Discussion
Prolonged intubation (>7 days) remains most common indication of tracheostomy as clinical consensus guidelines. In this study, twelve (85.7%) patients received intubation for more than 14 days. It is generally accepted that for mechanical ventilation and respiratory failure, a tracheostomy should not be considered in a person who cannot readily benefit from the advantages that the airway may offer. Moreover, tracheostomy for a patient with COVID-19 imposes a significant risk of nosocomial infection. For the most patients in our study, clinicians exerted their efforts to help them weaning from the ventilator, in the hope of circumventing the need for a tracheostomy. Thus, tracheostomy was delayed to more than 14 days after the intubation. Meanwhile, the majority of patients had developed cerebrovascular disorders, which require airway protection and a slow process of recovery. With decreased use of sedation and pulmonary rehabilitation after tracheostomy, it may contribute to increase the incidence of weaning success. Our experience suggests that tracheostomy for prolonged intubation and airway protection can be considered to be the last resort to the treatment of COVID-19 patients. A initial gross examination report of a COVID-19 autopsy demonstrated the existence of massive thick secretions in bronchi and bronchiole, which indicated the importance of effective and aggressive pulmonary toilet for patients with COVID-19.4 Compared with intubation, tracheostomy tube bypasses the upper airway, which results in more effective suction of the secretions and less sputum crust in cannula. Case 2, case 3 and case 5 had endotracheal cannula obstruction, which is possibly related to thick secretions validated by surgical findings. The need for pulmonary toilet in patients with COVID-19, particularly, in the condition of thick secretions is a strong indication of tracheostomy.
Powered air-purifying respirators (PAPRs) can provide higher protection, better vision, and more comfort compare with the typical headgear worn in conjunction with an N95 mask. Early in the outbreak of SARS, some anesthetists, who just wore standard surgical facemasks, gowns and gloves, contracted SARS following intubation of suspected patients.5 Compared with the intubation procedure, tracheostomy takes more time and increases the risk of exposure to low airway virus. Thus, we recommend PAPRs as protective equipment for performing tracheostomy on patients with COVID-19.
Sufficient hemostasis before the incision of the trachea is necessary. In our procedure, minor wound bleeding from the skin edges and blood vessel bleeding were adequately controlled with ligation and suture. We recommend to avoid the usage of epinephrine due to its temporary hemostasis effect, which increases the rebleeding rate, especially in individuals treated with anticoagulant therapy. Electrocautery should also be avoided to prevent aerosolizing viral particles. Bedside tracheostomy proves to be a reasonable and practical procedure. Multiple disconnection and reconnection of the breathing circuit during a COVID-19 patient transport may facilitate the transmission of the virus. Secondly, transport will pose significant risks and inconvenience to critically ill patients. Thirdly, in ICU, all attending medical staffs armed with PAPRs were adequately protected from virus. Finally, in our study, bedside tracheostomy was not technically challenging for skilled surgeons. The overall procedure took only about 20 minutes, with approximate 30 seconds of apnea for each patient.
PT has been increasingly used in ICU and was considered a superior alternative to OT. The addition of endoscopic guidance to PT has further increased the safety of this procedure by visualization of the tracheostomy site.6 The indications for PT are the same as for an OT with particular attention to some contraindications.6 Case 2, case 4 and case 7 with obese neck, case 8 with previous thyroid surgery, case 13 with previous tracheostomy and case 6 with a large thyroid isthmus were not ideal candidates for PT. Case 7 was selected to use PT, resulting in the injury of thyroid and constant bleeding, which leads to the requirement of revision OT.
In our study, we performed OT for all the cases. In fact, in the setting of the highly infectious disease, OT was selected over PT because it was entailed a lower risk of aerosolization.7 The placement of the cannula was confirmed by air aspiration and bubble formation during PT, which may produce viral droplets and aerosols.8 The insertion of a bronchoscope into an airway already compromised by intraluminal dilators results in further obstruction of the ventilatory path, worsening the hypoventilation.9 On the other hand, in order to prevent aerosols, the ventilator should be stopped when the airway was opened and autonomous respiration must be refrained.7Although PT takes less time than OT for skilled surgeons, our experiences indicated that the time spent from tracheotomy to insertion of the tube during ventilation suspension in OT was shorter than the one in PT. Under such circumstances, PT may have longer duration of airway loss and more risk of hypoxia than OT in critically ill patients with COVID-19.