key: cord-0761376-iwqfvytn
authors: Lederer, Wolfgang; Isser, Markus
title: Barrier resuscitation by lay rescuers during COVID-19 pandemic
date: 2021-07-29
journal: Med Hypotheses
DOI: 10.1016/j.mehy.2021.110648
sha: 46e59cb4aa85b79628965e3fac4c73934c008cd6
doc_id: 761376
cord_uid: iwqfvytn

Aerosols generated from chest compressions and ventilation attempts in patients with cardiac arrest may cause airborne infections. Accordingly, the interim international resuscitation guidelines have restricted basic life support by lay rescuers to compression only and the use of an automated external defibrillator during the COVID-19 pandemic. Although these measures may diminish the risk of infection for laypersons, the missing respiratory support can be detrimental for patients with hypoxia-related cardiac arrest. To overcome this shortcoming we want to introduce a special tool that allows ventilation during barrier resuscitation by laypersons. We hypothesize that the application of a device made of a polyvinyl chloride shield with a centrally installed S-shaped ventilation pipe with integrated filter can provide adequate ventilation while concurrently protecting patient and rescuer from airborne agents. Aerosols from air leakage are removed by adhesion and drainage below the barrier. No specific training other than basic life support is needed. We suggest that a tool of this kind be considered essential equipment and stored together with disposable gloves in public access locations.

Presumably, the current pandemic involving severe acute respiratory syndrome-associated 21 corona virus 2 (SARS-CoV-2) will have lasting effects on basic life support and put an end to 22 mouth-to-mouth ventilation as performed until now. This applies to both on-site performance 23 and training (1) . Mouth-to-mouth ventilation has always been a critical issue in 1 cardiopulmonary resuscitation (CPR). On the one hand, it means overcoming disgust and 2 revulsion. On the other hand, the brain has limited tolerance for hypoxia, but its oxygen 3 demand is a multiple of that of other organs of equal tissue mass. Reluctance to perform 4 mouth-to-mouth ventilation is one of the major reasons for low bystander-initiated CPR(2). 5 Baldi et al. reported that only one-third of lay rescuers is willing to perform mouth-to-mouth 6 ventilation during CPR of an unknown cardiac arrest victim compared to almost 90 per cent 7 when the victim is known(2). The updated interim international resuscitation guidelines have 8 restricted basic life support by lay rescuers to compression only and the use of an automated 9 external defibrillator during the COVID-19 pandemic (3) . Although chest compression-only 10 CPR for lay rescuers was associated with an increase in the incidence of survival with 11 favorable neurological outcome out-of-hospital cardiac arrests (OHCA) of cardiac origin(4), 12 ventilation is particularly important in cardiac arrest of non-cardiac origin and in children, 13 where most cardiac arrest cases from hypoxia occur (5, 6) . We would like to present a tool that has the potential to increase safety for both rescuer and 20 patient during basic life support. The tool is made of an S-shaped ventilation pipe inserted in 21 the center of a 120 x 120 cm polyvinyl chloride (PVC) shield. The design of the pipe was 22 inspired by that of the previous Safar tube (7) . The shield serves to blanket the patient in order 23 to diminish the risk of contamination from aerosols, vomitus, blood and body secretions.

Hypothesis 1 We hypothesize that the application of a device made of a PVC shield and a centrally installed 2 S-shaped ventilation pipe with integrated filter can provide adequate ventilation during CPR 3 ( Fig.1) . We further hypothesize that this tool can diminish potential contamination from 4 aerosols, vomitus, blood and body secretions and protect patient and rescuer from airborne 5 agents by removing aerosols from air leakage by adhesion and drainage below the barrier. We 6 suggest that a tool of this kind be considered essential equipment and stored together with 7 disposable gloves in AED public access locations. The hypothesis differs from current thinking as the interim international resuscitation 10 guidelines have restricted basic life support by lay rescuers to compression only and the use of 11 an automated external defibrillator during the COVID-19 pandemic(3). There was an increase 12 in OHCA in spring 2020 with a significant reduction in survival related to the pandemic in 13 Northern Italy (8) . Correspondingly, a transient two-fold increase in OHCA incidence, coupled 14 with a reduction in survival, was observed during the same period in Paris(9). The authors 15 reported a higher rate of OHCA at home, less common bystander CPR, less frequent 16 shockable rhythms, and longer EMS arrival times (8, 9) .

The scientific logic of the hypothesis is based on: 19 1) the known practicability of airway management with the Safar tube (7), 20 2) the potential of PVC to diminish aerosols by adhesion and drainage(10,11), 21 3) the efficiency of filters to protect from airborne infections(12).

Evaluation of the hypothesis 1 Evidence in support: 2 1) Low cost 3 We constructed a preliminary model composed of a 120 x 120 cm PVC shield and a centrally 4 installed S-shaped ventilation pipe with integrated filter for bystander CPR. The device is 5 made of a plasticized PVC shield (d50 universalpresenning; JUFOL GmbH, Krumbacher Str. 2) Applicability 10 Our preliminary model is suitable for patients from school age to adulthood. The technique is simple. One hand applies a nose pinch with thumb and index finger to seal 23 the nostrils. The other hand slightly presses the patient's lips against the ventilation pipe 24 below the filter and tightens the foil to the skin by exerting gentle laminar pressure. it was difficult to seal the mouth when using the original Safar tube, the combination of tube 7 and foil made it rather easy to seal oral and nasal openings. Amazingly, even the stiff oral 8 opening of the manikin was successfully sealed by pressing the foil against the perioral 9 surface (Fig.2 ).

Our hypothesis should be tested in an experimental setting. Ease of handling could be 11 assessed with volunteers applying the foil during CPR training on a manikin. Comparison 12 between SaVe foil and a pocket mask inserted into a PVC foil would be worth testing. 13 Nevertheless, analysis of the potential protection from infection is difficult. Furthermore, the 14 feasibility of the device can be assessed only on-site in real emergencies. 

There is a need for ventilation during basic life support in cases with hypoxia-induced cardiac 18 arrest (13) . Ventilation is particularly important in pediatric CPR where hypoxia is the most 19 common cause of cardiac arrest (5, 6) . Unfortunately, mouth-to-mouth ventilation cannot even 20 be practiced in hands-on training without endangering the health of trainees(1).

The device is predestined for bystander use in stressful CPR situations. It is suitable for 22 patients from school age to adulthood and can be applied easily without complicated 23 adjustment. Increasing safety and motivation in lay rescuers is vital as bystander CPR and 1 public location of emergencies were reported to be independent prognostic factors for survival 2 to hospital discharge in OHCA patients(16). If the device is stored together with AEDs in 3 public locations the device would be on hand in approximately 5% to 10% of cases(17).

Conflicts of Interest Statement: 6 All authors declare that they have no financial or personal interests that may influence this 7 work. 

The challenge of laypeople cardio-15 pulmonary resuscitation training during and after COVID-19 pandemic

Mouth-to-mouth: an obstacle to cardiopulmonary 18 resuscitation for lay-rescuers

Interim guidance for basic and advanced life 2 support in adults, children, and neonates with suspected or confirmed COVID-19

From the Emergency Cardiovascular Care Committee and Get With The Guidelines-4

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Dissemination of Chest

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Mouth-to-mouth airway

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Clear plastic drapes may be effective at limiting 13 aerosolization and droplet spray during extubation: implications for COVID-19

Resuscitation by Lifeguards in COVID-19 Era: A Pilot Study Comparing Three Sets 18 of Personal Protective Equipment

Emergency airway, ventilation, and cardiac resuscitation

Upper airway patency 23 during ventilation with a new airway device-the glossopalatinal tube

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Ventilation with Safar Ventilation Foil (SaVe Foil): S-shaped ventilation pipe made of two 16 medium sized Guedel tubes and VT-30 Pediatric Neonatal Electrostatic Filter

Ventilation with Safar Ventilation Foil (SaVe Foil): A 120 x 120 cm polyvinyl chloride shield 20 with the inserted centrally installed S-shaped ventilation pipe prior to mouth-to-pipe 21 ventilation