key: cord-0887799-6srm6t7d
authors: Chen, Q.; Lim, B.; Ong, S.; Wong, W. Y.; Kong, Y.-C.
title: Rapid Ramp-up of Powered Air-Purifying Respirator (PAPR) Training for Infection Prevention and Control during the COVID-19 Pandemic
date: 2020-04-15
journal: Br J Anaesth
DOI: 10.1016/j.bja.2020.04.006
sha: c40c5c4a297a302c5d84826d2b8047e325f5ea6d
doc_id: 887799
cord_uid: 6srm6t7d

nan

Frequent involvement in aerosol-generating procedures (AGPs) such as tracheal intubation, extubation and open airway procedures including tracheostomy and bronchoscopy 1 exposes our staff to high risk of contamination. Proper use of a hooded powered air-purifying respirators (PAPRs) offers better protection against respiratory pathogens during AGPs, with an Assigned Protection Factor (APF) of up to 1000 compared to an APF of 10 for a N95 respirator 2 . Our hospital uses two types of PAPRs: the Jupiter TM with 3M TM HT-101 Lightweight Hood (Figure 1 ), and the Versaflo TM TR-300 with 3M TM Hood Assembly S-855. In the initial phase of our pandemic response plan, our department prioritised JIT resources for infection prevention and control measures against AGP, with a focus on PAPR training, as these are infrequently used, and their effectiveness requires a high level of staff involvement.

Pre-requisites -All staff had been N95 mask-fitted and had undergone two PAPR training sessions with competency checks, one each for Jupiter TM and Versaflo TM PAPRs. These covered the basic operation and donning and doffing of the PAPRs.

Timeline -Our department's infection prevention and control team was formed on 28 January 2020 and aimed to complete departmental PAPR training before Singapore progressed to a heightened risk. We allocated two weeks each for the training of Jupiter TM and Versaflo TM PAPR, and this allowed comprehensive one-on-one training for all 96 anaesthetists within February 2020.

Focus -The IPC team developed a concise JIT training programme with the highly specific focus of safe donning, doffing and decontamination of PAPR, managing PAPR failure, and performing procedures while wearing PAPR.

Training design -Immersive learning and pre-training interventions 3 were employed to optimise capability development within the limited time we had. We produced a preparatory instructional video to enhance pre-learning and expedite the practical session (add URL here). Pictograms and cognitive aids were displayed in the operating rooms (ORs) and Emergency Airway Management Response (EAMR) kit. Educational materials were uploaded on the Intranet and shared via an online platform. Trainees had the option of video recording their training performance for subsequent reflection.

Training scenarios -We prioritized infection prevention and control training for AGPs in two clinical settings -EAMR and the conduct of general anaesthesia (GA) in a COVID-19 patient in the OR. The training placed emphasis on the expected role of the anaesthetist: senior doctors performed tracheal intubation while wearing the PAPR, whereas junior doctors focused on OR preparation and assisting the senior.

Trainee scheduling -We prioritised doctors who may encounter clinical scenarios with minimal logistical support. This included registrars who provide EAMR after hours. We collaborated with the roster maker to assign PAPR-competent anaesthetists to the ORs designated for contagious pathogens.

Principles behind respiratory protection -As a prescriptive model may not always fit unpredictable clinical circumstances, we assisted doctors in developing thought processes that enable them to make safe infection prevention and control decisions independently. Although PAPR may be used for AGPs, the anaesthetist should rely on their best judgement based on patient and medical team safety, bearing in mind that the acuity of the situation, e.g. critical patient conditions requiring urgent intubation, may preclude safe donning, doffing and decontamination of a PAPR.

Logistics -We coordinated with the OR Director for manpower deployment as training had to be prioritised, and doctors had to be released from routine clinical work. We were able to locate two ORs to conduct training as business-as-usual workload gradually reduced. We liaised with the Nursing Officer to obtain PAPR units for training, while maintaining sufficient operational units for clinical use.

For a realistic learning experience, in situ simulation was employed. This allowed doctors to familiarise themselves with the actual OR set-up, and identify possible barriers with the use of PAPR during patient care. The agenda of each session included: Thought processes and step-by-step instructions are detailed in Figure 1 , which includes practical pointers to achieve maximal protection. Figure 1 is tailored to the use of Jupiter TM PAPR in the OR, but the same principles can be applied to the use of any PAPR in a variety of clinical settings.

To validate and improve our processes, a multidisciplinary OR drill was organised for an elective tracheostomy, which is a high-risk AGP requiring robust IPC measures for staff protection. Participants' proficiency in PAPR use was supervised and evaluated by our infection prevention and control team. An inter-professional debrief was conducted to refine our processes further. For example, we observed that our standard isolation gown with back ties may inadvertently expose one's back and risk contamination of the PAPR, hence the wrap-around surgical gown is now recommended when a PAPR is used.

Training -Hospital Level 3 Workflow for use of PAPR in an EAMR and for emergency OR cases was tested in the broader context of a hospital-level drill, where a manikin-simulated COVID-19 patient was intubated in the general ward and subsequently transferred for scans and procedures. This drill led to further improvements to the EAMR logistical support by providing a trained OR nurse to bring the Jupiter TM PAPR to the anaesthetist at the EAMR location, assist in safe donning and doffing, and set up of a doffing area.

With rigorous infection prevention and control measures and PAPR training, we managed to keep patient-to-doctor transmission at 0% from January to March 2020, while providing seamless care for the majority of COVID-19 patients in Singapore.

The authors declare no conflcits of interest To prevent contamination and wastage of medical supplies, the anaesthetic drug cart and intubation trolley is not kept in the operating room (OR). Upon contact with a COVID-19 patient, it is not advisable to exit and re-enter the OR in order to obtain additional drugs or equipment. All necessary drugs and equipment thus need to be prepared in advance.

For the same reasons, the doffing area should be prepared in advance. Action Plan

2.

3.

Place anaesthetic and analgesic agents, vasopressors, paralytics, reversal agents, antibiotics, antiemetic agents and other necessary drugs in a disposable drug tray.

Consider the number of additional fluid bags, syringes, needles, infusion lines that are needed for the case.

Prepare airway equipment including but not limited to oral airway, preferably a disposable video-laryngoscope, bougie and/or stylet, endotracheal tube (ETT) of various sizes, suction equipment, Spencer-Wells clamp and gauze to clamp ETT, anti-viral HME filters and a rescue supraglottic airway (if difficult airway is anticipated). 4. 5. 6.

Prepare a suitable area that is large enough for safe doffing. Staff may have to doff separately to avoid cross-contamination. Two to three trolleys lined with impervious sheets, a biohazard waste receptable, gloves, alcohol wipes and alcohol hand rub should be readily available.

Doffing assistant should be in full PPE -cap, eye protection, N95 mask and gown. We recommend that the doffing assistant don inner and outer gloves.

Consider laying out a few pairs of gloves in preparation for the doffing process to avoid contamination of a clean box of gloves.

Thought Process Ensure PAPR unit is checked and functioning well.

A malfunctioning PAPR will expose the staff to unfiltered contaminated air. Emergency doffing of a malfunctioning PAPR unit also leads to a much higher chance of contamination.

The N95 mask worn must be clean. Staff should don two pairs of gloves if they are performing 'dirty' procedures e.g. intubation. The PAPR should be protected because it is not easy to decontaminate. Action Plan

2.

Turn on the blower unit. Check airflow with airflow indicator tube. Ensure white ball above meniscus. In our hospital, all units are regularly checked with the calibration tube (black ball).

Perform the occlusion test. Ensure red light appears and alarm sounds when outflow occluded. After occlusion is released, ensure green light appears and alarm ceases.

Ensure tubing is protected fully by a plastic sleeve that is secured on both ends with twist ties. Connect tubing to blower unit and hood.

Wear N95 mask followed by shower cap, which helps to prevent accidental dislodgement of N95 straps during doffing. Ensure shower cap covers both ears. Tape shower cap and spectacles (if any). 5. 6. 7. 8.

Consider donning a surgical hood to protect the ears and neck when using PAPR hoods that do not cover these areas. The hood is tied behind the neck and needs to be removed carefully to avoid contamination.

Don the PAPR unit and PAPR hood. Wear inner gloves, disposable gown and outer gloves. Ensure blower unit is protected by gown, for example, by using a wrap-around surgical gown.

Ensure that outer gloves overlap with sleeves of gown (red arrow) adequately so that the elastic wrist cuffs are always protected.

Engage the help of a spotter or mirror to ensure adequate coverage of face, neck, back and hands.

Minimising generation of aerosols is crucial in reducing risk of staff infection. Action Plan

2.

Minimise number of non-essential personnel during intubation. Use anti-viral HME filters. Optimise mask seal with an air-cushion mask. Adequate pre-oxygenation and rapid sequence induction should be performed to avoid bagmask ventilation.

Ensure complete paralysis prior to attempting intubation. Optimise first intubation attemptpatient positioning, experienced operator, appropriate choice of laryngoscope and intubation adjuncts.

Inflate ETT cuff as soon as intubation is performed. Top up paralytic if a short-acting agent was used for intubation. Connect ETT to breathing circuit as soon as possible. If there are delays, consider clamping the ETT with a pair of Spencer-Wells clamp.

Auscultation is not easy. Direct visualisation of ETT passing through the vocal cords on the videolaryngoscope, observation of chest rise and ETCO 2 monitoring are recommended. If auscultating, do not put stethoscope directly to ears. Ears must be protected by the surgical hood and/or shower cap. 5. 6. 7. 8.

Consider using an in-line suction device which allows closed-circuit suctioning of ETT secretions.

If disconnection of circuit is necessary, leave the HME filter attached to the ETT (red arrow) and ensure that the patient is wellparalysed. The HME filter should be attached as proximally to the patient as possible.

Ensure proximity of a biohazard waste receptable to dispose of contaminated items.

Place items for decontamination in a disposable kidney dish.

Extubation is a critical process as coughing and removal of ETT may lead to aerosolization and dissemination of virus. Steps should be taken to prevent this.

The main principle is that any contact should be 'clean-to-clean' and 'dirty-todirty'.

Minimise number of non-essential personnel during extubation. Ensure that the biohazard waste receptable is in close proximity to discard the ETT immediately.

Consider deep extubation or use of remifentanil infusion to reduce coughing, if it is deemed clinically appropriate.

Delegate tasks efficiently e.g. anaesthetic nurse to hold suction catheter and deflate ETT cuff, senior anaesthetist to extubate and gently disconnect ETT from circuit while junior anaesthetist applies face mask to patient's face immediately upon extubation and re-connects circuit as soon as possible.

1.

2.

Perform thorough and gentle oropharyngeal and tracheal suctioning prior to extubation. As the PAPR unit and breathing tube will need to be re-used, it is important to decontaminate them thoroughly to prevent infection transmission to the next user. Always start by decontaminating the cleanest items. Wiping of equipment should always be in one direction, ensuring all surfaces are covered with alcohol. Action Plan

2.

3.

Decontamination should be performed in appropriate PPEcap, eye protection, either N95 mask (if already donned) or surgical mask, gown and gloves.

With an alcohol wipe in each hand, detach the tubing from the blower unit. Clean the tubing with alcohol wipes using a rotational motion to catch the grooves on the tubing.

Using a new alcohol wipe, clean the hard components of the blower unit, ensuring all surfaces are covered with alcohol.

Using a new alcohol wipe, clean the fabric straps and buckles. 5. 6. 7. If conditions allow, shower thoroughly and change into a new set of scrubs.

Place the decontaminated items on the 'clean' trolley to dry.

Using new alcohol wipes, clean the non-disposable equipment that were used and place them in biohazard bags.

Pass these items to the anaesthetic nurse. Several of these items may need to undergo further disinfection or sterilisation.

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