Estimating Preventable COVID19 Infections Related to Elective Outpatient Surgery in Washington State: A Quantitative Model

Yuemei Zhang; Sheng-Ru Cheng

is the (which was not peer-reviewed) The copyright holder for this preprint In order to predict the lower bounds for the number of preventable patient and healthcare worker infections, we decided to minimize the number of unique healthcare workers (HCW) that patients would interact with in an elective outpatient setting. We derived this number for two reasons: 1. The number of clinical staff involved specifically in perioperative care for outpatient elective surgeries is unavailable and 2. Given the current state of the pandemic, institutions may attempt to minimize the numbers of non-essential staff involved in the care of each patient in order to reduce the risks of COVID-19 transmission. At minimum, each patient must interact with 4.5 HCW: one anesthesiologist, one surgeon or proceduralist, one circulator, one scrub technician, and 0.5 pre-operative / Post-Anesthesia Care Unit (PACU) nurses for both pre-op and post-op care, since the PACU nursing ratio is usually 1 nurse to 2 patients and the same nurse can care for a patient during pre-op and post-op. Note that the actual number of HCW that patients will interact with can often be higher. The number of patients that each set of perioperative staff works with varies depending on the length of surgery and scheduling preferences. Based on the clinical experiences of one of our authors, we will use the assumption that each HCW is responsible for an average of 5 cases or 5 unique patients. Thus, we came up with the ratio of 4.5 HCW / 5 patients, or 0.9 HCW/patient. Given our estimate of 3047 ambulatory surgery patients per day, this approximates 2742 HCWs involved in ambulatory surgery care per day.