Saudi Critical Care Journal

: 2021  |  Volume : 5  |  Issue : 3  |  Page : 46--49

Helium-oxygen mixture bag, a novel way for extubation of COVID-19 patients: Simulation and proof of concept

Mohammed A Bawazeer1, Talal I Dahhan2, Marame K Gattan3, Ahmad A Nahhas4, Hejab J Almutairi4, Matthew Y J. Ko5, Stephen E Lapinsky6,  
1 Department of Critical Care Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
2 Department of Critical Care Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia; Department of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, Duke University, Durham, North Carolina, USA
3 Alfaisal University; King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia; Duke University Emergency Medicine and Durham VA Medical Center, Durham, North Carolina, USA
4 King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
5 Sinai Health System, University of Toronto, Toronto, Canada
6 Interdepartmental Division of Critical Care Medicine, Sinai Health System, University of Toronto, Toronto, Canada

Correspondence Address:
Mohammed A Bawazeer
Department of Critical Care Medicine, (MBC 94), King Faisal Specialist Hospital and Research Centre, P.O Box 3354, Riyadh 11211
Saudi Arabia


Background: Coronavirus disease 2019 (COVID-19) has been a worldwide pandemic in 2020; necessitating significant changes in patient-care procedures. Because of the risk of transmission to health care workers (HCWs) and the shortage of personal protective devices worldwide, novel protective barriers during aerosol-generating procedures have been developed. The intubation box has been proposed and gained popularity. A safe way for extubating patients with COVID-19 in critical care settings does not exist. This report discusses the development and assessment of the efficacy of using a Helium-Oxygen mixture (Heliox) filled bag during the extubation phase for the protection of HCW. Study Design and Methods: This methodology was developed at two tertiary care hospitals in Riyadh, Saudi Arabia and Toronto, Canada. We describe a novel way using a bag filled with Heliox bag. We performed extubation of an intubated manikin with and without using the Heliox bag. The cough during extubation was simulated using a fluorescent dye-filled balloon, which was inflated with a hidden oxygen tube until it bursts. We used an ultraviolet (UV) light source to assess the aerosols generated during extubation. Results: During extubation using the Heliox bag, droplets of the fluorescent dye were all contained within the Heliox bag and only found on the manikin chest. While during extubation without using Heliox bag, using the UV light, we found droplets of the fluorescent dye on the HCW mask and hand, the bed, the floor, and wall of the room. Conclusion: In our simulated experiment, we found that the Heliox bag is an easy and reproducible way for extubating patients with COVID-19 and any other airborne disease. We also found that the Heliox bag is an effective way to protect HCW.

How to cite this article:
Bawazeer MA, Dahhan TI, Gattan MK, Nahhas AA, Almutairi HJ, J. Ko MY, Lapinsky SE. Helium-oxygen mixture bag, a novel way for extubation of COVID-19 patients: Simulation and proof of concept.Saudi Crit Care J 2021;5:46-49

How to cite this URL:
Bawazeer MA, Dahhan TI, Gattan MK, Nahhas AA, Almutairi HJ, J. Ko MY, Lapinsky SE. Helium-oxygen mixture bag, a novel way for extubation of COVID-19 patients: Simulation and proof of concept. Saudi Crit Care J [serial online] 2021 [cited 2022 Aug 20 ];5:46-49
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Full Text


Coronavirus disease 2019 COVID-19 has been a worldwide pandemic in 2020.[1] Many health care workers (HCW) have been infected during the care of patients who tested positive.[1],[2] There is a worldwide increasing demand for personal protective equipment (PPEs).[1],[2] Safe practice is warranted to prevent transmission of the disease from the patients to HCW. Airway management during the care of these patients is an aerosol-generating procedure and imposes a risk of infection to HCW.[3] Intubation and extubation may result in cough, which can generate significant aerosol formation.[4] In sequence with that, small particles may remain in the air, which is not visible by the naked eyes.[5] However, it has been proposed to use medications to decrease agitation along with cough suppressants during and after extubation.[1],[6]

To increase safety during intubation, a recently proposed Barrier Enclosure device (The Aerosol Box) can be used,[7] as can the Carton-Made Protective Shield.[8] There are a few techniques were suggested to be used for postanesthesia extubation for patients with suspected or confirmed COVID-19, which may be a higher risk procedure.[2],[4],[5],[6] However, a safe technique for extubation of these patients in Critical Care Settings does not exist so far. The purpose of this simulation experiment is to assess the safety of extubation of patients with COVID-19 using a bag filled with Helium-Oxygen mixture (Heliox bag).

 Study Design and Methods

This methodology was developed and evaluated at two Tertiary Care centers. They are King Faisal Specialist Hospital and Research Center in Riyadh, Saudi Arabia and Mount Sinai Hospital in Toronto, Canada. It describes and assesses the efficacy of a novel way to extubate patients with COVID-19 or any other airborne or droplets risk of transmission. The aim was to extubate a patient inside a large plastic bag to contain aerosols and secretions, and Heliox was used to keep the bag inflated and upright during the procedure. The procedure was used on several COVID-19 patients in Toronto before the formal evaluation in Riyadh. An institutional review board was obtained to perform this experiment and videotaping the investigators during the experiment.

Required equipment

Intubated Manikin, (Laerdal® Airway Management Trainer)Transparent bag to be filled with medical HelioxMedical Helium-oxygen Tank (20/80)Yankauer suction catheter and tubingEndotracheal tube (ETT) inside airway of the manikinEmpty 10 mL syringe for ETT cuff deflationOxygen supply for postextubation oxygenation (Simple face mask or high flow oxygen)Anesthesia facemask and Ambu bagSmall plastic balloonsOxygen tube to be hidden inside the patient to fill the balloonFluorescent dyeUltraviolet (UV) light sourceProfessional video photographer from the audio-visual department.

Extubation procedure using the Helium-Oxygen mixture bag

Ideally extubation should be performed in a negative pressure roomOnly personnel involved in patient care are allowed inside the room (respiratory therapist [RT] registered nurse [RN], and team leader), to limit exposureAll staff inside the room should be wearing proper PPERT will fill the transparent bag with Helium-oxygen mixture at a rate of 10–40 Lpm (depending on the regulator) for 1–2 min until the bag is full enough to allow working space from the outside of the bagKeep Yankauer suction and 10 mL syringe inside the bag at all timesThe already intubated manikin will be in bed with Head-up at 45°Simple Oxygen facemask will be placed on the patient's forehead without turning the O2 flow onRT on the same side as the ventilatorRN on the side opposite to the ventilator holding the Heliox bagThe team leader is ready at the foot of the bedTeam leader or RT explains the procedure to the patient including the application of the Heliox bag, and to remain calm and cooperativeRN will suction the orogastric tube for any gastric residualsRT to suction the ETT using in-line and preoxygenate by turning the fraction of inspired oxygen to 100%RT and RN are going to cover the patient's head with Heliox-filled bag down to mid-chest, and secure in place [Figure 1] and [Figure 2]RN will gently suction the mouth using the Yankauer, holding the suction from outside the bag while reassuring the patientRT will turn off the ventilator, disconnect the circuit, and then deflate the ETT and extubate the patient, working from outside the bag, through the plastic [Figure 3]Keep the Yankauer suction and ETT inside the bag at all timesRT will move the oxygen mask downward from the forehead and apply it over the patient's mouth and nose and turn on the flowOnce the patient is settled and not coughing anymore, the Heliox bag can be slowly removed safelyRN and RT will remove the transparent bag together with its content (ETT, Yankaeur Suction Catheter, orogastric tube syringe, 10 cc syringe) by rolling the bag from outside to insideRN will turn up the suction to maximum and apply gentle pressure on the top of the bag to help bag deflation with the help of the RT. Keep the mouth of the bag occluded with both hands, only suction tubing is coming out of the bag at this time. Do not actively express the bag; otherwise, aerosolized contents will enter the roomOnce the Heliox bag is fully deflated, disconnect the suction from the wallBag with its contents can be placed in biohazards waste container.{Figure 1}{Figure 2}{Figure 3}

Cough simulation

The plastic balloon was prefilled with 10 mL of fluorescent dyeThe balloon was placed into the oropharynx of the manikin, while attached to an oxygen source to facilitate its inflation to the point until it pops to simulate a coughThe distance of contamination of the aerosols (fluorescent dye) was assessed.

 The Experiments and Results

Experiment 1 (extubation without Helium-Oxygen mixture bag)

As the team simulates the process of extubation, the balloon containing the fluorescent dye was inflated until it popped. Afterward, the UV light was applied over the experiment's premises and the participants to detect the presence/absence of the fluorescein dye as it is proposed to simulate aerosols. The whole process was with you video recorded [Supplementary Video 1].

Using the UV light, we found fluorescent dye droplets on the patients' bed and gown, the floor, wall of the room, and most importantly they were found on the HCW extubating the patient [Figure 4]a, [Figure 4]b, [Figure 4]c.{Figure 4}

Experiment 2: (Extubation with Helium-Oxygen mixture Bag)

The plastic bag was prefilled with Heliox before extubation. It was placed securely around the manikin's torso. Afterward, extubation was done. At this point, the balloon containing the fluorescein dye was inflated until it popped. The UV light was applied over the experiments premises and the participants to detect the presence/absence of the fluorescein dye as it is proposed to simulate viral spread. At the end of the extubation process, the Heliox bag with the Yankauer suction tube inside of it will be rolled off the manikin from the outside inwards and be disposed off in the appropriate bin to simulate safe disposal of biohazard material. The whole process was video recorded [Supplementary Video 1].

Using the UV light source, the droplets were all contained within the bag and nothing was found outside the bag. HCW were examined and their PPE were free from any droplets [Figure 5].{Figure 5}


Using the above described technique, we demonstrated the safety of using Heliox bag for extubation of patients to minimize exposure of HCW during a highly infectious aerosolized procedure. There are other techniques were proposed on how to extubate patients during post anesthesia phase. Matava et al. describe a very similar simulation experiment on a pediatric manikin. They used a three-layer plastic drape covering the bed and linen underneath the patient, another drape covering patient's torso and a third one covering the patient's head. This technique was effective in the containment of aerosols within the drapes.[2] Hung et al. used a modified technique using the plastic drapes. They made a hole at the apex of a “tent” in the drape through which the ETT with the filter is passed through. The goal of the tent is to contain the aerosols after extubation.[5] A third technique was described by D'Silva using a “mask-over tube”. During this technique, they moved the ETT to one side of the moth and a facemask is applied on the patient. They used 2 filters; one connected to the ETT and another is connected to the facemask.[6] Our technique is the only one that can be used in critical care settings. It has the advantage of providing a less claustrophobia-inducing environment as the plastic protective layer is not applied directly to the patient's face. It showed similar findings to the other simulation experiment.

Regarding cough simulation, different experiments used different ways. Matava et al. used a medical air gun to generate cough peak expiratory flow rate between 150-180 L/min.[2] They also used fluorescent dye and UV light to detect particles. During Hung experiment, they used a nebulizer to generate droplet nuclei, which were visible by the naked eyes.[5] Our technique is similar to the one used by Canelli et al. when they described the “aerosol box” for intubation.[7] We found forceful blowing a pre-placed balloon is easily done, cheap and reproducible.

The use of medical helium-oxygen mixture has been well described in the literature. It has been used before because of its low viscosity and given to patients with narrowed airways, such as Bronchial asthma exacerbation. It has been shown to decrease inspiratory efforts and provides some comfort if given in the postextubation period.[9] We found using Helium-oxygen mixture can give a working space around the patient's face. This space will contain all droplets, which were suctioned away in a closed circuit and discarded.

This technique was adopted at both hospitals in Toronto and Riyadh. After doing many simulation sessions to all our physicians and Respiratory therapists, It was easy to teach and reproducible. The advantages of using this technique include, it is the only technique that has been described in critical care settings and the potential advantages of using medical helium-oxygen gas mixtures that were mentioned before. Bag transparency will allow better monitoring and communicating with the patient. Sitting the patient up 30°−45° will improve the work of breathing postextubation. The potential disadvantages include being a low-fidelity simulation experiment and the availability of helium-oxygen mixture. Some hospitals may not have this medical gas. A Tank of Helium-oxygen mixture costs between $185 and 250 US dollars; which might be an issue in some areas.


During our simulation experiment with simple cough simulation, we conclude that using the Heliox bag during the extubation phase is easy and reproducible. Using the Heliox bag can effectively decrease the risk of contamination and protect HCW.


MB is the guarantor of the paper, taking responsibility of the integrity of the work as a whole, from inception to published article. SL and MK take credit for development of the Heliox bag technique. MB was responsible for idea maturation and simulation experiment. MB, TL, MQ, AN and HA were all participants of the simulation experiment and they were actors during videotaping. MB, TL, MQ, AN, HA, MK and SL participated and contributed in writing and editing the manuscript. We would like to acknowledge efforts of Mr. Osama Aldurihem, (Professional producer/director) from Department of Brand and Content Development at King Faisal Specialist Hospital and Research Center for videotaping and producing the final supplementary video.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


1Meng L, Qiu H, Wan L, Ai Y, Xue Z, Guo Q, et al. Intubation and ventilation amid the COVID-19 outbreak: Wuhan's experience. Anesthesiol J Am Soc Anesthesiol 2020;132:1317-32.
2Matava CT, Yu J, Denning S. Clear plastic drapes may be effective at limiting aerosolization and droplet spray during extubation: Implications for COVID-19. Can J Anaesth 2020;67:902-4.
3Tran K, Cimon K, Severn M, Pessoa-Silva CL, Conly J. Aerosol generating procedures and risk of transmission of acute respiratory infections to healthcare workers: A systematic review. PLoS One 2012;7:e35797.
4Brown J, Gregson FK, Shrimpton A, Cook TM, Bzdek BR, Reid JP, et al. A quantitative evaluation of aerosol generation during tracheal intubation and extubation. Anaesthesia 2021;76:174-81.
5Hung O, Hung D, Hung C, Stewart R. A simple negative-pressure protective barrier for extubation of COVID-19 patients. Can J Anaesth 2020;67:1478-80.
6D'Silva DF, McCulloch TJ, Lim JS, Smith SS, Carayannis D. Extubation of patients with COVID-19. Br J Anaesth 2020;125:e192-5.
7Canelli R, Connor CW, Gonzalez M, Nozari A, Ortega R. Barrier enclosure during endotracheal intubation. N Engl J Med 2020;382:1957-8.
8Lai YY, Chang CM. A carton-made protective shield for suspicious/confirmed COVID-19 intubation and extubation during surgery. Anesth Analg 2020;131:e31-3.
9Jaber S, Carlucci A, Boussarsar M, Fodil R, Pigeot J, Maggiore S, et al. Helium-oxygen in the postextubation period decreases inspiratory effort. Am J Respir Crit Care Med 2001;164:633-7.