Closed tracheal suctioning systems in the era of COVID-19: is it time to consider them as a gold standard?

Abstract

Tracheal suctioning is one of the most common activities performed in intensive care units (ICU) and is recognised as a high-risk procedure by the World Health Organization (WHO) and Centers for Disease Control (CDC). Aerosol-generating procedures on critical patients with COVID-19 present an increased risk of contamination for medical workers. In the time of the Sars-Cov-2 pandemic, with a massive number of patients with COVID-19 admitted to the ICU, the open tracheal suction technique (OTST) represents a serious threat for medical workers, even if they are wearing full personal protective equipment. Closed tracheal suction systems (CTSS) allow the removal of tracheobronchial secretions without disconnecting ventilatory circuits, preventing alveolar derecruitment, gas exchange deterioration and hypoxia. CTSS reduce the risk of pathogens entering the respiratory circuit and appear to be a cost-effective solution. CTSS should be considered mandatory for patients in the ICU with an artificial airway, in order to reduce bioaerosol exposure risk for medical workers and contamination of the surrounding environment.

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Tracheal suctioning (TS) is probably one of the most common procedures performed by critical care nurses and respiratory therapists in intensive care units (ICU). The World Health Organization (WHO) and Centers for Disease Control (CDC) recognise TS as a high-risk procedure, as well as the administration of nebulised therapies, non-invasive mechanical ventilation, tracheal intubation, fiberbronchoscopy, tracheostomy and cardiopulmonary resuscitation. Intensive care patients with an artificial airway, either a tracheal tube or a tracheostomy cannula, require TS to remove secretions and to maintain device patency. Major complications of endotracheal suctioning are mainly related to gas exchange deterioration and may lead to hypoxia, cardiac dysrhythmias, and respiratory or cardiac arrest (Elmansoury and Said, 2017). TS may also cause infectious complications, increasing the risk of developing ventilator-associated pneumonia (VAP).

Two suction techniques are currently used in the ICU: a standard open tracheal suctioning technique (OTST) and a closed technique through specifically designed devices, known as closed tracheal suction systems (CTSS). OTST requires a disconnection of the ventilator circuit in order to introduce a suction catheter into the artificial airway. Sterile technique and the use of disposable suction catheters and sterile gloves is encouraged during open suctioning to reduce the risk of contamination, thus increasing workload and costs. One of the main disadvantages of OTST, particularly in patients with severe respiratory failure, is the loss of lung volume and positive end-expiratory pressure (PEEP) during the procedure, with a consequent oxygen desaturation. Closed suction devices were developed by the medical industry in the late 1980s and consist of a multiple-use sterile suction catheter, protected in a transparent plastic sleeve and connected to the artificial airway through a standard 15-mm connector. CTSS allow the removal of tracheobronchial secretions without disconnecting ventilatory circuits, preventing alveolar derecruitment and hypoxia. CTSS is also reported to be less time-consuming and easier to use by critical care nurses.

Even if CTSS reduce the risk of pathogens entering the respiratory circuit, previous studies on infectious complications, VAP and mortality found no significant differences between the open suction technique and closed suction systems (Kuriyama et al., 2015; Solà and Benito, 2007). Cost-effectiveness of one technique versus the other is subject to controversy and depends on the price of devices in relation to the number of daily tracheal suctions. Closed tracheal suction system devices can remain on the ventilator circuit for several days if they are managed according to the manufacturers’ instructions. Comparing costs for a suction catheter (€0.18 each) and sterile gloves (€0.10) used in our ICU, considering a mean number of nine tracheal suctions a day (three/shift) at €2.54, closed suction systems (€8.87) appear to be a good cost-effective choice when used for more than three days.

While several studies and reviews described the effects of OTST and CTSS on ventilation changes, infective complications and costs, few articles have analysed the risk for healthcare professionals performing this manoeuvre. Aerosol-generating procedures on critical patients with COVID-19 present an increased risk of contamination for medical workers and OTST is the most frequent aerosol-generating procedure in the ICU. Airborne bacterial concentration has a significant increase during open suctioning procedures and may cause environmental contamination in the surrounding area. Moreover, breathing circuits with active humidification systems can increase droplet evaporation. A recent review by Bahl et al. (2020) reported that the horizontal extent of droplet spread, evaluated in experimental or modelling studies and in human subjects, may be in the range of 1–8 m. In consideration of the potential extent of droplet and airborne spread, it is difficult to define a safe distance range around a patient in the ICU. According to some guidelines and recommendations about airway management in patients with COVID-19, closed suctioning systems should be applied immediately after intubation to limit aerosolisation.

During the SARS-Cov-2 pandemic, with a massive number of patients with COVID-19 admitted to ICUs, OTST represents a serious threat for medical workers, even when they are wearing full protective equipment (Tran et al., 2012). The massive insertion of physicians and nurses in the intensive care setting without previous ICU experience, associated with an incredibly increate workload, may constitute another risk factor. With reference to the SARS epidemic in 2002, 21% of cases were medical workers, a percentage even higher in some countries such as Hong Kong, Singapore and Canada. As of April 2020, over 20,000 Italian healthcare professionals have been infected by SARS-CoV-2, with 1.57 deaths per million population.

The safety of healthcare professionals should be considered a priority and every strategy should be pursued to protect those who are providing care. CTSS appeared to be extremely cost-effective and should be considered mandatory for patients in the ICU with an artificial airway, in order to reduce the risk of bioaerosol exposure for medical workers and contamination of the surrounding environment.