Foreign Body Airway Obstruction, Incidence, Survival EMS-treatment and First Aid Treatment by Laypersons

Background Foreign body airway obstruction is a partial or complete blockage of airways, due to a foreign body (for example food, toys, coins etc.) Blocked airways will untreated result in cardiac arrest by hypoxia.

Previous research describes foreign body airway obstruction as an uncommon cause of Out-of-Hospital Cardiac Arrest (OHCA) accounting for approximately 1.1-1.4% of all OHCA. Reported incident rates of foreign body airway obstruction (FBAO) causing hypoxic cardiac arrest are unclear. It is reported to be as high as 11 per 100,000 person-years, comprising 10% of all OHCA, and neither Emergency Medical Services (EMS) treatment or first aid by layperson are well described. When organizing prevention campaigns for serious FBAO leading to cardiac arrest, knowledge on items with poor outcomes, vulnerable age-groups and treatments (appropriate and non-appropriate) initiated by both laypersons and EMS-personnel is essential. Previous studies suggest a bimodal distribution of FBAO compromised of the very young ingesting toys or other non-food related items (coins, balloons etc.) and elderly ingesting mainly food items . Several comorbidities are well documented to be over-represented in fatal cases in FBAO, notably cerebral infarction; dementia; schizophrenia; depression and Parkinson's disease .

However, FBAO leading to hypoxic cardiac arrest is a reversible cause that can easily be treated, and therefore prevented. Hence, hypoxic cardiac arrest due to FBAO provides a great potential for increasing overall survival from OHCA if efficient campaigns are implemented to provide the correct diagnosis, to facilitate prompt treatment from both EMS-personnel and laypersons. Such campaigns must be guided by evidence, realistic estimates of population and reliable baseline measures to evaluate effect.

Although, only minor studies present data from arrival to the hospital, several studies imply that the most common food items involved in FBAO is meat, bread, rice cakes, fruits and rice. There is a need to include prehospital data in a national study, to include relevant treatment administered by EMS or laypersons educated in first aid. A study by Igarashi et al. implies that the actions of laypersons has a significant impact on survival and that they, more often than not, use the Heimlich maneuver of abdominal thrust. However, only few patients in this study (12%) is treated by laypersons. More knowledge on the actions of bystanders are needed. The European Resuscitation Council currently recommend laypersons to deliver five back blows followed by an abdominal thrust/Heimlich maneuver if a person is suffering from severe FBAO (unable to cough). For health care personnel, including EMS, the MaGill forceps is first-choice when removing foreign bodies, with significantly higher survival rates reported. However, a complete report of all airway treatments and additional factors known to impact survival have not yet been reported.

There is approximately 5.400 OHCA annually in Denmark. The most updated 30-survival (2018) is 15,7%. This is among some of the highest in the world. A multitude of efforts and campaigns are targeting the different aspects of OHCA to improve survival. Although not yet verified, several sources report that approximately 3-4.5% of the entire Danish population (approximately 200.000-255.000 citizens) attend certified cardio pulmonary resuscitation (CPR) and automatic external defibrillator (AED) courses annually. These courses supposedly include recognition and treatment of FBOA.