CMAAO CORONA Facts and Myth Buster : Series 11

India

Dr K K Aggarwal, President Confederation of Medical Associations of Asia and Oceania, HCFI and Past National President IMA

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

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

This decontamination process would open up re-use of N95 masks originally designed for single use, and it uses vaporized hydrogen peroxide gas to clean the respirators. ASP’s STERRAD series sterilization machines, which are covered under the EUA, are in use in around 6,300 hospitals already (they’re commonly used for sterilizing other pieces of clinical equipment, but have not previously been intended for use with N95 masks) and there are around 9,930 in operation across the U.S., each with the capability of processing around 480 masks per day. The FDA has previously cleared another similar system for N95 decontamination: Battelle’s vaporized hydrogen peroxide process.

Post-Ventilator Mortality :

In a report on nearly 4000 COVID-19 patients from the UK who were admitted to ICUs, two thirds of the subset who required mechanical ventilation died, as did one fifth of the subset who required basic respiratory support. For comparison, the report shows that of ICU patients with viral pneumonia who required mechanical ventilation from 2017 to 2019, slightly more than one third died.

Antibody Tests to Leave Quarantine ?

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

COVID-19: Two Different Lung :

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

One subset has 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. That means a step-up in forced inspiratory oxygen (FiO2), followed by a sideways step in positive end-expiratory pressure (PEEP) and initiation of early proning. This is group of patients who are very responsive to this strategy.
A second group of patients, however, do not respond. This subset has large lung volumes and evidence that the lungs are compliant and elastic, or at least that they have some modified elasticity. These patients may have a very severe hypoxemic hypoxia. They have been likened in presentation to patients who have high-altitude pulmonary edema. In that subset of patients, one of our considerations will be to determine whether there is pulmonary edema, interstitial damage, and loss of compliance. In that scenario, first of all, we 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.

If ECMO is not available utilize strategies for alveolar recruitment. So, when we see that a patient is refractory to oxygen delivered via nasal cannula, even up to 7 L, move 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 we implement these alveolar recruitment Strategies, we further obstruct right ventricular ejection. We actually put the patients into what I would call 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, we 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 that stepwise progression that is part of the ARDSNet protocol.

Patients who do respond to non- ventilation strategies :

Patients are those who have a primary hypoxia that is responsive to oxygen therapy. In that situation, we might progress from nasal cannula to high-flow oxygen. We might consider continuous positive airway pressure (CPAP) or bilevel positive airway pressure (BiPAP). These patients actually can respond quite beautifully to noninvasive strategies. In the world of COVID, 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 our PUI patients suspected of COVID-19.
Minimize cross contamination with healthy patients on other hospital units.
Provide clear and direct communications with our HCWs.
Educate HCWs on optimal donning and doffing techniques.
Minimize our HCW exposure risk.
Efficiently use our personal protective equipment (PPE) supply.

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 :

Designated as the default service for all PUI patients suspected of COVID-19 and confirmed COVID-19 cases requiring Hospitalisation.

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

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 was “yes,” then the patient was accepted to the PUI unit and tested upon arrival. Patients who are found to be COVID-19 positive at the outside institution, but who required transfer for other clinical reasons, to be placed on this PUI unit as well.

Minimising HCW Exposure Risk :

Maintain a log outside each patient’s room to track the details of staff encounters.
Have only one medical provider (either the attending physician or APP) assigned to each patient to limit personnel exposure.
Remove all learners (e.g. residents and students) from this unit.
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)
Provided updates to the patients by calling into the rooms.
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
Medical providers – with the help of the pharmacist and nursing – time a patient’s medications to help reduce the number of entries into the room.
Eliminate any unnecessary blood draws, imaging, and other procedures
Avoid nebulizer treatments and non-invasive positive pressure ventilation to reduce any aerosol transmission of the virus.

Other Ideas :

The use of elongated intravenous (IV) tubing, such that the IV poles and pumps were stationed outside the patient’s room, would be useful 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 our non-PUI patients and to standardize the cleaning process.

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

{Dr Lippert assistant professor of internal medicine at Wake Forest School of Medicine]

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