A Review of Current Literature of Interest to the Office-Based Anesthesiologist.

Abstract

In response to the COVID-19 pandemic, guidance issued from the World Health Organization and the Centers for Disease Control and Prevention recommend minimizing aerosol generating procedures (AGPs) and adopting personal protective equipment and engineering practices when AGPs must be performed. Tracheal intubation and extubation have been classified as AGPs; however, the underlying evidence for this classification is weak and based upon data from studies of other viral respiratory infections. Using mean airborne particles as a surrogate for infection risk, this study quantified the number of aerosolized particles generated in the intubation field using high resolution, real-time monitoring. Tracheal intubation, including face mask ventilation, produced very low quantities of aerosolized particles compared with a volitional cough. Tracheal extubation, particularly when associated with coughing, produced particle levels 15-fold greater than intubation but 35-fold less than volitional coughing. Thus, the study does not support the designation of tracheal intubation as an AGP. Extubation without coughing was found to be quantitatively different than extubation with coughing. Acknowledging that coughing is sometimes interpreted as an indicator of the return of protective reflexes after extubation, practices to reduce aerosolization and coughing following extubation are warranted. The authors caution that no broad conclusions about the risk of actual SARS-CoV-2 infection can be drawn from this study due to several limitations, including the relatively small number of observations, the limited spatial area of aerosolization studied, and the absence of known COVID-19 patients in the study. Comment: This study raises several considerations for the dental anesthesia provider. Intubation appears to have several advantages for limiting and controlling exposure to potentially infectious aerosol in the intraoperative period. Extubation and recovery appear to carry the highest risk of infection particularly when associated with coughing. Patients with a reactive airway and other conditions are known to be more prone to experience coughing, laryngospasm, and other complications associated with extubation. Nonintubated airway management techniques are often viewed as providing less mechanical irritation to the trachea than endotracheal intubation; however, coughing and other respiratory complications are more likely to occur in the minimally protected, nonintubated airway during the perioperative period. This is especially true during lighter levels of sedation or following stimulation from oral secretions, bleeding, and manipulation of the head. Deeper levels of sedation and anesthesia, such as those achieved during anesthesia induction, as well as the use of opioids help to control coughing. A recent review of the risks of extubation and coughing in the COVID-19 era by Sibert et al may be of interest to many dental anesthesia providers. (Saxen MA)