FDA clears N95 decontamination process that could clean up to 4 million masks per day

The USFDA has granted an emergency use authorization (EUA) for a decontamination process by a company named Advanced Sterilization Products (ASP) that could sterilize as many as 4 million N95 respirators per day for re-use.

This decontamination process would enable re-use of N95 masks that are originally designed for single use. The process utilizes vaporized hydrogen peroxide gas to clean the respirators. ASP’s STERRAD series sterilization machines, covered under the EUA, are being used in some 6,300 hospitals already (commonly used for sterilizing other pieces of clinical equipment, but have not previously been intended for use with N95 masks). There are around 9,930 in operation across the U.S., each with the capacity of processing around 480 masks per day.

The FDA had previously cleared another similar system for N95 decontamination - the Battelle’s vaporized hydrogen peroxide process.

Post-Ventilator Mortality

A report on around 4000 COVID-19 patients from the UK admitted to ICUs revealed that two-thirds of the subset who required mechanical ventilation died, as did one-fifth of the subset who required basic respiratory support.

The report also stated that of ICU patients with viral pneumonia who required mechanical ventilation from 2017 to 2019, a little over one-third died. 

Antibody Tests to Leave Quarantine?

Blood tests for antibodies to SARS-CoV-2 have been suggested as a way to allow those with immunity to the virus to safely return to work. However, more scientific research is needed before antibody tests could be used this way.

COVID-19: Two Different Lung Pathologies

There are two subsets of patients with COVID-19 lung disease.

1. One subset presents with a loss of compliance and will be responsive to primary acute respiratory distress syndrome (ARDS) Clinical Network Mechanical Ventilation Protocol (with ARDS categorized by the most recent Berlin definition) for resuscitation, alveolar recruitment, and improvement in gas exchange. This refers to a step-up in forced inspiratory oxygen (FiO2), followed by a sideways step in positive end-expiratory pressure (PEEP) and initiation of early proning. These patients are very responsive to this strategy.
2. A second group of patients is there who do not respond.  This subset has large lung volumes and evidence of lungs being compliant and elastic, or at least that they have some modified elasticity. These patients may have a very severe hypoxemic hypoxia. They have been equated in presentation to patients who have high-altitude pulmonary edema. In that subset of patients, one of the considerations is to determine if there is pulmonary edema, interstitial damage, and loss of compliance. In that case, first of all, there is a need to limit fluid resuscitation and apply alveolar recruitment strategies: higher PEEP, airway pressure release ventilation (APRV), ventilation, or high frequency oscillatory ventilation. Extracorporeal membrane oxygenation (ECMO) should also be considered early on if you have the ability; in conjunction with that, we would prone position.

In case of non-availability of ECMO, use strategies for alveolar recruitment. So, when a patient is refractory to oxygen delivered via nasal cannula, even up to 7 L, consider moving to a non-rebreather mask. If the patient is still refractory with hypoxemic hypoxia, add strategies to recruit the alveoli. These patients typically have some heart rate variability, although some have noted that these patients may not have tachycardia.

As these alveolar recruitment Strategies are implemented, right ventricular ejection is further obstructed. We put the patients into a nosocomial or iatrogenic or idiopathic state of right ventricular failure. When we see that a patient is failing to respond to nasal cannula, including non-rebreather, it is time to quickly move to intubation and early ventilation strategies. Most of the time, we just start at or rapidly move to a peak of 14-cm PEEP or above along with high-dose FiO2, skipping some of the stepwise progression that is part of the ARDSNet protocol. [Medscape]

Patients who respond to non-ventilation strategies 

These Patients have a primary hypoxia that is responsive to oxygen therapy. In this case, we may progress from nasal cannula to high-flow oxygen. We can consider continuous positive airway pressure (CPAP) or bilevel positive airway pressure (BiPAP). These patients actually can respond to noninvasive strategies. In the case of COVID-19, there have been some significant concerns regarding aerosolization of particles with all but the nasal cannula in these instances.

How to Set Up a COVID-19 Person under Investigation Unit: Goals

To deliver dedicated, comprehensive, and high-quality care to PUI patients suspected of COVID-19.

To minimize cross contamination with healthy patients on other hospital units.

To provide clear and direct communications with HCWs.

To educate HCWs on optimal donning and doffing techniques.

To minimize our HCW exposure risk.

To efficiently use personal protective equipment (PPE) supply.

[Medscape]

How to Set Up a COVID-19 Person under Investigation Unit: Unit and Team Characteristics 

Attending physician and advanced practice provider

Designated care coordinator (social worker/case manager)

Pharmacist

Respiratory therapist

Physical/occupational therapist

Speech language pathologist

Unit medical director

Nurse manager.

Patient Flow

Hospital medicine was designated as the default service for all PUI patients suspected of COVID-19 and confirmed COVID-19 cases requiring hospitalization.

These patients are admitted to this PUI unit directly from the emergency department (ED), or are transferred from outside institutions.

Those patients admitted from ED are to be tested for COVID-19 prior to arriving on the unit.

Other suspected COVID-19 patients arriving as transfers from outside institutions should be screened by the patient placement specialist team.

 [Medscape]

What are the screening questions

"Has the patient had a fever or cough and been in contact with a laboratory-confirmed COVID-19 patient?"

"Has the patient had a fever and cough?"

If the answer to either screening question is "yes," then the patient is accepted to the PUI unit and tested upon arrival.

Patients found to be COVID-19 positive at the outside institution, but who require transfer for other clinical reasons, to be placed on this PUI unit as well. [Medscape]

Minimizing HCW Exposure Risk

1. Maintain a log outside each patients room to track the details of staff encounters.
2. Have only one medical provider (either the attending physician or APP) assigned to each patient to limit personnel exposure.
3. Remove all learners (e.g. residents and students) from this unit.
4. Limit the number of entries into patient rooms to only critical staff directly involved in patient care (dietary and other ancillary staff not allowed to enter the rooms)
5. Provide updates to the patients by calling into the rooms.
6. Care coordination, pharmacy, and other staff members also to utilize the same approach of calling into the room to speak with the patient regarding updates
7. Medical providers, with the help of the pharmacist and nursing, time a patients medications to help reduce the number of entries into the room.
8. Eliminate any unnecessary blood draws, imaging, and other procedures
9. Avoid nebulizer treatments and non-invasive positive pressure ventilation to reduce any aerosol transmission of the virus.

[Medscape]

Other Ideas

The use of elongated intravenous (IV) tubing, such that the IV poles and pumps are stationed outside the patients room, would help in reducing the amount of PPE required as well as HCW exposure to the patient.

Having designated chest radiography, computed tomography, and magnetic resonance imaging scanners for these PUI patients to help minimize contamination with non-PUI patients and to standardize the cleaning process.

Supply HCWs with designated scrubs at the beginning of their shifts, so that they can discard them at the end of their shifts for decontamination/sterilization purposes. This would help reduce HCWs fear of potentially exposing their families at home.

Provide HCWs with a designated place to stay, such as a hotel or other living quarters, to reduce HCWs fear of potentially exposing their families at home.

Providers and staff to utilize designated phones to conduct patient history and review of systems information-gathering, to decrease the time spent in the room, the availability of more sophisticated audiovisual equipment could also improve the quality of the interview.

[Medscape]

Dr KK Aggarwal

President CMAAO, HCFI and Past National President IMA