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 beneļ¬t 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.