key: cord-0044169-zkzjo45k authors: Ip, Vivian; Sondekoppam, Rakesh title: Absence of Evidence Is Not the Evidence of Absence: Clinical Consideration when Interpreting Guidelines for the COVID-19 Pandemic date: 2020-05-29 journal: J Am Coll Surg DOI: 10.1016/j.jamcollsurg.2020.05.013 sha: c9eaa1bae35b557081f77f44954cd5f50ef0846c doc_id: 44169 cord_uid: zkzjo45k nan As the global prevalence of novel coronavirus 2019 (COVID-19) increases, with a death toll exceeding that during wartime, scientists and clinicians alike are racing against time to provide clarity on pathogenesis, mode of transmission, and to research potential treatment and vaccines amid the pandemic. In the meantime, hospital guidance 1 is essential to protect health care providers (HCPs) and for disease containment. However, definitive guidelines are often elusive given the rapid emergence of new data and the time constraints for robust evidence. The algorithm presented by Forrester and colleagues 1 suggested screening all preoperative patients whenever feasible for COVID-19 status. This is essential, rather than depending on unreliable screening protocols. To prevent false reassurance with potential serious implications of infecting multiple HCPs, highly sensitive screening for COVID-19 is necessary. Given increasing evidence of asymptomatic spread, 2 estimating the extent of asymptomatic carriers based on the prevalence of COVID-19 in the community may be underestimated, unless widespread screening occurs to identify the true negatives. 3 Nonetheless, pitfalls with screening for atypical presentation, such as conjunctivitis in the absence of influenza-like symptoms and possible variation in screening sensitivity over the progression of COVID-19 from upper respiratory tract to pneumonia, are not well researched. Guidance on some aspects of personal protective equipment (PPE), such as neck covering for aerosol-generating medical procedures (AGMPs), remains uncertain. The anterior neck was found to be the most frequent zone for contamination after PPE doffing. 4 However, neck covering was not mentioned in the algorithm. 1 Despite a lack of evidence of HCP infection from neck contamination, which is difficult to prove, it is a plausible concept, as neck cleaning is not normally performed. Furthermore, while the globally recommended practice of social distancing is unattainable in the hospital setting, universal masking should be a recommendation for both staff and patients to prevent droplet spread. This is particularly relevant when there is a paucity of evidence regarding droplet travel distance, asymptomatic or presymptomatic transmission, 2 and the significance of short-range aerosol spread. 5 Amid the COVID-19 pandemic, one of the ways to obviate the need for AGMPs is the use of regional anesthesia and sedation, especially in extremity operations, which may become the "new normal." 6 Nonetheless, one must ensure that the sensory/motor block is appropriate for surgical anesthesia to prevent an urgent need to convert to general anesthesia. Furthermore, level II PPE is recommended, which means HCPs don surgical mask and barrier PPE, and the patient also wears a surgical mask to prevent droplet transmission, with or without oxygen underneath. The aforementioned are only examples of uncertainty in many guidelines in which supporting evidence is scarce. An absence of evidence is not the evidence of absence. Given time, more data will emerge on COVID-19, but until then, physicians should consider clinical judgment and resources in decision-making to protect HCPs and patients . 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 Precautions for operating room team members during the COVID-19 pandemic Transmission of 2019-nCoV infection from an asymptomatic contact in Germany Development of a laboratory-safe and low-cost detection protocol for SARS-CoV-2 of the coronavirus disease 2019 (COVID-19) Contamination: a comparison of 2 personal protective systems The airborne lifetime of small speech droplets and their potential importance in SARS-CoV-2 transmission Online ahead of print COVID-19 pandemic: the 3 R's (reuse, refine and replace) of personal protective equipment (PPE) sustainability Disclosure Information: Nothing to disclose 27 pm 1 ยช 2020 by the American College of Surgeons