key: cord-0895579-16vj1rs2
authors: Minami, Takuma; Kai, Shinichi; Tanaka, Tomoharu; Ito, Isao; Kato, Genta; Nagao, Miki; Date, Hiroshi; Hirai, Toyohiro; Ohtsuru, Shigeru; Chin, Kazuo
title: Non-invasive ventilation using a novel ventilator and non-vented full-face mask for patients with respiratory failure during the COVID-19 pandemic: Report of three cases
date: 2022-04-06
journal: Respir Investig
DOI: 10.1016/j.resinv.2022.03.005
sha: cbb2c9f64050f08ebd44f7bf859a84751a1e9cf8
doc_id: 895579
cord_uid: 16vj1rs2

The Japanese government’s latest manual on COVID-19 management mentions non-invasive ventilation (NIV). Before this version, we experienced three cases in which COVID-19 was a concern. Each case had one of the following conditions: obesity hypoventilation syndrome, amyotrophic lateral sclerosis, acute heart failure with acute kidney injury with hypercapnia. The guidelines indicate that patients with these diseases are good candidates for NIV. NIV was used in a negative pressure room with staff in personal protective equipment. We describe the use of NIV instruments with anti-viral filters and a non-vented mask, including a new NIV machine for COVID-19 respiratory care.

While non-invasive ventilation (NIV; continuous positive airway pressure (CPAP), or non-invasive positive pressure ventilation, NPPV) is useful for managing respiratory failure [1] , the use of NIV for patients with coronavirus disease 2019 (COVID-19) is controversial due to the possibility of aerosols escaping from the equipment. NIV has usually been avoided in Japan because the government's manual on COVID-19 did not discuss the use of NIV for the respiratory care of patients with COVID-19 [2] until version 6.0 [3] , even though high flow nasal cannula (HFNC) oxygen therapy and NIV have been considered useful for treating COVID-19 patients in other countries [4] [5] [6] . HFNC can provide oxygen at concentrations nearing 100%, but expiratory positive airway pressure (EPAP) is only 2 or 3 cmH2O. The most recent study comprising 13,931 patients showed that overall, non-invasive respiratory support (NIRS) in patients with COVID-19 was safe, improved resource utilization, and was associated with possibly better outcomes than conventional oxygen therapy [7] . For patients with COVID-19, NIV with inlet and outlet anti-virus filters in addition to non-vented filters with an artificial nose or anti-virus filters is suitable. Since NIRS, including NIV, will be used more frequently in the management of COVID-19 patients in Japan in the near future, pulmonologists in Japan need to know how to use NIV machines to prevent the spread of aerosols and contamination of the J o u r n a l P r e -p r o o f ventilator. Here, we describe three cases in whom a new NIV machine suitable for COVID-19 patients was used. On admission to our hospital, a 78-year-old male with heart failure and kidney disease had a pH of 6.88, PaCO2 of 116.2 mmHg, PaO2 of 54.7 mmHg, HCO3of 21.0 mmol/L, and BE of -11.9 mEq/L (oxygen administration 10 L/min with a mask). Normal NPPV was used at the first hospital, and the patient was transferred to our hospital for renal replacement therapy during the third wave of the COVID-19 pandemic in Japan (January 2021). Chest X-ray showed cardiomegaly, pulmonary edema, and bilateral pleural effusion (Figure 1-b) . After admission to our hospital, the new NIV (E-30 ventilator) with the non-vented mask was used because we could not exclude COVID-19 infection. His SARS-CoV-2 PCR test was negative on day two, and continuous hemodiafiltration was performed until day three. The patient was discharged home on day 19.

Here, we have described three cases treated with novel NIV equipment with three filters to use each NIV machine with appropriate filters and exhalation ports (Fig. 2) .

The early Japanese government's manual recommended that COVID-19 patients be intubated and mechanically ventilated [8] if SpO2 could not be maintained ≥93% despite inhalation of 5 L/min O2 by nasal cannula or masks.

It is expected that NIV will be used more frequently in the near future after being cited in the latest manual by the Japanese government. Our three cases were good candidates for NIV according to the guidelines [1] . More than 500,000 patients are on home CPAP therapy in Japan, and more than 20,000 patients are treated by home NPPV therapy, including adaptive servo-ventilation (ASV) [9] . Therefore, including the usage of CPAP or NPPV in the intensive care unit (ICU), information on managing patients with respiratory care at home during the next pandemic should be more available. In addition, NIV may be useful for patients with hypoxemic COVID-19 as it can be administered with the patient in a prone position.

Although the feasibility and clinical impact of CPAP and NPPV were also reported in J o u r n a l P r e -p r o o f patients with COVID-19 pneumonia [5, 6] , an increased number of medical staff members with COVID-19, as determined by positive serology or pharyngeal swabs, was reported in non-ICU non-invasive respiratory support settings caring for patients with COVID-19.

However, all infected workers recovered well [5] . In comparing CPAP with NPPV, it should be recognized that NPPV is usually associated with more aerosol leaks than CPAP.

Therefore, NIV should be used in a negative pressure room or red zone with staff wearing personal protective equipment as with case 1, in which case there was no transmission to the medical staff.

There are several limitations to our report. First, only one patient was a true COVID-19 patient. Nevertheless, recent large-scale data have supported NIV as a significantly useful method for patients with COVID-19 [7, 10] . Second, since the machine used was a new machine for patients with COVID-19, it might have a negative effect in supporting patients' breathing, such as high circuit resistance, difficulty in patient synchronization, and loss of humidity. Indeed, the second case initially became hypercapnic following the start of this system but improved after the parameters of the machine were reset. Therefore, physicians should carefully observe patients when this machine is first used.

Each patient in this report had a different pathophysiologically severe condition, was

The Japanese Respiratory Society Noninvasive Positive Pressure Ventilation (NPPV)

Guidelines (second revised edition)

Japanese Ministry of Health, Labor and Welfare

Japanese Ministry of Health, Labor and Welfare

The National Health Service. NHS Guidance on use of NIV in adults with coronavirus | INTENSIVE Review

Feasibility and clinical impact of out-of-ICU noninvasive respiratory support in patients with COVID-19-related pneumonia

Continuous positive airway pressure to avoid intubation J o u r n a l P r e -p r o o f in SARS-CoV-2 pneumonia: a two-period retrospective case-control study

Non-invasive respiratory support in the management of acute COVID-19 pneumonia: considerations for clinical practice and priorities for research

Japanese Ministry of Health, Labor and Welfare

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