrivalMental changeIntracerebral hemorrhage
162014ArrivalNo respirationSudden cardiac arrest
172014ArrivalPost-CPR stateAcute myocardial infarction
182015DepartureNo respirationChild C liver cirrhosis
192015ArrivalNo respirationChild C liver cirrhosis
202015ArrivalCardiac arrestAcute myocardial infarction
212015ArrivalNo respirationSudden cardiac arrest
222016ArrivalNo respirationSudden cardiac arrest
232016ArrivalDyspneaHepatocellular carcinoma
242016ArrivalNo respirationHyperkalemia
252016ArrivalNo respirationSudden cardiac arrest
262017DepartureNo respirationSudden cardiac arrest
272017DepartureCardiac arrestSudden cardiac arrest
282017ArrivalDead on arrivalSudden cardiac arrest
292017ArrivalNo respirationPulmonary embolism
302017ArrivalNo respirationSudden cardiac arrest
312017DepartureDead on arrivalSudden cardiac arrest
322018DepartureLoss of ConsciousnessHepatocellular carcinoma
332018ArrivalNo respirationAcute myocardial infarction
342018DepartureNo respirationAcute myocardial infarction
352018DepartureMental changeHepatocellular carcinoma
362018DepartureDead on ArrivalDrowning
CPR, Cardiopulmonary resuscitation.

4. Discussion

The analysis of the 846 patients who visited the ED from the airport showed that the most common medical problem diagnosed was related to abdominal pain. Comparative analysis demonstrated that the mean age of the patients in the airport group was higher, and the proportions of pediatric patients and injury-related visits were lower than that in the direct ED visit group. Regarding treatment outcomes, higher admission and mortality rates were identified in the airport group than in the direct ED visit group, and the most common causes of death were sudden cardiac arrest and acute myocardial infarction.

This study describes the clinical symptoms (chief complaints) of patients, who had emergency medical events in an airport, which is a unique environment, their demographic classification, diagnoses, and treatment outcomes after proper consultation and examination in a tertiary hospital emergency medical center. Our study is different from previous studies in that most previous studies showed data of inflight emergencies based on records written by flight-related personnel, using the initial chief complaints as a parameter to classify the patients. In addition, information on treatment outcomes and proper diagnosis were not included in those studies [7, 8, 9, 10, 11, 12]. Some articles with information on proper diagnosis and treatment outcomes were focused on individual diseases, such as stroke, venous thrombosis, pulmonary thromboembolism, and pneumothoraxes [17, 18, 19, 20]. Peterson et al. [6] conducted a large high-quality retrospective study on 11,920 IME cases, a thorough study that included descriptions of the symptoms of IMEs, classification of the patients after consultation, and their treatment outcomes. Nevertheless, a detailed demographic classification was not included in that study [6]. A similar study based on the clinic in an airport was performed in Japan. A certain number of cases of mild severity was included in that study. Information regarding disease severity was derived from clinical data, and the severity of transferred cases and their outcomes were described in limited detail, with only 36 cases mentioned [21].

The data of the present study showed that 0.5 emergency patients were transferred to our center per day. This is a lower number than the 3–4 patients per day reported in a Japanese airport clinic study [21], and the 2.7 cases per day reported in the study by Peterson et al. [6]. This difference could be attributed to the nature of our center, which is a tertiary referral hospital where more severe cases are referred to from the airport clinic. The number of patients transferred annually increased gradually, with 122 patients in the first year of study and 277 patients in the fifth year; 7.2 deaths were recorded per year, a result similar to the 7–8 cases per year reported in Japan and 5.64 cases per year reported in the study by Peterson et al. [6].

Regarding disease entities, syncope was not included in our classification criteria. The final common pathway of syncope is the same regardless of the underlying cause: about 10 s of complete disruption of blood flow or nutrient delivery to both cerebral cortices or to the brainstem reticular activating system, or reduction of cerebral perfusion by 35%–50%. More commonly, an inciting event causes a drop in cardiac output, which decreases oxygen and substrate delivery to the brain [22]. The Framingham Heart Study described the most common causes of syncope, which included vasovagal (reflex mediated, 21%), cardiac (10%), orthostatic (9%), medication-related (7%), neurologic (4%), and unknown (37%) causes [23]. Each syncope case in the present study was classified into categories of proper disease entities, except for syncope cases of unknown causes, which were classified as cardiovascular cases.

Excluding syncope, abdominal pain was the most common symptom of IMEs in most previous studies, with incidences ranging from 9.8% to 32.2%, which is in accordance with the 19.62% noted in our study data [6, 7, 8, 9, 10, 11, 12, 21]. Cerebrovascular diseases were the second most common reason (17.13%) for transfer to the ED in the present study. The Japanese study indicated that cerebrovascular disease was the second most common reason (10.9%) for transfer to the hospital, but fifth from the clinical data.

There are some limitations to the present study. First, analysis was limited owing to the retrospective nature of the study. Second, generalization of the findings can be limited because the study was performed in a single center. In addition, regional characteristics could be involved because of the urban location of the center. Third, although most emergency cases were transferred to our center and enrolled in this study, some cases could be omitted owing to the situation of the center or a patient’s strong objection to transfer.

5. Conclusions

The group of patients who visited our emergency center from the airport had a lower proportion of pediatric patients, higher disease severity, and a higher LOS than those who directly visited the emergency center. Analysis of the consultation data of the center indicated that abdominal disease was the most common medical problem, and that mortality was higher among the group of patients who visited our emergency center from the airport than among the group of patients who visited the center directly. Regarding dead patients, the proportion of males among the dead patients was 3.5 times higher than that of females. The most common causes of death were sudden cardiac arrest and acute myocardial infarction. More thorough, larger, and prospective studies of different medical events in airports are necessary.

Author contributions

Conceptualization—DJY, YJL, JHP. Data curation—DJY, YJL. Formal analysis—YJL. Methodology—YJL, WKL, SK. Supervision—SBH, JHK, AD, JHP. Writing—original draft—DJY, YJL. Writing—review & editing—YJL, WKL.

Ethics approval and consent to participate

This study was approved by the Institutional Review Board of Inha University Hospital (IRB No. 2019-04-009). The board waived the need for informed consent.

Acknowledgment

Thanks to all the peer reviewers for their opinions and suggestions.

Funding

This work was supported by INHA UNIVERSITY Research Grant (2020). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Conflict of interest

The authors declare no conflict of interest.

Data availability

The data used to support the findings of this study are available from the corresponding author upon request.

References

IATA. <iata-annual-review-2020.pdf>. Available at: https://www.iata.org/en/publications/annual-review/ (Accessed: 21 March 2021).

[Google Scholar]

Dowdall N. “Is there a doctor on the aircraft?” Top 10 in-flight medical emergencies. British Medical Journal. 2000; 321: 1336–1337.

[Google Scholar]

Buehrle E GA. Notfallmedizin im Flugzeug: Erste Hilfe über den Wolken. Deutsches Ärzteblatt. 2005; 102: 338–343. (In German)

[Google Scholar]

Martin-Gill C, Doyle TJ, Yealy DM. In-Flight Medical Emergencies: A Review. The Journal of the American Medical Association. 2018; 320: 2580.

[Google Scholar]

DeHart RL. Health issues of air travel. Annual Review of Public Health. 2003; 24: 133–151.

[Google Scholar]

Peterson DC, Martin-Gill C, Guyette FX, Tobias AZ, McCarthy CE, Harrington ST, et al. Outcomes of medical emergencies on commercial airline flights. The New England Journal of Medicine. 2013; 368: 2075–2083.

[Google Scholar]

Mahony PH, Myers JA, Larsen PD, Powell DMC, Griffiths RF. Symptom-based categorization of in-flight passenger medical incidents. Aviation, Space, and Environmental Medicine. 2011; 82: 1131–1137.

[Google Scholar]

Sand M, Bechara F, Sand D, Mann B. Surgical and medical emergencies on board European aircraft: a retrospective study of 10189 cases. Critical Care. 2009; 13: R3.

[Google Scholar]

Hung KKC, Cocks RA, Poon WK, Chan EYY, Rainer TH, Graham CA. Medical Volunteers in Commercial Flight Medical Diversions. Aviation, Space, and Environmental Medicine. 2013; 84: 491–497.

[Google Scholar]

Kim JH, Choi-Kwon S, Park YH. Comparison of inflight first aid performed by cabin crew members and medical volunteers. Journal of Travel Medicine. 2017; 24: 1–6.

[Google Scholar]

Sirven JI, Claypool DW, Sahs KL, Wingerchuk DM, Bortz JJ, Drazkowski J, et al. Is there a neurologist on this flight? Neurology. 2002; 58: 1739–1744.

[Google Scholar]

Kesapli M, Akyol C, Gungor F, Akyol AJ, Guven DS, Kaya G. Inflight Emergencies during Eurasian Flights. Journal of Travel Medicine. 2015; 22: 361–367.

[Google Scholar]

ACI world traffic rankings 2019. Available at: https://aci.aero/news/2019/03/13/preliminary-world-airport-traffic-rankings-released/ (Accessed: 21 March 2021).

[Google Scholar]

Bullard MJ, Unger B, Spence J, Grafstein E. Revisions to the Canadian Emergency Department Triage and Acuity Scale (CTAS) adult guidelines. Canadian Journal of Emergency Medicine. 2008; 10: 136–151.

[Google Scholar]

J Murray M. The Canadian Triage and Acuity Scale: a Canadian perspective on emergency department triage. Emergency Medicine. 2003; 15: 6–10.

[Google Scholar]

Choi H, Ok JS, An SY. Evaluation of Validity of the Korean Triage and Acuity Scale. Journal of Korean Academy of Nursing. 2019; 49: 26–35.

[Google Scholar]

Hu X, Cowl CT, Baqir M, Ryu JH. Air Travel and Pneumothorax. Chest. 2014; 145: 688–694.

[Google Scholar]

Pareés I, Horga A, Santamarina E, Mendióroz M, Fernández-Cádenas I, del Río-Espínola A, et al. Stroke after prolonged air travel associated with a pulmonary arteriovenous malformation. Journal of the Neurological Sciences. 2010; 292: 99–100.

[Google Scholar]

Humaidan H, Yassi N, Weir L, Davis SM, Meretoja A. Airplane stroke syndrome. Journal of Clinical Neuroscience. 2016; 29: 77–80.

[Google Scholar]

Kuipers S, Cannegieter SC, Middeldorp S, Robyn L, Büller HR, Rosendaal FR. The absolute risk of venous thrombosis after air travel: a cohort study of 8,755 employees of international organisations. PLoS Medicine. 2007; 4: e290.

[Google Scholar]

Makino T, Asano Y, Takuhiro K, Koido Y, Mashiko K, Yamamoto Y, et al. International airport and emergency medical care. Journal of Nippon Medical School. 2002; 69: 185–191.

[Google Scholar]

Tintinalli JE. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide (pp. 326). 9th edn. McGraw-Hill Education/medical : NY. 2019.

[Google Scholar]

Soteriades ES, Evans JC, Larson MG, Chen MH, Chen L, Benjamin EJ, et al. Incidence and Prognosis of Syncope. New England Journal of Medicine. 2002; 347: 878–885.

[Google Scholar]