This study highlights key trends with the potential to evoke change in current proposed procedural guidelines[13-15]. The demand for IR procedures in COVID-free patients remains high during this pandemic. While postponement of procedures might be feasible in a relatively shorted outbreak such as SARS-CoV, these measures might prove detrimental to patients as the pandemic is slated to persist. The adherence to standard infection control protocols and strategic deployment of resources (elaborated in the subsequent paragraph) proved effective in maintaining operational capability and controlling disease spread. The vast majority of patients undergoing IR procedures were in fact COVID-free. This emphasizes the need for procedural planning to consider the needs of COVID-free patients. Key differences exist between the SARS-CoV outbreak and the COVID-19 pandemic. There were notably less infected patients during the SARS-CoV outbreak (n = 238)[19, 20]; compared to the COVID-19 pandemic (n = 47,126). The SARS-CoV outbreak lasted approximately three months in Singapore, compared to the current pandemic into its 6th month. Unlike the COVID-19 pandemic, our institution treated SARS-CoV patients solely for the entire outbreak duration. This limited us to comparing IR procedures between the two outbreaks to only the infected patients (Table 3). Comparing the differences in IR procedures between the two outbreaks, we note the lack of a tandem increase in the number of IR procedures performed for the infected patients despite the increase in patient load. We postulate this to be due to the intensivists performing more critical care procedures (e.g., venous accesses and thoracocentesis) in this pandemic compared to the SARS-CoV outbreak. In addition, more complex IR procedures were performed for patients' pre-existing condition (e.g., hepatic tumor embolization) and previously unknown coronavirus related manifestations (e.g., thoracic endografting for aortic thrombosis with distal embolization).
To balance infection risks and timely delivery of care for the COVID-free patients, we utilized the strategy of "list compression". Firstly, Tier 1 cases were deferred for an additional month, and this created vacancies in the schedule. The vacated schedules were then utilized to bring forward Tier 2 cases, effectively reducing their waiting times. This is reflected in similar total IR caseloads between the two study periods (Table 1). This strategy is consistent with treatment prioritization principles[13, 15], optimizes available resources, and averts post-pandemic rebound of case backlogs. Additionally, it allowed expedited treatment of Tier 2 cases under the specter of the sudden cessation of services, should the pandemic worsen. A caveat to this approach given the fluid nature in a pandemic, was that majority of our Tier 2 cases were outpatient-based treatments that do not burden inpatient resources and could be rescheduled at short notice. The only exception to our approach was to indefinitely defer treatments (e.g., aortic arch repairs) deemed to have a high potential of occupying intensive care resources, until a suitable time after the pandemic's peak. Furthermore, manpower diversion to COVID-19 related efforts was mitigated by additional staffing, due to curtailment of research and teaching activities, as well as overseas travel/vacation restrictions. Non-essential travel of physicians and patients was mitigated by telemedicine, including the use of telemedicine for nuclear medicine physicians for the administration of radioembolization.
Limitations exist to the broad application of our results. Unlike many other countries, our mortality and need for intensive care among COVID-19 patients remain the lowest in the world. While we modeled our capacity preparation on countries that experienced COVID-19 peaks before us (such as Italy and the United Kingdom), our healthcare system was never overwhelmed. Additionally, the NCID, with its IR facilities, served as a surge capacity and a physical buffer for the first 15 weeks into the pandemic, a resource not available in most institutions. Our practice, particularly the infection control policies and related resources, were also shaped by our prior experience as the designated hospital for the SARS-CoV outbreak in 2003 and the H1N1 pandemic in 2009. Our experience, therefore, can be expected to be different from other centers.
To conclude, our study showed that COVID-19 patients accounted for a small fraction of IR procedures, while the demand for IR procedures for the COVID-free patients remained high and similar to pre-pandemic levels. Application of treatment prioritization guidelines, when combined with standard infection control measures, can allow safe and timely delivery of care to COVID-free patients in caseload volumes similar to pre-pandemic levels. These findings should be considered in the operational planning of a sustainable care delivery model in IR, considering the expected prolonged COVID-19 pandemic and in subsequent infectious disease outbreaks.