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Feasibility of Prehospital Emergency Anesthesia in the Cabin of an AW169 Helicopter Wearing Personal Protective Equipment During Coronavirus Disease 2019

Open AccessPublished:August 23, 2021DOI:https://doi.org/10.1016/j.amj.2021.08.008

      Abstract

      Objective

      Prehospital emergency anesthesia in the form of rapid sequence intubation (RSI) is a critical intervention delivered by advanced prehospital critical care teams. Our previous simulation study determined the feasibility of in-aircraft RSI. We now examine whether this feasibility is preserved in a simulated setting when clinicians wear personal protective equipment (PPE) for aerosol-generating procedures (AGPs) for in-aircraft, on-the-ground RSI.

      Methods

      Air Ambulance Kent Surrey Sussex is a helicopter emergency medical service that uses an AW169 cabin simulator. Wearing full AGP PPE (eye protection, FFP3 mask, gown, and gloves), 10 doctor-paramedic teams performed RSI in a standard “can intubate, can ventilate” scenario and a “can't intubate, can't oxygenate” (CICO) scenario. Prespecified timings were reported, and participant feedback was sought by questionnaire.

      Results

      RSI was most commonly performed by direct laryngoscopy and was successfully achieved in all scenarios. The time to completed endotracheal intubation (ETI) was fastest (287 seconds) in the standard scenario and slower (370 seconds, P = .01) in the CICO scenario. The time to ETI was not significantly delayed by wearing PPE in the standard (P = .19) or CICO variant (P = .97). Communication challenges, equipment complications, and PPE difficulties were reported, but ways to mitigate these were also reported.

      Conclusion

      In-aircraft RSI (aircraft on the ground) while wearing PPE for AGPs had no significant impact on the time to successful completion of ETI in a simulated setting. Patient safety is paramount in civilian helicopter emergency medical services, but the adoption of in-aircraft RSI could confer significant patient benefit in terms of prehospital time savings, and further research is warranted.
      The coronavirus (severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2]) pandemic (coronavirus disease 2019 [COVID-19]) has challenged civilian helicopter emergency medical services (HEMS) operations both clinically and organizationally.
      • Hilbert-Carius P
      • Braun J
      • Abu-Zidan F
      • et al.
      Pre-hospital care & interfacility transport of 385 COVID-19 emergency patients: an air ambulance perspective.
      Prehospital critical care teams such as HEMS have adapted, overcome, and continued to deliver high-acuity trauma and medical care to patients at their time of need.
      • Hilbert-Carius P
      • Braun J
      • Abu-Zidan F
      • et al.
      Pre-hospital care & interfacility transport of 385 COVID-19 emergency patients: an air ambulance perspective.
      SARS-CoV-2 is transmitted through droplet, contact, and aerosol routes.
      • Liu Z
      • Wu Z
      • Zhao H
      • Zuo M.
      Personal protective equipment during tracheal intubation in patients with COVID-19 in China: a cross-sectional survey.
      Aerosol-generating procedures (AGPs), such as tracheal intubation or extubation, suction of the airway, and cardiopulmonary resuscitation, are thought to increase the risk of virus transmission to medical teams

      Airborne transmission of severe acute respiratory syndrome coronavirus-2 to healthcare workers: a narrative review. Available at: https://associationofanaesthetists-publications.onlinelibrary.wiley.com/doi/full/10.1111/anae.15093. Accessed May 8, 2021.

      • El-Boghdadly K
      • Wong DJN
      • Owen R
      • et al.
      Risks to healthcare workers following tracheal intubation of patients with COVID-19: a prospective international multicentre cohort study.
      with a 3 to 6 times greater risk of infection.
      • Liu Z
      • Wu Z
      • Zhao H
      • Zuo M.
      Personal protective equipment during tracheal intubation in patients with COVID-19 in China: a cross-sectional survey.
      Endotracheal intubation (ETI) is thought to pose the greatest risk of nosocomial transmission to health care workers
      • El-Boghdadly K
      • Wong DJN
      • Owen R
      • et al.
      Risks to healthcare workers following tracheal intubation of patients with COVID-19: a prospective international multicentre cohort study.
      yet forms a significant proportion of critical care interventions provided by HEMS teams. Undertaking prehospital RSI in a safe and familiar environment contributes positively to patient safety.
      In-aircraft RSI (aircraft-on-the-ground) may confer significant time savings in patients requiring time-critical intervention.
      • Kornhall D
      • Hellikson F
      • Näslund R
      • Lind F
      • Broms J
      • Gellerfors M.
      A protocol for helicopter in-cabin intubation.
      Air Ambulance Kent Surrey Sussex (AAKSS) is currently exploring the feasibility of conducting more in-aircraft critical care interventions. Currently, with aircraft engines shut down, the provision of in-aircraft RSI is permitted.
      • McHenry AS
      • Curtis L
      • Ter Avest E
      • et al.
      Feasibility of prehospital rapid sequence intubation in the cabin of an AW169 helicopter.
      Principally, in-aircraft RSI should afford the same level of patient safety as when performed outside the aircraft; therefore, it is not intended or suitable for all patients. Individual psychomotor skills, mental rehearsal, and simulated team-based training are pivotal to optimizing the process.
      SARS-CoV-2 compelled our service to explore in-cabin RSI during the COVID-19 pandemic. The objective of this study was to assess the feasibility of in-aircraft RSI (aircraft on the ground) while wearing recommended personal protective equipment (PPE) for AGPs in a simulated setting.

      Methods

      Study Design

      A prospective simulation study akin to our previously published work was undertaken.
      • McHenry AS
      • Curtis L
      • Ter Avest E
      • et al.
      Feasibility of prehospital rapid sequence intubation in the cabin of an AW169 helicopter.
      Simulation was performed in both a “can intubate, can ventilate” (standard) and “can't intubate, can't oxygenate” (CICO) scenario, as described by McHenry et al.
      • McHenry AS
      • Curtis L
      • Ter Avest E
      • et al.
      Feasibility of prehospital rapid sequence intubation in the cabin of an AW169 helicopter.
      Prespecified time points were recorded in real time. The primary end point was the time to successful ETI. Participants completed a post simulation questionnaire on their experience of the scenario.

      Setting and Participants

      The study was conducted in the high-fidelity simulation suite at AAKSS over a 1-month period. The simulation suite contains a replica AW169 cabin simulator (Fig. 1) in which the bespoke modular in-cabin simulator and stretcher system offers 360-degree video and audio capability. As per AAKSS aviation protocols, Alpha-Eagle 400 helmets (MEL Aviation Ltd, Sudbury, Suffolk, UK) were connected to the intercom, enabling direct communication with the investigators during each scenario (K.H./A.S.M./J.E.G.) and audio input via a continuous loop recording was played. Pre-requisite training qualifies the HEMS doctor-paramedic team to perform this level of intervention. A pragmatic, convenience sampling was used due to operational COVID-19 restrictions.
      Figure 1
      Figure 1The dimensions of the AW169 simulator. The height of the translating patient loading system, aircraft ceiling, and seating are annotated. The airway assistant and airway kit dump are positioned in front of seat 2A.

      Alterations to the Standard Operating Procedures Regarding AGPs During the COVID-19 Pandemic

      Infection prevention measures in-line with National Health Service England and local interpretation on PPE for ambulance services were used. Level 3 PPE comprised the following: double gloves, eye protection, a fit-tested FFP3 respirator mask or powered respirator protective hood (PRPH) (Versaflo; 3M, St. Paul, MN), and either a Tyvek suit or a surgical gown.
      The avoidance of bag-valve-mask ventilation during the apnoeic period because of the risk of dispersion of aerosolized virus in the health care environment is recommended. In addition, an adult endotracheal closed suction system (TRACH-CLEAR, Intersurgical, UK) was inserted into the airway circuit during ETI.

      Data Collection and End Points

      Prespecified timings were documented in real time by investigators (K.H./A.S.M./J.E.G). The primary end point was the time to securing the endotracheal tube (ETT) (in seconds). Successful ETI was defined as securing of the ETT with simulated confirmation of end-tidal carbon dioxide capnography. In the CICO variant, the intubator was unable to pass the ETT, and a decision was made to proceed to emergency front of neck access.

      Ethical Considerations

      National Institute for Health Research criteria for service evaluation were met. Internal approval by the AAKSS Research, Audit and Development Committee was gained. Written informed consent was gained. Participant information was anonymized and stored on electronic devices with technical encryption. Study registration was gained through the University of Surrey.

      Statistical Analysis

      Descriptive statistics with frequencies, the median, and the associated interquartile ranges (IQRs) are reported. The Wilcoxon signed rank and Mann-Whitney U tests were used to assess the differences between each group for paired and unpaired data, respectively, with P < .05 regarded as statistically significant. All analyses were completed using SPSS Version 26.0 (IBM Corp, Armonk, NY).

      Results

      The time taken for each doctor-paramedic team to perform ETI in the standard scenario (Table 1) and the CICO scenario (Table 2) is reported. In each scenario, an ETI was successfully achieved. The average time to ETI was 287 seconds (IQR, 260-338 seconds) in the standard variant and 370 seconds (IQR, 359-416 seconds) in the CICO scenario. Previously, we reported the average time to RSI in the standard (non-PPE) scenario as 243 seconds (median = 14 seconds), and the average time to RSI in the CICO (non-PPE) scenario as 360 seconds (median = 41 seconds).
      Table 1The Time to Endotracheal Intubation in the Standard Variant
      Standard Variant
      Primary deviceDLVLDLDLDLVLVLDLDLDL
      Start of checklist0000000000
      End of checklist9088108130108111123210161160
      Rocuronium94162162182168162213290244245
      Surgical airway decision point
      ETT in airway199177238282182246274381335317
      Bougie removed201178239285232246282387336324
      Cuff inflated205180242287234248283391340326
      BVM connected210185244298244258287401344342
      Position checked240190260306260275299409351348
      Seconds240190260306260275299409351348
      BVM = bag valve mask; DL = direct laryngoscopy; ETT = endotracheal tube; VL = video laryngoscopy.
      Table 2The Time to Endotracheal Intubation in the “Can't Intubate, Can't Oxygenate” (CICO) Variant
      CICO Variant
      Primary deviceDLVLDLDLDLVLVLDLDLDL
      Start of checklist0000000000
      End of checklist1029011415010810611512384134
      Rocuronium140108134219160160150183130199
      Surgical airway decision point345252260355344290150338259370
      ETT in airway346279295427378330357443345454
      Bougie removed348282310428380339365449346456
      Cuff inflated348282314430383346366458347462
      BVM connected350290316438385357367424355468
      Position checked364298320448395360375425357478
      Seconds364298320448395360375425357478
      BVM = bag valve mask; DL = direct laryngoscopy; ETT = endotracheal tube; VL = video laryngoscopy.
      As expected, the time to ETI in the standard (PPE) scenario versus the CICO (PPE) scenario was significantly different (P = .01). The time to ETI in the standard (non-PPE) scenario was not significantly different to the standard (PPE) variant (P = .19) and not significantly different between the CICO (PPE) scenario and the CICO (non-PPE) scenario (P = .97) (Table 3).
      Table 3The Time to Endotracheal Intubation in Personal Protective Equipment (PPE) Versus Non-PPE Scenarios in Both the Standard and the “Can't Intubate, Can't Oxygenate” (CICO) Variants
      Scenario ComparisonMedian Difference (Seconds)P Value
      Standard PPE versus CICO PPE83.01
      Standard non-PPE
      Previous scenario timings as reported in McHenry et al.7
      versus standard PPE
      44.19
      CICO non-PPE
      Previous scenario timings as reported in McHenry et al.7
      versus CICO PPE
      10.97
      a Previous scenario timings as reported in McHenry et al.
      • McHenry AS
      • Curtis L
      • Ter Avest E
      • et al.
      Feasibility of prehospital rapid sequence intubation in the cabin of an AW169 helicopter.

      Questionnaires

      Seventeen participant questionnaires were completed. Professional registration varied to include HEMS paramedics and medical specialities including emergency medicine, anesthetics, general practice, and intensive care medicine. The average doctor prehospital experience was 5 years (IQR, 1-27 years) and 16 years for paramedics (IQR, 5-22 years).
      Seven intubators chose direct laryngoscopy, and 3 chose video laryngoscopy. Eye protection consisted mainly of the helmet visor (19/20) and protective glasses (1/20); the PRPH was not used by anyone. Surgical gowns were worn in every scenario (20/20). Four of 17 participants felt that PPE affected the ability to perform RSI. Communication challenges were reported and included the following: the visor fogging up, speech distorted by the FFP3 mask, harder to be heard, and microphone position on the FFP3 moved. Efforts to mitigate the challenges to communication included raising their voice, the suggestion that PRPH may have been beneficial, prior planning of unanticipated events, the use of hand signals, closed-loop communication, and reliance on nonverbal cues. Other challenges reported included background noise reduced bandwidth and limited access to their personal kit, which were mitigated by ensuring a good brief between the crew with verbalization of crew positions and preferred equipment in the event of thoracostomy/surgical airway.

      Discussion

      In-aircraft, aircraft on-the-ground, simulated RSI wearing PPE is feasible in a simulated setting. Use of the replica bespoke AW169 cabin coupled with the real-time audio and visual distractions during simulation makes us feel that the simulation was of sufficient quality to infer real-world feasibility. The addition of PPE provided a degree of communication challenge, but medical teams felt this could be mitigated to a degree. The expected and observed, and perhaps worthy, increase in time was perhaps enough to indicate the due diligence the team was giving to such a critical intervention. This was noted in the standard scenario more so than the CICO scenario, where perhaps a practice effect occurred. There was no significant effect on the time to successful ETT placement.
      Real-life simulation training, which was afforded by the exact replica AW169 simulator, ensures the refinement of protocols, the facilitation of practice changes, and the identification of safety gaps in which to apply corrective actions immediately,
      • Lababidi HMS
      • Alzoraigi U
      • Almarshed AA
      • et al.
      Simulation-based training programme and preparedness testing for COVID-19 using system integration methodology.
      ,
      • Pan D
      • Rajwani K.
      Implementation of simulation training during the COVID-19 pandemic.
      which has proven irreplaceable during the COVID-19 pandemic. Simulation studies of paramedic ETI (wearing PPE) and intubating through a box barrier showed no difference to first-pass success
      • Feldman O
      • Samuel N
      • Kvatinsky N
      • Idelman R
      • Diamand R
      • Shavit I.
      Endotracheal intubation of COVID-19 patients by paramedics using a box barrier: a randomized crossover manikin study.
      ; however, Cağlar et al

      Çağlar A, Kaçer İ, Hacımustafaoğlu M, Öztürk B, Öztürk S. Impact of personal protective equipment on prehospital endotracheal intubation performance in simulated manikin. Australas Emerg Care. doi:10.1016/j.auec.2020.11.003; accessed May 9, 2021.

      reported an increased time to intubation and a reduced overall first-pass success rate. The authors reported the limitations of their work, highlighting that manikins were intubated at floor level and therefore were initially not optimized, unlike our simulations. The limitations of the current study included the relatively small number of HEMS team participants and the standard limitations associated with simulation research.
      Prehospital airway management or the ETI success rate is an important measure of provider and emergency medical services system success but more importantly a marker of patient safety.
      • Lossius HM
      • Røislien J
      • Lockey DJ.
      Patient safety in pre-hospital emergency tracheal intubation: a comprehensive meta-analysis of the intubation success rates of EMS providers.
      Communication between the medical team is critical. Speech discrimination scores between normal and PPE-wearing subjects highlight the difficulty in the interpretation of speech
      • Hampton T
      • Crunkhorn R
      • Lowe N
      • et al.
      The negative impact of wearing personal protective equipment on communication during coronavirus disease 2019.
      and the importance of clear concise spoken words with additional hand signaling as required.
      Infection control measures required by health care professionals performing ETI during COVID-19 have forced HEMS and critical care services to implement rapid operational change to long-withstanding standard operating procedures. We report that wearing PPE did not significantly change to the time to RSI. Nevertheless, it did provide communication challenges and logistical and equipment considerations.

      Conclusion

      In-aircraft RSI (aircraft on-the-ground) while wearing PPE for AGPs had no significant impact on the time to successful completion of ETI in a simulated setting. A civilian HEMS service must always have patient safety as the paramount goal, but the adoption of in-aircraft RSI could confer significant patient benefit in terms of prehospital time savings; further research is warranted in this area.

      References

        • Hilbert-Carius P
        • Braun J
        • Abu-Zidan F
        • et al.
        Pre-hospital care & interfacility transport of 385 COVID-19 emergency patients: an air ambulance perspective.
        Scand J Trauma Resusc Emerg Med. 2020; 28: 94
        • Liu Z
        • Wu Z
        • Zhao H
        • Zuo M.
        Personal protective equipment during tracheal intubation in patients with COVID-19 in China: a cross-sectional survey.
        Br J Anaesth. 2020; 125: e420-3422
      1. COVID-19 infection prevention and control guidance: aerosol generating procedures. GOV.UK. Available at:https://www.gov.uk/government/publications/wuhan-novel-coronavirus-infection-prevention-and-control/covid-19-infection-prevention-and-control-guidance-aerosol-generating-procedures. Accessed May 8, 2021.

      2. Airborne transmission of severe acute respiratory syndrome coronavirus-2 to healthcare workers: a narrative review. Available at: https://associationofanaesthetists-publications.onlinelibrary.wiley.com/doi/full/10.1111/anae.15093. Accessed May 8, 2021.

        • El-Boghdadly K
        • Wong DJN
        • Owen R
        • et al.
        Risks to healthcare workers following tracheal intubation of patients with COVID-19: a prospective international multicentre cohort study.
        Anaesthesia. 2020; 75: 1437-1447
        • Kornhall D
        • Hellikson F
        • Näslund R
        • Lind F
        • Broms J
        • Gellerfors M.
        A protocol for helicopter in-cabin intubation.
        Air Med J. 2018; 37: 306-311
        • McHenry AS
        • Curtis L
        • Ter Avest E
        • et al.
        Feasibility of prehospital rapid sequence intubation in the cabin of an AW169 helicopter.
        Air Med J. 2020; 39: 468-472
      3. COVID-19: guidance for ambulance services. GOV.UK. Available at: https://www.gov.uk/government/publications/covid-19-guidance-for-ambulance-trusts/covid-19-guidance-for-ambulance-trusts. Accessed May 8, 2021.

        • Lababidi HMS
        • Alzoraigi U
        • Almarshed AA
        • et al.
        Simulation-based training programme and preparedness testing for COVID-19 using system integration methodology.
        BMJ Simul Technol Enhanc Learn. 2021; 7: 126-133
        • Pan D
        • Rajwani K.
        Implementation of simulation training during the COVID-19 pandemic.
        Simul Healthc. 2021; 16: 46-51
        • Feldman O
        • Samuel N
        • Kvatinsky N
        • Idelman R
        • Diamand R
        • Shavit I.
        Endotracheal intubation of COVID-19 patients by paramedics using a box barrier: a randomized crossover manikin study.
        PLoS One. 2021; 16e0248383
      4. Çağlar A, Kaçer İ, Hacımustafaoğlu M, Öztürk B, Öztürk S. Impact of personal protective equipment on prehospital endotracheal intubation performance in simulated manikin. Australas Emerg Care. doi:10.1016/j.auec.2020.11.003; accessed May 9, 2021.

        • Lossius HM
        • Røislien J
        • Lockey DJ.
        Patient safety in pre-hospital emergency tracheal intubation: a comprehensive meta-analysis of the intubation success rates of EMS providers.
        Crit Care. 2012; 16: R24
        • Hampton T
        • Crunkhorn R
        • Lowe N
        • et al.
        The negative impact of wearing personal protective equipment on communication during coronavirus disease 2019.
        J Laryngol Otol. 2020; 134: 577-581