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Acta Biomed 2024; Vol. 95, N. 3: e2024110 DOI: 10.23750/abm.v95i3.15669 © Mattioli 1885
Health professions
Suction-based airway clearance devices for foreign body
airway obstruction: protocol for a systematic review
Natalino Palermo1, Miguel Angel Paludi2, Francesco Limonti3, Angelica Semeraro4,
Daniele Ermanno5, Sandro Ganzino6, Nicola Ramacciati7
1Department of district Valle Crati, health company, Cosenza, Italy; 2Department of Covid health company Cosenza, Italy;
3Department of operating room health company, Cosenza, Italy; 4Department of united neurology local health company, Bari,
Italy; 5Department of ophthalmology operational united, health company, Crotone, Italy; 6Department of emergency health
company, Cosenza, Italy; 7Department of Pharmacy, Health and Nutritional Sciences (DFSSN) of the University of Calabria
Abstract. Background and aim: is paper outlines a protocol for a scoping review that will critically appraise
the existing evidence base on the efficacy of airway clearance devices for foreign body airway obstruction.
Methods: e search was conducted in the MEDLINE, CINAHL, the Cochrane Library, and Scopus data-
bases. e quality, validity, and relevance of each study will be systematically evaluated using formal risk of
bias/quality assessment tools, such as e Critical Appraisal and Data Extraction Tool. Results: e systematic
review will identify and appraise all available studies on the efficacy of suction-based airway clearance devices
for foreign body airway obstruction. e review will summarize the findings of the included studies and
provide an overall assessment of the evidence on the devices’ efficacy. Conclusions: e systematic review will
inform best practices in airway management by providing a comprehensive evaluation of the current literature
on the effectiveness of new devices for foreign body airway obstruction treatments. (www.actabiomedica.it)
Key words: foreign body airway obstruction, anti-choking, airway clearance devices, resuscitation, basic life
support, systematic review protocol
Introduction
Airway obstruction refers to a condition where
normal breathing is impeded due to various factors,
both direct and indirect, disrupting the efficient ex-
change of gases with the surrounding environment.
Prolonged obstruction leads to hypoxemia and hy-
poxia, resulting in oxygen deficiency in the blood and
tissues, adversely affecting delicate organs such as the
brain (1). Continual hypoxic conditions cause tissue
dysfunction, leading to a sequence of events: loss of
consciousness, irreversible brain damage, coma, and
ultimately patient fatality. Even survival post-incident
may result in severe cerebral hypoxia, leading to ir-
reversible motor and/or sensory impairments due to
nervous tissue necrosis. Despite being preventable,
foreign body airway obstructions (FBAO) pose a sig-
nificant global threat, contributing to injuries and fa-
talities. Annually, the United States reports over 5000
choking-related deaths, while England and Wales
record approximately 400 fatalities attributed to this
cause (2). In Japan, it stands as the leading cause of
accidental death (3). Food ingestion accounts for the
majority of airway obstructions, and mortality rates
correlate with age (4). However, retrospective data on
foreign body airway obstructions may underestimate
their incidence. Notably, in one study, individuals aged
over 74 years accounted for 56% of cases (5). e causes
of choking involve three main factors: intrinsic or ex-
trinsic airway obstructions, inadequate environmental
oxygen concentration, and presence of chemicals dis-
rupting normal respiration (6). Airway obstructions
Acta Biomed 2024; Vol. 95, N. 3: e2024110
2
can be partial or complete. Partial obstructions permit
minimal air passage, allowing some ventilation and in-
creasing the likelihood of expelling the foreign body
through coughing. us, encouraging a conscious indi-
vidual to cough aids in expelling the foreign body due
to the higher pressures generated (6). Conversely, com-
plete obstructions hinder air passage due to the foreign
body, resulting in hypoxia, loss of consciousness, and
cardiac arrest within minutes. Prompt treatment in-
volves traditional techniques like the Heimlich maneu-
ver, including back blows and abdominal thrusts (7).
However, these techniques may fail in specific cases,
complicating rescue efforts, especially with immobi-
lized patients in wheelchairs, pregnant individuals, or
those who are pathologically obese, highlighting the
need to determine the most appropriate and effective
technique (8). e most established airway clearance
methods date back to 1975 when Dr. Heimlich intro-
duced sub-diaphragmatic pressure as a means to ex-
pel obstructive objects. Prior to this, tracheotomy and,
where feasible, bronchoscopy were commonly us (4).
Recent years have seen the exploration and testing
of alternative solutions in some regions, focusing on
new airway clearance devices (ACDs) using port-
able aspiration and negative pressure within the air-
ways (7). ese devices come in non-invasive e.g.,
LifeVac© (LifeVac LLC, Nesconset, New York, NY,
USA) and minimally invasive types e.g., DeChoker©
(LLC, Wheat Ridge, CO, USA). e LifeVac is a
non-invasive device resembling a plunger with a valve
adhering to the patient’s mouth, generating unidirec-
tional suction to remove foreign bodies. Conversely,
the DeChoker utilizes an oropharyngeal tube and a
plunger-like mechanism to lower the tongue and cre-
ate oropharyngeal communication. Equipped with a
face mask, it employs negative pressure to expel for-
eign bodies (9). However, their effectiveness remains
unproven, and the International Liaison Committee
on Resuscitation (ILCOR) has refrained from specific
recommendations due to the lack of evidence regard-
ing safety, effectiveness, and user training for these de-
vices. Currently, no study has directly compared these
devices with standard airway clearance maneuvers (9).
Nevertheless, in practice, DeChoker and LifeVac de-
vices have proven reliable in resolving foreign body
obstructions when traditional techniques failed,
particularly in training scenarios, care facilities, and
non-medical environments (10). While ACD device
introduction holds promise in improving FBAO man-
agement, comprehensive clinical research is impera-
tive to confirm their efficacy and safety. is protocol
outlines the plan for an update of previous systematic
reviews (8, 10).
Methods and analysis
Study design
is systematic review protocol presents the meth-
ods and procedures used to critically appraise the exist-
ing evidence base on the efficacy of negative-pressure,
anti-choking devices in alleviating severe foreign body
airway obstructions (FBAOs). e review assessed the
strength of this evidence and identified any further re-
search areas that warrant investigation before recom-
mending widespread incorporation of these devices
into resuscitation guidelines. e overarching goal of
this review is to establish optimal standards in airway
management practices. e PRISMA-P guidelines
were followed for the protocol (11), while the PRISMA
guidelines will be used for the review article (12).
Search methods
To ensure a comprehensive review, meticulously
formulated search strings were crafted and deployed
across various databases. ese encompassed exhaus-
tive exploration in esteemed databases like MEDLINE
(via the PubMed interface), CINAHL (accessible
through the Embase interface), the Cochrane Library,
and Scopus. Furthermore, the search was delimited to
publications released within the last five years - from
January 1, 2019 - to encapsulate the most recent and
relevant research findings in such field. e research
will be conducted specifically from January 27th to
January 2024 31st. We will use the PICO framework,
which will allow us to select the studies to consider.
Based on the relevance of our research question, this
framework allows us to demarcate the study area (see
Table 1.). In Box 1, the search string formulated for
the MEDLINE database is displayed.
Acta Biomed 2024; Vol. 95, N. 3: e2024110 3
Quality appraisal
e comprehensive assessment will employ vali-
dated risk of bias and quality assessment tools, notably
the Crowe Critical Appraisal Tool (CCAT), facilitat-
ing a meticulous examination of the studies (13). ese
assessments will be independently conducted by two
researchers. Any disparities in their evaluations will
undergo rigorous discussions aiming for consensus.
If discrepancies persist without resolution, a third im-
partial reviewer will be engaged to provide an objective
assessment, thereby ensuring a conclusive resolution.
e CCAT serves as a versatile instrument capable of
assessing the methodological quality across a diverse ar-
ray of research designs, including quasi-experimental,
descriptive-exploratory-observational, qualitative, sys-
tematic review, and true experimental designs. With 22
items categorized into 8 distinct sections - Preliminaries,
Introduction, Design, Sampling, Data Collection, Ethi-
cal Matters, Results, and Discussion - the CCAT pro-
vides a comprehensive framework for evaluation (14).
Data extraction and analysis
e study will adhere to the Preferred Report-
ing Items for Systematic Reviews and Meta-Analyses
Protocols (PRISMA) guideline (12). Data extrac-
tion and analysis will be conducted in a two-phase
process. Initially, two authors will independently
scrutinize the titles and abstracts of retrieved litera-
ture to identify potential articles for inclusion in the
systematic review. Discrepancies in assessments will
be resolved through discussion between the authors,
with involvement from a third party in the event of
unresolved matters. Subsequently, the same two au-
thors will independently acquire full texts for selected
articles and perform data abstraction using standard-
ized forms. Any inconsistencies in the abstracted data
will be addressed through discussion between the au-
thors, with involvement from a third party if necessary.
To ensure high standards of quality and reliability in
the systematic review, we will implement a rigorous
evaluation process. is process will thoroughly assess
Table 1. Research Question Breakdown according to the PICO Model.
P (Problem) I (Intervention) C (Comparison) O (Outcome)
• Foreign body airway
obstruction
• FBAO
• Adult choking emergencies
• Choking incidences
• Choking victim
• Life-threatening choking
situation
• Foreign body asphyxia
• Aspiration
• Negative pressure devices
for airway obstruction
• LifeVac
• Dechoker
• Suction-based airway
clearance devices
• Anti-Choking Device
• ACD
• Heimlich maneuver
• Traditional airway clearance
methods
• Abdominal thrusts
• Conventional methods
• Successful removal
• Time to removal
• Management of choking
• Safety
• Efficacy
• Ease of application
• Easy to use
• Usability
• Complications
• Adverse events
• Effective
• Effectivenes
• Appropriate
• Pratical
• Effective resuscitation
• Benefits
• Harms
• Potential associated risks
• Delayed resuscitation
• First line treatment
• Aspirate stomach content
• Aspiration pneumonia post
intervention
• Chest infection
• Trauma
Acta Biomed 2024; Vol. 95, N. 3: e2024110
4
data - as well as animal studies, experimental, or lab-
oratory models - are outside the scope of this review.
Additionally, studies exclusively focusing on infant pop-
ulations below one-year-old (the unique anatomy and
physiology of neonates and infants make them a dis-
tinct population with specific requirements) and those
confined solely to animal research will be excluded from
consideration. ese criteria were carefully crafted to
ensure the review’s scope encompasses a comprehensive
range of relevant studies while delineating boundaries to
maintain precision and relevance in the analysis.
Data abstraction
e review adopts a systematic approach to ex-
tract relevant data, encompassing study design, par-
ticipant demographics, and outcome measures from
each included study. ese studies are then categorized
based on their respective levels of evidence, facilitating
a comparative assessment of the strength and reliabil-
ity of their findings.
Synthesis
e key findings from each study were meticu-
lously presented in a synoptic tabular format to allow for
a coherent and structured comparison. Subsequently,
these findings were critically analyzed and discussed
within the context of their respective evidence levels,
fostering a comprehensive and informed synthesis of
the cumulative evidence. No predetermined plans have
been outlined for conducting subgroup analysis as part
of this review. e focus remains on a comprehensive
analysis encompassing diverse studies within the es-
tablished scope and criteria. e findings of the studies
were summarized in a narrative format, and the focus
was on identifying patterns and themes in the data. e
qualitative summary was also used to identify areas for
further research. To assess the strength of evidence in
the reviewed articles, it was employed the hierarchy of
evidence proposed by Polit and Beck (15).
Conclusion
Our systematic review examined different air-
way obstruction devices to assess their effectiveness in
the methodological robustness and relevance of each
included study.
Inclusion criteria and exclusion criteria
e inclusion criteria for this systematic review en-
compass a broad range of pertinent studies while main-
taining a clear focus on relevant content. Studies of any
design published in peer-reviewed journals are eligible
for consideration. e content of these studies is not
restricted, allowing for a comprehensive analysis of vari-
ous study types. Participants included in these studies
should consist of humans aged over one year, along with
mannequins or cadavers experiencing foreign body air-
way obstructions. e interventions encompass a spec-
trum of prevailing airway obstruction devices, such as
negative-pressure devices, suction-based airway clear-
ance devices, and Anti-Choking Devices. Addition-
ally, the review will consider various scenarios serving
as comparators or controls, including no action, the
Heimlich maneuver, traditional airway clearance meth-
ods, and abdominal thrusts. is review aims to incor-
porate studies conducted across diverse clinical settings,
embracing hospitals and community healthcare facili-
ties worldwide. In contrast, exclusion criteria delineate
parameters to maintain the focus and integrity of the
review. Unpublished studies, including conference ab-
stracts and trial protocols, will be excluded. Similarly,
editorial pieces and opinion articles lacking primary
Box 1. The search string formulated for MEDLINE
database.
(successful removal OR time to removal OR management
of choking OR safety OR efficacy OR ease of application
OR easy to use OR usability OR complications OR adverse
events OR effective OR effectivenes OR appropriate OR
pratical OR effective resuscitation OR benefits OR harms
OR potential associated risks OR delayed resuscitation OR
first line treatment OR aspirate stomach content OR aspi-
ration pneumonia OR post intervention OR chest infec-
tion OR trauma) AND (((((((Foreign body asphyxia) OR
(life threatening choking situation)) OR (choking victim))
OR (choking incidences)) OR (choking emergencies))
OR (‘Foreign body airway obstruction’ OR (FBAO)))
AND (((((Negative pressure devices for airway obstruc-
tion) OR (LifeVac)) OR (Dechoker)) OR (suction based
airway clearance)) OR (Anti Choking Device))) Filters:
from 2019 - 2023
Acta Biomed 2024; Vol. 95, N. 3: e2024110 5
standard techniques due to safety, effectiveness, and
training concerns.
What will be the main findings?
e findings of our systematic review aim to of-
fer evidence supporting the potential effectiveness of
ACDs in clearing foreign body airway obstructions
(FBAOs), especially when traditional methods like the
Heimlich maneuver prove unsuccessful.
Where and on whom will the research have an impact?
Improved techniques or devices for clearing air-
way obstructions could significantly impact patient
care, especially in scenarios where traditional methods
might fail. If proven effective and safe through robust
research, these devices could potentially save lives and
reduce complications associated with FBAO, particu-
larly among vulnerable populations like the elderly or
those with physical limitations.
Study registration
is systematic review was registered with PROS-
PERO on 11 November 2023 (CRD42023477631).
Conflict of Interest: Each author declares that he or she has no
commercial associations (e.g. consultancies, stock ownership,
equity interest, patent/licensing arrangement etc.) that might pose
a conflict of interest in connection with the submitted article.
Authors Contribution: NP contributed to the conception; MAP,
FL, AS contributed equally to the conception, design, draft of
the paper; DE and SG contributed equally to the conception, re-
view and editing of the paper; NR contributed to the conception,
supervision and methodology of the paper.
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Correspondence:
Received: 25 January 2024
Accepted: 7 May 2024
Natalino Palermo, Dr
Department of district Valle Crati
Via Ippocrate c/o Ospedale Acri, Acri, Italy
E-mail: natalino.palermo@aspcs.it
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