Coronavirus Disease-2019: Modified Underwater Seal Chest Drain System

To the Editor:

Coronavirus disease 2019 (COVID-19) is an acute respiratory disease caused by a novel coronavirus (severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2]), transmitted mostly through respiratory droplets, direct contact with infected persons, and through contaminated surfaces/objects. Even though the virus survives on environmental surfaces for a varied period of time, it is easily inactivated by chemical disinfectants. In this COVID-19 pandemic situation, our top priority every day should be the prevention of transmission of infectious diseases to patients and to protect healthcare workers.

COVID-19 remains viable in aerosol form and is transmitted by droplets.¹ As such, we are facing problems in patients who require chest tube drainage for pneumothorax, especially in cardiothoracic and pulmonary medicine wards and critical care units. There may be a high risk of aerosolization in cases of pneumothorax with active air leak and in COVID-19 patients with an intercostal drainage tube in-situ requiring high positive end-expiratory pressure mechanical ventilation. The need for the use of an intercostal drain in any COVID-19–positive patient always will increase the risks of aerosolization from the chest drain and, in particular, the chest drain bottle. This may represent an under-recognized means of viral spread, which may put patients and healthcare professionals at risk of infection. When air leaks into a chest drain bottle, it causes the fluid inside to bubble, and the aerosolization that likely is to occur inside the drain bottle then then escapes through the suction port or safety valve, potentially becoming an important mode of viral transmission. Therefore, to overcome this potential mode of transmission, we modified a underwater seal system (Romo Seal; Romsons Disposable Medical Devices, New Delhi, India) by attaching the heat and moisture exchanger filter with a cut endotracheal tube to the unit that is open to the atmosphere. In addition, we filled the chest drain bottle with 100 mL of 1% sodium hypochlorite solution in place of water (Fig 1 ). In COVID-19 patients with a chest drain and persistent air leak, the British Thoracic Society² recommends strategies to minimize droplet exposure via the chest drain circuit, such as connecting it to wall suction or a digital drain circuit. The British Thoracic Society also advises reducing the frequency of intercostal chest drain drainage to twice weekly. However, attaching the chest drain to the wall suction compromises mobilization of the patient.

Fig 1.

Modified underwater seal drainage system. HME, heat and moisture exchanger.

There are several advantages of using sodium hypochlorite solution in an underwater seal drain, including the following:

• 1.The prevention of aerosolization that likely occurs inside the drain bottle and may escape through the suction port or safety valve.
• 2.If the safety valve is connected with wall suction, there is always potential risk of increasing intrathoracic pressure, which is minimized by using this hypochlorite solution.
• 3.Because the pleural fluid is presumed to be disinfected by sodium hypochlorite, it reduces the chance of viral transmission during its disposal.

Conflict of Interest

None.