We read with great interest the recent editorial by Huang et al. regarding the unfortunately timely topic of considerations attendant to running a nuclear medicine department in the context of the COVID-19 epidemic, which complements similar work on diagnostic imaging and hospital-wide preparedness . As the pandemic has unfolded in a somewhat sequential manner , lessons learned in one geographic domain are of great value to physicians who practice in locations that are earlier on the learning curve.
One area of concern which we did not see covered in the comprehensive treatment relates to performance of ventilation scans, a standard component of ventilation/perfusion studies performed to exclude pulmonary embolus . The population of patients who are short-of-breath and considered for pulmonary embolus certainly overlap with individuals who may be suffering effects of COVID-19 infection. Beyond standard methods of decontamination, which are relevant to all patients with suspicion of infection [2,6], is there a specific concern that patients performing ventilation studies will expose others to airborne virus by exhalation into the aerosolization system? Do we need to take any additional precautions to minimize airborne distribution of virus, such as requiring technologists to don respiratory mask to protect against airborne virus? Are there any changes in protocol that we can implement to mitigate risk?
Both early and current literature have documented a small degree of contamination produced by leakage of the radioactive aerosol from the closed delivery system into the room [7–9]; this would seem to indicate that there is potential for expired air and aerosolized secretions to contaminate personnel. Optimized techniques may minimize, but not eliminate, a small degree of airborne contamination . In addition, patients frequently cough following inhalation of radiopharmaceutical, which may also expose nuclear medicine workers to aerosolized secretions. It, therefore, seems appropriate to equip technologists in the imaging suite with adequate respiratory equipment such as N-95 masks if ventilation is performed. The United States Center for Disease Control and Prevention recommends that when performing aerosol-generating procedures, health care personnel in the room should wear an N95 or higher-level respirator, eye protection, gloves, and a gown . To reduce the necessity of these measures, especially in patients with known infection, it may be preferable to shift to diagnostic algorithms that include perfusion but skip ventilation [11–13], thereby minimizing potential for aerosolization. If ventilation scans are subsequently deemed necessary in a specific patient, a repeat study can be obtained the following day with heightened vigilance and precautions. Where ever possible, a negative pressure room would be preferred. Ultimately, the best solution at every facility will depend on local circumstances, including availability of personal protective equipment.
We wanted to thank Huang et al. for the rapid dissemination of critical information regarding preparations for the nuclear medicine department during the COVID-19 epidemic. We hope that our considerations regarding escape of aerosolized droplets during the performance of ventilation scans will likewise be beneficial and minimize person-to-person transmission within the nuclear medicine suite.
Conflicts of interest
There are no conflicts of interest.
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