Risk to health from COVID-19 for anaesthetists and intensivists - a narrative review

Abstract

Healthcare workers are at an increased risk of infection, harm and death from COVID-19. Close and prolonged exposure to individuals infectious with SARS-CoV-2 leads to infection. A person's individual characteristics (age, sex, ethnicity and comorbidities) then influence the subsequent risk of COVID-19 leading to hospitalisation, critical care admission or death. While relative risk is often reported as a measure of individual danger, absolute risk is more important and dynamic, particularly in the healthcare setting. Individual risk interacts with exposure and environmental risk-factors, and the extent of mitigation to determine overall risk. Hospitals are a unique environment in which there is a significantly increased risk of infection for all healthcare workers. Anaesthetists and intensivists particularly are at high risk of exposure to SARS-CoV-2 infected patients due to their working environments and exposure to certain patient groups. However, the available evidence suggests that the risk for this group of individuals is not currently increased. This review examines factors associated with increased risk of infection with SARS-CoV-2, increasing severity of COVID-19 and death. A risk tool is proposed that includes personal, environmental and mitigating factors, and enables an individualised dynamic 'point-of-time' risk assessment.

Keywords: COVID-19; healthcare worker; intensive care; mortality; pandemic; risk.

Figure 1

Relationship between COVID‐19 disease progression, locations of deaths in the UK and data sources. ISARIC, International Severe Acute Respiratory and Emerging Infection Consortium [15]; ICNARC, The Intensive Care National Audit and Research Centre [16]; ONS, Office for National statistics [18], OpenSAFELY [23]. [Colour figure can be viewed at wileyonlinelibrary.com]

Figure 2

Figure from the Intensive Care National Audit and Research Centre (ICNARC) [16] showing hazard ratios for death after admission to intensive care. (a) age modified to indicate an approximately 50% increase in risk for an increase in age of 10 years (red lines) and the inflection point at just below 60 years age (blue circle). (b) Sex and ethnicity. (c) Body mass index modified to show approximately 50% risk increase at above 55 kg.m^‐2 (red lines). (d) Severe immunocompromise. (e) Quintiles of social deprivation. © ICNARC 2020. These data derive from the ICNARC report on COVID‐19 in critical care (26 June 2020) in the Case Mix Programme Database ICNARC, London, UK. The Case Mix Programme is the national clinical audit of patient outcomes from adult critical care co‐ordinated by the Intensive Care National Audit and Research Centre (ICNARC). For more information on the representativeness and quality of these data, please contact ICNARC. [Colour figure can be viewed at wileyonlinelibrary.com]

Figure 3

The dynamic interaction of environmental and personal risk. Baseline risk in represented by the yellow cross and the black dotted line. As environmental risk is increased, the cross moves upward and mitigation moves it down. Increased or decreased personal risk moves the cross left or right, respectively. Overall risk is shown on the green arrow. [Colour figure can be viewed at wileyonlinelibrary.com]