Discussion
Advantages of “early” tracheotomy in prolonged MV are generally acknowledged8. However, transmission risks in Covid-19 patients lead to much longer time threshold (up to 3 weeks from intubation) in most guidelines, dealing with the issue1-4, and we followed this suggestion.
Only few real-life data have been published 7, with mixed techniques. Differently from such report, to avoid aerosolisation and airflow from lower airways we always opened the trachea above the ETT cuff through an open surgical technique in fully paralyzed patients, as recommended 1,4. The described isthmus transection7should be avoided as well, especially in a bedside procedure, because it increases operating time and complication rate.
However, there are 2 moments when pulmonary airspace is not sealed and airflow can be generated: the step of pushing downward the cuff and, most of all, the “no-seal” time. These two steps must be the shortest possible. To stabilize intrapulmonary pressure, in both steps we held ventilation at the end of expiration before the cuff is deflated until it is fully reinflated. In addition, we clamped the tube with an ECMO clamp in the no-seal time, to obtain 3 small but potentially decisive achievements: a) to disconnect the ETT from the circuit without allowing airflow to environment; b) to connect in advance the circuit to the cannula while still holding ventilation; c) to reduce alveolar de-recruitment.
As for the surgical technique, we describe above some tricks, which, applied by all the members of the team in coordination, allowed us to reduce the no-seal time to less than 2 second. The only problem during the procedures was in one case misting up of the goggles, probably due to insufficient use of surfactant, a trivial issue to keep in mind and avoid.
In conclusion, tracheotomy has been shown to be an aerosol generating procedure that increases the risk of transmission to healthcare workers, with an odds ratio of 4.15 for transmission in those who performed tracheotomies during the SARS epidemic 9. The present results on COVID patients are still preliminary, and largest series are expected, but they suggest that such risks can be significantly reduced with an extensive and appropriate use of PPE, a proper surgical technique and at the same time additional rational measures and tricks both by all the members of the team in coordination.